Skylights and Unit Skylights
Remake batch 23: rewritten from scratch under the authoring cheatsheet with datasheet constraints; scope boundaries restated against the remade neighbors
Showing changes from Rev 3
to Rev 4
in Skylights and Unit Skylights.
---
title: Skylights and Unit Skylights
category: Building Envelope
−toc_depth: 3
description: >
− When to use: Supply and installation of factory-assembled unit skylights and
− tubular daylighting devices (TDDs) set into sloped or flat roof assemblies for
− commercial, institutional, industrial, and residential overhead daylighting.
− Covers curb-mounted, deck-mounted (self-flashing), and ridge units; fixed and
− operable (venting) configurations; single-, double-, and triple-dome or glazed
− units; integral curbs, flashing, condensate management, and fall-protection
− screening; and NAFS performance for structural load, air, water, thermal
− (U-factor, SHGC), and visible light transmittance.
− Not intended for: Continuous sloped glazing and structural glass roofs (use
− [[sync/glazing]]); roof membrane waterproofing and underlayment (use
− [[sync/membrane-roofing]]); metal roof panels with integral translucent panels
− (use [[sync/metal-roof-panels]]); general sheet metal flashing and trim (use
− [[sync/sheet-metal-flashing-and-trim]]); roof hatches and smoke vents (use
− [[sync/roof-hatches-and-smoke-vents]]); vertical wall fenestration (use
− [[sync/windows]]); and selective demolition of existing skylights (use
− [[sync/selective-demolition]]).
+ When to use: Factory-assembled unit skylights and tubular daylighting devices rated as complete products under the North American Fenestration Standard and set into the roof plane of commercial, institutional, industrial, multifamily, and residential buildings. Covers curb-mounted, deck-mounted (self-flashing), ridge, and continuous-run units, roof windows on a slope above the weather line, fixed units, manually and electrically operated units including operable skylights opened for smoke exhaust, and tubular daylighting devices; the glazing infill of the unit, whether formed acrylic or polycarbonate with its IBC Chapter 26 combustibility class or an insulating glass unit with the laminated inboard lite or retention screen IBC Chapter 24 requires; the factory curb, integral flange, and factory flashing kit; condensation gutters and weeps; insect screens, fall-protection screens, and the fall-protection rating of the unit; performance class and grade, air leakage, water penetration, impact resistance, condensation resistance, U-factor, solar heat gain coefficient, and visible transmittance; field water testing; and the manufacturer and installer warranties. Applies to new units and to replacement units set into existing openings.
+ Not intended for: Continuous sloped glazing, structural glass roofs, and glazed canopies built up from framing and individual lites rather than furnished as rated units; the membrane base flashing and cricket at a curb on a membrane roof ([[sync/membrane-roofing]]); the curb framing, panel penetration treatment, prefabricated metal roof curb, and cricket on a metal panel roof ([[sync/metal-roof-panels]]); the underlayment and step flashing that receive a deck-mounted unit on a shingle roof ([[sync/asphalt-shingle-roofing]]); counterflashing, copings, and other architectural sheet metal at the curb ([[sync/sheet-metal-flashing-and-trim]]); site-built wood curbs and nailers ([[sync/rough-carpentry]]) and site-built steel curbs ([[sync/miscellaneous-metals]]); roof hatches and gravity smoke and heat vents listed to UL 793 ([[sync/roof-hatches-and-smoke-vents]]); daylight-responsive control of the electric lighting below the skylight ([[sync/lighting-controls]]); personal fall arrest anchors near the opening ([[sync/fall-protection-anchorage]]); removal of existing units ([[sync/selective-demolition]]); vertical windows and window walls ([[sync/windows]]); and glass specified independently of a rated unit for vertical work ([[sync/glazing]]).
---
# Scope {toc}
−## This standard covers the supply and installation of factory-assembled unit skylights and tubular daylighting devices set into sloped or flat roof assemblies to introduce daylight through the roof plane. {note}
+## This standard governs factory-assembled unit skylights and tubular daylighting devices that introduce daylight through the roof plane: the frame, the glazing infill, the factory curb or integral flange, the operator where the unit opens, the condensation management built into the unit, the screens and fall-protection rating that make the opening safe, and the setting, flashing coordination, testing, and warranty of the complete unit. {note}
−## Unit skylights are pre-engineered, factory-glazed assemblies labeled to a North American Fenestration Standard (NAFS) performance grade, distinct from site-glazed sloped glazing built up from individual lites. {note}
+## A unit skylight arrives from one manufacturer as a finished product, glazed, sealed, and labeled to a performance class and grade under the North American Fenestration Standard. The Contractor sets it on a curb or over a prepared opening and flashes it into the roof; the Contractor does not field-glaze it or field-fabricate its frame. That is the boundary between a unit skylight and sloped glazing: sloped glazing is framing and lites assembled on the building and engineered as a system, and it is not a rated unit. Continuous sloped glazing, structural glass roofs, and glazed canopies are outside this standard and are not assigned to another standard by it. {note}
−## The following mounting and operating configurations are within scope: {note}
−- Curb-mounted fixed units set on a site-built or manufacturer-supplied insulated curb.
−- Deck-mounted (self-flashing) fixed units whose integral flange flashes directly to the roof deck on steep-slope roofs.
−- Curb-mounted operable (venting) units with manual crank, chain-drive, or electric operators, including roof windows on steep-slope residential roofs.
−- Single-, double-, and triple-dome plastic-glazed units and insulating-glass-unit (IGU) glazed units.
−- Tubular daylighting devices (TDDs) consisting of a roof dome, reflective tube, and ceiling diffuser.
−- Gang or continuous-row units mounted on a common curb or on abutting individual curbs.
+## A tubular daylighting device is a unit skylight in a different shape: a small roof dome over a reflective tube that carries daylight to a diffuser at the ceiling. It is rated under the same fenestration standard and is specified here because the roof penetration, the flashing, the dome, and the energy performance are the same problems at a smaller scale. {note}
−## Custom architectural assemblies (barrel vaults, pyramids, and structural glass roofs) that exceed standard catalog products approach curtainwall territory and are outside the scope of this standard. {note}
+## The following product families are within this standard: {note}
−## Very large or structurally complex custom assemblies should be specified under [[sync/glazing]] rather than this standard.
+- Curb-mounted unit skylights set on a factory curb or on a curb furnished under the roofing, carpentry, or metal work.
+- Deck-mounted unit skylights whose integral flange is flashed directly into a steep-slope roof covering.
+- Ridge units and continuous-run units composed of factory modules on a common curb.
+- Roof windows: operable units set within reach on a steep slope above the weather line, including the roof windows the window standard sends here.
+- Fixed units, manually operated units, and electrically operated units, including operable skylights opened by the fire alarm system for smoke exhaust.
+- Tubular daylighting devices with their domes, tubes, flashings, and diffusers.
+- Replacement units set into an existing opening after the existing unit has been removed under the demolition work.
−## Skylight flashing references the details of [[sync/sheet-metal-flashing-and-trim]] but the membrane or panel waterproofing into which the unit is set is the work of [[sync/membrane-roofing]] or [[sync/metal-roof-panels]]. {note}
+## The following are outside this standard and are governed where named: {note}
−## Units listed and installed to serve as automatic smoke and heat vents are not unit skylights for the purpose of this standard; they are covered by [[sync/roof-hatches-and-smoke-vents]]. {note}
+- The membrane base flashing carried up the curb, the cricket on the upslope side of the curb, and the roofing warranty at a curb on a membrane roof: [[sync/membrane-roofing]].
+- The curb framing, the prefabricated metal roof curb, the panel penetration treatment, and the cricket on a metal panel roof: [[sync/metal-roof-panels]].
+- The underlayment, ice barrier, and step flashing that receive a deck-mounted unit on a shingle roof: [[sync/asphalt-shingle-roofing]].
+- Counterflashing, curb caps, and copings in architectural sheet metal: [[sync/sheet-metal-flashing-and-trim]].
+- Site-built wood curbs, nailers, and blocking: [[sync/rough-carpentry]]. Site-built steel curbs and curb angles: [[sync/miscellaneous-metals]].
+- Roof hatches and the gravity smoke and heat vents listed to UL 793 that IBC Section 910 requires: [[sync/roof-hatches-and-smoke-vents]].
+- The photosensors, controllers, and dimming that reduce the electric lighting below a skylight: [[sync/lighting-controls]].
+- The anchors and horizontal lifelines to which a worker's personal fall arrest equipment attaches: [[sync/fall-protection-anchorage]]. The screen, guard, or rated cover at the skylight opening itself is governed here.
