Glazed Curtain Walls
Neutrality remake batch: from-scratch field derivation with project parameters and derived fields
Showing changes from Rev 6
to Rev 7
in Glazed Curtain Walls.
−---
−title: Glazed Curtain Walls
−category: Architectural / Openings
−toc_depth: 3
−description: >
− When to use: Aluminum-framed glazed curtain wall — stick-built (field-assembled) or unitized (shop-assembled, panelized) — serving as the primary non-load-bearing exterior wall enclosure spanning vertically across one or more floors and supported back to the building structure at slab edges or spandrel beams. Covers framing system selection (stick vs. unitized; captured/mechanically-glazed vs. two-side and four-side structural silicone glazing); the pressure-equalized rain-screen versus face-sealed water-management principle; thermally broken extruded aluminum framing; mullion depth and reinforcing by wind load and span; coordination of insulating, laminated, and spandrel glass infill; design wind pressure and air, water, and structural test targets; thermal transmittance (U-factor), solar heat gain, condensation resistance, acoustic, seismic interstory-drift, and thermal-movement performance; anchorage and movement accommodation at the slab edge; perimeter air and water seal continuity to the building air barrier and joint sealants; organic and anodized finishes; fabrication and installation; and laboratory and field mockup testing.
− Not intended for: Punched windows and operable aluminum windows set in a separate exterior wall assembly; ground-floor entrance and storefront systems (see [[sync/aluminum-entrances-and-storefronts]]); the glass and glazing materials themselves where specified alone (see [[sync/glazing]] for glass type, makeup, heat treatment, coatings, and IGU requirements); structural glass walls with point-supported fittings, glass fins, and cable-net walls; sloped overhead glazing, skylights, and glazed canopies where additional fallout and snow-load provisions apply; opaque metal wall panel and rainscreen cladding systems; and window-wall systems supported and stacked floor-to-floor within each story (a related but distinct assembly that does not span the slab edge).
−---
−
−# Scope {toc}
−
−## This standard governs the furnishing, fabrication, and installation of aluminum-framed glazed curtain wall as the primary non-load-bearing exterior enclosure of a building. {note}
−
−## The work shall include the extruded aluminum framing (mullions, transoms, pressure plates, and covers), the thermal break, the glazing infill and its retention, the perimeter and intermediate seals, the anchorage back to the building structure, and the continuity of the air and water control layers across the curtain wall perimeter.
−
−## The curtain wall elevations, mullion grid, design wind pressures, floor-line and anchor locations, glass types, and spandrel locations shall be [[drawing: as indicated on the contract drawings]].
−
−## This standard establishes the minimum performance, material, fabrication, and installation requirements applicable to all of those conditions.
−
−## A curtain wall is defined by what it does structurally: it carries no building floor or roof load, it spans vertically across one or more stories, and it transfers only its own dead weight and the wind load acting on its surface back to the building structure at discrete anchors. This is the property that separates a curtain wall from a storefront (supported on the slab at its base and typically one story tall) and from a window wall (which stacks within each story between the slab above and the slab below). {note}
−
−## Because the curtain wall hangs across the slab edge, it must simultaneously resist wind, exclude water and air, control heat flow and condensation, and accommodate the building's movement — floor live-load deflection, thermal expansion, and seismic interstory drift — without cracking glass, fracturing seals, or losing anchorage. Every performance category cross-couples to the others, and the wall shall be treated as a single engineered system. {note}
−
−## The curtain wall scope ends at the glass and at the perimeter seal. {note}
−
−## The glass and insulating-glass-unit requirements — heat treatment, load resistance, coatings, laminated makeups, spandrel frit, and IGU durability — are governed by [[sync/glazing]] and are referenced, not duplicated, here.
−
−## The continuity of the building air barrier into the curtain wall perimeter shall be coordinated with [[sync/air-barriers]].
−
−## The perimeter joint sealants shall be coordinated with [[sync/joint-sealants]].
−
−## Flashing, closures, and sheet metal at the perimeter shall be coordinated with [[sync/sheet-metal-flashing-and-trim]].
−
−## The thermal envelope continuity at spandrels and slab edges shall be coordinated with [[sync/building-thermal-insulation]].
−
−## Ground-floor entrances and storefronts integrated below the curtain wall are governed by [[sync/aluminum-entrances-and-storefronts]].
−
−# Referenced Standards {toc}
−
−## Materials, fabrication, performance testing, and installation shall comply with the latest adopted edition of the referenced standards.
−
−## Where the contract documents or the adopted building code impose more stringent requirements than a referenced standard, the more stringent requirement shall govern.
−
−## The Contractor shall resolve conflicts in writing with the Engineer of Record before proceeding.
−
−## Referenced Standards List {toc}
−
−| Standard | Title |
−|----------|-------|
−| AAMA/WDMA/CSA 101/I.S.2/A440 | North American Fenestration Standard (NAFS) — Specification for Windows, Doors, and Skylights |
−| AAMA CW-10 | Care and Handling of Architectural Aluminum from Shop to Site |
−| AAMA CW-13 | Structural Sealant Glazing Systems |
−| AAMA CW-RS-1 | The Rain Screen Principle and Pressure-Equalized Wall Design |
−| AAMA 501 | Methods of Test for Exterior Walls |
−| AAMA 501.1 | Standard Test Method for Water Penetration of Windows, Curtain Walls and Doors Using Dynamic Pressure |
−| AAMA 501.2 | Quality Assurance and Diagnostic Water Leakage Field Check of Installed Storefronts, Curtain Walls, and Sloped Glazing Systems |
−| AAMA 501.4 | Recommended Static Test Method for Evaluating Window Wall, Curtain Wall, and Storefront Systems Subjected to Seismic and Wind-Induced Inter-Story Drift |
−| AAMA 501.5 | Test Method for Thermal Cycling of Exterior Walls |
−| AAMA 501.6 | Recommended Dynamic Test Method for Determining the Seismic Drift Causing Glass Fallout from a Wall System |
−| AAMA 501.7 | Recommended Static Test Method for Evaluating Curtain Wall and Storefront Systems Subjected to Vertical Inter-Story Movement |
−| AAMA 503 | Voluntary Specification for Field Testing of Newly Installed Storefronts, Curtain Walls, and Sloped Glazing Systems |
−| AAMA 507 | Standard Practice for Determining the Thermal Performance Characteristics of Fenestration Systems in Commercial Buildings |
−| AAMA 611 | Voluntary Specification for Anodized Architectural Aluminum |
−| AAMA 1503 | Voluntary Test Method for Thermal Transmittance and Condensation Resistance of Windows, Doors, and Glazed Wall Sections |
−| AAMA 2604 | Voluntary Specification, Performance Requirements and Test Procedures for High Performance Organic Coatings on Aluminum Extrusions and Panels |
−| AAMA 2605 | Voluntary Specification, Performance Requirements and Test Procedures for Superior Performing Organic Coatings on Aluminum Extrusions and Panels |
−| ASTM B221 | Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes |
−| ASTM E283 | Standard Test Method for Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences |
−| ASTM E330 | Standard Test Method for Structural Performance of Exterior Windows, Doors, Skylights, and Curtain Walls by Uniform Static Air Pressure Difference |
−| ASTM E331 | Standard Test Method for Water Penetration of Exterior Windows, Skylights, Doors, and Curtain Walls by Uniform Static Air Pressure Difference |
−| ASTM E1105 | Standard Test Method for Field Determination of Water Penetration of Installed Exterior Windows, Skylights, Doors, and Curtain Walls, by Uniform or Cyclic Static Air Pressure Difference |
−| ASTM E1300 | Standard Practice for Determining Load Resistance of Glass in Buildings |
−| ASTM E1886 | Standard Test Method for Performance of Exterior Windows, Curtain Walls, Doors, and Impact Protective Systems Impacted by Missile(s) and Exposed to Cyclic Pressure Differentials |
−| ASTM E1996 | Standard Specification for Performance of Exterior Windows, Curtain Walls, Doors, and Impact Protective Systems Impacted by Windborne Debris in Hurricanes |
−| ASTM E2190 | Standard Specification for Insulating Glass Unit Performance and Evaluation |
−| ASTM C1135 | Standard Test Method for Determining Tensile Adhesion Properties of Structural Sealants |
−| ASTM C1184 | Standard Specification for Structural Silicone Sealants |
−| ASTM C1401 | Standard Guide for Structural Sealant Glazing |
−| ASTM C920 | Standard Specification for Elastomeric Joint Sealants |
−| NFRC 100 | Procedure for Determining Fenestration Product U-factors |
−| NFRC 200 | Procedure for Determining Fenestration Product Solar Heat Gain Coefficient and Visible Transmittance at Normal Incidence |
−| ASTM E90 / E413 | Laboratory Measurement of Airborne Sound Transmission Loss / Classification for Rating Sound Insulation (STC) |
−| ASTM E1332 | Standard Classification for Rating Outdoor-Indoor Sound Attenuation (OITC) |
−| IBC Chapter 24 | International Building Code — Glass and Glazing |
−
−# Submittals {toc}
−
−## Action Submittals {toc}
−
−### The following submittals shall be submitted for review and returned before fabrication begins.
−
−```datasheet
−label: Action Submittals Required
−type: checkbox
−options:
− - "Curtain wall shop drawings (elevations, sections, and details)"
− - "Structural calculations signed and sealed by licensed PE"
− - "Thermal analysis (AAMA 1503 / AAMA 507) and NFRC ratings"
− - "Laboratory test reports (E283, E331, AAMA 501.1, E330)"
− - "Seismic drift / thermal cycling test reports (where required)"
− - "Structural silicone adhesion and compatibility test results (SSG)"
− - "Framing, gasket, sealant, anchor, and finish product data"
− - "Finish samples on actual or equivalent extrusion profile"
−default: "Curtain wall shop drawings (elevations, sections, and details)"
−```
−
−### Framing, glazing, and structural submittals shall be coordinated into a single review package so that mullion depths, glazing-pocket geometry, IGU thicknesses, anchor preparations, and movement provisions are reconciled against one another before any product is fabricated.
−
−### Shop drawings shall provide elevations of every curtain wall condition drawn to scale, with the mullion grid, transom lines, floor lines, spandrel locations, glass type designations keyed by lite, and dimensions of all framing members and rough openings.
−
−### Section and plan details shall be provided at the head, base, jamb, typical vertical mullion, typical horizontal, slab-edge anchor, spandrel, corner, and every transition to an adjacent envelope assembly.
−
−### Details shall show the thermal break, the glazing-pocket and pressure-plate arrangement, the gasket compression, the structural silicone bite and glue-line where SSG is used, the pressure-equalization and weep provisions, the perimeter sealant joints, the anchor type and adjustment range, and the air- and water-barrier continuity.
−
−### Wind-load and dead-load calculations for the framing, the glazing retention, and the anchorage shall be signed and sealed by a professional engineer licensed in the project jurisdiction, demonstrating compliance with the design pressures established in the project structural drawings.
−
−### The structural calculations shall address mullion spans and deflection limits, mullion reinforcing where required, glass load distribution coordinated with [[sync/glazing]] (ASTM E1300), anchor capacity at every condition, and the accommodation of thermal movement and seismic interstory drift.
−
−### Where structural silicone glazing is used, the calculations shall size the structural bite and glue-line thickness for both the wind load and the glass dead-load weight.
−
−### Thermal transmittance (U-factor) and condensation resistance results per AAMA 1503, or a thermal simulation per AAMA 507, shall be submitted for the framing and for the complete fenestration product.
−
−### Whole-product NFRC 100 U-factor and NFRC 200 SHGC and VLT shall be submitted where the energy code requires certified ratings.
−
−### Laboratory test reports for the curtain wall system shall document air infiltration per ASTM E283, static water penetration per ASTM E331, dynamic water penetration per AAMA 501.1, and structural performance per ASTM E330.
−
−### Where required, seismic interstory drift per AAMA 501.4 and thermal cycling per AAMA 501.5 test reports shall be submitted.
−
−### Where structural silicone glazing is used, the structural sealant manufacturer's adhesion and compatibility test results (per ASTM C1135 and the manufacturer's protocol) shall be submitted for the specific glass coating, the specific framing finish, the setting blocks and spacer materials, and any backer or substrate the structural sealant will contact.
−
−### The structural sealant shall conform to ASTM C1184 and the design shall comply with ASTM C1401.
−
−### Manufacturer's published product data shall be submitted for the framing system, gaskets, sealants, thermal-break material, anchors, and finish, including the system's tested performance ratings.
−
−### Samples of each finish, minimum 12 in. by 12 in., shall be submitted on the actual extrusion profile or on a representative profile of equivalent thickness, demonstrating color, gloss, and finish quality.
−
−### For anodized finishes the samples shall demonstrate the lot-to-lot color range so that color variation across the facade can be evaluated.
−
−## Closeout Submittals {toc}
−
−### At substantial completion the Contractor shall provide the following closeout submittals before final acceptance:
−
−- As-built elevations reflecting any field changes to the mullion grid, glass types, or anchorage
−- Field test reports per AAMA 503 (chamber) or AAMA 501.2 (diagnostic hose) and ASTM E1105 where field water testing was performed
−- Mockup test reports, including any deficiencies identified and the corrective actions taken before production release
−- Cleaning and maintenance instructions for the framing finish, glass, gaskets, and sealants, including approved cleaning products and products that shall not be used on the finish
−- Warranty documentation from the curtain wall manufacturer, the structural silicone sealant manufacturer (SSG), the IGU manufacturer, and the finish applicator
−
−```datasheet
−label: Closeout Submittals Required
−type: checkbox
−options:
− - "As-built elevations"
− - "Field test reports (AAMA 503 / AAMA 501.2 / ASTM E1105)"
− - "Mockup test reports and corrective-action record"
− - "Cleaning and maintenance instructions"
− - "Curtain wall system warranty (minimum 2 years)"
− - "Finish warranty (20 years for AAMA 2605)"
− - "Structural silicone glazing warranty (SSG)"
− - "IGU warranty (minimum 10 years against seal failure)"
−default: "As-built elevations"
−```
−
−# Quality Assurance {toc}
−
−## Manufacturer and Fabricator Qualifications {toc}
−
−### The curtain wall manufacturer shall demonstrate a minimum of ten years of continuous production of aluminum curtain wall systems of the type and performance specified.
−
−### The curtain wall manufacturer shall provide independent laboratory test reports for the specific system demonstrating compliance with the air, water, and structural performance required by this standard and the drawings.
−
−### The fabricator and erector shall demonstrate a minimum of five years of experience with curtain wall of comparable scope, height, and complexity.
−
−## Structural Silicone Quality Program {toc}
−
−### Where structural silicone glazing is used, the glazier shall be trained and approved by the structural silicone sealant manufacturer for the specific system.
−
−### The structural sealant manufacturer shall review the structural joint design, confirm substrate compatibility and adhesion before production, and provide on-site instruction at the start of glazing.
−
−### SSG glazing shall be performed in a controlled shop environment wherever practicable.
−
−### Field-applied structural silicone shall be used only where the system design requires it and only under the manufacturer's field quality program.
−
−### A documented quality-control program shall record, for each production run, the sealant lot, mixing (for two-part), cure verification, bead dimension, and the daily adhesion (snap/peel) tests.
−
−### In a structurally glazed wall the silicone is the load path that holds the glass on the building — there is no mechanical capture on the structural edges — so an undetected adhesion or cure failure is a glass-fallout hazard, not merely a leak. Adhesion and compatibility are verified before and during production precisely because they cannot be inspected after the fact in a cured, glazed unit. {note}
−
−## Mockup {toc}
−
−### A laboratory performance mockup of representative bays is the standard verification for curtain wall and is the appropriate default for any project of consequential height or area. {note}
−
−### The mockup type and scope required for the curtain wall system shall be specified, with a laboratory performance mockup as the default for projects of consequential height or area.
−
−```datasheet
−label: Curtain Wall Mockup Required
−type: select
−options:
− - "Visual mockup — color, finish, and glass type confirmation only"
− - "Laboratory mockup — performance chamber test (E283, E331, AAMA 501.1, E330)"
− - "Laboratory mockup plus AAMA 501.4 interstory drift and AAMA 501.5 thermal cycling"
− - "Field mockup — typical bays installed in place and field tested (AAMA 503 / ASTM E1105)"
− - "Laboratory performance mockup plus field mockup (both)"
−default: "Laboratory mockup — performance chamber test (E283, E331, AAMA 501.1, E330)"
−```
−
−### The laboratory performance mockup shall include a typical vision area, a spandrel, a horizontal and vertical mullion intersection, a corner or movement joint, an anchor condition, and the transition to an adjacent assembly.
−
−### The mockup shall be tested as a complete system so the air barrier, water management, anchorage, and movement provisions are evaluated together.
−
−### Deficiencies found in the mockup shall be corrected and re-tested before production fabrication is released.
−
−### A visual-only mockup confirms appearance but does not verify performance and shall be used only where a separate, tested system of record establishes the performance.
−
−## Professional Engineer of Record for the Curtain Wall {toc}
−
−### The framing, glazing retention, and anchorage shall be designed by, and the structural calculations signed and sealed by, a professional engineer licensed in the project jurisdiction.