+- Removal of an existing skylight, protection of the opening, and the temporary weather closure before the replacement unit arrives: [[sync/selective-demolition]].
+## Skylights shall comply with the sloped glazing and skylight provisions of IBC Chapter 24, the light-transmitting plastic provisions of IBC Chapter 26, and the wind provisions of IBC Chapter 16, each as adopted in [[parameter: adopted-building-code]].
+
+## Each unit shall be furnished as a complete factory-assembled product, glazed and sealed by the manufacturer, from a single manufacturer for all units of one type on the project.
+
+## Where a unit within this scope is set on a curb, flashing, or roof assembly furnished under another scope of work, the Contractor shall identify that interface on the shop drawings and shall coordinate the curb dimensions, the flashing sequence, and the warranty boundary with the furnishing trade before the unit is ordered.
+
# Referenced Standards {toc}
−## Products and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited or a different edition is enforced by the authority having jurisdiction.
+## Units, glazing, finishes, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited in the Contract Documents.
## Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
−## NAFS-26 (AAMA/WDMA/CSA 101/I.S.2/A440-26) is the current edition at the time of writing and supersedes the 2022 edition, but many jurisdictions still reference NAFS-22 until their code cycle updates; the locally adopted edition governs. {note}
+## The fenestration standard is revised on a cycle that runs ahead of code adoption, so the edition a unit is labeled to and the edition the adopted code references are often different. The label edition is what the manufacturer tested to; the code edition is what the inspector checks. A unit labeled to the newer edition satisfies the older one in every case this standard relies on. {note}
| Standard | Title |
|----------|-------|
| AAMA/WDMA/CSA 101/I.S.2/A440 (NAFS) | North American Fenestration Standard/Specification for Windows, Doors, and Skylights |
−| ASTM E1300 | Standard Practice for Determining Load Resistance of Glass in Buildings |
−| ASTM E2112 | Standard Practice for Installation of Exterior Windows, Doors and Skylights |
−| IBC Section 2405 | Sloped Glazing and Skylights (Chapter 24) |
−| IBC Section 1507.5 | Skylights and Sloped Glazing (Chapter 15, Roof Assemblies) |
−| ASCE 7 | Minimum Design Loads and Associated Criteria for Buildings and Other Structures |
−| NFPA 13 | Standard for the Installation of Sprinkler Systems |
−| OSHA 29 CFR 1926.502 | Fall Protection Systems Criteria and Practices |
−| OSHA 29 CFR 1910.29 | Fall Protection Systems and Falling Object Protection Criteria |
+| AAMA 1503 | Voluntary Test Method for Thermal Transmittance and Condensation Resistance of Windows, Doors and Glazed Wall Sections |
+| AAMA 501.2 | Quality Assurance and Diagnostic Water Leakage Field Check of Installed Storefronts, Curtain Walls, and Sloped Glazing Systems |
+| AAMA 611 | Voluntary Specification for Anodized Architectural Aluminum |
+| 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 |
+| ASTM E283 | Determining Rate of Air Leakage Through Exterior Windows, Skylights, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen |
+| ASTM E330 | Structural Performance of Exterior Windows, Doors, Skylights and Curtain Walls by Uniform Static Air Pressure Difference |
+| ASTM E547 | Water Penetration of Exterior Windows, Skylights, Doors, and Curtain Walls by Cyclic Static Air Pressure Difference |
+| ASTM E1105 | Field Determination of Water Penetration of Installed Exterior Windows, Skylights, Doors, and Curtain Walls by Uniform or Cyclic Static Air Pressure Difference |
+| ASTM E1300 | Determining Load Resistance of Glass in Buildings |
+| ASTM E1886 | Performance of Exterior Windows, Curtain Walls, Doors, and Impact Protective Systems Impacted by Missile(s) and Exposed to Cyclic Pressure Differentials |
+| ASTM E1996 | Performance of Exterior Windows, Curtain Walls, Doors, and Impact Protective Systems Impacted by Windborne Debris in Hurricanes |
+| ASTM E2112 | Installation of Exterior Windows, Doors and Skylights |
+| ASTM C1036 | Flat Glass |
+| ASTM C1048 | Heat-Strengthened and Fully Tempered Flat Glass |
+| ASTM C1172 | Laminated Architectural Flat Glass |
+| ASTM E2190 | Insulating Glass Unit Performance and Evaluation |
+| ASTM D635 | Rate of Burning and/or Extent and Time of Burning of Plastics in a Horizontal Position |
+| ASTM D1929 | Determining Ignition Temperature of Plastics |
+| ASTM D4802 | Poly(Methyl Methacrylate) Acrylic Sheet |
+| ASTM D1003 | Haze and Luminous Transmittance of Transparent Plastics |
+| ANSI Z97.1 | Safety Glazing Materials Used in Buildings |
+| 16 CFR 1201 | Safety Standard for Architectural Glazing Materials |
| NFRC 100 | Procedure for Determining Fenestration Product U-factors |
−| NFRC 200 | Procedure for Determining Fenestration Product SHGC and Visible Transmittance |
+| NFRC 200 | Procedure for Determining Fenestration Product Solar Heat Gain Coefficient and Visible Transmittance at Normal Incidence |
+| NFRC 500 | Procedure for Determining Fenestration Product Condensation Index Ratings |
| ASHRAE 90.1 | Energy Standard for Sites and Buildings Except Low-Rise Residential Buildings |
−| ENERGY STAR (Skylights) | ENERGY STAR Program Requirements for Residential Skylights |
+| IECC | International Energy Conservation Code |
+| IBC | International Building Code (Chapter 16, Chapter 24 Section 2405, Chapter 26 Section 2610) |
+| ASCE 7 | Minimum Design Loads and Associated Criteria for Buildings and Other Structures |
+| 29 CFR 1910.28 | Duty to Have Fall Protection and Falling Object Protection |
+| 29 CFR 1910.29 | Fall Protection Systems and Falling Object Protection Criteria and Practices |
+| 29 CFR 1926.502 | Fall Protection Systems Criteria and Practices |
# Submittals {toc}
## Action Submittals {toc}
−### The Contractor shall submit the following action submittals for review before fabrication or ordering:
−- Product data for each skylight type, including frame material, glazing makeup, operator type, and accessories.
−- Shop drawings showing unit dimensions, curb details, flashing integration, fastening, cricket locations, and condensate provisions.
−- NAFS performance label data confirming performance grade, design pressure, and gateway test results for each unit.
−- NFRC-certified whole-product U-factor, SHGC, and visible light transmittance values for each glazing configuration.
−- Glazing certification identifying glass type (tempered, laminated, heat-strengthened) or plastic type and impact rating for sloped use.
−- Fall-protection details for screens, guards, or covers, with the load rating and the party responsible for installation.
−- Glazing and finish samples in the specified color and tint.
+### The Contractor shall submit the following for the Engineer of Record's review and approval before any unit is ordered:
+- Product data for each unit type, identifying the frame material and finish, the glazing material, form, and makeup, the operator, the curb or flange, the condensation provision, the screens, and every accessory.
+- The NAFS product designation and the certification or test report for each unit type, showing the performance class, the performance grade, the positive and negative design pressures, and the air leakage and water penetration results.
+- NFRC-certified whole-product U-factor, solar heat gain coefficient, and visible transmittance for each glazing makeup, and the condensation index or condensation resistance factor where the datasheet requires one.
+- The light-transmitting plastic classification per ASTM D635 and the ignition temperature per ASTM D1929 for each plastic glazing, and the glass type, heat treatment, interlayer, and insulating unit certification for each glass glazing.
+- Impact test reports per ASTM E1886 and ASTM E1996 for each unit type where impact resistance applies.
+- Shop drawings showing each unit in plan and section with its curb or flange, the curb height above the finished roof, the fastening to the curb, the flashing interface with the roofing, the cricket location, the condensation gutter and weep locations, the operator and its power and control rough-in, and the fall-protection screen or guard.
+- The fall-protection test report or rating for each unit, screen, or cover offered as fall protection, stating the rated load and the test method.
+- Samples of the glazing in each material, tint, and diffusion, and of the frame finish in each color.
+- Installer qualification statement with references for the unit types and roof types on this project.
+
```datasheet
−label: Required action submittals
+label: Action Submittals Required
type: checkbox
options:
− - Product data (each type)
− - Shop drawings (curb, flashing, fastening)
− - NAFS performance label data
− - NFRC U-factor / SHGC / VLT certification
− - Glazing/plastic type certification (sloped use)
− - Fall-protection details and load rating
− - Glazing and finish samples
+ - "Product data for each unit type"
+ - "NAFS designation and certification or test report for each unit type"
+ - "NFRC-certified U-factor, SHGC, VT, and condensation rating"
+ - "Plastic classification and glass certification for each glazing"
+ - "Impact test reports where impact resistance applies"
+ - "Shop drawings of each unit with curb, flashing, operator, and screen"
+ - "Fall-protection test report or rating"
+ - "Glazing and finish samples"
+ - "Installer qualification statement"
default:
− - Product data (each type)
− - Shop drawings (curb, flashing, fastening)
− - NAFS performance label data
− - NFRC U-factor / SHGC / VLT certification
+ - "Product data for each unit type"
+ - "NAFS designation and certification or test report for each unit type"
+ - "NFRC-certified U-factor, SHGC, VT, and condensation rating"
+ - "Plastic classification and glass certification for each glazing"
+ - "Shop drawings of each unit with curb, flashing, operator, and screen"
+ - "Fall-protection test report or rating"
+ - "Glazing and finish samples"
+constraint: all_of
```
−## Closeout Submittals {toc}
+### A submittal for a unit that will be set on a curb furnished by another trade shall include the curb dimensions the unit requires, so that the curb can be checked against them before it is built.
−### The Contractor shall submit the following closeout submittals before final acceptance:
−- Manufacturer's written product and installation warranties.
−- Operation and maintenance data for operable units, operators, sensors, and shades.
−- Record documents showing as-installed unit locations, sizes, and accessories.
−- Final fall-protection certification confirming installed screens or guards meet the rated load.
+### The Contractor shall not order units before the action submittal for that unit type has been accepted.
+## Informational Submittals {toc}
+
+### The Contractor shall submit the following for record before installation begins:
+
+- Pre-installation conference minutes, including the agreed sequence and the flashing responsibility at each roof type.
+- Written acceptance of each curb or opening by the installer, or a written notice of a curb that is out of square, out of level, undersized, or short of the height this standard requires.
+- The manufacturer's written confirmation of the warranty type and term available for each unit as submitted.
+- Field water test reports for each unit or sample tested.
+- The manufacturer's field inspection report where the warranty is conditioned on one.
+
```datasheet
−label: Required closeout submittals
+label: Informational Submittals Required
type: checkbox
options:
− - Product and installation warranties
− - Operation and maintenance data
− - Record documents (as-installed)
− - Fall-protection certification
+ - "Pre-installation conference minutes"
+ - "Curb and opening acceptance or notice of deficiency"
+ - "Manufacturer confirmation of available warranty"
+ - "Field water test reports"
+ - "Manufacturer field inspection report"
default:
− - Product and installation warranties
− - Operation and maintenance data
− - Fall-protection certification
+ - "Pre-installation conference minutes"
+ - "Curb and opening acceptance or notice of deficiency"
+ - "Manufacturer confirmation of available warranty"
+ - "Field water test reports"
+constraint: all_of
```
−## Informational Submittals {toc}
+## Closeout Submittals {toc}
−### The Contractor shall submit the following informational submittals when required by the Contract Documents:
−- Structural calculations for custom or non-catalog units signed by a licensed engineer.
−- Manufacturer's field-service or inspection reports for installed units.
−- Energy compliance documentation demonstrating skylight-to-roof ratio and U-factor/SHGC conformance with the adopted energy code.
+### The Contractor shall submit the following at substantial completion, before the skylight work is accepted:
+- Executed manufacturer warranties for the unit, the insulating glass or plastic glazing, and the finish, each naming the Owner.
+- Executed installer warranty.
+- Operation and maintenance data for operators, controls, sensors, screens, and shades, including the cleaning methods and cleaning agents the glazing manufacturer permits.
+- Record drawings showing each installed unit by type, size, and location, and every field modification.
+- A fall-protection statement identifying, for each opening, the screen, guard, or rated unit that protects it and its rated load.
+- Spare keys, cranks, poles, and remote controls furnished with the operators.
+
```datasheet
−label: Required informational submittals
+label: Closeout Submittals Required
type: checkbox
options:
− - Structural calculations (custom units)
− - Field-service / inspection reports
− - Energy compliance documentation
+ - "Executed manufacturer warranties"
+ - "Executed installer warranty"
+ - "Operation and maintenance data"
+ - "Record drawings of installed units"
+ - "Fall-protection statement for each opening"
+ - "Operator cranks, poles, keys, and remote controls"
default:
− - Energy compliance documentation
+ - "Executed manufacturer warranties"
+ - "Executed installer warranty"
+ - "Operation and maintenance data"
+ - "Record drawings of installed units"
+ - "Fall-protection statement for each opening"
+constraint: all_of
```
# Quality Assurance {toc}
−## Each unit skylight shall bear a permanent NAFS label identifying the manufacturer, performance grade, design pressure, and the certification or inspection agency. {note}
+## Product Certification and Labeling {toc}
−## Units shall be certified to the specified NAFS performance grade by an accredited certification and labeling program.
+### Each unit shall bear a permanent label from an accredited certification program identifying the manufacturer, the NAFS performance class and grade, the positive and negative design pressures, and the certification agency.
−## Glazing in sloped applications shall comply with IBC Section 2405.2 for permitted glazing types and, where required, screening or retention against fall-out.
+### Each unit shall bear a temporary NFRC label stating the whole-product U-factor, solar heat gain coefficient, and visible transmittance, and the label shall remain in place until the building inspector has recorded it or has released it.
−## Thermal performance values shall be NFRC-certified whole-product values.
+### Thermal values submitted for code compliance shall be whole-product values determined under NFRC 100 and NFRC 200, and center-of-glass values shall not be substituted for them.
−## Center-of-glass values shall not be substituted for whole-product values in code or energy-model submittals.
+### A center-of-glass value describes the glazing alone and ignores the frame, the spacer, and the curb edge, which together carry most of the heat loss of a small unit. A skylight's whole-product U-factor is commonly half again the center-of-glass value, and the code tables are written against the whole product. {note}
−## The installer shall be trained or approved by the skylight manufacturer for the specified product line.
+## Installer Qualifications {toc}
−## A mock-up or first-unit installation should be reviewed and approved before remaining units are installed where the project includes more than ten units or any custom configuration.
+### The installer shall have the experience indicated in the datasheet installing unit skylights of the types and on the roof types in this project.
−# Environmental and Service Conditions {toc}
+```datasheet
+label: Installer Experience on Unit Skylight Installation
+type: range
+unit: years
+min: 0
+max: 15
+setpoints: [0, 2, 3, 5, 10, 15]
+default: 3
+constraint: min
+```
−## Skylights are exposed to the full range of roof-plane loads and environmental stresses: wind uplift and inward pressure, snow and live loads, thermal cycling, ultraviolet exposure, hail, and condensation driven by interior humidity. {note}
+### Where the manufacturer conditions its warranty on an installer it has trained or authorized, the installer shall hold that authorization for the product line at the time of installation.
−## Design pressure shall be established from the project wind and snow loads determined per ASCE 7 and IBC Chapter 16 for the building height, exposure, and roof zone.
+## Pre-Installation Conference {toc}
−## Glazing load resistance shall be verified per ASTM E1300 for glass units under the governing wind and snow load.
+### A pre-installation conference shall be held before any curb is built and before any unit is set.
−## In cold climates, interior humidity contacts cold frame and glazing surfaces and produces condensation that is often mistaken for leakage. {note}
+### Attendance shall include the skylight installer, the roofing Contractor, the carpentry or metal trade furnishing any site-built curb, the electrical Contractor where any unit is electrically operated, the General Contractor, and the Engineer of Record.
−## Units shall include thermally broken frames and condensate management to prevent moisture damage.
+### The conference shall settle, in writing, which trade furnishes and installs each curb, the base flashing, the counterflashing, and the cricket at each roof type; the curb height; the sequence of roofing, curb, and unit; the operator rough-in; the field test method; and the point at which the roofing warranty ends and the skylight warranty begins.
+### Most skylight leaks are reported at a boundary: the membrane stops short of the curb top, the counterflashing is nobody's, or the unit is set before the roofing is complete and the flashing is cut to suit. The conference exists to assign each piece to a named trade before anything is built. {note}
+
+## Mock-Up {toc}
+
+### A mock-up shall be provided as indicated in the datasheet.