−
−### The curtain wall is a delegated-design (deferred-submittal) system in most jurisdictions: the contract drawings establish the performance criteria, geometry, and design pressures, and the specialty engineer engaged by the curtain wall contractor completes the member sizing, connection design, and anchorage within those criteria. {note}
−
−# Performance Requirements {toc}
−
−## Performance Class and Design Pressure {toc}
−
−```datasheet
−label: Design Wind Pressure (Inward / Outward, Wall Field)
−type: range
−unit: psf
−drawing_ref: true
−options:
− min: 20
− max: 150
− setpoints: [20, 30, 40, 50, 60, 75, 90, 110, 130, 150]
−default: 50
−```
−
−```datasheet
−label: Corner / Edge Zone Local Pressure
−type: range
−unit: psf
−drawing_ref: true
−options:
− min: 30
− max: 200
− setpoints: [30, 45, 60, 80, 100, 130, 160, 200]
−default: 80
−```
−
−### The curtain wall design positive and negative wind pressures shall be derived from the project structural drawings and the building-code wind determination for the project location, height, exposure category, and the zone (field, edge, or corner) in which each portion of the wall falls.
−
−### Corner and parapet zones carry substantially higher local pressures than the wall field; the system, the glass, and the anchors in those zones shall be designed for the higher local pressure rather than the field pressure.
−
−### Selection of the performance tier follows building height and exposure: low- and mid-rise walls in sheltered exposures carry modest pressures, while high-rise walls and exposed or coastal sites routinely require design pressures well above the storefront range, which is the principal reason curtain wall framing is deeper and more heavily reinforced than storefront framing. {note}
−
−## Structural Performance and Deflection {toc}
−
−```datasheet
−label: Framing Deflection Limit Normal to Wall (Design Wind Load)
−type: radio
−options:
− - "L/175 or 3/4 in., whichever is smaller (standard)"
− - "L/240 or 3/4 in., whichever is smaller (stricter, large lites or stone/panel infill)"
− - "Per project structural specifications"
−default: "L/175 or 3/4 in., whichever is smaller (standard)"
−```
−
−```datasheet
−label: Dead-Load Deflection Limit at Glass-Supporting Horizontals
−type: radio
−options:
− - "L/360 or 1/8 in., whichever is smaller (standard, protects glass edge engagement)"
− - "Per glazing manufacturer's published limit for the lite size"
−default: "L/360 or 1/8 in., whichever is smaller (standard, protects glass edge engagement)"
−```
−
−### The framing shall withstand the design positive and negative wind pressures without permanent deformation, glass breakage, anchor failure, or loss of air or water seal, verified per ASTM E330.
−
−### A proof load test at 1.5 times the design pressure shall produce no permanent deformation in any framing member exceeding 0.2 percent of its span.
−
−### Framing deflection normal to the wall under the design wind load shall not exceed L/175 of the clear span, or 3/4 in., whichever is smaller.
−
−### Deflection of a member carrying glass shall additionally be limited so that the glass edge engagement (bite) is not lost and the glazing pocket does not open.
−
−### Excessive mullion deflection is a direct cause of glazing-pocket leakage and gasket disengagement. {note}
−
−## Air Infiltration {toc}
−
−```datasheet
−label: Air Infiltration Maximum (ASTM E283 at 6.24 psf)
−type: range
−unit: cfm/sf
−options:
− min: 0.01
− max: 0.06
− setpoints: [0.01, 0.03, 0.04, 0.06]
−default: 0.06
−```
−
−### Air infiltration through the fixed curtain wall shall be tested per ASTM E283 at a static pressure differential of 6.24 psf (equivalent to a 50 mph wind) and shall not exceed 0.06 cfm per square foot of wall area.
−
−### Air leakage is controlled at a continuous interior air-seal plane — the gaskets, the inner glazing seal, and the framing joinery — which is why the air barrier of the wall is detailed at the interior, not the exterior. A leaky air seal not only wastes energy but drives interior-air moisture into the framing cavities, where it condenses against the cold exterior aluminum and emerges as apparent "leakage." {note}
−
−## Water Penetration {toc}
−
−```datasheet
−label: Static Water Penetration Test Pressure (ASTM E331)
−type: range
−unit: psf
−options:
− min: 6.24
− max: 20
− setpoints: [6.24, 8, 10, 12, 15, 20]
−default: 12
−```
−
−```datasheet
−label: Dynamic Water Penetration Test (AAMA 501.1)
−type: radio
−options:
− - "Required at the same pressure as the static test (standard for curtain wall)"
− - "Not required (low-rise, sheltered exposure only)"
−default: "Required at the same pressure as the static test (standard for curtain wall)"
−```
−
−### Water penetration shall be tested by both static and dynamic methods.
−
−### The static test per ASTM E331 shall be performed at a pressure equal to a defined fraction of the design wind pressure, typically 20 percent, with a minimum test pressure of 6.24 psf and a typical practical maximum near 20 psf.
−
−### The dynamic test per AAMA 501.1 shall apply the same water rate while a propeller or aircraft-engine-driven air stream produces the test pressure dynamically, which more realistically reproduces the gusting, turbulent pressures a real wall sees.
−
−### No uncontrolled water shall pass beyond the interior face during either test.
−
−### Water that enters the glazing pocket or framing cavities shall drain back to the exterior through the weep and pressure-equalization system and shall not be visible on the interior.
−
−## Thermal Transmittance, Solar Gain, and Condensation Resistance {toc}
−
−```datasheet
−label: Whole-Product U-Factor (NFRC 100 / AAMA 1503)
−type: range
−unit: Btu/h·sf·°F
−drawing_ref: true
−options:
− min: 0.24
− max: 0.65
− setpoints: [0.24, 0.28, 0.32, 0.38, 0.42, 0.50, 0.55, 0.65]
−default: 0.42
−```
−
−```datasheet
−label: Solar Heat Gain Coefficient (NFRC 200)
−type: range
−unit: SHGC (unitless)
−drawing_ref: true
−options:
− min: 0.18
− max: 0.50
− setpoints: [0.18, 0.22, 0.25, 0.30, 0.35, 0.40, 0.50]
−default: 0.30
−```
−
−```datasheet
−label: Condensation Resistance Factor (CRF) Minimum (AAMA 1503)
−type: range
−unit: CRF
−options:
− min: 45
− max: 80
− setpoints: [45, 55, 60, 65, 70, 75, 80]
−default: 65
−```
−
−### The complete fenestration product shall meet the U-factor, SHGC, and VLT required by the energy-compliance documentation.
−
−### The framing thermal transmittance and condensation resistance shall be determined by test per AAMA 1503 or by simulation per AAMA 507.
−
−### Whole-product U-factor and SHGC shall be certified per NFRC 100 and NFRC 200 where the energy code requires certified ratings.
−
−### A continuous thermal break in the framing shall be provided.
−
−### A continuous thermal break is essential because bare aluminum is a powerful thermal bridge, and an un-broken mullion both wastes energy and drops the interior framing surface below the indoor dew point, producing condensation that streaks the glass, stains finishes, and over time corrodes and grows mold. The thermal break interrupts the metal-to-metal path so the interior surface stays warm enough to resist condensation at the project's design interior humidity. {note}
−
−### A CRF below approximately 55 indicates a high risk of interior condensation on the framing edges in cold climates; CRF of 65 or higher is appropriate for most heated commercial applications in climate zones 5 through 7. {note}
−
−### Buildings with elevated interior humidity (natatoriums, hospitals, food processing) shall require CRF of 70 or higher and shall be reviewed against the project's interior dew point with the curtain wall manufacturer.
−
−## Acoustic Performance {toc}
−
−```datasheet
−label: Acoustic Rating Required
−type: select
−drawing_ref: true
−options:
− - "Not required — no acoustic specification"
− - "STC 35–38 (moderate urban noise control)"
− - "STC 39–45 (transit-adjacent, healthcare, hospitality)"
− - "OITC 30–35 (aircraft / heavy traffic exterior noise)"
− - "OITC 36 and above (severe exterior noise exposure)"
−default: "Not required — no acoustic specification"
−```
−
−### Where the contract documents require acoustic performance, the assembly shall meet the specified Sound Transmission Class (STC, per ASTM E90 / E413) or, for exterior environmental noise such as aircraft and traffic, the Outdoor-Indoor Transmission Class (OITC, per ASTM E1332).
−
−### The framing seals and any spandrel back-up shall not short-circuit the rated glass.
−
−### Acoustic performance is governed primarily by the glass makeup coordinated under [[sync/glazing]] — asymmetric lites, acoustic laminated interlayers, and wider air spaces — but the framing seals and any spandrel back-up also contribute. {note}
−
−## Seismic Interstory Drift and Thermal Movement {toc}
−
−```datasheet
−label: Seismic Interstory Drift Accommodation
−type: select
−drawing_ref: true
−options:
− - "Not applicable — low seismic, drift not governing"
− - "Standard — AAMA 501.4 static drift test to design drift"
− - "Enhanced — AAMA 501.4 plus AAMA 501.6 dynamic glass-fallout test (high seismic)"
−default: "Standard — AAMA 501.4 static drift test to design drift"
−```
−
−```datasheet
−label: Design Interstory Drift to Be Accommodated
−type: range
−unit: in
−drawing_ref: true
−options:
− min: 0.25
− max: 3.0
− setpoints: [0.25, 0.5, 0.75, 1.0, 1.5, 2.0, 3.0]
−default: 0.75
−```
−
−### The curtain wall shall accommodate the design seismic interstory drift and the design thermal movement without glass breakage, glass fallout, or loss of the perimeter seal.
−
−### The framing, the glazing pocket clearances, and the anchors shall be detailed to absorb the imposed drift — through glass-to-frame clearance, sliding/rocking glazing pockets, or articulated splice joints — rather than transmitting it into the glass.
−
−### Drift accommodation shall be verified per AAMA 501.4 (static) and, where glass fallout is a design concern, per AAMA 501.6 (dynamic).
−
−### Thermal movement shall be accommodated at horizontal stack joints and at anchor slots sized for the calculated expansion and contraction of the aluminum across the project temperature range.
−
−### Because the wall is anchored to the structure at each floor and spans the slab edge, the relative horizontal movement of one floor with respect to the next is imposed directly on the wall. {note}
−
−## Impact and Wind-Borne Debris Resistance {toc}
−
−```datasheet
−label: Impact / Wind-Borne Debris Requirement
−type: select
−drawing_ref: true
−options:
− - "Not required — project is not in a wind-borne debris region"
− - "Required — ASTM E1996 small missile (elevations above 30 ft)"
− - "Required — ASTM E1996 large missile (within 30 ft of grade)"
− - "Required — large missile plus enhanced design pressure (coastal high-velocity zones)"
−default: "Not required — project is not in a wind-borne debris region"
−```
−
−### For projects in hurricane wind-borne debris regions, the curtain wall and its glazing shall be tested per ASTM E1886 and shall comply with ASTM E1996 for the applicable wind zone and missile category.
−
−### Impact-rated assemblies require laminated glass (coordinated under [[sync/glazing]]), a framing system and glazing retention proven to hold the laminated lite in the frame through the cyclic pressure following impact, and structural perimeter anchorage.
−
−### Impact ratings apply to the tested assembly as a whole and shall not be transferred between systems or glass types without an updated test report.
−
−# System Type and Configuration {toc}
−
−## Stick-Built vs. Unitized {toc}
−
−### The fundamental system decision is whether the wall is assembled piece-by-piece in the field (stick-built) or shop-assembled into pre-glazed panels that are hung on the building as units (unitized). {note}
−
−### The curtain wall system type shall be specified, stating whether the wall is stick-built, unitized, or a hybrid of the two.
−
−```datasheet
−label: Curtain Wall System Type
−type: radio
−drawing_ref: true
−options:
− - "Stick-built — field-assembled and field-glazed (low/mid-rise, irregular geometry)"
− - "Unitized — shop-assembled, pre-glazed panels interlocked in the field (high-rise, large area)"
− - "Hybrid — unitized typical with stick-built infill at special conditions"
−default: "Stick-built — field-assembled and field-glazed (low/mid-rise, irregular geometry)"
−```
−
−### Stick-built systems ship as loose extrusions, anchors, and glass and are erected and glazed in place; they have a lower material cost and more field adjustability and are well suited to low- and mid-rise work and irregular geometry, but they put glazing, sealing, and quality control in the field — at height, exposed to weather, and harder to inspect. {note}
−
−### Unitized systems are fabricated, glazed, and sealed (including structural silicone, where used) in the controlled shop environment, then craned into place and interlocked at split mullions and stack joints; they cost more per square foot and require crane access and tight dimensional control, but they erect far faster, achieve more consistent water and air performance, and remove the structural glazing from the field. Unitized construction is the predominant choice for high-rise and large-area facades for these reasons. {note}
−
−## Glazing Method — Captured vs. Structural Silicone {toc}
−
−### The glass may be retained mechanically (captured) or by structural silicone (SSG).
−
−```datasheet
−label: Glazing Method
−type: select
−drawing_ref: true
−options:
− - "Captured — four-side mechanical (pressure plate and cover, gasketed) (standard)"
− - "Two-side structural silicone (captured horizontals, structural verticals, or inverse)"
− - "Four-side structural silicone (all edges bonded, flush mullion-free exterior)"
−default: "Captured — four-side mechanical (pressure plate and cover, gasketed) (standard)"
−```
−
−### In a captured (mechanically glazed) system the glass is held on all four edges by a continuous exterior pressure plate and a snap-on cover, compressing gaskets against both faces; this is the most robust and inspectable retention and is the appropriate default. {note}
−
−### In structural silicone glazing the structural silicone bonds the glass to the framing and carries the wind load into the frame without a mechanical capture on the structural edges — two-side SSG captures the horizontals and structurally bonds the verticals (or vice versa), and four-side SSG bonds all four edges for a fully flush, mullion-free exterior appearance. {note}
−
−### SSG is selected for its appearance and for the slightly better thermal and water performance of an uninterrupted exterior, but it transfers the entire load path to the sealant; this is why ASTM C1184 sealant conformance, ASTM C1401 design, factory application, and the adhesion/compatibility program above are mandatory for SSG and why field-applied four-side SSG is generally avoided. {note}
−
−## Water Management — Pressure-Equalized vs. Face-Sealed {toc}
−
−### A curtain wall manages water by one of two principles. {note}
−
−### A face-sealed (barrier) wall relies on a single continuous exterior seal to stop all water at the outer face; it is simpler but unforgiving, because any breach in that single line lets water in with no second line of defense. {note}
−
−### A pressure-equalized rain-screen wall, the modern standard described in AAMA CW-RS-1, accepts that some water will pass the outer screen and instead defeats the forces that drive water inward. The glazing pocket and internal cavities are vented to the exterior so the air pressure inside the cavity equalizes with the wind pressure outside; with no pressure difference across the outer screen, the dominant force pushing water through joints is removed, and the small amount of water that does enter is collected on internal gutters and drained back out through weeps. The interior line is then sealed for air, and the exterior screen sheds the bulk of the water — two lines of defense instead of one. {note}
−
−### Pressure-equalized rain-screen design shall be the appropriate default for curtain wall; face-sealed design shall be limited to low-exposure conditions.
−
−```datasheet
−label: Water Management Principle
−type: radio
−drawing_ref: true
−options:
− - "Pressure-equalized rain screen — vented/weeped cavity, internal drainage (standard)"
− - "Face-sealed (barrier) — single exterior seal (low-rise, sheltered exposure only)"
−default: "Pressure-equalized rain screen — vented/weeped cavity, internal drainage (standard)"
−```
−
−## Mullion Sightline and Depth {toc}
−
−```datasheet
−label: Mullion Face Width (Sightline)
−type: select
−drawing_ref: true
−options:
− - "2 in (51 mm) — minimal sightline, light to moderate loads"
− - "2-1/2 in (64 mm) — standard commercial sightline (typical)"
− - "3 in (76 mm) — wider sightline, larger lites or higher loads"
−default: "2-1/2 in (64 mm) — standard commercial sightline (typical)"
−```
−
−```datasheet
−label: Mullion Depth
−type: range
−unit: in
−drawing_ref: true
−options:
− min: 3
− max: 12
− setpoints: [3, 4, 5, 6, 7.5, 9, 10.5, 12]
−default: 6
−```
−
−```datasheet
−label: Mullion Reinforcing
−type: radio
−drawing_ref: true
−options:
− - "Not required — aluminum mullion adequate for span and pressure"
− - "Steel tube reinforcement inside mullion cavity for span/pressure"
− - "Deeper mullion in lieu of reinforcing"
−default: "Not required — aluminum mullion adequate for span and pressure"
−```
−
−### The mullion face width (sightline) is an architectural decision; the mullion depth is a structural one, driven by the span between anchors and the design wind pressure. {note}
−
−### Deeper mullions and supplemental steel reinforcing shall be used to resist higher loads and longer spans.
−
−### The mullion depth shall be confirmed against the manufacturer's span tables and the signed structural calculations for the actual span and pressure, including the higher corner-zone pressure where applicable.
−
−# Framing and Materials {toc}
−
−## Aluminum Extrusions {toc}
−
−```datasheet
−label: Aluminum Alloy and Temper
−type: radio
−options:
− - "6063-T6 structural framing; 6063-T5 trim and covers (as required by member function)"
− - "6063-T6 throughout"
−default: "6063-T6 structural framing; 6063-T5 trim and covers (as required by member function)"
−```
−
−### Framing extrusions — mullions, transoms, pressure plates, covers, and trim — shall conform to ASTM B221, alloy 6063 in temper T5 or T6 as appropriate to the structural and finishing requirements of each profile.
−
−### Temper T6 shall be used for structural mullions and transoms; temper T5 is acceptable for non-structural pressure plates, covers, and trim.
−
−### The minimum wall thickness of primary structural members shall be 0.090 in. (2.3 mm); non-structural trim shall be not less than 0.062 in. (1.6 mm).
−
−### Members shall be of adequate section to meet the deflection limits above without relying on the glass for stiffness.
−
−## Thermal Break {toc}
−
−```datasheet
−label: Thermal Break Type
−type: select
−options:
− - "Polyamide strut (glass-reinforced nylon, mechanically crimped) — higher performance"
− - "Poured-and-debridged polyurethane — moderate performance"
−default: "Polyamide strut (glass-reinforced nylon, mechanically crimped) — higher performance"
−```
−
−### Framing members shall be thermally broken with a continuous thermal barrier between the interior and exterior aluminum.
−
−### A polyamide strut (pultruded glass-fiber-reinforced nylon mechanically crimped into the profiles) or a poured-and-debridged polyurethane barrier may be used.
−
−### The thermal-break dimension shall be selected to meet the project U-factor and CRF targets.
−
−### Polyamide struts provide higher thermal performance, greater structural shear transfer between the inner and outer aluminum, and reliable dual-color (different interior and exterior) finishing, while poured-and-debridged is acceptable for moderate-performance walls. {note}
−
−## Steel Reinforcing and Fasteners {toc}
−
−### Steel reinforcing inserted within mullion cavities shall be hot-dip galvanized or otherwise corrosion-protected and shall be isolated from the aluminum to prevent galvanic corrosion.
−
−### Exposed and concealed fasteners and anchors shall be stainless steel or another corrosion-resistant material compatible with both the aluminum and the embedded or structural steel they connect to.
−
−### Dissimilar metals in contact shall be separated by a non-conductive isolator or coating.
−
−## Gaskets {toc}
−
−### Glazing gaskets shall be extruded EPDM, silicone, or thermoplastic of the durometer and profile specified by the framing system, providing continuous compression against both glass faces at captured edges.
−
−### Gaskets shall be installed in continuous lengths with splices located and sealed at corners per the manufacturer's instructions.
−
−### A discontinuity at a gasket corner is a common, avoidable leak path. {note}
−
−# Glazing Infill {toc}
−
−## The glass and insulating glass units are governed by [[sync/glazing]], which establishes glass type, heat treatment, load resistance per ASTM E1300, coatings and coating surface, laminated makeups, spandrel frit, IGU certification per ASTM E2190, and the safety-glazing requirements of IBC Chapter 24. {note}
−
−## This standard does not duplicate the glazing requirements; it establishes only how the glass is retained, supported, sealed, and drained within the curtain wall framing, and the coordination obligations between the two scopes. {note}
−
−## The glass type, makeup, and performance for each lite shall be [[drawing: as indicated on the contract drawings and glazing schedule]].
−
−## Glass-to-Framing Coordination {toc}
−
−### The IGU overall thickness, edge bite, edge clearance, and weight shall be coordinated between the glazing scope ([[sync/glazing]]) and the framing system so that the glazing pocket, setting blocks, and structural-silicone bite (where SSG is used) suit the actual unit.
−
−### The IGU secondary seal and any coating that a structural silicone bead will contact shall be confirmed compatible with that silicone under the adhesion/compatibility program.
−
−### An incompatible secondary seal or coating defeats the structural bond and the IGU seal alike. {note}
−
−## Spandrel Areas {toc}
−
−```datasheet
−label: Spandrel Infill Type
−type: select
−drawing_ref: true
−options:
− - "Fritted/opacified spandrel glass with insulated back-pan (typical)"
− - "Shadow-box spandrel (clear or coated glass over a finished back-pan with airspace)"
− - "Opaque insulated metal infill panel"
− - "Not applicable — no spandrel areas"
−default: "Fritted/opacified spandrel glass with insulated back-pan (typical)"
−```
−
−### Spandrel glass (heat-strengthened with frit or opacifier, per [[sync/glazing]]) or an opaque infill panel shall be set in the same framing with a shadow box or insulated back-pan as detailed.
−
−### The spandrel cavity shall be detailed for the high heat that builds behind opaque glass and for continuity of the air and thermal control layers with the adjacent vision areas and with [[sync/building-thermal-insulation]].
−
−### At spandrel (non-vision) areas the curtain wall conceals the floor edge, structure, and back-up insulation. {note}
−
−# Finishes {toc}
−
−```datasheet
−label: Aluminum Finish
−type: select
−drawing_ref: true
−options:
− - "Fluoropolymer organic coating, AAMA 2605 (superior, 20-yr class) — exterior default"
− - "Fluoropolymer organic coating, AAMA 2604 (high performance)"
− - "Anodized, AAMA 611 Architectural Class I (integral color, abrasion resistant)"
− - "Anodized, AAMA 611 Architectural Class II (interior or low-exposure)"
−default: "Fluoropolymer organic coating, AAMA 2605 (superior, 20-yr class) — exterior default"
−```
−
−## Exposed aluminum shall receive an anodized or organic-coated finish as scheduled.
−
−## Organic (fluoropolymer) coatings to AAMA 2604 provide good color and chalk/fade resistance for typical commercial work.
−
−## AAMA 2605 (the highest-performing fluoropolymer class) shall be specified where the longest finish life and the best color and gloss retention are required, which is the appropriate default for tall and prominent facades that cannot easily be refinished.
−
−## Anodized finishes to AAMA 611 provide a durable, abrasion-resistant integral-color finish; architectural Class I anodizing (the thicker coating) shall be used for exterior exposure.
−
−# Anchorage and Movement {toc}
−
−## Anchorage to the Building Structure {toc}
−
−```datasheet
−label: Anchor Type
−type: select
−drawing_ref: true
−options:
− - "Slab-edge embedded plate with welded/bolted clip (typical)"
− - "Cast-in channel anchor with serrated/adjustable connection"
− - "Through-slab or face-of-slab bolted anchor"
− - "Spandrel-beam or steel-edge anchor"
−default: "Slab-edge embedded plate with welded/bolted clip (typical)"
−```
−
−### The curtain wall shall be anchored to the building structure at each floor, typically at the slab edge or to an embedded plate, spandrel beam, or cast-in anchor, [[drawing: as indicated on the contract drawings and anchorage details]].
−
−### Anchors shall be three-way adjustable (in, out; up, down; and in-and-out of plane) to absorb construction tolerances of the structure without forcing the framing out of plane or out of plumb.
−
−### The anchor design, the embedment or attachment, and the load path into the structure shall be by the curtain wall engineer and coordinated with the building structural engineer.
−
−### The anchor shall transfer wind load (in and out) and the curtain wall dead weight (gravity) into the structure, and shall do so while permitting the movements below.
−
−## Movement Accommodation {toc}
−
−```datasheet
−label: Vertical Movement Joint Provision
−type: radio
−drawing_ref: true
−options:
− - "Telescoping stack joint at each floor (unitized) (standard for unitized)"
− - "Slotted/expansion horizontal mullion (stick-built)"
− - "Per manufacturer's tested movement detail"
−default: "Per manufacturer's tested movement detail"
−```
−
−### The framing and anchorage shall accommodate, without distress: the live-load and creep deflection of the supporting floor edges; the differential vertical movement between floors; the thermal expansion and contraction of the aluminum over the project temperature range; and the seismic interstory drift established above.
−
−### Vertical movement shall be taken at horizontal stack/expansion joints (the telescoping split between a panel and the one below in a unitized wall, or the slotted/expansion horizontal in a stick wall).
−
−### The dead load of each segment shall bear at a defined point while the joint above is free to move.
−
−### Anchor slots and shims shall preserve the design movement range after erection.
−
−### An anchor inadvertently welded or bolted solid where it was meant to slide will transfer building movement into the glass and is a defect. {note}
−
−# Air and Water Seal Continuity {toc}
−
−## The single most common source of curtain wall failure is not the wall itself but the perimeter — the transition where the curtain wall meets the adjacent construction at the head, jamb, base, and at any penetration or interruption. {note}
−
−## The wall's own air and water performance is verified by testing, but the perimeter joint is built in the field, at the interface between two trades, and is where the air barrier and water barrier of the curtain wall must be made continuous with the air barrier and water barrier of the surrounding wall. A discontinuity here lets air and water bypass an otherwise sound wall. {note}
−
−## Air Barrier Continuity {toc}
−
−### The interior air-seal plane of the curtain wall shall be made continuous with the building air barrier of the adjacent assemblies, coordinated with [[sync/air-barriers]].
−
−### The transition membrane or sealant shall bridge from the curtain wall's interior air seal to the adjacent air barrier with a detailed, continuous, and durable connection that accommodates the differential movement between the curtain wall and the adjacent structure.
−
−### The connection shall be detailed on the shop drawings and verified on the mockup.
−
−## Perimeter Water Seal and Flashing {toc}
−
−```datasheet
−label: Perimeter Sealant
−type: select
−options:
− - "Silicone — ASTM C920 Type S, Grade NS, Class 50/100 (highest movement, longest life)"
− - "Polyurethane — ASTM C920 Type S, Grade NS, Class 35 (paintable, moderate movement)"
−default: "Silicone — ASTM C920 Type S, Grade NS, Class 50/100 (highest movement, longest life)"
−```
−
−### The perimeter water seal shall direct any water that reaches the perimeter back to the exterior.
−
−### Sill and base conditions shall be flashed with an end-dammed pan, coordinated with [[sync/sheet-metal-flashing-and-trim]], so that water draining from the curtain wall's internal weep system and any water at the perimeter is collected and drained out, not onto or into the construction below.
−
−### Perimeter sealant joints between the curtain wall frame and the adjacent construction shall be elastomeric sealant conforming to ASTM C920, sized for the calculated movement and installed over the correct backer per [[sync/joint-sealants]].
−
−### The sealant manufacturer shall confirm compatibility with the curtain wall finish and the adjacent substrate.
−
−# Fabrication {toc}
−
−```datasheet
−label: Structural Silicone Application (SSG Systems)
−type: radio
−options:
− - "Factory/shop applied and cured under QC program (standard for SSG)"
− - "Field applied only where system design requires, under manufacturer field QC"
−default: "Factory/shop applied and cured under QC program (standard for SSG)"
−```
−
−## Framing shall be fabricated to the dimensions and tolerances of the reviewed shop drawings, with members cut, machined, and prepared for assembly in the shop.
−
−## Joints in the framing shall be sealed against air and water as the system design requires.
−
−## For unitized systems, the panels shall be assembled, glazed, sealed, and — where structural silicone is used — structurally glazed and cured in the controlled shop environment under the quality program above before shipment.
−
−## Structural silicone shall not be loaded until it has reached the cure required by the sealant manufacturer.
−
−## Aluminum shall be protected from shop through site per AAMA CW-10.
−
−## Finished surfaces shall be protected with a strippable coating or covering, and finished members shall not be stored or handled in a way that abrades or contaminates the finish.
−
−# Installation {toc}
−
−## Anchorage and Erection {toc}
−
−### The Contractor shall install the curtain wall plumb, level, and in plane within the system tolerances, anchored to the structure at the locations and with the adjustment shown on the reviewed shop drawings.
−
−### Anchors shall be set and adjusted to absorb the as-built tolerances of the structure, then secured so that the design movement range remains free at the movement joints.
−
−### Welded anchor connections shall be touched up with corrosion-protective coating; dissimilar metals shall be isolated.
−
−## Sequence and Coordination {toc}
−
−### Erection shall be sequenced with the adjacent envelope trades so the air-barrier and water-barrier transitions can be made continuous as the wall goes up, rather than retrofitted behind a completed wall.
−
−### Routing, anchor, and transition conditions shall be coordinated against [[drawing: the building structural drawings and exterior envelope details]] and with [[sync/air-barriers]], [[sync/joint-sealants]], and [[sync/sheet-metal-flashing-and-trim]] before erection.
−
−## Perimeter Seal to the Air Barrier {toc}
−
−### The perimeter air-barrier transition shall be installed as the wall is erected, continuously connecting the curtain wall's interior air seal to the adjacent air barrier per [[sync/air-barriers]], and shall be inspected before it is concealed.
−
−### The perimeter water seal and pan flashing shall be installed so that the curtain wall weep drainage and any perimeter water discharge to the exterior.
−
−## Glazing, Setting Blocks, and Weep System {toc}
−
−```datasheet
−label: Weep / Pressure-Equalization Openings
−type: radio
−options:
− - "Provided and kept clear at each glazing pocket per system design (standard)"
− - "Not applicable — face-sealed (barrier) system"
−default: "Provided and kept clear at each glazing pocket per system design (standard)"
−```
−
−### Field glazing (stick systems) shall be performed only after the framing is installed plumb, level, and weather-protected and the glazing pockets are clean and dry.
−
−### Each lite shall be set on setting blocks at the quarter points (or as the glazing manufacturer directs for the lite size), centered in the pocket with the required edge clearance, face clearance, and bite per [[sync/glazing]] and the framing manufacturer's glazing instructions.
−
−### The pressure-equalization and weep openings shall be kept clear and unobstructed by gaskets, setting blocks, or sealant.
−
−### A blocked weep defeats the rain-screen drainage and traps water against the IGU edge seal, which is a leading cause of premature IGU failure. {note}
−
−# Field Quality Control {toc}
−
−## Field Water Testing {toc}
−
−```datasheet
−label: Field Water Test Method
−type: select
−options:
− - "AAMA 503 chamber test with ASTM E1105 (certified field performance)"
− - "AAMA 501.2 diagnostic hose check (leak location / quality assurance)"
− - "Both — diagnostic 501.2 during construction, 503 for acceptance"
− - "Not required"
−default: "AAMA 501.2 diagnostic hose check (leak location / quality assurance)"
−```
−
−### Where the contract documents require field water testing of the installed wall, the wall shall be tested per AAMA 503 with ASTM E1105 (calibrated chamber) at a pressure equal to two-thirds of the laboratory test pressure, or checked diagnostically per AAMA 501.2 (calibrated spray nozzle, no chamber) to locate leaks.
−
−### Leakage found in field testing shall be located, corrected, and re-tested.
−
−### The diagnostic AAMA 501.2 hose check is valuable for finding the location of a leak during construction but does not substitute for AAMA 503 chamber testing where certified field performance is required. {note}
−
−## Mockup Verification {toc}
−
−### Where a mockup is required, the field or laboratory mockup shall be tested and accepted before production release as established under Quality Assurance.
−
−### The installed wall shall match the accepted mockup in materials, details, and workmanship.
−
−# Cleaning and Protection {toc}
−
−```datasheet
−label: Finish and Glass Cleaning Restrictions
−type: select
−options:
− - "Approved non-abrasive cleaners only — no abrasives, scrapers, or acids/alkalis"
− - "Per finish and glass manufacturers' written cleaning procedures"
−default: "Per finish and glass manufacturers' written cleaning procedures"
−```
−
−## Finished aluminum and glass shall be protected from damage and from construction contaminants from delivery through substantial completion, consistent with AAMA CW-10.
−
−## Welding, cutting, and grinding shall not be performed near installed glass or finished aluminum without sacrificial protection.
−
−## Weld spatter and grinding sparks permanently damage glass and finishes. {note}
−
−## At substantial completion the aluminum and glass shall be cleaned with non-abrasive cleaners approved by the finish and glass manufacturers.
−
−## Abrasive pads, scrapers, and acidic or alkaline construction-residue cleaners shall not contact the finish, the glass coatings, or the IGU edge seals.
−
−# Warranty {toc}
−
−```datasheet
−label: System Workmanship Warranty Term
−type: range
−unit: years
−options:
− min: 2
− max: 10
− setpoints: [2, 5, 10]
−default: 2
−```
−
−```datasheet
−label: Finish Warranty Term
−type: range
−unit: years
−options:
− min: 5
− max: 20
− setpoints: [5, 10, 20]
−default: 20
−```
−
−```datasheet
−label: IGU Seal Warranty Term
−type: range
−unit: years
−options:
− min: 10
− max: 15
− setpoints: [10, 15]
−default: 10
−```
−
−## The Contractor shall warrant the curtain wall system against defects in materials and workmanship, including air and water infiltration in excess of the specified performance, for a period of not less than two years from substantial completion.
−
−## The finish warranty shall be a minimum of twenty years for AAMA 2605 fluoropolymer coatings (or the published term for the scheduled finish) against color fade, chalk, and film integrity.
−
−## The structural silicone glazing warranty (for SSG systems) shall cover adhesive and cohesive failure of the structural sealant for the sealant manufacturer's published term.
−
−## The insulating glass unit warranty (coordinated under [[sync/glazing]]) shall be a minimum of ten years against seal failure.
−
−## Warranties shall be written in the name of the Owner and shall be transferable for the warranty term.