+
```datasheet
−label: Climate zone (ASHRAE 90.1)
−type: select
+label: Mock-Up Required Before Production Installation
+type: radio
options:
− - CZ1 - CZ3 (warm / mixed)
− - CZ4 - CZ5 (mixed / cold)
− - CZ6 - CZ8 (cold / very cold)
−default: CZ4 - CZ5 (mixed / cold)
+ - "In-place first unit of each type reviewed before remaining units are set"
+ - "Freestanding mock-up of one unit on a sample curb at a location the Engineer of Record selects"
+ - "Not required"
```
+### An in-place first unit costs nothing beyond the review and catches the curb, flashing, and sequence problems on the roof where they will recur. A freestanding mock-up lets the flashing be cut open and the water test run before the roofing is at risk, at the cost of a sample curb. On a project with a handful of units of one type, neither buys much. {note}
+
+### Where a mock-up is indicated in the datasheet, production installation shall not proceed until the Engineer of Record has accepted the mock-up in writing.
+
+### An accepted in-place first unit may remain in the finished work where it is undamaged and conforms to the accepted submittals.
+
+### The Engineer of Record shall be the initial arbiter of whether an accepted mock-up establishes the standard of workmanship for a disputed unit.
+
+# Environmental and Service Conditions {toc}
+
+## Roof-Plane Loads {toc}
+
+### A skylight carries every load the roof carries at that point, plus the loads a vertical window never sees: snow bears directly on the glazing, sliding snow from a steeper roof above impacts the upslope face, drifts form against the curb, and hail strikes the glazing square on. Wind acts in both directions. The positive design pressure of a skylight on a snow roof is often set by snow rather than wind, and the fenestration standard tests skylights at a positive load that reflects that. {note}
+
+### The Engineer of Record shall establish the positive and negative design pressures for each skylight location from ASCE 7 and [[parameter: adopted-building-code]] for the building's risk category, exposure, roof height, and roof zone, including the roof snow load, drift, and sliding snow at the unit.
+
+### Glass glazing shall be sized for load resistance under ASTM E1300 for the governing design load and the glass type, heat treatment, and support condition of the unit.
+
+### Plastic glazing shall retain its impact resistance and shall not crack under the design load at [[parameter: site-ambient-temperature-minimum]].
+
+## Impact Resistance {toc}
+
+### Whether impact resistance applies to each skylight shall be determined from [[parameter: wind-borne-debris-region]] together with the height of the opening above grade, and shall be as indicated in the datasheet.
+
```datasheet
−label: Design ground snow load
−type: range
−unit: psf
−min: 0
−max: 100
−step: 5
−drawing_ref: "structural roof load schedule"
−default: deferred
+label: Impact Resistance Required
+type: radio
+options:
+ - "Required"
+ - "Not required"
+derived: "[[parameter: wind-borne-debris-region]] and the height of the opening above grade"
+default: derived
```
+### Where impact resistance is required, each unit shall be tested as a complete unit per ASTM E1886 at the missile level ASTM E1996 assigns for the opening height and the building's risk category, followed by the cyclic pressure sequence, and shall be furnished in the construction tested.
+
+### Where impact resistance is required and the glazing is plastic, the plastic shall be of the thickness and material tested, and acrylic shall not be substituted for polycarbonate in a unit tested with polycarbonate.
+
+## Condensation and Interior Humidity {toc}
+
+### The inside face of a skylight is the coldest surface in the room and sits where warm moist air collects, so condensation forms on it before it forms anywhere else. Water running off the frame onto the ceiling below is reported as a leak, and in a cold climate the volume over a winter is enough to stain gypsum and rot a light well. The unit manages it with a thermal break in the frame, an insulating glazing makeup, and a gutter that collects what still forms and weeps it to the outside. {note}
+
+### The condensation resistance of each unit shall be not less than the value indicated in the datasheet, determined as a condensation resistance factor per AAMA 1503 or as a condensation index per NFRC 500.
+
```datasheet
−label: Ultimate design wind speed
+label: Condensation Resistance Factor
type: range
−unit: mph
−min: 90
−max: 200
−step: 5
−drawing_ref: "structural wind design data"
−default: deferred
+unit: CRF
+min: 20
+max: 80
+step: 1
+constraint: min
```
−# Performance Grade and Structural Requirements {toc}
+### Where the space below the skylight is held above 35 percent relative humidity in the heating season, including natatoriums, kitchens, laundries, and humidified spaces, the Contractor shall obtain the manufacturer's written confirmation that the unit as submitted is warrantable for that service.
−## NAFS classifies fenestration into performance classes R, LC, CW, and AW in ascending order of structural, air, and water severity; the class drives the gateway test pressures and the minimum design pressure. Specifying a residential R-class unit in a commercial, institutional, or high-wind application is a common and serious error, since CW or AW class is required for most commercial and high-exposure projects. {note}
+# Performance Class and Grade {toc}
−## Unit skylights shall meet or exceed the specified NAFS performance grade for class and design pressure.
+## Performance Class {toc}
−## The structural test load shall be not less than 150% of the design pressure without glass breakage or permanent deformation that impairs function.
+### Each unit shall be certified to the NAFS performance class indicated in the datasheet.
−## Water resistance shall be demonstrated at a test pressure of not less than 15% of the design pressure, and not less than 15 psf.
−
−## Air infiltration shall not exceed the limit for the specified performance class at the standard test pressure.
−
```datasheet
−label: NAFS performance class
+label: NAFS Performance Class
type: radio
options:
− - R (residential)
− - LC (light commercial)
− - CW (commercial window)
− - AW (architectural)
−default: CW (commercial window)
+ - "R"
+ - "LC"
+ - "CW"
+ - "AW"
```
+### The four classes are ordered by severity. Class R is tested at the lightest gateway pressure and is the class of most residential deck-mounted units and roof windows. Class LC adds a higher gateway pressure and tighter deflection limits for low-rise commercial work. Class CW adds a heavier structural test, a tighter air leakage limit at a higher test pressure, and a life-cycle test on operable units, and it is the class most commercial curb-mounted units carry. Class AW is tested at the highest pressures with the tightest air leakage and deflection limits and a longer life cycle, for high-rise, high-exposure, or institutional work where the unit is expected to outlast several roofs. Each step up narrows the product field and raises the cost. {note}
+
+## Performance Grade {toc}
+
+### The performance grade of each unit shall be not less than the design pressure indicated in the datasheet, and not less than the positive and negative design pressures the Engineer of Record establishes for the unit's location.
+
```datasheet
−label: Design pressure (DP) rating
+label: Performance Grade (Design Pressure)
type: range
unit: psf
min: 15
max: 100
−step: 5
−default: 30
+setpoints: [15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100]
+drawing_ref: "the structural general notes and roof wind and snow design criteria"
+default: deferred
+constraint: min
```
+### Each unit shall resist a structural test load of 1.5 times the design pressure in each direction, per ASTM E330, without glass breakage, plastic fracture, permanent deformation that impairs operation, or disengagement of the glazing from the frame.
+
+### Where the datasheet performance grade is below the design pressure the Engineer of Record establishes for a location, the higher value shall govern that location, and the Contractor shall identify every such location in the action submittal.
+
+## Air Leakage {toc}
+
+### Air leakage through each fixed unit shall not exceed the rate indicated in the datasheet, tested per ASTM E283 at the pressure NAFS assigns to the performance class.
+
```datasheet
−label: Maximum air infiltration
+label: Air Leakage Rate
type: range
−unit: cfm/ft²
−min: 0.05
+unit: 'cfm/ft²'
+min: 0.1
max: 0.5
−step: 0.05
+step: 0.1
default: 0.3
+constraint: max
```
−# Mounting Configuration {toc}
+### Where the performance class is AW, air leakage shall not exceed 0.1 cfm/ft² at the AW test pressure regardless of the datasheet value.
−## Curb-Mounted Units {toc}
+### Operable units shall be tested for air leakage in the closed and latched position, and the datasheet rate shall apply to the operable unit as well as to the fixed unit.
−### Curb-mounted units set on a raised curb are the standard configuration for flat and low-slope roofs; the curb lifts the unit above the drainage plane and provides a surface for base flashing. {note}
+## Water Penetration {toc}
−### Curb-mounted units shall be set on a curb extending not less than 4 inches (102 mm) above the finished roof plane, per IBC Section 2405.4.
+### Each unit shall show no water penetration when tested per ASTM E547 at a pressure not less than 15 percent of its positive design pressure and not less than the gateway water test pressure NAFS assigns to its performance class.
−### On re-roofing projects, curbs should extend not less than 8 inches above the finished roof to maintain base-flashing height over the new assembly.
+### Water penetration for a skylight is defined at the interior face of the unit, and water that reaches the condensation gutter and weeps back out is not penetration. Water that passes the gutter, or that collects in a gutter with blocked weeps and overflows, is. {note}
−### The curb shall be insulated to limit thermal bridging and condensation at the perimeter of the opening.
+# Thermal and Daylighting Performance {toc}
+## U-Factor and Solar Heat Gain {toc}
+
+### The whole-product U-factor of each unit shall not exceed the value indicated in the datasheet, determined per NFRC 100.
+
```datasheet
−label: Curb type
−type: radio
−options:
− - Manufacturer-supplied insulated curb
− - Site-built wood curb with separate insulation
− - Site-built steel curb with separate insulation
−default: Manufacturer-supplied insulated curb
+label: Whole-Product U-Factor
+type: range
+unit: Btu/h·ft²·°F
+min: 0.2
+max: 1.2
+step: 0.01
+derived: "the skylight criteria of [[parameter: adopted-energy-code]] for [[parameter: climate-zone]] and the compliance path the project uses"
+default: derived
+constraint: max
```
+### The whole-product solar heat gain coefficient of each unit shall not exceed the value indicated in the datasheet, determined per NFRC 200.
+
```datasheet
−label: Curb height above finished roof
+label: Whole-Product Solar Heat Gain Coefficient
type: range
−unit: in
−min: 4
−max: 12
−step: 1
−default: 8
+unit: SHGC
+min: 0.1
+max: 0.9
+step: 0.01
+derived: "the skylight criteria of [[parameter: adopted-energy-code]] for [[parameter: climate-zone]] and the compliance path the project uses"
+default: derived
+constraint: max
```
−## Deck-Mounted (Self-Flashing) Units {toc}
+### The energy code tabulates skylight U-factor and solar heat gain coefficient separately from vertical fenestration, by climate zone, and sets a prescriptive limit on skylight area as a fraction of the roof. A project that exceeds the area limit, or that uses the daylighting allowance for a larger area, moves to a trade-off or performance path, and the values that path requires can be tighter than the prescriptive table. A unit that meets the table is therefore not automatically a unit that meets the project. {note}
−### Deck-mounted units carry an integral flange that flashes directly into the roof underlayment; they are engineered for steep-slope shingle or tile roofs, not low-slope membrane roofs. {note}
+### The aggregate skylight area and the compliance path shall be as the energy compliance documentation for the project states, and the Contractor shall not add, enlarge, or substitute a unit in a way that changes either without the Engineer of Record's written acceptance.
−### Specifying self-flashing units on a low-slope membrane roof voids the roofing waterproofing warranty and is a recurring source of leaks. {note}
+## Visible Transmittance {toc}
−### Low-slope membrane roofs shall use a curb-mounted unit rather than a deck-mounted (self-flashing) unit.
+### The whole-product visible transmittance of each unit shall be not less than the value indicated in the datasheet, determined per NFRC 200.
−### Deck-mounted units shall be installed only on roof slopes of 3:12 or steeper unless the manufacturer certifies a lower slope.
+```datasheet
+label: Whole-Product Visible Transmittance
+type: range
+unit: VT
+min: 0.1
+max: 0.9
+step: 0.01
+constraint: min
+```
−### The integral flange shall be integrated with the roof underlayment and primary roofing per [[sync/sheet-metal-flashing-and-trim]] and the roofing manufacturer's instructions.
+### Visible transmittance is the daylight a skylight delivers for the heat it admits. Where the energy code requires toplighting in a large enclosed space, it also sets a floor on the transmittance of the skylights that provide it, and a diffusing or tinted glazing selected for glare control can fall below that floor. A high ratio of visible transmittance to solar heat gain coefficient is what makes a skylight a daylighting device rather than a heat source. {note}
+### Where the energy code requires the skylights to serve a daylight zone with daylight-responsive control, the transmittance indicated in the datasheet shall be not less than the minimum [[parameter: adopted-energy-code]] sets for skylights in that zone, and the control of the electric lighting in that zone is governed by [[sync/lighting-controls]].
+
+# Unit Configuration {toc}
+
+## Unit Type {toc}
+
+### Units shall be of the type indicated in the datasheet, and where the project uses more than one type, the type at each location shall be as indicated on [[drawing: the skylight schedule]].
+
```datasheet
−label: Mounting method
−type: radio
+label: Unit Type
+type: select
options:
− - Curb-mounted
− - Deck-mounted (self-flashing)
−default: Curb-mounted
+ - "Unit skylight"
+ - "Continuous-run unit skylight on a common curb"
+ - "Ridge unit skylight"
+ - "Roof window"
+ - "Tubular daylighting device"
```
−# Glazing {toc}
+### A unit skylight is one module over one opening, the simplest to flash and to replace. A continuous run joins factory modules end to end on a common curb to light a corridor or a bay; it gains a continuous flashing and loses the ability to replace one module without disturbing its neighbors. A ridge unit straddles the ridge of a pitched roof with glazing on both slopes and needs a curb framed to the ridge. A roof window is an operable unit set within reach on a steep slope, sized and hinged for a person to open, and is the product the residential market calls a skylight. A tubular daylighting device lights a space that has no room for a framed opening, through a ceiling with a plenum or attic above it, at a fraction of the roof opening and with no view. {note}
−## Glazing Type and Makeup {toc}
+### Unit locations and quantities shall be as indicated on [[drawing: the roof plan]].
−### Glazing makeup determines thermal performance, light transmittance, and impact resistance; plastic domes offer high transmittance and light weight, while IGUs deliver the lower U-factors required for cold-climate commercial compliance. {note}
+### The nominal size of each unit shall be as indicated in the datasheet.
−### Sloped glazing shall be tempered, laminated, or heat-strengthened glass, or an approved plastic, as permitted by IBC Section 2405.2; annealed monolithic glass shall not be used in sloped applications.
+```datasheet
+label: Unit Nominal Size
+type: text
+drawing_ref: "the skylight schedule"
+default: deferred
+```
−### Where glass could fall from the opening on breakage, the glazing shall be laminated or shall be screened or retained as required by IBC Section 2405.3.
+### A catalog size carries the shortest lead time and the lowest cost; a custom size is a custom product with its own test or engineering evaluation and a fabrication lead time measured in months. {note}
−### Double- and triple-dome and insulating-glass units shall maintain a sealed air or gas space free of internal condensation.
+### The Contractor shall identify every unit of a size or shape outside the manufacturer's catalog in the procurement schedule, with its fabrication lead time.
+## Mounting {toc}
+
+### Units shall be mounted as indicated in the datasheet.
+
```datasheet
−label: Glazing configuration
+label: Mounting
type: radio
options:
− - Single dome (acrylic or polycarbonate)
− - Double dome (acrylic or polycarbonate)
− - Triple dome (acrylic or polycarbonate)
− - Double insulating glass unit (IGU)
− - Triple insulating glass unit (IGU)
−default: Double dome (acrylic or polycarbonate)
+ - "Curb-mounted"
+ - "Deck-mounted with integral flange"
```
+### A curb-mounted unit sits on a raised curb that lifts it above the drainage plane and gives the roofing a vertical surface to flash to; it is the configuration of every low-slope roof and of most commercial steep-slope roofs. A deck-mounted unit carries an integral flange that laps into the roof covering like a vent flashing, sits lower and looks cleaner, and depends on a steep slope and a shingled or tiled covering to shed water across the flange. On a membrane roof the flange has nothing to lap into. {note}
+
+### Units on a membrane roof, a metal panel roof, or any roof with a slope below 3:12 shall be curb-mounted unless the manufacturer's installation instructions certify the deck-mounted unit for that slope and covering and the roofing manufacturer accepts it in writing.
+
+## Curb {toc}
+
+### The curb for each unit shall be as indicated in the datasheet.
+
```datasheet
−label: Glazing material (glass units)
+label: Curb Source
type: select
options:
− - Tempered glass
− - Laminated glass
− - Heat-strengthened glass
− - Laminated over tempered
−default: Laminated glass
+ - "Factory-furnished insulated curb"
+ - "Site-built wood curb"
+ - "Site-built steel curb"
+ - "Prefabricated metal roof curb furnished with the metal roof panel work"
```
+### A factory curb arrives insulated, square, and sized to the unit, with the unit's weep and condensation path designed to it, and the skylight warranty covers the curb. A site-built wood curb is framed to the opening by the carpentry trade and is the usual curb on a membrane roof over a wood or steel deck; its height, squareness, and insulation are field work, and the warranty boundary sits at its top. A site-built steel curb serves a steel deck or a concrete deck where wood is not wanted. A prefabricated metal roof curb is designed to the panel profile and is furnished and set under the metal roof panel work, with the skylight set on it. {note}
+
+### A factory-furnished curb shall be furnished under this standard, insulated by the manufacturer, and set by the skylight installer.