+---
+title: Glazed Curtain Walls
+category: Architectural / Openings
+description: >
+ When to use: Aluminum-framed glazed curtain wall acting as the primary non-load-bearing exterior enclosure of a building — stick-built, semi-unitized, and unitized systems that span vertically across one or more stories and hang from the building frame at discrete anchors. Covers the assembly method, the water management principle and internal drainage, mechanically captured and structurally silicone-glazed retention, framing member sizing and thermal barriers, the vision and spandrel glazing selection tree the framing delivers, aluminum finishes, air and water penetration resistance, thermal transmittance and condensation resistance, acoustic performance, wind pressure and deflection criteria, thermal and seismic movement accommodation, wind-borne debris impact resistance, perimeter fire containment at the floor edge, anchorage and movement joints, perimeter air and water barrier continuity, fabrication, mockups, erection, and field water and air testing.
+
+ Not intended for: Ground-floor entrances, entrance doors, and storefront framing bearing on the slab within a single story ([[sync/aluminum-entrances-and-storefronts]]); window wall that stacks within each story between the slab above and the slab below; punched windows and operable aluminum windows set into a separate exterior wall assembly; glass and glazing specified independently of a framing system ([[sync/glazing]]); point-supported structural glass walls, glass fin walls, and cable-net walls; sloped glazing, skylights, and glazed canopies carrying snow load and overhead fallout provisions; opaque metal panel and rainscreen cladding systems; the building air barrier and its transition membranes outside the curtain wall perimeter ([[sync/air-barriers]]); joint sealants specified independently ([[sync/joint-sealants]]); and sheet metal flashing, closures, and trim outside the curtain wall frame ([[sync/sheet-metal-flashing-and-trim]]).
+---
+
+# Scope {toc}
+
+## This standard governs the design, fabrication, finishing, and installation of aluminum-framed glazed curtain wall serving as the primary non-load-bearing exterior enclosure of a building. {note}
+
+## A curtain wall is defined by what it does structurally: it carries no floor or roof load, it spans vertically across one or more stories, and it transfers only its own weight and the wind acting on its face back to the building frame at discrete anchors. That is the property that separates it from a storefront, which bears on the slab within a single story, and from a window wall, which stacks within each story between the slab above and the slab below. {note}
+
+## The work of this standard includes the extruded aluminum framing and its thermal barrier, the glazing infill and the means that retains it, the internal drainage and pressure-equalization provisions, the anchorage back to the building structure, the movement joints, and the perimeter air and water seals that tie the wall into the surrounding enclosure. {note}
+
+## Because the wall hangs across the floor edge, it resists wind, excludes water and air, controls heat flow and condensation, and absorbs the building's movement at the same time and through the same members. A change made for one of those purposes moves the others, so the wall is designed, tested, and accepted as one engineered system rather than as a collection of parts. {note}
+
+## The following are governed elsewhere and are outside this standard: {note}
+
+- the glass and insulating glass units where they are specified independently of a framing system, including monolithic glazing set into other assemblies ([[sync/glazing]])
+- ground-floor entrances, entrance doors, and the storefront framing that receives them ([[sync/aluminum-entrances-and-storefronts]])
+- the building air barrier and the transition membranes beyond the curtain wall perimeter ([[sync/air-barriers]])
+- joint sealants outside the curtain wall perimeter joint ([[sync/joint-sealants]])
+- sheet metal flashing, copings, closures, and trim outside the curtain wall frame ([[sync/sheet-metal-flashing-and-trim]])
+- thermal insulation in the back-up construction behind spandrel areas ([[sync/building-thermal-insulation]])
+- window wall, punched windows, operable windows, sloped glazing, skylights, and point-supported structural glass assemblies
+- the structural frame, embedded plates, and cast-in anchors furnished under the structural work, up to the face at which the curtain wall anchor connects
+
+## This standard carries its own glazing selection tree because the framing system and the glazing infill are delivered, tested, warranted, and accepted as one product under one performance rating. Glass selected apart from the frame that holds it cannot be assigned an air, water, structural, or thermal rating. {note}
+
+## The extent, elevations, and mullion grid of the curtain wall shall be as indicated on [[drawing: the exterior elevations and curtain wall details]].
+
+## Vision, spandrel, and opaque infill areas shall be located as indicated on [[drawing: the exterior elevations]].
+
+## Glass types shall be keyed to each lite as indicated on [[drawing: the glazing schedule]].
+
+## Anchor locations and the supporting structure at each floor shall be as indicated on [[drawing: the project structural drawings]].
+
+## Penetrations of the curtain wall for louvers, vents, grilles, and equipment shall be located as indicated on [[drawing: the exterior elevations and the mechanical plans]].
+
+# Referenced Standards {toc}
+
+## Materials, fabrication, testing, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
+
+## Where two referenced standards, the contract documents, or the Authority Having Jurisdiction impose conflicting requirements, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
+
+## The adopted building code and the adopted energy code shall take precedence over every other reference on any matter those codes address directly.
+
+| Standard | Title |
+|----------|-------|
+| AAMA/WDMA/CSA 101/I.S.2/A440 | North American Fenestration Standard/Specification for Windows, Doors, and Skylights |
+| AAMA CW-DG-1 | Aluminum Curtain Wall Design Guide Manual |
+| AAMA CW-RS-1 | The Rain Screen Principle and Pressure-Equalized Wall Design |
+| AAMA CW-10 | Care and Handling of Architectural Aluminum from Shop to Site |
+| AAMA CW-13 | Structural Sealant Glazing Systems |
+| AAMA 501 | Methods of Test for Exterior Walls |
+| AAMA 501.1 | Standard Test Method for Water Penetration of Windows, Curtain Walls and Doors Using Dynamic Pressure |
+| AAMA 501.2 | Quality Assurance and Diagnostic Water Leakage Field Check of Installed Storefronts, Curtain Walls, and Sloped Glazing Systems |
+| AAMA 501.4 | Recommended Static Test Method for Evaluating Curtain Wall and Storefront Systems Subjected to Seismic and Wind Induced Inter-Story Drift |
+| AAMA 501.5 | Test Method for Thermal Cycling of Exterior Walls |
+| AAMA 501.6 | Recommended Dynamic Test Method for Determining the Seismic Drift Causing Glass Fallout from a Wall System |
+| AAMA 501.7 | Recommended Static Test Method for Evaluating Curtain Wall and Storefront Systems Subjected to Vertical Inter-Story Movement |
+| AAMA 503 | Voluntary Specification for Field Testing of Newly Installed Storefronts, Curtain Walls, and Sloped Glazing Systems |
+| AAMA 507 | Standard Practice for Determining the Thermal Performance Characteristics of Fenestration Systems in Commercial Buildings |
+| AAMA 611 | Voluntary Specification for Anodized Architectural Aluminum |
+| AAMA 800 | Voluntary Specifications and Test Methods for Sealants |
+| AAMA 1503 | Voluntary Test Method for Thermal Transmittance and Condensation Resistance of Windows, Doors, and Glazed Wall Sections |
+| AAMA 2603 | Voluntary Specification, Performance Requirements and Test Procedures for Pigmented Organic Coatings on Aluminum Extrusions and Panels |
+| AAMA 2604 | Voluntary Specification, Performance Requirements and Test Procedures for High Performance Organic Coatings on Aluminum Extrusions and Panels |
+| AAMA 2605 | Voluntary Specification, Performance Requirements and Test Procedures for Superior Performing Organic Coatings on Aluminum Extrusions and Panels |
+| ASCE 7 | Minimum Design Loads and Associated Criteria for Buildings and Other Structures |
+| ASTM B209 | Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate |
+| ASTM B221 | Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes |
+| ASTM A123 | Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products |
+| ASTM C920 | Standard Specification for Elastomeric Joint Sealants |
+| ASTM C1036 | Standard Specification for Flat Glass |
+| ASTM C1048 | Standard Specification for Heat-Strengthened and Fully Tempered Flat Glass |
+| ASTM C1087 | Standard Test Method for Determining Compatibility of Liquid-Applied Sealants with Accessories Used in Structural Glazing Systems |
+| ASTM C1135 | Standard Test Method for Determining Tensile Adhesion Properties of Structural Sealants |
+| ASTM C1172 | Standard Specification for Laminated Architectural Flat Glass |
+| ASTM C1184 | Standard Specification for Structural Silicone Sealants |
+| ASTM C1249 | Standard Guide for Secondary Seal for Sealed Insulating Glass Units Used in Structural Sealant Glazing Applications |
+| ASTM C1401 | Standard Guide for Structural Sealant Glazing |
+| ASTM E90 | Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements |
+| ASTM E119 | Standard Test Methods for Fire Tests of Building Construction and Materials |
+| ASTM E283 | Standard Test Method for Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences |
+| ASTM E330 | Standard Test Method for Structural Performance of Exterior Windows, Doors, Skylights, and Curtain Walls by Uniform Static Air Pressure Difference |
+| ASTM E331 | Standard Test Method for Water Penetration of Exterior Windows, Skylights, Doors, and Curtain Walls by Uniform Static Air Pressure Difference |
+| ASTM E413 | Classification for Rating Sound Insulation |
+| ASTM E783 | Standard Test Method for Field Measurement of Air Leakage Through Installed Exterior Windows and Doors |
+| ASTM E1105 | Standard Test Method for Field Determination of Water Penetration of Installed Exterior Windows, Skylights, Doors, and Curtain Walls, by Uniform or Cyclic Static Air Pressure Difference |
+| ASTM E1300 | Standard Practice for Determining Load Resistance of Glass in Buildings |
+| ASTM E1332 | Standard Classification for Rating Outdoor-Indoor Sound Attenuation |
+| ASTM E1886 | Standard Test Method for Performance of Exterior Windows, Curtain Walls, Doors, and Impact Protective Systems Impacted by Missile(s) and Exposed to Cyclic Pressure Differentials |
+| ASTM E1996 | Standard Specification for Performance of Exterior Windows, Curtain Walls, Doors, and Impact Protective Systems Impacted by Windborne Debris in Hurricanes |
+| ASTM E2188 | Standard Test Method for Insulating Glass Unit Performance |
+| ASTM E2190 | Standard Specification for Insulating Glass Unit Performance and Evaluation |
+| ASTM E2307 | Standard Test Method for Determining Fire Resistance of Perimeter Fire Barriers Using Intermediate-Scale, Multi-story Test Apparatus |
+| ANSI Z97.1 | Safety Glazing Materials Used in Buildings — Safety Performance Specifications and Methods of Test |
+| 16 CFR Part 1201 | Safety Standard for Architectural Glazing Materials |
+| IBC | International Building Code |
+| IECC | International Energy Conservation Code |
+| ASHRAE 90.1 | Energy Standard for Sites and Buildings Except Low-Rise Residential Buildings |
+| NFPA 285 | Standard Fire Test Method for Evaluation of Fire Propagation Characteristics of Exterior Non-Load-Bearing Wall Assemblies Containing Combustible Components |
+| NFRC 100 | Procedure for Determining Fenestration Product U-factors |
+| NFRC 200 | Procedure for Determining Fenestration Product Solar Heat Gain Coefficient and Visible Transmittance at Normal Incidence |
+
+# Submittals {toc}
+
+## Action Submittals {toc}
+
+### The Contractor shall submit the following for review and shall not release any curtain wall component for fabrication until the corresponding submittal has been reviewed and returned:
+
+- shop drawings giving scaled elevations of every curtain wall condition, with the mullion grid, transom lines, floor lines, movement joints, vision and spandrel areas, and the glass type designation of each lite
+- shop drawing sections and plans at the head, sill, base, jamb, typical vertical mullion, typical horizontal, floor-edge anchor, spandrel, outside and inside corner, movement joint, and every transition to an adjacent enclosure assembly
+- shop drawing details showing the thermal barrier, the glazing pocket and its retention, the gasket compression or the structural silicone bite and glue-line, the drainage and pressure-equalization path, the perimeter sealant joints, and the continuity of the air and water control layers
+- product data for the framing system, giving the tested air, water, structural, and thermal ratings of the system as configured for this project
+- product data for the gaskets, sealants, thermal barrier material, setting blocks, anchors, fasteners, and finish
+- product data for each glazing makeup, giving the lite thicknesses, heat treatment, coating and coating surface, interlayer, cavity gas, edge spacer, and the certification the unit carries
+- finish samples not less than 12 in. by 12 in. on the extrusion profile that will be used, or on a profile of equivalent thickness, showing color, gloss, and texture
+- for an anodized finish, a set of samples showing the full lot-to-lot color range that will be accepted across the facade
+- a glazing sample of each vision and spandrel makeup, not less than 12 in. by 12 in., showing color, coating appearance, and frit or opacifier pattern
+
+```datasheet
+label: Action Submittal Package
+type: checkbox
+options:
+ - "Curtain wall shop drawing elevations"
+ - "Shop drawing sections, plans, and anchor details"
+ - "Framing system product data with tested ratings"
+ - "Gasket, sealant, thermal barrier, and anchor product data"
+ - "Glazing makeup product data"
+ - "Finish samples on the extrusion profile"
+ - "Anodized lot-to-lot color range samples"
+ - "Vision and spandrel glazing samples"
+```
+
+### The framing, glazing, anchorage, and structural submittals shall be assembled into one coordinated review package so that mullion depths, glazing pocket geometry, glazing unit thickness and weight, anchor preparations, and movement provisions are reconciled against one another before any component is fabricated.
+
+### A partial submittal that defers any one of those items to a later package shall be returned without review.
+
+## Informational Submittals {toc}
+
+### The Contractor shall submit the following supporting calculations, test reports, and certifications with or before the action submittals:
+
+- structural calculations for the framing, the glazing retention, and the anchorage, signed and sealed by a professional engineer licensed in the project jurisdiction
+- laboratory test reports for the system as configured for this project, covering air infiltration, static water penetration, dynamic water penetration, and structural performance
+- thermal transmittance and condensation resistance results for the framing and for the complete product, by the determination method specified in this standard
+- certified whole-product U-factor, solar heat gain coefficient, and visible light transmittance where the adopted energy code requires a certified rating
+- seismic interstory drift, vertical interstory movement, and thermal cycling test reports where those tests are required by this standard
+- missile impact and cyclic pressure test reports where impact resistance is required by this standard
+- structural silicone adhesion and compatibility results for the specific glass coating, framing finish, setting blocks, spacers, gaskets, and every other material the structural sealant will contact
+- the listing for the perimeter fire containment system, identifying the tested assembly and the ratings it achieved
+- the listing for the exterior wall assembly where compliance with NFPA 285 is required by this standard
+- thermal movement calculations for the framing and the movement joints, using the temperature ranges specified in this standard
+- qualification records for the manufacturer, the fabricator, and the erector
+- the structural sealant manufacturer's written approval of the glazier for the specific system
+
+```datasheet
+label: Informational Submittal Package
+type: checkbox
+options:
+ - "Signed and sealed structural calculations"
+ - "Laboratory air, water, and structural test reports"
+ - "Thermal transmittance and condensation resistance results"
+ - "Certified U-factor, SHGC, and VLT ratings"
+ - "Seismic drift and thermal cycling test reports"
+ - "Missile impact and cyclic pressure test reports"
+ - "Structural silicone adhesion and compatibility results"
+ - "Perimeter fire containment system listing"
+ - "NFPA 285 assembly listing"
+ - "Thermal movement calculations"
+ - "Manufacturer, fabricator, and erector qualification records"
+ - "Glazier approval by the structural sealant manufacturer"
+```
+
+## Closeout Submittals {toc}
+
+### The Contractor shall submit the following before the curtain wall is accepted:
+
+- as-built elevations recording every field change to the mullion grid, glass types, anchorage, and movement joints
+- mockup test reports, including each deficiency found, the corrective action taken, and the date production fabrication was released
+- field water and air test reports, identifying each location tested, the pressure applied, and the result
+- cleaning and maintenance instructions for the framing finish, the glass, the gaskets, and the sealants, naming the products approved for cleaning and the products that shall not contact the finish or the glass coatings
+- a re-glazing procedure identifying the sequence, the parts, and the special tools needed to replace a single lite without disturbing adjacent lites
+- warranty documentation from the curtain wall manufacturer, the finish applicator, the insulating glass fabricator, and the structural sealant manufacturer where structural silicone glazing is used
+- a signed receipt from the Owner for the extra stock materials delivered
+
+```datasheet
+label: Closeout Submittal Package
+type: checkbox
+options:
+ - "As-built elevations"
+ - "Mockup test reports and corrective action record"
+ - "Field water and air test reports"
+ - "Cleaning and maintenance instructions"
+ - "Re-glazing procedure"
+ - "Warranty documentation"
+ - "Extra stock receipt"
+```
+
+# Quality Assurance {toc}
+
+## Manufacturer, Fabricator, and Erector Qualifications {toc}
+
+### The curtain wall manufacturer shall have produced aluminum curtain wall systems of the type and performance specified for not less than ten years.
+
+### The curtain wall manufacturer shall furnish independent laboratory test reports for the specific system, at the configuration and the design pressure required by this project, demonstrating the air, water, and structural performance this standard requires.
+
+### The fabricator shall have fabricated curtain wall of comparable scope, height, and complexity for not less than five years.
+
+### The erector shall have erected curtain wall of comparable scope, height, and complexity for not less than five years.
+
+### Where the Contractor proposes a manufacturer, fabricator, or erector whose record does not meet these criteria, the Engineer of Record shall make the initial determination whether the proposed record is equivalent, and shall do so in writing before the subcontract is awarded.