+
+### A site-built wood curb shall be furnished under [[sync/rough-carpentry]], a site-built steel curb under [[sync/miscellaneous-metals]], and a prefabricated metal roof curb under [[sync/metal-roof-panels]], each built to the dimensions on the accepted skylight shop drawings.
+
+### The curb shall extend above the finished roof surface by not less than the height indicated in the datasheet, and by not less than the base flashing height the roofing work requires.
+
```datasheet
−label: Plastic glazing material (dome units)
−type: select
−options:
− - Acrylic
− - Polycarbonate
− - Acrylic outer / polycarbonate inner
−default: Acrylic
+label: Curb Height Above Finished Roof Surface
+type: range
+unit: in
+min: 4
+max: 24
+setpoints: [4, 6, 8, 10, 12, 14, 18, 24]
+default: 8
+constraint: min
```
−## Tint, Coating, and Light Transmittance {toc}
+### The building code sets a floor of 4 in for a curb on a low-slope roof; the roofing industry details a base flashing of 8 in, and a re-roof over an existing assembly, a ballasted roof, or a snow roof needs more. A curb that is short of the base flashing height forces the roofer to cut the flashing short or to run it over the curb top under the unit, and the first is a leak and the second voids the unit's weep path. {note}
−### Tint and low-emissivity coatings balance daylight against solar heat gain; clear glazing maximizes visible light transmittance, while tints and low-e coatings reduce heat gain and glare. {note}
+### Site-built curbs shall be insulated to the thermal resistance of the adjacent roof insulation, and the insulation shall be furnished with the curb under the roofing work or the carpentry work, whichever furnishes the curb.
−### The low-emissivity coating type and surface shall be selected for the climate, favoring solar-heat-gain control in cooling-dominated climates and heat-loss control in heating-dominated climates.
+### The curb shall be square, level across its top within 1/8 in, and sized so that the unit's frame bears on the curb top across its full perimeter.
+### The installer shall accept each curb in writing before the unit is set, or shall give written notice of a curb that is out of square, out of level, undersized, or short of the required height, and shall not set a unit on a curb that has not been corrected.
+
+## Operation {toc}
+
+### Units shall operate as indicated in the datasheet.
+
```datasheet
−label: Glazing tint / diffusion
+label: Operation
type: select
options:
− - Clear
− - Lightly diffused (white translucent)
− - Bronze tint
− - Gray tint
−default: Lightly diffused (white translucent)
+ - "Fixed"
+ - "Manually operated by crank, chain, or pole"
+ - "Electrically operated"
+ - "Solar-powered electrically operated"
+ - "Electrically operated and opened by the fire alarm system for smoke exhaust"
+default: "Fixed"
```
+### A fixed unit has no hardware to leak around, wear, or be left open in the rain, and is the unit of nearly every commercial roof. A manual operator suits a roof window within reach or a unit over a space with a pole; it adds a hinge, a seal, and a latch to the leak path. An electric operator serves a unit out of reach and adds a power and control rough-in that is missed more often than any other item in this scope; a solar-powered operator removes the rough-in and adds a battery. An operable skylight opened by the fire alarm provides natural smoke exhaust or purge for an atrium or a high space under an engineered smoke control design; it is not the listed gravity smoke and heat vent IBC Section 910 requires, which is a different product under a different standard. {note}
+
+### Operable units shall carry hinges, operators, latches, and weatherstripping rated with the unit at its performance class, and the operable unit shall meet the air leakage and water penetration requirements of this standard in the closed position.
+
+### Operable units shall be furnished with the accessories indicated in the datasheet.
+
```datasheet
−label: Low-emissivity coating
−type: radio
+label: Operable Unit Accessories
+type: checkbox
options:
− - None
− - Solar-control low-e (cooling climates)
− - High-solar-gain low-e (heating climates)
−default: Solar-control low-e (cooling climates)
+ - "Insect screen"
+ - "Rain sensor that closes the unit"
+ - "Wall-mounted control switch"
+ - "Handheld remote control"
+ - "Interior shade or blind"
+ - "Interface to the building automation system"
+constraint: all_of
```
−```datasheet
−label: Visible light transmittance (VLT)
−type: range
−min: 0.2
−max: 0.75
−step: 0.05
−default: 0.5
−```
+### Electrically operated units shall be furnished with a motor and controller rated for the operator's duty, with limit switches at both ends of travel, and with the power and control rough-in located as indicated on [[drawing: the electrical drawings]].
−# Thermal Performance {toc}
+### The Contractor shall confirm the operator rough-in with the electrical Contractor before the roof deck is closed, and shall not set an electrically operated unit before its rough-in is in place.
−## Energy codes cap skylight U-factor and SHGC by climate zone, and ASHRAE 90.1 limits skylight area to a fraction of the roof to control heat loss and gain; thermal values must come from NFRC whole-product certification, not center-of-glass approximations. {note}
+### Where a unit is opened by the fire alarm system for smoke exhaust, the operator shall open the unit fully on a signal from the fire alarm control panel, shall hold it open without power, and shall be returned to the closed position only by a manual reset; the interface to the fire alarm system is governed by [[sync/fire-alarm-systems]].
−## The skylight U-factor shall not exceed the maximum permitted for the climate zone and skylight-to-roof ratio by the adopted energy code.
+### Where a unit is opened by the fire alarm system for smoke exhaust, the operator shall open the unit against the design wind load and snow load at the roof.
−## The skylight SHGC shall not exceed the maximum permitted for the climate zone and occupancy by the adopted energy code.
+# Glazing {toc}
−## Total skylight area shall not exceed 3% of the gross roof area under ASHRAE 90.1 unless a daylighting-control credit or energy trade-off compliance path is documented.
+## Glazing Material and Form {toc}
−## Frames in climate zones 4 and above shall be thermally broken to meet energy requirements and to control frame condensation.
+### Glazing shall be of the material indicated in the datasheet.
```datasheet
−label: Maximum skylight U-factor
−type: range
−unit: Btu/h·ft²·°F
−min: 0.25
−max: 0.7
−step: 0.05
−default: 0.45
+label: Glazing Material
+type: select
+options:
+ - "Acrylic"
+ - "Polycarbonate"
+ - "Glass"
```
+### Acrylic is the clearest plastic, holds its transmittance for decades under ultraviolet exposure, and is the glazing of most formed domes; it is brittle in the cold and in a hail event, and it burns. Polycarbonate is the toughest, holds a hailstone and a dropped tool that would break acrylic or glass, and carries the better combustibility class; untreated it yellows and hazes under ultraviolet, so a polycarbonate dome depends on its co-extruded or coated ultraviolet protection. Glass is flat, carries the lowest U-factor as a sealed insulating unit with a low-emissivity coating, gives a true view, does not yellow, and is the heaviest and the most expensive to ship and to set; it needs the laminated inboard lite or retention screen the code requires over an occupied space. {note}
+
+### The form of the glazing shall be as indicated in the datasheet.
+
```datasheet
−label: Maximum skylight SHGC
+label: Glazing Form
+type: select
+options:
+ - "Formed dome"
+ - "Formed pyramid"
+ - "Flat"
+derived: "the glazing material selected in the datasheet: plastic glazing is formed to a dome, glass is flat"
+default: derived
+```
+
+### A formed plastic glazing gains its stiffness from its shape, so a dome or pyramid spans an opening a flat sheet of the same thickness cannot and sheds water, snow, and dirt by its slope; a flat plastic glazing is limited to small units. Glass is flat and spans by thickness and heat treatment. {note}
+
+### The number of glazing layers in each unit shall be as indicated in the datasheet.
+
+```datasheet
+label: Glazing Layers
type: range
−min: 0.17
−max: 0.6
−step: 0.01
−default: 0.4
+unit: layers
+min: 1
+max: 3
+step: 1
+default: 2
+constraint: exact
```
+### A single layer is a formed dome alone, with the U-factor of a single sheet, and is sold for unconditioned buildings and for the warmest climates. A second layer, whether a second dome with a sealed or vented air space or an insulating glass unit, roughly halves the heat loss and is what the energy code tables assume for a commercial skylight. A third layer serves the coldest climates and the humidified space, at a weight and a cost the frame and the curb must carry. {note}
+
+## Plastic Glazing {toc}
+
+### Plastic glazing shall be a light-transmitting plastic classified per ASTM D635 and ASTM D1929 under IBC Chapter 26, of the class indicated in the datasheet.