+
+## Delegated Structural Design {toc}
+
+### The framing member sizing, the glazing retention design, the connection design, and the anchorage design shall be performed by a professional engineer licensed in the project jurisdiction and engaged by the curtain wall contractor.
+
+### The structural calculations shall be signed and sealed by that engineer and shall demonstrate compliance with the design wind pressures, deflection limits, and movement criteria this standard and the contract documents establish.
+
+### The calculations shall address the mullion spans and deflections, the mullion reinforcement, the distribution of glass load into the framing per ASTM E1300, the capacity of every anchor condition, and the accommodation of thermal movement and interstory drift.
+
+### Where structural silicone glazing is used, the calculations shall size the structural bite and the glue-line thickness for the wind load and for the dead weight of the glass carried by the sealant.
+
+### The curtain wall is a delegated design in most jurisdictions: the contract documents fix the geometry, the performance criteria, and the design pressures, and the specialty engineer completes the member sizing, connection design, and anchorage within those criteria. The design responsibility boundary follows that split, which is why the criteria in this standard are written as targets the specialty engineer designs to rather than as member sizes. {note}
+
+## Structural Silicone Glazing Quality Program {toc}
+
+### Where structural silicone glazing is used, the glazier shall hold written approval from the structural sealant manufacturer for the specific system, issued before any structural sealant is applied.
+
+### The structural sealant manufacturer shall review the structural joint design, confirm substrate adhesion and compatibility before production begins, and provide on-site instruction at the start of structural glazing.
+
+### Adhesion and compatibility shall be verified per ASTM C1135 and ASTM C1087 for the specific glass coating, the specific framing finish, the setting blocks, the spacers, the gaskets, and every other material the structural sealant will contact.
+
+### The insulating glass unit secondary seal used behind a structural silicone bead shall conform to ASTM C1249.
+
+### A written quality control record shall be kept for each production run, recording the sealant lot number, the mixing verification for a two-part sealant, the cure verification, the bead dimensions, and the results of the daily adhesion tests.
+
+### The Contractor shall bear the cost of every adhesion, compatibility, and cure test required by this program, and the cost of re-testing after any failure.
+
+### Structural sealant shall not be loaded, handled, shipped, or glazed into the building until it has reached the cure the sealant manufacturer publishes for the section applied.
+
+### In a structurally glazed wall the silicone is the load path that holds the glass on the building, because the bonded edges carry no mechanical capture. An adhesion or cure failure that goes undetected is a fallout hazard rather than a leak, and it cannot be found by inspecting a cured, glazed unit from either face — which is why the verification is front-loaded into the production process instead of the finished product. {note}
+
+# Design Wind Pressures {toc}
+
+## The curtain wall, its glazing, its retention, and its anchors shall be designed for the inward and outward design wind pressures indicated in the datasheet.
+
+```datasheet
+label: Inward Design Wind Pressure at the Wall Field Zone
+type: range
+unit: psf
+drawing_ref: "as indicated on the project structural drawings"
+options:
+ min: 15
+ max: 200
+ setpoints: [15, 20, 25, 30, 40, 50, 60, 75, 90, 110, 130, 150, 175, 200]
+default: deferred
+```
+
+```datasheet
+label: Outward Design Wind Pressure at the Wall Field Zone
+type: range
+unit: psf
+drawing_ref: "as indicated on the project structural drawings"
+options:
+ min: 15
+ max: 200
+ setpoints: [15, 20, 25, 30, 40, 50, 60, 75, 90, 110, 130, 150, 175, 200]
+default: deferred
+```
+
+```datasheet
+label: Inward Design Wind Pressure at the Corner and Edge Zones
+type: range
+unit: psf
+drawing_ref: "as indicated on the project structural drawings"
+options:
+ min: 15
+ max: 300
+ setpoints: [15, 20, 25, 30, 40, 50, 60, 75, 90, 110, 130, 150, 175, 200, 250, 300]
+default: deferred
+```
+
+```datasheet
+label: Outward Design Wind Pressure at the Corner and Edge Zones
+type: range
+unit: psf
+drawing_ref: "as indicated on the project structural drawings"
+options:
+ min: 15
+ max: 300
+ setpoints: [15, 20, 25, 30, 40, 50, 60, 75, 90, 110, 130, 150, 175, 200, 250, 300]
+default: deferred
+```
+
+## Each portion of the wall shall be designed for the pressure of the zone in which it falls, and framing, glazing, and anchors within a corner or edge zone shall not be designed for the wall field pressure.
+
+## The design wind pressures are components-and-cladding pressures determined per ASCE 7 from the site wind speed, the building's risk category, its height, and its exposure, and they are established by the project's structural design rather than by the curtain wall contractor. The zone pressures differ because flow separation at corners, parapets, and roof edges produces local suctions several times the pressure acting on the middle of a wall, over a strip whose width ASCE 7 ties to the building's least horizontal dimension and its height. {note}
+
+## The magnitude of the design pressure is the single largest driver of framing depth, reinforcement, glass thickness, and anchor size, and it is the principal reason a curtain wall for a tall or exposed building looks nothing like one for a low, sheltered building even when the two share a sightline. {note}
+
+# Structural Performance and Deflection Limits {toc}
+
+## The framing shall resist the inward and outward design wind pressures without permanent deformation, glass breakage, anchor distress, or loss of the air or water seal, verified per ASTM E330.
+
+## The system shall be subjected to a structural overload of 1.5 times the design wind pressure in each direction, after which no framing member shall retain a permanent deformation exceeding 0.2 percent of its clear span.
+
+## Framing deflection normal to the plane of the wall under the design wind pressure shall not exceed the limit indicated in the datasheet.
+
+```datasheet
+label: Framing Deflection Limit Normal to the Wall
+type: select
+options:
+ - "L/175 of the clear span, or 3/4 in., whichever is less"
+ - "L/240 of the clear span, or 3/4 in., whichever is less"
+ - "L/175 for clear spans of 13 ft 6 in. and less, and L/240 plus 1/4 in. for longer spans"
+ - "L/360 of the clear span, or 3/4 in., whichever is less"
+default: "L/175 of the clear span, or 3/4 in., whichever is less"
+```
+
+## Deflection of a glass-supporting horizontal member under the dead load of the glass it carries shall not exceed the limit indicated in the datasheet.
+
+```datasheet
+label: Dead Load Deflection Limit of Glass-Supporting Horizontal Members
+type: select
+options:
+ - "L/360 of the span, or 1/8 in., whichever is less"
+ - "L/500 of the span, or 1/8 in., whichever is less"
+ - "1/16 in. maximum, independent of span"
+default: "L/360 of the span, or 1/8 in., whichever is less"
+```
+
+## Framing deflection shall not, at the design wind pressure, reduce the glass edge engagement below the bite the glazing design requires, and shall not open the glazing pocket.
+
+## Framing members shall be sized to meet these limits on their own section and reinforcement, and shall not rely on the stiffness of the glazing infill.
+
+## Deflection limits on a curtain wall are serviceability criteria, not strength criteria: a mullion that deflects too far leaks and disengages its gaskets long before it approaches failure, and the extra deflection concentrates load into the glass edge and the glazing pocket. A tighter limit is chosen where the lites are large, where the infill is heavy or brittle, or where the interior finish abuts the framing closely enough that visible movement matters. {note}
+
+# Air Infiltration {toc}
+
+## Air infiltration through the fixed curtain wall shall be tested per ASTM E283 at a static pressure differential of 6.24 psf and shall not exceed the rate indicated in the datasheet.
+
+```datasheet
+label: Maximum Air Infiltration Rate
+type: range
+unit: cfm/ft²
+options:
+ min: 0.01
+ max: 0.06
+ setpoints: [0.01, 0.02, 0.03, 0.04, 0.06]
+default: 0.06
+```
+
+## The rate shall be measured over the gross wall area of the test specimen, including the perimeter of the specimen frame.
+
+## Air leakage is controlled at a continuous interior seal plane formed by the inner gaskets, the inner glazing seal, and the sealed framing joinery, which is why the air control layer of a curtain wall is detailed at the interior face rather than the exterior. Placing it there also keeps humid interior air out of the framing cavities, where it would otherwise condense against cold exterior aluminum and appear at the sill as what looks like a leak. {note}
+
+# Water Penetration Resistance {toc}
+
+## Water penetration shall be tested statically per ASTM E331 at the pressure indicated in the datasheet.
+
+```datasheet
+label: Static Water Penetration Test Pressure
+type: range
+unit: psf
+derived: "20 percent of the inward design wind pressure at the wall field zone, not less than 6.24 psf"
+options:
+ min: 6.24
+ max: 30
+ setpoints: [6.24, 8, 10, 12, 15, 20, 25, 30]
+default: derived
+```
+
+## Water penetration shall be tested dynamically per AAMA 501.1 where the datasheet requires the dynamic test.
+
+```datasheet
+label: Dynamic Water Penetration Test per AAMA 501.1
+type: radio
+options:
+ - "Required"
+ - "Not required"
+default: "Required"
+```
+
+## The dynamic test shall be performed at the same test pressure and the same water application rate as the static test.
+
+## No uncontrolled water shall appear beyond the innermost plane of the wall during either test.
+
+## Water that enters the glazing pocket or the framing cavities shall be collected on internal gutters and drained back to the exterior, and shall not reach the interior face.
+
+## The static test applies a steady pressure across the specimen while water is sprayed at a fixed rate. The dynamic test applies the same water rate while a propeller or engine-driven air stream generates the pressure, which reproduces the fluctuating, turbulent pressures a wall actually sees and drives water into joints that a steady pressure leaves alone. The two tests find different defects, which is why a system is commonly asked to pass both. {note}
+
+## A test pressure set as a fraction of the design wind pressure keeps the water criterion proportional to the exposure the wall was designed for. Above roughly 20 psf the test stops discriminating between systems and starts measuring the test chamber, which is why the practical ceiling on a laboratory water test sits near that value even on walls designed for far higher wind pressures. {note}
+
+# Thermal Transmittance and Solar Control {toc}
+
+## The whole-product thermal transmittance and solar heat gain coefficient shall satisfy [[parameter: adopted-energy-code]] for the compliance path the project uses.
+
+## The whole-product U-factor shall not exceed the value indicated in the datasheet.
+
+```datasheet
+label: Maximum Whole-Product U-Factor
+type: range
+unit: Btu/h·ft²·°F
+derived: "the [[parameter: adopted-energy-code]] fenestration criteria for the project location and the compliance path the project uses"
+options:
+ min: 0.2
+ max: 0.7
+ setpoints: [0.2, 0.24, 0.28, 0.32, 0.36, 0.4, 0.45, 0.5, 0.55, 0.6, 0.7]
+default: derived
+```
+
+## The whole-product solar heat gain coefficient shall not exceed the value indicated in the datasheet.
+
+```datasheet
+label: Maximum Whole-Product Solar Heat Gain Coefficient
+type: range
+derived: "the [[parameter: adopted-energy-code]] fenestration criteria for the project location and the compliance path the project uses"
+options:
+ min: 0.15
+ max: 0.7
+ setpoints: [0.15, 0.18, 0.2, 0.22, 0.25, 0.28, 0.3, 0.35, 0.4, 0.45, 0.5, 0.6, 0.7]
+default: derived
+```
+
+## The whole-product visible light transmittance shall be not less than the value indicated in the datasheet.
+
+```datasheet
+label: Minimum Whole-Product Visible Light Transmittance
+type: range
+options:
+ min: 0.1
+ max: 0.7
+ setpoints: [0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.6, 0.7]
+```
+
+## Thermal performance shall be established by the determination method indicated in the datasheet.
+
+```datasheet
+label: Thermal Performance Determination Method
+type: select
+options:
+ - "Physical test of the framing and product per AAMA 1503"
+ - "Two-dimensional thermal simulation per AAMA 507"
+ - "Certified simulation and labeling per NFRC 100 and NFRC 200"
+```
+
+## The three determination methods are not interchangeable in what they produce. A physical AAMA 1503 test measures one framing section under one set of conditions and yields both a U-factor and a condensation resistance factor. An AAMA 507 simulation models the assembled product from validated component data and is what makes a site-built wall of many configurations tractable. An NFRC certified rating is a labeled, third-party-verified whole-product number, and it is the form most energy codes ask for when they require certified fenestration ratings. {note}
+
+## Solar heat gain and visible transmittance move together, because both are properties of the same coating stack on the same glass. Pushing the solar heat gain coefficient down without losing daylight is the entire purpose of a spectrally selective low-emissivity coating, and the ratio of the two values is the measure of how well a given coating does it. {note}
+
+# Condensation Resistance {toc}
+
+## The condensation resistance factor of the product, determined per AAMA 1503, shall be not less than the value indicated in the datasheet.
+
+```datasheet
+label: Minimum Condensation Resistance Factor
+type: range
+options:
+ min: 35
+ max: 80
+ setpoints: [35, 40, 45, 50, 55, 60, 65, 70, 75, 80]
+```
+
+## The Contractor shall submit, with the framing submittal, a comparison of the interior framing and glass surface temperatures at the winter design condition against the interior design dew point stated in the contract documents.
+
+## Where that comparison shows an interior surface temperature at or below the interior design dew point, the Contractor shall report the condition to the Engineer of Record in writing before fabrication.
+
+## Bare aluminum is a powerful thermal bridge. An unbroken mullion both wastes energy and drops the interior framing surface below the indoor dew point, producing condensation that streaks the glass, stains adjacent finishes, and over time corrodes the frame and supports mold growth on abutting materials. The thermal barrier interrupts the metal path so the interior surface stays above the dew point the building actually runs at. {note}
+
+## The condensation resistance factor is a single index derived from measured surface temperatures under one standardized condition, so it ranks products rather than predicting performance in a specific building. The value a project needs rises with the interior humidity it maintains and falls with the winter design temperature it sees — a natatorium, a hospital, a museum, or a food processing space carries a far higher interior dew point than an office, and the same framing that is dry in one is wet in the other. {note}
+
+# Acoustic Performance {toc}
+
+## Acoustic performance shall be rated on the basis indicated in the datasheet.
+
+```datasheet
+label: Acoustic Rating Basis
+type: select
+options:
+ - "No acoustic rating required"
+ - "Sound Transmission Class per ASTM E90 and ASTM E413"
+ - "Outdoor-Indoor Transmission Class per ASTM E1332"
+ - "Both Sound Transmission Class and Outdoor-Indoor Transmission Class"
+default: "No acoustic rating required"
+```
+
+## Where a Sound Transmission Class is required, the assembly shall achieve not less than the class indicated in the datasheet.
+
+```datasheet
+label: Minimum Sound Transmission Class
+type: range
+options:
+ min: 30
+ max: 50
+ setpoints: [30, 32, 35, 38, 40, 42, 45, 48, 50]
+```
+
+## Where an Outdoor-Indoor Transmission Class is required, the assembly shall achieve not less than the class indicated in the datasheet.
+
+```datasheet
+label: Minimum Outdoor-Indoor Transmission Class
+type: range
+options:
+ min: 25
+ max: 40
+ setpoints: [25, 27, 30, 32, 35, 37, 40]
+```
+
+## The acoustic rating shall be established by test of the complete assembly, including the framing, the glazing, the perimeter seals, and any spandrel back-up construction within the tested specimen.
+
+## The framing seals and the spandrel back-up shall not bypass the rated glazing.
+
+## The two metrics weight the frequency spectrum differently. Sound Transmission Class is weighted toward speech frequencies and describes partitions between occupied spaces well. Outdoor-Indoor Transmission Class extends the measurement lower, where aircraft, rail, and truck traffic put most of their energy, and a wall can hold a high Sound Transmission Class while performing poorly against low-frequency exterior noise. Which metric to specify follows from what the wall is being asked to keep out. {note}
+
+## Acoustic performance in a glazed wall is dominated by the glazing makeup — asymmetric lite thicknesses, acoustic interlayers, and wider cavities all break the coincidence dip that a symmetric unit has. The framing contributes through the continuity of its seals and through the flanking path a spandrel back-pan can open between floors. {note}
+
+# Thermal and Seismic Movement Criteria {toc}
+
+## The framing, the glazing pockets, the movement joints, and the anchors shall accommodate the movements specified in this section without glass breakage, glass fallout, permanent deformation, seal rupture, or noise.
+
+## The seismic design provisions applicable to the curtain wall shall be those the adopted building code assigns to [[parameter: seismic-design-category]].
+
+## Thermal movement shall be calculated over the design temperature changes indicated in the datasheet.
+
+```datasheet
+label: Design Ambient Air Temperature Change for Thermal Movement
+type: range
+unit: °F
+options:
+ min: 80
+ max: 160
+ setpoints: [80, 100, 120, 140, 160]
+default: 120
+```
+
+```datasheet
+label: Design Metal Surface Temperature Change for Thermal Movement
+type: range
+unit: °F
+options:
+ min: 120
+ max: 220
+ setpoints: [120, 140, 160, 180, 200, 220]
+default: 180
+```
+
+## The wall shall accommodate the design interstory drift indicated in the datasheet.