+
```datasheet
−label: Skylight-to-roof area ratio cap
−type: radio
+label: Light-Transmitting Plastic Class
+type: checkbox
options:
− - 3% (prescriptive, no daylighting controls)
− - 5% (with daylighting controls)
− - Trade-off compliance path
−default: 3% (prescriptive, no daylighting controls)
+ - "CC1"
+ - "CC2"
+default:
+ - "CC1"
+ - "CC2"
+constraint: any_of
```
−# Frame, Finish, and Operation {toc}
+### The combustibility class sets the area the code permits a plastic skylight to cover and the separation it requires from the next skylight and from the roof edge, with the larger area and the closer spacing going to class CC1. Polycarbonate and some acrylic formulations are classified CC1; most acrylic is CC2. The class is a property of the sheet the manufacturer forms, not of the unit, and a substituted sheet changes it. {note}
−## Frame Material and Finish {toc}
+### Plastic skylights shall comply with the area, separation, slope, and curb provisions IBC Section 2610 sets for their class, as adopted in [[parameter: adopted-building-code]].
−### Frame material affects durability, thermal performance, and appearance; thermally broken aluminum is the commercial default, while fiberglass, PVC, and wood-clad frames serve residential and specialty applications. {note}
+### Acrylic sheet shall conform to ASTM D4802 and shall be formed from cast or continuously cast sheet.
−### Aluminum frames in climate zones 4 and above shall incorporate a thermal break.
+### Polycarbonate sheet shall carry ultraviolet protection on its weather face by co-extrusion or by a factory-applied coating, and the manufacturer shall warrant its transmittance and haze over the glazing warranty term.
+### Formed plastic glazing shall be free of surface defects, inclusions, and optical distortion visible from the floor below, and the Engineer of Record shall be the initial arbiter of whether a defect is visible.
+
+### Where a plastic glazing is specified as a dome over a second dome, the two domes shall be formed as separate sheets and shall be separated by a sealed or vented air space that keeps the inner dome free of condensation and dirt.
+
+## Glass Glazing {toc}
+
+### Glass glazing shall be a sealed insulating glass unit certified per ASTM E2190, with the outboard and inboard lites indicated in the datasheet.
+
```datasheet
−label: Frame material
−type: radio
+label: Outboard Lite
+type: select
options:
− - Thermally broken aluminum
− - Aluminum (non-thermally-broken)
− - Fiberglass
− - PVC
− - Wood-clad
−default: Thermally broken aluminum
+ - "Fully tempered glass"
+ - "Heat-strengthened glass"
+ - "Laminated heat-strengthened glass"
+ - "Laminated fully tempered glass"
+default: "Fully tempered glass"
```
```datasheet
−label: Aluminum finish
+label: Inboard Lite
type: select
options:
− - Clear anodized
− - Color anodized
− - Factory-applied fluoropolymer paint
− - Mill finish
−default: Factory-applied fluoropolymer paint
+ - "Laminated heat-strengthened glass"
+ - "Laminated fully tempered glass"
+ - "Laminated annealed glass"
+ - "Fully tempered glass with a retention screen below"
+ - "Heat-strengthened glass with a retention screen below"
+default: "Laminated heat-strengthened glass"
```
−## Operation {toc}
+### The outboard lite takes the hail, the snow, and the thermal shock of a cold night followed by full sun, so it is heat-treated; fully tempered glass carries four times the strength of annealed and breaks into small fragments, heat-strengthened carries twice the strength and breaks into larger pieces that stay in the frame, and a laminated outboard lite adds impact resistance for a wind-borne debris region. The inboard lite is the one that can fall on a person. The code requires it to be laminated, so that a broken lite hangs in the opening, or to be backed by a retention screen that catches it; the laminated inboard lite is the norm because the screen blocks light and collects dirt. Laminated annealed glass is permitted as the inboard lite where thermal stress is low, at the lowest cost and the lowest strength. {note}
−### Operable (venting) units provide ventilation and smoke purge but add operator hardware and, for electric units, a power and control rough-in that must be coordinated with the electrical drawings. {note}
+### Where the inboard lite is not laminated, a retention screen shall be installed below the glazing as IBC Section 2405.3 requires, of the mesh, wire size, and support the code sets, unless the code exempts the unit by its area, its slope, or its height above the walking surface.
−### Omitting the operator power rough-in for electric venting units is a common coordination gap caught at rough inspection; rough-in shall be coordinated with the electrical work before roofing is closed in.
+### Heat-strengthened and fully tempered glass shall conform to ASTM C1048, laminated glass to ASTM C1172 with the interlayer thickness IBC Section 2405.3 requires for the inboard lite, and flat glass to ASTM C1036.
−### Operable units shall be furnished with the specified operator and weatherstripping rated for the unit's performance grade.
+### Glass in a skylight within the hazardous locations IBC Chapter 24 defines shall be safety glazing per 16 CFR 1201 or ANSI Z97.1 at the category the code assigns.
−### Electric venting units shall be provided with the power and low-voltage control rough-in shown on the electrical drawings.
+### The low-emissivity coating on glass glazing shall be as indicated in the datasheet.
```datasheet
−label: Operation type
+label: Low-Emissivity Coating
+type: select
+options:
+ - "None"
+ - "Low solar gain low-emissivity coating"
+ - "Moderate solar gain low-emissivity coating"
+ - "High solar gain low-emissivity coating"
+```
+
+### A low-emissivity coating lowers the U-factor by reflecting long-wave heat back toward its source; the three families differ in how much solar gain they admit. A low solar gain coating blocks most of the solar heat and is the coating of a cooling-dominated climate and of any skylight over an occupied space in summer. A high solar gain coating admits the sun's heat while still holding the room's heat, for a heating-dominated climate where the skylight's winter gain is wanted. A moderate coating sits between them for a mixed climate. No coating gives the highest transmittance and the highest heat loss. {note}
+
+### The gas fill of the insulating glass unit shall be as indicated in the datasheet.
+
+```datasheet
+label: Insulating Glass Unit Gas Fill
type: radio
options:
− - Fixed (non-venting)
− - Manual crank-operated
− - Chain-drive operated
− - Electric operator
− - Solar-powered electric operator
−default: Fixed (non-venting)
+ - "Air"
+ - "Argon"
+ - "Krypton"
```
+### Argon lowers the U-factor of a half-inch space by a few hundredths at little cost and is lost slowly through the edge seal over the unit's life; krypton does the same in a narrower space at a much higher cost, for a triple unit where the spaces are thin; air gives up those hundredths and has nothing to lose. {note}
+
+## Glazing Appearance {toc}
+
+### The tint and diffusion of the glazing shall be as indicated in the datasheet.
+
```datasheet
−label: Operable accessories
−type: checkbox
+label: Glazing Tint and Diffusion
+type: select
options:
− - Rain sensor (auto-close)
− - Interior blind / shade
− - Between-pane blind
− - Insect screen
−default:
− - Insect screen
+ - "Clear"
+ - "White diffusing"
+ - "Bronze tint"
+ - "Gray tint"
+ - "Prismatic diffusing"
```
−# Curb, Flashing, and Condensate Management {toc}
+### Clear glazing delivers the most light and a view of the sky, and it also delivers a moving patch of direct sun on the floor that is glare in an office and a hazard in a gymnasium. White diffusing glazing spreads the light across the room with no direct beam and no view, at a lower transmittance, and is the glazing of most industrial and institutional domes. A bronze or gray tint cuts transmittance and solar gain together and keeps the view, which suits a residential roof window more than a daylighting skylight. Prismatic diffusing glazing refracts the direct beam into diffuse light at a higher transmittance than white, for the daylighting skylight over a large space. {note}
−## Cricket and Saddle {toc}
+### Plastic glazing shall have the luminous transmittance and haze the datasheet transmittance requires, measured per ASTM D1003.
−### A cricket diverts water around the upslope side of a skylight; without it, water ponds against the upslope curb and eventually infiltrates. {note}
+# Frame and Finish {toc}
−### An upslope cricket or saddle shall be provided where the unit width exceeds 24 inches and the roof slope is less than 1:2.
+## Frame Material {toc}
−### The cricket shall be coordinated with and installed by the roofing work under [[sync/membrane-roofing]] or [[sync/metal-roof-panels]].
+### Frames shall be of the material indicated in the datasheet.