+
+```datasheet
+label: Design Interstory Drift
+type: range
+unit: in
+drawing_ref: "as indicated on the project structural drawings"
+options:
+ min: 0.25
+ max: 4
+ setpoints: [0.25, 0.5, 0.75, 1, 1.25, 1.5, 2, 2.5, 3, 4]
+default: deferred
+```
+
+## The wall shall accommodate the design vertical movement of the supporting floor edges indicated in the datasheet.
+
+```datasheet
+label: Design Vertical Movement at the Floor Edge
+type: range
+unit: in
+drawing_ref: "as indicated on the project structural drawings"
+options:
+ min: 0.25
+ max: 2
+ setpoints: [0.25, 0.375, 0.5, 0.75, 1, 1.5, 2]
+default: deferred
+```
+
+## Static interstory drift performance shall be verified per AAMA 501.4 where the datasheet requires that test.
+
+```datasheet
+label: Static Interstory Drift Test per AAMA 501.4
+type: radio
+derived: "[[parameter: seismic-design-category]] and the design interstory drift"
+options:
+ - "Required"
+ - "Not required"
+default: derived
+```
+
+## Dynamic glass fallout performance shall be verified per AAMA 501.6 where the datasheet requires that test.
+
+```datasheet
+label: Dynamic Glass Fallout Test per AAMA 501.6
+type: radio
+derived: "[[parameter: seismic-design-category]] and the design interstory drift"
+options:
+ - "Required"
+ - "Not required"
+default: derived
+```
+
+## Vertical interstory movement performance shall be verified per AAMA 501.7 where the datasheet requires a laboratory mockup that includes that test.
+
+## Drift shall be absorbed by glass-to-frame clearance, by a glazing pocket that permits the lite to rock or slide within the frame, or by articulated joints in the framing, rather than by transmitting the movement into the glass.
+
+## Because the wall is anchored to the structure at every floor and spans the floor edge, the horizontal movement of one floor relative to the next is imposed directly across the height of one panel. The wall has no choice about receiving that movement; the only design question is which element absorbs it. {note}
+
+## The two seismic tests answer different questions. The static AAMA 501.4 test imposes the design drift slowly and asks whether the wall still holds its seals and its glass afterward. The dynamic AAMA 501.6 test drives the wall at increasing amplitude until the glass falls out, and reports the drift at which that happened — a fallout threshold rather than a pass or fail against the design drift. Projects where falling glass is the governing risk, rather than water leakage after an event, are the ones for which the second test is written. {note}
+
+## Aluminum expands roughly twice as much as steel and about three times as much as concrete over the same temperature change, and a dark facade in full sun runs far hotter than the air around it. That is why the movement calculation uses a metal surface temperature change substantially larger than the ambient air temperature change: the mullion, not the weather station, sets the movement the joints must take. {note}
+
+# Wind-Borne Debris Impact Resistance {toc}
+
+## Whether impact resistance applies to this curtain wall shall be determined from [[parameter: wind-borne-debris-region]] together with the height of each glazed opening above grade.
+
+## The curtain wall shall provide the impact resistance indicated in the datasheet.
+
+```datasheet
+label: Wind-Borne Debris Impact Resistance
+type: select
+derived: "[[parameter: wind-borne-debris-region]] and the height of the glazed opening above grade"
+options:
+ - "Not required"
+ - "Small missile impact per ASTM E1996"
+ - "Large missile impact per ASTM E1996 Missile C"
+ - "Large missile impact per ASTM E1996 Missile D"
+ - "Large missile impact per ASTM E1996 Missile E"
+default: derived
+```
+
+## Impact-rated assemblies shall be tested per ASTM E1886 for missile impact followed by the cyclic pressure sequence, and shall comply with ASTM E1996 for the wind zone and missile level required.
+
+## The framing and its glazing retention shall hold the impacted lite in the frame through the entire cyclic pressure sequence.
+
+## The perimeter anchorage of an impact-rated assembly shall be designed for the loads the impact and cyclic pressure sequence imposes, and shall not be reduced to the anchorage of an equivalent non-impact assembly.
+
+## An impact rating belongs to the tested assembly as a whole — that framing, that retention, that glazing makeup, that anchorage. Substituting any one of them voids the rating, and the substitution shall not be made without a test report covering the assembly as substituted.
+
+## The rating is a system property because the failure mode is a system failure: the missile cracks the laminated lite, and everything that follows depends on whether the interlayer stays bonded and the frame keeps holding the cracked lite while the wind cycles it thousands of times. Glass that survives the impact still fails the test if the frame lets go. {note}
+
+# Perimeter Fire Containment at the Floor Edge {toc}
+
+## A perimeter fire containment system shall be installed in the void between the back of the curtain wall and the edge of the floor slab where the datasheet requires one.
+
+```datasheet
+label: Perimeter Fire Containment System
+type: radio
+derived: "the fire-resistance rating of the floor assembly at the slab edge"
+options:
+ - "Required"
+ - "Not required"
+default: derived
+```
+
+## The perimeter fire containment system shall be a system tested per ASTM E2307 and listed for the ratings indicated in the datasheet, installed exactly as the listing describes.
+
+```datasheet
+label: Perimeter Fire Containment F-Rating
+type: range
+unit: hours
+derived: "the fire-resistance rating of the floor assembly at the slab edge"
+options:
+ min: 1
+ max: 4
+ setpoints: [1, 2, 3, 4]
+default: derived
+```
+
+## The listing shall cover the curtain wall framing, the spandrel infill, the back-pan, and the insulation as actually furnished, and a listing for a different wall construction shall not be substituted.
+
+## The building thermal insulation shall not be used to fill the floor edge void unless that insulation is a component of the tested and listed containment assembly.
+
+## The curtain wall contractor and the installer of the containment system shall be present together at the first floor edge condition installed, and that condition shall be inspected and accepted before the work is repeated.
+
+## The floor edge void is the one place in a rated building where a continuous vertical gap runs from floor to floor immediately behind a wall that will fail early in a fire. The containment system closes that gap for the rated period, and it is tested with a curtain wall in front of it precisely because the wall's behavior — glass falling out, aluminum melting, the spandrel opening — is part of what the system has to survive. {note}
+
+# NFPA 285 Assembly Compliance {toc}
+
+## The exterior wall assembly shall comply with NFPA 285 where the datasheet requires that compliance.
+
+```datasheet
+label: NFPA 285 Assembly Compliance
+type: radio
+derived: "the building construction type and height, and the presence of foam plastic or other combustible components in the spandrel and back-up assembly"
+options:
+ - "Required"
+ - "Not required"
+default: derived
+```
+
+## Compliance shall be demonstrated by a listing or an engineering evaluation covering the assembly as furnished, including the spandrel glazing, the back-pan, the insulation, the perimeter fire containment, the water-resistive barrier, and every combustible component within the assembly.
+
+## No component within the assembly shall be substituted after the listing or evaluation is accepted unless a revised listing or evaluation covering the substitution is submitted and accepted.
+
+## NFPA 285 tests whether a fire venting out of a window can run up the outside of the building inside the wall assembly. A curtain wall spandrel is a common place for that to happen, because the cavity behind opacified glass is a natural chimney and it is frequently filled with foam plastic insulation. The test evaluates the whole stack-up rather than any single material, which is why a compliant assembly is defined by its listing rather than by the flame-spread rating of its parts. {note}
+
+# Curtain Wall Assembly Method {toc}
+
+## The curtain wall shall be assembled by the method indicated in the datasheet.
+
+```datasheet
+label: Curtain Wall Assembly Method
+type: select
+options:
+ - "Stick-built, field-assembled from loose members and field-glazed"
+ - "Semi-unitized, shop-assembled ladder frames erected and field-glazed"
+ - "Unitized, shop-assembled and shop-glazed panels interlocked in the field"
+ - "Unitized typical bays with stick-built framing at special conditions"
+```
+
+## The assembly method indicated in the datasheet shall not be changed after the shop drawings are reviewed unless the Engineer of Record accepts the change in writing.
+
+## Where any portion of the wall is field-glazed, the Contractor shall provide weather protection over the glazing pocket sufficient to keep it clean and dry until the lite is set.
+
+## A stick-built wall arrives as loose extrusions, anchors, gaskets, and glass, and is assembled and glazed in place. It costs less in material, tolerates irregular geometry and late dimensional change, and needs no crane, but it puts glazing, sealing, and quality control on the building at height, in weather, where the work is slower to perform and harder to inspect. {note}
+
+## A unitized wall is fabricated, glazed, sealed, and cured in the shop, then lifted and interlocked at split mullions and stack joints. It costs more per square foot and demands tight dimensional control of the structure and crane access to every elevation, but it erects several times faster, produces more consistent air and water performance because the seals are made under controlled conditions, and takes structural glazing off the building entirely. {note}
+
+## A semi-unitized wall splits the difference: shop-assembled framing ladders are hung on the building and glazed in the field, which recovers some of the shop assembly benefit without shipping and craning glazed panels. {note}
+
+## The choice tracks the constraints of the specific building far more than the size of the project. Repetitive elevations, high floor counts, an aggressive erection schedule, and limited access for field work push toward unitized construction; irregular geometry, late design change, restricted crane access, and small total area push toward stick construction. {note}
+
+# Water Management Principle {toc}
+
+## The curtain wall shall manage water by the principle indicated in the datasheet.
+
+```datasheet
+label: Water Management Principle
+type: select
+options:
+ - "Pressure-equalized rain screen with a vented and compartmented glazing pocket"
+ - "Internally drained and back-drained without pressure equalization"
+ - "Face-sealed barrier wall relying on a single continuous exterior seal"
+```
+
+## The glazing pocket and every framing cavity shall drain to the exterior at each horizontal, and the drainage path shall be continuous from the point where water can enter to the point where it discharges.
+
+## Weep and vent openings shall be sized, located, and protected as the tested system requires, and shall discharge clear of the wall face below.
+
+## Weep and vent openings shall not be obstructed by gaskets, setting blocks, sealant, insulation, or the perimeter seal.
+
+## Where the pressure-equalized principle is specified, the cavity shall be compartmented at corners, at parapets, and at the vertical spacing the tested system requires, so that a single cavity cannot bridge two zones of differing exterior pressure.
+
+## The three principles differ in how many lines of defense the wall has. A face-sealed wall stops all water at one continuous exterior seal, so any breach in that line admits water with nothing behind it. An internally drained wall accepts that the outer line leaks, catches what passes on internal gutters, and drains it back out. A pressure-equalized rain screen adds one more step: it vents the cavity to the exterior so cavity pressure rises to match the wind pressure on the outer face, which removes the pressure difference that drives water inward through the outer joints in the first place. {note}
+
+## Pressure equalization only works if the vented cavity is compartmented. An uncompartmented cavity running past a building corner connects a zone of high positive pressure to a zone of suction, and the cavity then carries water sideways under the very pressure difference the venting was meant to eliminate. {note}
+
+## The venting that equalizes pressure is also the drainage path and also a potential air leakage path, which is why the air control layer sits at the interior of a drained wall and the exterior screen is asked only to shed bulk water. {note}
+
+# Glazing Retention Method {toc}
+
+## The glazing infill shall be retained by the method indicated in the datasheet.
+
+```datasheet
+label: Glazing Retention Method
+type: select
+options:
+ - "Mechanically captured on all four edges by a pressure plate and cover"
+ - "Two-side structural silicone glazing with the vertical edges bonded and the horizontal edges captured"
+ - "Two-side structural silicone glazing with the horizontal edges bonded and the vertical edges captured"
+ - "Four-side structural silicone glazing"
+ - "Four-side structural silicone glazing with mechanical toggle retention"
+default: "Mechanically captured on all four edges by a pressure plate and cover"
+```
+
+## Requirements in this section for structural silicone glazing apply where a structural silicone retention method is selected in the datasheet.
+
+## Where structural silicone glazing is selected, the structural sealant shall conform to ASTM C1184 and the structural joint shall be designed in accordance with ASTM C1401 and AAMA CW-13.
+
+## Where structural silicone glazing is selected, the structural sealant shall be of the type indicated in the datasheet.
+
+```datasheet
+label: Structural Silicone Sealant Type
+type: select
+options:
+ - "Not applicable to a mechanically captured system"
+ - "One-part structural silicone conforming to ASTM C1184"
+ - "Two-part structural silicone conforming to ASTM C1184"
+```
+
+## Where structural silicone glazing is selected, the structural sealant shall be applied at the location indicated in the datasheet.
+
+```datasheet
+label: Structural Silicone Application Location
+type: select
+options:
+ - "Not applicable to a mechanically captured system"
+ - "Shop applied and shop cured under the quality control program"
+ - "Field applied under the sealant manufacturer's written field quality program"
+```
+
+## Where structural silicone glazing is selected, the structural bite and the glue-line thickness shall be sized by the delegated engineer for the design wind pressure and, on any edge that carries glass weight, for the dead load as well.
+
+## Where structural silicone glazing is selected, no organic sealant, tape, gasket, setting block, or spacer shall contact the structural bead unless that material has passed the compatibility program in this standard.
+
+## A captured system holds the lite on all four edges between an exterior pressure plate and a gasket bearing on the inner face, with a snap-on cover concealing the plate. The retention is mechanical, the gasket compression is visible and measurable, and a failed seal leaks rather than releases the glass. {note}
+
+## A structurally glazed system bonds the glass to the frame with silicone that carries the wind load into the framing without a mechanical capture on the bonded edges. Two-side glazing bonds one pair of edges and captures the other; four-side glazing bonds all four and produces a flush exterior with no pressure plate interrupting the glass. A toggle system adds a mechanical retention device engaging a channel in the structural bead, which restores a secondary load path on the bonded edges. {note}
+
+## Structural glazing is chosen for the flush exterior it produces and for the reduction in thermal bridging and water collection that removing the exterior pressure plate brings. What it costs is the load path: the sealant becomes the only thing holding the glass on the building, which is why the conformance, design, compatibility, application, and cure requirements around it are written as hard obligations rather than as recommendations. {note}
+
+# Framing Member Sizing and Sightline {toc}
+
+## The exterior face width of the framing members shall be as indicated in the datasheet.
+
+```datasheet
+label: Mullion Face Width at the Exterior Sightline
+type: range
+unit: in
+drawing_ref: "as indicated on the exterior elevations and curtain wall details"
+options:
+ min: 1.75
+ max: 6
+ setpoints: [1.75, 2, 2.5, 3, 3.5, 4, 5, 6]
+default: deferred
+```
+
+## The mullion depth shall be as indicated in the datasheet.
+
+```datasheet
+label: Mullion Depth
+type: range
+unit: in
+derived: "the clear span between anchors, the governing design wind pressure, and the specified deflection limit"
+options:
+ min: 2.5
+ max: 16
+ setpoints: [2.5, 3, 4, 5, 6, 7.5, 9, 10.5, 12, 14, 16]
+default: derived
+```
+
+## Mullion reinforcement shall be as indicated in the datasheet.
+
+```datasheet
+label: Mullion Reinforcement
+type: select
+derived: "the clear span between anchors, the governing design wind pressure, and the specified deflection limit"
+options:
+ - "None, extruded aluminum section alone"
+ - "Internal aluminum reinforcing insert"
+ - "Internal steel tube reinforcement"
+ - "Structural steel mullion behind an aluminum cover"
+default: derived
+```
+
+## The mullion depth and reinforcement shall be confirmed against the manufacturer's published span capacities for the actual clear span and the actual design pressure, including the corner and edge zone pressures where the member falls within those zones.
+
+## Face width and depth answer to different masters. The face width is what a viewer sees and is set by the architectural intent for the facade. The depth is what resists the wind, and it follows from the span between anchors and the pressure on the member. Two walls can share a sightline and differ by a factor of three in depth. {note}
+
+## Once the depth needed exceeds what is available in the system's profiles, the remaining options are to reinforce the existing mullion with an internal insert, to reduce the span by adding an anchor, or to move to a deeper system. Steel reinforcement adds stiffness in the depth already available, at the cost of weight, galvanic isolation, and a longer thermal path through the member. {note}
+
+# Aluminum Extrusions {toc}
+
+## Framing extrusions shall conform to ASTM B221.
+
+## Aluminum sheet used for covers, back-pans, and closures shall conform to ASTM B209.
+
+## Primary structural framing members shall be of the alloy and temper indicated in the datasheet.
+
+```datasheet
+label: Structural Framing Alloy and Temper
+type: select
+options:
+ - "Alloy 6063-T6"
+ - "Alloy 6063-T5"
+ - "Alloy 6005A-T61"
+ - "Alloy 6061-T6"
+default: "Alloy 6063-T6"
+```
+
+## Pressure plates, covers, and trim shall be of the alloy and temper indicated in the datasheet.
+
+```datasheet
+label: Pressure Plate, Cover, and Trim Alloy and Temper
+type: select
+options:
+ - "Alloy 6063-T5"
+ - "Alloy 6063-T6"
+ - "Alloy 6463-T5"
+ - "Alloy 6005A-T61"
+default: "Alloy 6063-T5"
+```
+
+## The wall thickness of primary structural framing members shall be not less than the thickness indicated in the datasheet.
+
+```datasheet
+label: Minimum Wall Thickness of Primary Structural Framing Members
+type: range
+unit: in
+options:
+ min: 0.062
+ max: 0.188
+ setpoints: [0.062, 0.07, 0.078, 0.09, 0.1, 0.125, 0.156, 0.188]
+default: 0.09
+```
+
+## The wall thickness of non-structural covers and trim shall be not less than the thickness indicated in the datasheet.
+
+```datasheet
+label: Minimum Wall Thickness of Non-Structural Covers and Trim
+type: range
+unit: in
+options:
+ min: 0.05
+ max: 0.09
+ setpoints: [0.05, 0.062, 0.07, 0.078, 0.09]
+default: 0.062
+```
+
+## Exposed extrusions shall be free of die lines, scratches, dents, and other surface defects visible from a distance of 10 ft under the finished lighting condition, and the Engineer of Record shall make the initial determination where the parties disagree whether a defect is visible.
+
+## The 6063 alloys extrude to fine detail and take an even anodic film, which is why they dominate architectural framing. The higher-strength alloys buy section capacity at the cost of extrudability and of anodizing color consistency, so they appear where a member is working hard rather than across a whole system. Temper matters for the same reason the alloy does: a cover that only has to stay flat can be a softer temper than a mullion carrying wind to an anchor. {note}
+
+# Thermal Barrier {toc}
+
+## Framing members shall incorporate a continuous thermal barrier separating the interior aluminum from the exterior aluminum, unless the datasheet specifies non-thermally-broken framing.
+
+## The thermal barrier shall be of the type indicated in the datasheet.
+
+```datasheet
+label: Thermal Barrier Type
+type: select
+options:
+ - "Pultruded glass-fiber-reinforced polyamide struts mechanically crimped into the profiles"
+ - "Poured and debridged polyurethane"
+ - "Non-thermally-broken framing"
+```
+
+## The thermal barrier shall be continuous around every glazing pocket, at every framing intersection, and through every splice, and shall not be interrupted by a fastener, an anchor, a reinforcement, or a drainage opening that bridges the interior and exterior aluminum.
+
+## The barrier shall transfer the shear the delegated engineer's design assigns to it, and where the design treats the profile as acting compositely the barrier shall be qualified for that shear transfer by test.
+
+## A polyamide strut is a structural member in its own right: it is crimped mechanically into knurled channels in both halves of the profile and carries shear between them, which lets the composite section be counted on structurally and permits the interior and exterior halves to carry different finishes. A poured and debridged barrier is formed by filling a cavity in the extrusion with polyurethane and then machining out the metal bridge beneath it, which is simpler to produce and gives a shallower thermal path. {note}
+
+## The barrier is only as good as its continuity. A single steel fastener or an unbroken reinforcing insert crossing from inside to outside re-establishes the metal path the barrier was installed to break, and it does so locally at exactly the point where the interior surface is coldest. {note}
+
+# Steel Reinforcement, Fasteners, and Dissimilar Metals {toc}
+
+## Steel reinforcement placed within a framing cavity shall be hot-dip galvanized per ASTM A123 or otherwise protected against corrosion for the design life of the wall.
+
+## Fasteners and anchors, whether exposed or concealed, shall be stainless steel or another corrosion-resistant material compatible with both the aluminum and the steel they connect.
+
+## Aluminum shall be isolated from steel, from concrete, and from masonry by a non-conductive separator, a coating, or a gasket at every point of contact.
+
+## Fasteners shall not penetrate the thermal barrier, and shall not bridge the interior and exterior aluminum of a thermally broken member.
+
+## Exposed fasteners shall be finished to match the member they penetrate.
+
+## Aluminum in contact with a more noble metal in the presence of moisture corrodes preferentially, and a curtain wall is wet at every joint by design. The separation requirement is not cosmetic — a corroding aluminum interface at an anchor loses the section it was designed with, in the one place on the wall where losing it matters most. {note}
+
+# Glazing Gaskets and Framing Joint Seals {toc}
+
+## Glazing gaskets shall be extruded from the material indicated in the datasheet.
+
+```datasheet
+label: Glazing Gasket Material
+type: select
+options:
+ - "EPDM"
+ - "Silicone"
+ - "Thermoplastic elastomer"
+ - "Neoprene"
+default: "EPDM"
+```
+
+## Gaskets in contact with a structural silicone bead shall be silicone, regardless of the material indicated in the datasheet for gaskets elsewhere in the system.
+
+## Gaskets shall bear continuously against both glass faces at every captured edge, at the compression the tested system requires.
+
+## Gaskets shall be installed in continuous lengths, and corners shall be formed with vulcanized or molded corner pieces, or shall be cut and sealed by the method the system manufacturer publishes.
+
+## Splices in a gasket shall be located away from corners and shall be sealed.
+
+## Framing joints within the fabricated assembly shall be sealed against air and water in the manner the tested system requires, and the sealant used shall be compatible with the gaskets, the finish, and any structural sealant it contacts.
+
+## A discontinuity where a gasket turns a corner is the single most common leak found on a curtain wall mockup, and it is entirely avoidable. The gasket is under compression along its length, so a butt cut at a corner opens under thermal movement even when it looks tight the day it is installed. {note}
+
+# Aluminum Finishes {toc}
+
+## Exposed exterior aluminum shall receive the finish indicated in the datasheet.
+
+```datasheet
+label: Exterior Exposed Aluminum Finish
+type: select
+options:
+ - "Fluoropolymer organic coating conforming to AAMA 2605"
+ - "Fluoropolymer organic coating conforming to AAMA 2604"
+ - "Organic coating conforming to AAMA 2603"
+ - "Powder coating conforming to AAMA 2604"
+ - "Class I architectural anodic coating conforming to AAMA 611"
+ - "Class II architectural anodic coating conforming to AAMA 611"
+ - "Mill finish, uncoated and unanodized"
+```
+
+## Exposed interior aluminum shall receive the finish indicated in the datasheet.
+
+```datasheet
+label: Interior Exposed Aluminum Finish
+type: select
+options:
+ - "Matching the exterior finish"
+ - "Fluoropolymer organic coating conforming to AAMA 2605"
+ - "Fluoropolymer organic coating conforming to AAMA 2604"
+ - "Organic coating conforming to AAMA 2603"
+ - "Powder coating conforming to AAMA 2604"
+ - "Class I architectural anodic coating conforming to AAMA 611"
+ - "Class II architectural anodic coating conforming to AAMA 611"
+ - "Mill finish, uncoated and unanodized"
+default: "Matching the exterior finish"
+```
+
+## The finish color shall be as indicated in the datasheet.
+
+```datasheet
+label: Framing Finish Color
+type: text
+drawing_ref: "as indicated on the exterior elevations and the finish schedule"
+default: deferred
+```
+
+## The finish shall be applied to the extrusion before fabrication cuts are made, or the cut ends shall be finished after cutting, so that no unfinished aluminum is exposed in the completed work.
+
+## Anodized members shall be produced from extrusions of a single alloy and, wherever the quantity permits, from a single production lot, so that color variation across an elevation stays within the range shown by the accepted samples.
+
+## Where the color of an anodized member falls outside the range shown by the accepted samples, the member shall be rejected and replaced at the Contractor's cost.
+
+## Organic coating and anodizing fail in different ways and are inspected differently. An organic coating is a film applied over the metal, and its performance classes are graduated by how long the film holds color, gloss, and adhesion under weathering — the higher classes carry longer chalk and fade limits and correspondingly longer warranties. An anodic coating is grown from the metal itself, so it cannot peel, and it is graded by film thickness; its color comes from the alloy and the process, which is why lot-to-lot variation is a real risk on anodized work and a non-issue on coated work. {note}
+
+## Where a facade is tall enough or prominent enough that refinishing in place would be impractical, the length of the finish's service life becomes a durability decision rather than a cost decision, because the realistic alternative to a long-lived finish is replacement rather than recoating. {note}
+
+# Vision Glazing Infill {toc}
+
+## The vision glazing unit shall be of the configuration indicated in the datasheet.
+
+```datasheet
+label: Vision Glazing Unit Configuration
+type: select
+options:
+ - "Monolithic glass"
+ - "Laminated monolithic glass"
+ - "Double-glazed insulating glass unit"
+ - "Triple-glazed insulating glass unit"
+default: "Double-glazed insulating glass unit"
+```
+
+## Laminated lites within the glazing unit shall be positioned as indicated in the datasheet.
+
+```datasheet
+label: Laminated Lite Position in the Glazing Unit
+type: select
+options:
+ - "No laminated lite"
+ - "Outboard lite laminated"
+ - "Inboard lite laminated"
+ - "Both outboard and inboard lites laminated"
+default: "No laminated lite"
+```
+
+## Laminated glass shall conform to ASTM C1172 and shall use the interlayer indicated in the datasheet.
+
+```datasheet
+label: Laminated Glass Interlayer
+type: select
+options:
+ - "Not applicable to an unlaminated makeup"
+ - "Polyvinyl butyral"
+ - "Acoustic-grade polyvinyl butyral"
+ - "Ionoplast"
+ - "Ethylene-vinyl acetate"
+ - "Cast-in-place resin"
+```
+
+## Vision glass shall be heat treated as indicated in the datasheet, and heat-treated glass shall conform to ASTM C1048.
+
+```datasheet
+label: Vision Glass Heat Treatment
+type: select
+derived: "the ASTM E1300 load resistance analysis for the lite size and design wind pressure, together with the thermal stress analysis for the specified coating, tint, and shading condition"
+options:
+ - "Annealed"
+ - "Heat-strengthened"
+ - "Fully tempered"
+ - "Fully tempered and heat-soak tested"
+default: derived
+```
+
+## Glazing in a location the adopted building code identifies as a hazardous location shall be safety glazing complying with 16 CFR Part 1201 and ANSI Z97.1.
+
+## Float glass shall conform to ASTM C1036 and shall be of the substrate indicated in the datasheet.
+
+```datasheet
+label: Vision Glass Substrate
+type: select
+options:
+ - "Clear float glass"
+ - "Low-iron float glass"
+ - "Green tinted float glass"
+ - "Blue-green tinted float glass"
+ - "Blue tinted float glass"
+ - "Gray tinted float glass"
+ - "Bronze tinted float glass"
+```
+
+## The low-emissivity coating shall be applied to the surface indicated in the datasheet.
+
+```datasheet
+label: Low-Emissivity Coating Position
+type: select
+options:
+ - "No low-emissivity coating"
+ - "Surface 2"
+ - "Surface 3"
+ - "Surface 2 and surface 4"
+ - "Surface 4"
+```
+
+## A sputtered low-emissivity coating shall be edge-deleted at every bonded edge of the unit, back to sound glass, before the edge seal or any structural sealant is applied.
+
+## The insulating glass unit cavity shall be filled with the gas indicated in the datasheet.
+
+```datasheet
+label: Insulating Glass Unit Cavity Gas Fill
+type: select
+options:
+ - "Air"
+ - "Argon"
+ - "Krypton"
+ - "Argon and krypton mixture"
+```
+
+## The insulating glass unit shall use the edge spacer indicated in the datasheet.
+
+```datasheet
+label: Insulating Glass Unit Edge Spacer
+type: select
+options:
+ - "Aluminum box spacer"
+ - "Stainless steel box spacer"
+ - "Thermally improved composite spacer"
+ - "Thermoplastic spacer with an integral metal vapor barrier"
+ - "Silicone foam spacer"
+```
+
+## Insulating glass units shall be certified to ASTM E2190 and evaluated by the durability test sequence of ASTM E2188.
+
+## Each lite shall be sized and set with the edge clearance, face clearance, and bite the framing system and the glazing design require for the unit thickness and weight actually furnished.
+
+## Setting blocks shall be positioned at the quarter points of the sill, or at the positions the glass fabricator directs for the lite size, and shall not obstruct the drainage path.
+
+## The insulating glass unit thickness, weight, and edge construction shall be reconciled against the glazing pocket, the setting blocks, the gasket compression, and the structural bite before the framing is released for fabrication.
+
+## The coating surface number is counted from the exterior: surface 1 faces the weather, surface 2 faces the cavity from the outboard lite, and so on inward. A solar-control coating placed on surface 2 rejects heat before it enters the cavity, which is what makes it effective against cooling load; a coating on surface 3 does more for winter heat retention. A second low-emissivity coating on surface 4, the interior face, raises the interior glass surface temperature but is exposed to cleaning and handling. {note}
+
+## The cavity gas, the spacer, and the coating act on the same number. Argon and krypton conduct less heat than air, a thermally improved spacer stops the metal short-circuit around the cavity edge, and a low-emissivity coating suppresses radiant transfer across the cavity. The spacer's contribution shows up most strongly at the glass edge, which is where interior condensation forms first and where a condensation resistance factor is won or lost. {note}
+
+## Heat treatment is not a free upgrade. Heat-strengthened glass roughly doubles the strength of annealed glass and breaks into large fragments that tend to stay in the opening. Fully tempered glass is stronger still and is required where the code calls for safety glazing, but it dices on breakage and carries a small population of nickel sulfide inclusions that can cause spontaneous breakage years after installation. Heat soaking destroys most of those inclusions before the glass leaves the factory, which is what makes it worth its cost where a falling lite is the governing risk. {note}
+
+# Spandrel and Opaque Infill {toc}
+
+## Spandrel and opaque areas shall be infilled with the material indicated in the datasheet.
+
+```datasheet
+label: Spandrel Infill Type
+type: select
+options:
+ - "Ceramic-frit opacified spandrel glass over an insulated back-pan"
+ - "Opacifier-film spandrel glass over an insulated back-pan"
+ - "Shadow box with vision glass over a finished back-pan"
+ - "Opaque insulated metal panel"
+ - "Stone or composite panel infill"
+ - "No spandrel or opaque areas in this curtain wall"
+```
+
+## The back-pan shall be fabricated from the material indicated in the datasheet.
+
+```datasheet
+label: Spandrel Back-Pan Material
+type: select
+options:
+ - "Galvanized steel"
+ - "Aluminum"
+ - "Stainless steel"
+ - "No back-pan required by the specified infill type"
+```
+
+## Spandrel glass shall be heat-strengthened as a minimum.
+
+## The back-pan shall be sealed to the framing continuously so that it forms part of the air control layer, and its joints and penetrations shall be sealed with materials compatible with the framing finish.
+
+## The spandrel cavity shall be drained and vented to the exterior on the same principle as the vision glazing pocket, unless the tested system is qualified for a sealed spandrel cavity.
+
+## The insulation, the back-pan, and the air seal at the spandrel shall be positioned so that the thermal and air control layers of the curtain wall meet the corresponding layers of the back-up construction without a gap, coordinated with [[sync/building-thermal-insulation]] and [[sync/air-barriers]].
+
+## Where the spandrel assembly contains foam plastic or another combustible component, the assembly shall be the one covered by the NFPA 285 listing required by this standard.
+
+## A spandrel cavity behind opacified glass runs far hotter than any other part of the wall, because the glass absorbs solar energy and the opaque backing stops it from passing through. That heat is why spandrel glass is heat treated, why the frit or opacifier has to be a durable ceramic rather than a paint, and why insulation held tight against the back of the glass causes breakage. {note}
+
+## A shadow box substitutes a visible depth of finished cavity for an opacified lite, so the viewer sees through clear or coated glass into a dark recess. It gives a more consistent appearance with adjacent vision glass, and it makes the cavity's ventilation, dust control, and condensation behavior visible to anyone standing outside — which is why a shadow box is detailed with more care about cavity venting and interior finish quality than an opacified spandrel needs. {note}
+
+# Anchorage to the Building Structure {toc}
+
+## The curtain wall shall be anchored to the building structure at every floor by the anchor type indicated in the datasheet.
+
+```datasheet
+label: Anchor Type at the Building Structure
+type: select
+drawing_ref: "as indicated on the anchorage details"
+options:
+ - "Slab-edge embedded plate with a welded or bolted clip"
+ - "Cast-in serrated channel with an adjustable bolted connection"
+ - "Face-of-slab post-installed anchor"
+ - "Through-slab bolted anchor"
+ - "Spandrel beam or edge angle with a bolted or welded clip"
+default: deferred
+```
+
+## Each anchor shall transfer the wind load acting inward and outward, and the dead weight of the wall it supports, into the building structure.
+
+## Anchors shall be adjustable in three orthogonal directions through a range sized for the erection tolerances of the supporting structure, so that the framing can be set plumb, level, and in plane without forcing a member.
+
+## The dead weight of each segment of the wall shall bear at one defined point, and every other anchor supporting that segment shall be free to move vertically.
+
+## Anchor design, embedment or attachment, and the load path into the structure shall be performed by the delegated engineer and shall be reviewed by the building structural engineer of record before fabrication.
+
+## Where the as-built structure exceeds the erection tolerance the anchor was designed to absorb, the Contractor shall report the condition in writing and shall not modify an anchor, add a shim stack outside the reviewed detail, or field-weld a connection until the delegated engineer has accepted the remedy in writing.
+
+## Welds made in the field shall be cleaned and coated with a corrosion-protective coating, and the isolation between dissimilar metals shall be restored after welding.
+
+## The anchor is where two trades' tolerances meet, and they are not the same size. A concrete or steel frame is erected to tolerances measured in fractions of an inch per floor and can accumulate more than an inch of deviation over a facade; the curtain wall is fabricated to tolerances measured in sixteenths. Three-way adjustability at the anchor is what converts one into the other, and it is consumed at erection, not held in reserve. {note}
+
+# Movement Accommodation {toc}
+
+## Vertical movement between stacked segments of the wall shall be taken at the joint type indicated in the datasheet.
+
+```datasheet
+label: Vertical Movement Joint Type
+type: select
+derived: "the curtain wall assembly method and the design vertical movement at the floor edge"
+options:
+ - "Telescoping stack joint between vertically stacked units"
+ - "Slotted expansion horizontal member"
+ - "Expansion splice within the vertical mullion"
+ - "Sliding anchor connection above a fixed dead-load anchor"
+default: derived
+```
+
+## Movement joints shall accommodate the live-load and creep deflection of the supporting floor edges, the differential vertical movement between floors, the thermal movement of the framing over the design temperature changes, and the design interstory drift, acting in combination.
+
+## The movement range designed into each joint and each anchor slot shall remain free after erection, and shall not be consumed by shims, by sealant, by fasteners tightened across a slot, or by a field weld.
+
+## Gaskets, sealants, and splice seals at a movement joint shall maintain continuity of the air and water control layers through the full range of movement.
+
+## Anchor slots shall be inspected for free movement after the wall is erected and before the interior finishes conceal them.
+
+## An anchor or a splice inadvertently fixed where it was designed to slide does not announce itself. The wall looks correct, passes a water test, and then transfers building movement directly into the glass the first time the structure deflects or the facade heats unevenly. This is why the free movement of slots is verified as an inspection item rather than assumed from the shop drawings. {note}
+
+# Air and Water Barrier Continuity at the Perimeter {toc}
+
+## The interior air seal plane of the curtain wall shall be made continuous with the air barrier of every adjacent assembly, coordinated with [[sync/air-barriers]].
+
+## The transition between the curtain wall air seal and the adjacent air barrier shall be made with a membrane or sealant detailed to accommodate the differential movement between the curtain wall and the adjacent construction without rupture or debonding.
+
+## The transition detail shall be shown on the shop drawings, built in the mockup, and inspected in place before it is concealed.
+
+## The perimeter water seal shall collect any water reaching the perimeter and direct it back to the exterior.
+
+## The base and sill conditions shall receive an end-dammed pan flashing that receives the discharge of the curtain wall drainage system and any perimeter water, and drains it to the exterior clear of the construction below, coordinated with [[sync/sheet-metal-flashing-and-trim]].
+
+## The perimeter joint between the curtain wall frame and the adjacent construction shall be sealed with the sealant type indicated in the datasheet, sized for the calculated joint movement and installed over the correct backing per [[sync/joint-sealants]].
+
+```datasheet
+label: Perimeter Joint Sealant Type
+type: select
+options:
+ - "Silicone conforming to ASTM C920 Type S Grade NS Class 100/50"
+ - "Silicone conforming to ASTM C920 Type S Grade NS Class 50"
+ - "Silyl-terminated polyether conforming to ASTM C920 Type S Grade NS Class 50"
+ - "Polyurethane conforming to ASTM C920 Type S Grade NS Class 35"
+default: "Silicone conforming to ASTM C920 Type S Grade NS Class 100/50"
+```
+
+## The sealant manufacturer shall confirm in writing that the selected sealant is compatible with the curtain wall finish and with every adjacent substrate it will contact, and shall confirm whether a primer is required on each.
+
+## The wall itself is tested in a laboratory under controlled conditions; the perimeter is built in the field at the seam between two subcontracts. That asymmetry, rather than any weakness in the systems themselves, is why so many curtain wall leak investigations end at the head, the jamb, or the base rather than at the wall. {note}
+
+## A perimeter joint has to be both airtight and capable of movement, and those two demands pull against each other. The joint width, the backing, and the sealant's movement class are one design, not three independent choices, and the movement the joint actually sees comes from the same thermal and structural analysis that sized the wall's own movement joints. {note}
+
+# Fabrication {toc}
+
+## Framing shall be fabricated to the dimensions and tolerances of the reviewed shop drawings, with members cut, machined, drilled, and prepared for assembly in the shop.
+
+## Joints within the fabricated assembly shall be sealed against air and water infiltration as the tested system requires.
+
+## Where the wall is unitized or semi-unitized, panels shall be assembled, sealed, and where applicable structurally glazed and cured in a controlled shop environment before shipment.
+
+## Fabrication tolerances shall be held tightly enough that the interlock and the stack joint of adjacent units engage through their full design range at the erection tolerances of the structure.
+
+## Finished surfaces shall receive a strippable coating or a protective covering before the member leaves the shop.
+
+## Aluminum shall be handled, stored, packaged, and shipped in accordance with AAMA CW-10 from the finishing line to the point of installation.
+
+## A unitized wall has no field adjustment inside the panel: the interlock either engages or it does not, and every dimension that governs whether it does was fixed in the shop. This is why shop tolerance control on a unitized wall is a schedule risk rather than a quality preference — a panel that does not fit comes off the building and goes back to the shop. {note}
+
+# Mockups {toc}
+
+## Mockups shall be provided as indicated in the datasheet.
+
+```datasheet
+label: Visual Mockup
+type: radio
+options:
+ - "Required"
+ - "Not required"
+```
+
+```datasheet
+label: Laboratory Performance Mockup
+type: radio
+options:
+ - "Required"
+ - "Not required"
+```
+
+```datasheet
+label: Field Mockup
+type: radio
+options:
+ - "Required"
+ - "Not required"
+```
+
+## Where a laboratory performance mockup is required, it shall be subjected to the tests indicated in the datasheet, in the sequence the referenced test methods and AAMA 501 establish.
+
+```datasheet
+label: Laboratory Performance Mockup Test Sequence
+type: checkbox
+options:
+ - "Air infiltration per ASTM E283"
+ - "Static water penetration per ASTM E331"
+ - "Dynamic water penetration per AAMA 501.1"
+ - "Structural performance at design pressure per ASTM E330"
+ - "Structural overload at 1.5 times design pressure per ASTM E330"
+ - "Static interstory drift per AAMA 501.4"
+ - "Vertical interstory movement per AAMA 501.7"
+ - "Thermal cycling per AAMA 501.5"
+ - "Dynamic glass fallout per AAMA 501.6"
+ - "Missile impact and cyclic pressure per ASTM E1886"
+```
+
+## A laboratory performance mockup shall include a typical vision area, a spandrel or opaque area, an intersection of a vertical and a horizontal member, a movement or corner joint, an anchor condition, and the transition to at least one adjacent enclosure assembly.
+
+## A laboratory performance mockup shall be tested as a complete assembly so that the air seal, the drainage system, the anchorage, and the movement provisions are evaluated together rather than individually.
+
+## A visual mockup shall establish color, gloss, finish uniformity, glass appearance, and sightline only, and shall not be used as evidence of air, water, structural, or thermal performance.
+
+## A field mockup shall be erected in the permanent work at a location the Engineer of Record designates, using the same materials, details, crew, and sequence as the production work.
+
+## Deficiencies identified in any mockup shall be corrected and the affected test repeated until the mockup passes, and production fabrication shall not be released until it does.
+
+## The Contractor shall bear the cost of the mockup, of the initial testing, of every correction, and of every re-test following a failure.
+
+## The completed wall shall match the accepted mockup in materials, details, and workmanship.
+
+## A laboratory mockup tests the system; a field mockup tests the crew and the sequence. They fail in different ways, and a project that has reason to doubt either one is the project that benefits from that mockup. The laboratory mockup is also the only opportunity to find a system defect while changing it is still a drawing revision rather than a facade retrofit. {note}
+
+# Installation {toc}
+
+## The Contractor shall erect the curtain wall plumb, level, and in plane within the tolerance indicated in the datasheet.
+
+```datasheet
+label: Framing Erection Alignment Tolerance
+type: select
+options:
+ - "1/8 in. in 12 ft, and 1/4 in. maximum in any total run"
+ - "1/16 in. in 12 ft, and 1/8 in. maximum in any total run"
+ - "As established by the reviewed shop drawings and the system manufacturer's published erection tolerances"
+default: "1/8 in. in 12 ft, and 1/4 in. maximum in any total run"
+```
+
+## Anchors shall be set and adjusted to absorb the as-built deviation of the structure before they are secured.
+
+## Erection shall be sequenced with the adjacent enclosure trades so that the air and water barrier transitions are made as the wall rises rather than retrofitted behind completed work.
+
+## Field glazing shall be performed only after the framing is installed within tolerance, is protected from weather, and has a clean and dry glazing pocket.
+
+## Each lite shall be set centered in its pocket on setting blocks, with the edge clearance, face clearance, and bite the glazing design requires.
+
+## Gaskets shall be installed without stretching, and shall be cut long and eased into place so that they do not shrink back from the corners after installation.
+
+## The drainage and pressure-equalization openings shall be verified clear after glazing and after the perimeter seal is installed.
+
+## Field welding, cutting, and grinding shall not be performed within reach of installed glass or finished aluminum unless sacrificial protection is in place.
+
+## Damage to the finish, the glass, or a coating caused by field welding, cutting, or grinding shall be repaired by replacement of the damaged component at the Contractor's cost.
+
+## A gasket installed under tension is the most common self-inflicted leak on a field-glazed wall. Extruded elastomer stretched during installation recovers over the following weeks and pulls back from the corners, opening exactly the discontinuity the corner detail exists to prevent. {note}
+
+## A blocked weep is invisible from either face and defeats the entire drainage design. Water held in the glazing pocket sits against the insulating glass unit edge seal, which is the condition that leads to premature seal failure and fogging years after the wall was accepted. {note}
+
+# Field Quality Control {toc}
+
+## Field water penetration testing of the installed wall shall be performed by the methods indicated in the datasheet.
+
+```datasheet
+label: Field Chamber Water Test per AAMA 503 and ASTM E1105
+type: radio
+options:
+ - "Required"
+ - "Not required"
+```
+
+```datasheet
+label: Diagnostic Spray Water Check per AAMA 501.2
+type: radio
+options:
+ - "Required"
+ - "Not required"
+```
+
+```datasheet
+label: Field Air Leakage Test per ASTM E783
+type: radio
+options:
+ - "Required"
+ - "Not required"
+```
+
+## The field chamber water test shall be performed at the pressure indicated in the datasheet.
+
+```datasheet
+label: Field Water Test Pressure
+type: range
+unit: psf
+derived: "two-thirds of the static water penetration test pressure specified for the laboratory test"
+options:
+ min: 4
+ max: 20
+ setpoints: [4, 5, 6.24, 8, 10, 12, 15, 20]
+default: derived
+```
+
+## Field testing shall be performed at the frequency indicated in the datasheet, distributed across elevations, heights, and conditions rather than concentrated in one area.
+
+```datasheet
+label: Field Water Test Frequency
+type: range
+unit: ft² of wall per test
+options:
+ min: 2500
+ max: 20000
+ setpoints: [2500, 5000, 7500, 10000, 15000, 20000]
+```
+
+## The first field test shall be performed on the first representative area completed, so that any systemic defect is found before the detail is repeated across the facade.
+
+## Leakage found in field testing shall be located, corrected, and re-tested at the same location and at one additional location of the Engineer of Record's choosing.
+
+## The Contractor shall bear the cost of correcting a failure and of every re-test following a failure, and the Owner shall bear the cost of tests that pass beyond the frequency indicated in the datasheet.
+
+## Testing shall be performed by an independent agency engaged by the Contractor and shall be witnessed by the Engineer of Record or the Engineer's designated representative.
+
+## The chamber test and the spray check answer different questions. A calibrated chamber applies a known pressure difference across a known area and produces a pass or fail against a stated criterion, which is what a certified field performance result requires. A diagnostic spray check applies water to a small area without a chamber and is used to walk a leak back to its source. The second finds the defect; only the first proves the wall. {note}
+
+## Field pressure is set below the laboratory pressure because the installed wall is being asked to demonstrate the performance it was built to, not to repeat a qualification test the system already passed under controlled conditions with a specimen frame sealed into a chamber. {note}
+
+# Delivery, Storage, and Handling {toc}
+
+## Materials shall be delivered in the manufacturer's original packaging with the protective covering intact and with each item identified by the mark shown on the reviewed shop drawings.
+
+## Framing and glazing shall be stored off the ground, under cover, sloped to drain, and separated by non-staining spacers that allow air to circulate between stacked members and lites.
+
+## Aluminum shall not be stored in contact with mortar, plaster, concrete, or any alkaline material, and shall not be stored where runoff from those materials can reach it.
+
+## Glass shall be stored upright on padded supports and shall not be stored where the lites can trap water between them.
+
+## The strippable coating or protective covering shall remain in place until the surrounding work that could damage the finish is complete.
+
+## Damaged or contaminated materials shall be removed from the site and replaced at the Contractor's cost.
+
+## Water trapped between stacked lites in storage etches the glass surface permanently, and the damage is not visible until the lite is cleaned and set. Alkaline runoff does the same to an anodic film. Both are storage failures that surface as appearance rejections after installation, when correcting them means replacement. {note}
+
+# Cleaning and Protection {toc}
+
+## Finished aluminum and glass shall be protected from construction operations and from construction contaminants from delivery through substantial completion.
+
+## At substantial completion the aluminum and the glass shall be cleaned with clean water and a mild detergent applied with soft cloths or sponges.
+
+## Abrasive pads, blades, scrapers, powered cleaning equipment, and acidic or alkaline cleaning agents shall not contact the framing finish, the glass, the glass coatings, or the insulating glass unit edge seals.
+
+## Where a construction residue cannot be removed by the permitted cleaning method, the Contractor shall obtain the written cleaning procedure of the finish or glass manufacturer whose product is affected before attempting any other method.
+
+## Weep and vent openings shall be verified clear of cleaning residue after final cleaning is complete.
+
+## Cleaning agents and methods that would void the finish warranty or the glass coating warranty shall not be used, and the Contractor shall bear the cost of replacing any component whose warranty is voided by the cleaning method used.
+
+# Warranty {toc}
+
+## The Contractor shall warrant the curtain wall system against defects in materials and workmanship, including air infiltration and water penetration in excess of the performance specified, for the term indicated in the datasheet, beginning at substantial completion.
+
+```datasheet
+label: System Workmanship Warranty Term
+type: range
+unit: years
+options:
+ min: 1
+ max: 10
+ setpoints: [1, 2, 3, 5, 10]
+default: 2
+```
+
+## The exterior finish shall be warranted against loss of adhesion, chalking, fading, and film failure for the term indicated in the datasheet.
+
+```datasheet
+label: Exterior Finish Warranty Term
+type: range
+unit: years
+derived: "the exterior finish system specified and the term the coating or anodizing applicator publishes for that system"
+options:
+ min: 5
+ max: 30
+ setpoints: [5, 10, 15, 20, 30]
+default: derived
+```
+
+## Insulating glass units shall be warranted against seal failure, obstruction of vision by internal moisture, and internal dust accumulation for the term indicated in the datasheet.
+
+```datasheet
+label: Insulating Glass Unit Warranty Term
+type: range
+unit: years
+options:
+ min: 5
+ max: 20
+ setpoints: [5, 10, 15, 20]
+default: 10
+```
+
+## Where structural silicone glazing is used, the structural sealant shall be warranted against adhesive and cohesive failure for the term indicated in the datasheet.
+
+```datasheet
+label: Structural Silicone Glazing Warranty Term
+type: range
+unit: years
+options:
+ min: 5
+ max: 20
+ setpoints: [5, 10, 20]
+```
+
+## Warranties shall be written in the name of the Owner and shall remain transferable for the full term.
+
+## Work repaired or replaced under any of these warranties shall carry a new warranty for the full original term running from the date of the repair, or for the remainder of the original term, whichever ends later.
+
+## The party performing a warranty repair shall bear the cost of access to the work, of removing and reinstalling adjacent construction disturbed by the repair, and of repairing damage to the building and its contents caused by the defect or by the repair itself.
+
+## A warranty repair on a facade is rarely limited to the defective component: reaching it can require swing stage access, removal of interior finishes, or de-glazing adjacent lites. Leaving those costs unassigned turns a covered repair into a dispute about who pays to get to it, which is why they are assigned here rather than left to the warranty certificate. {note}
+
+# Extra Stock Materials {toc}
+
+## The Contractor shall deliver to the Owner the quantity of replacement glazing units indicated in the datasheet, of each vision and spandrel makeup used on the project.
+
+```datasheet
+label: Extra Stock Glazing Units
+type: range
+unit: units
+options:
+ min: 0
+ max: 20
+ setpoints: [0, 1, 2, 4, 6, 10, 20]
+```
+
+## The Contractor shall deliver to the Owner the length of each glazing gasket profile used on the project indicated in the datasheet.
+
+```datasheet
+label: Extra Stock Glazing Gasket Length
+type: range
+unit: ft
+options:
+ min: 0
+ max: 500
+ setpoints: [0, 50, 100, 200, 500]
+```
+
+## Extra stock materials shall be from the same production lot as the installed work, shall be labeled with the mark and the makeup they replace, and shall be stored where the Owner directs.
+
+## Extra stock glazing units shall be delivered with the setting blocks, gaskets, and fasteners a single lite replacement consumes.
+
+## A curtain wall lite is the hardest component on a building to obtain quickly after the project closes. Coating runs change, tint lots shift, and a fabricator can drop the makeup entirely, so a broken lite years later becomes a visible mismatch across a whole elevation. Attic stock bought from the original run is the only way to keep a later replacement invisible. {note}