```datasheet
−label: Upslope cricket required
−type: radio
+label: Frame Material
+type: select
options:
− - Required (unit width > 24 in)
− - Not required (unit width ≤ 24 in)
− - Required by drawings
−default: Required (unit width > 24 in)
+ - "Thermally broken aluminum"
+ - "Aluminum without a thermal break"
+ - "PVC"
+ - "Fiberglass"
+ - "Wood with exterior aluminum cladding"
```
−## Flashing {toc}
+### Aluminum is the frame of most commercial units: it holds a dome or a glass unit at any catalog size, takes an anodized or organic finish, and does not rot or warp on a roof. Without a thermal break the frame conducts the cold straight to the inside face and sweats in any climate with a heating season; with one, it meets the energy code and keeps the inside face above the dew point. PVC and fiberglass frames do not need a break and are the frames of residential deck-mounted units and tubular devices, limited in size and in the finishes they take. Wood with aluminum cladding is the roof window frame: wood inside for the finish, aluminum outside for the weather. {note}
−### Flashing integrates the unit with the roofing; a frequent failure is that contract documents do not state who fabricates and installs the flashing, leaving the roofing and skylight trades each assuming the other is responsible. {note}
+### Aluminum frames shall be thermally broken by a structural polymer barrier that separates the exterior and interior metal, unless the datasheet selects aluminum without a thermal break.
−### Responsibility for fabricating and installing curb base flashing, counterflashing, and any step or apron flashing shall be assigned explicitly in the Contract Documents.
+### Aluminum frame members shall be extruded of an alloy and temper the manufacturer publishes for the unit, with a wall thickness not less than that of the unit tested for the performance class.
−### Flashing shall be integrated with the roofing system per [[sync/sheet-metal-flashing-and-trim]] and ASTM E2112 to maintain continuity of the water-shedding plane.
+### Frame corners shall be mitered and mechanically fastened or welded, and sealed so that the frame cavity is closed to water at every corner.
−## Condensate Management {toc}
+### Frames shall drain any water that reaches the glazing rabbet to the exterior through the condensation gutter and weeps of this standard, and the glazing shall not be set in a frame that holds water against the glazing edge.
−### Condensate forming on the cold inner surfaces of frame and glazing must be captured and drained; without a weep path it accumulates inside the curb and is reported as a leak, generating callbacks.
+## Frame Finish {toc}
−### Curb-mounted and frame-glazed units shall include interior condensate gutters and a weep drainage path to the exterior.
+### The exterior finish of aluminum frames shall be as indicated in the datasheet.
```datasheet
−label: Condensate management
−type: radio
+label: Aluminum Frame Exterior Finish
+type: select
options:
− - Integral condensate gutter with weeps
− - Thermally broken frame with weep path
− - None (warm climate only)
−default: Integral condensate gutter with weeps
+ - "Mill finish"
+ - "Clear anodized to AAMA 611 Class I"
+ - "Color anodized to AAMA 611 Class I"
+ - "Organic coating to AAMA 2603"
+ - "High-performance organic coating to AAMA 2604"
+ - "Fluoropolymer coating to AAMA 2605"
```
−# Fall Protection {toc}
+### A skylight frame is seen from the roof and rarely from the ground, so the finish is chosen for durability more than for color. Mill finish costs nothing and chalks to a dull gray within a few years. Clear anodizing converts the surface and lasts as long as the metal; color anodizing does the same in bronze and black with lot-to-lot variation. The organic coatings are ordered by their qualifying exposure: one year of South Florida exposure for AAMA 2603, five for AAMA 2604, ten for AAMA 2605, which buys color and gloss retention where the frame is visible from an occupied space or where the project's other aluminum carries the same coating. {note}
−## A skylight in a roof is an opening; OSHA treats it as a fall hazard and requires a screen, guardrail, or cover wherever a worker could fall 4 feet or more, and the responsibility for that protection is frequently left unassigned among the skylight supplier, roofer, and general contractor. {note}
+### The finish color shall be as indicated in the datasheet.
−## Fall protection shall be provided at every skylight opening 4 feet or more above a lower level by an integral screen, a guardrail system, or a cover.
+```datasheet
+label: Frame Finish Color
+type: text
+drawing_ref: "the finish schedule"
+default: deferred
+```
−## Fall-protection screens and covers shall resist a load of not less than 200 lb applied perpendicularly at any point, per OSHA 29 CFR 1926.502 and 1910.29.
+### The interior finish of the frame and of any factory liner shall be as indicated in the datasheet.
−## Where a guardrail system is used, the top rail shall be 42 ± 3 inches above the walking surface.
+```datasheet
+label: Interior Finish of Frame and Liner
+type: select
+options:
+ - "Same finish as the exterior"
+ - "Factory-painted white"
+ - "Unfinished, to receive the interior finish work"
+```
−## Responsibility for furnishing and installing the fall-protection element shall be assigned explicitly in the Contract Documents.
+### The inside face of a curb-mounted unit is the top of the light well, and what it looks like depends on who finishes it. The exterior finish carried inside is the simplest and reads as a dark or metallic ring at the top of the well. A factory white matches a gypsum well and reflects light down it. Unfinished metal leaves the painting to the finish work, which has to mask the glazing and gets a field coat that chalks against a factory one. {note}
+### PVC and fiberglass frames shall be integrally colored or factory-coated, and the manufacturer shall warrant the color against fading and the frame against cracking over the unit warranty term.
+
+### Exterior wood frames shall be clad in aluminum on every face exposed to weather, and the cladding shall be finished as the datasheet indicates for aluminum frames.
+
+# Condensation Management {toc}
+
+## Condensation Gutter and Weeps {toc}
+
+### Units shall manage condensation as indicated in the datasheet.
+
```datasheet
−label: Fall-protection method
+label: Condensation Management
type: radio
options:
− - Integral skylight screen
− - Separate post-mounted guardrail
− - Safety net / cover
−default: Integral skylight screen
+ - "Integral condensation gutter drained to the exterior through weeps"
+ - "Integral condensation gutter without weeps"
+ - "None"
+default: "Integral condensation gutter drained to the exterior through weeps"
```
+### A gutter with weeps collects the water that condenses on the inside face and carries it outside, and it also carries out any water that passes the glazing seal, which is the leak path it is really there for. A gutter without weeps holds the condensation until it evaporates, which works where the volume is small and the frame is warm, and overflows where it is not. No gutter leaves every drop to run down the well, and is sold for unconditioned buildings and for the warmest climates. {note}
+
+### Weeps shall drain to the exterior above the roofing and shall be positioned so that the curb flashing and the counterflashing do not block them.
+
+### The condensation gutter shall be continuous around the perimeter of each glazing and shall carry a lip or dam that keeps collected water from running back onto the glazing or the frame face.
+
+### Where the datasheet indicates a thermally broken frame, the thermal break shall be continuous through the gutter so that the gutter itself is not the cold surface on which condensation forms.
+
+### The Contractor shall not block, fill, or seal a weep during flashing, counterflashing, or sealant work, and shall clear every weep before the unit is accepted.
+
+# Fall Protection {toc}
+
+## Protection at the Opening {toc}
+
+### A skylight is a hole in a walking surface with a cover that was not designed to be walked on. A worker stepping on an acrylic dome, or sitting on it to rest, breaks through it, and the fall is the full height of the room below. The federal walking-working surface rule treats the skylight as a hole and requires it to be guarded by a screen, a guardrail, or a cover built to hold the load; the fall-protection rating of the unit is the one way the skylight supplier can discharge that duty, and the screen or guard furnished by another trade is the other. {note}
+
+### Each skylight opening on a roof to which workers have access shall be protected by the method indicated in the datasheet.
+
```datasheet
−label: Screen / cover rated load
+label: Fall-Protection Method
+type: select
+options:
+ - "Integral screen furnished with the unit above or below the glazing"
+ - "Separate screen set over the curb by the skylight installer"
+ - "Unit rated by its manufacturer as a fall-protection cover"
+ - "Guardrail around the opening furnished under the metal work"
+ - "None at the unit, with the opening protected under the Owner's fall protection program"
+```
+
+### An integral screen is part of the unit, is tested with it, and is on the roof the day the unit is set; it shades the glazing slightly and is the simplest answer. A separate screen over the curb protects a unit that has none and is removable for glazing replacement. A unit rated as a cover is tested to carry a person's fall on the glazing itself, with nothing added and nothing to shade the light, at a premium for the heavier glazing and frame. A guardrail keeps the worker off the unit entirely, costs the most, and is the answer where a maintenance route passes the skylight. No protection at the unit relies on the Owner's program keeping workers away from it, which the rule permits only where that program actually does so. {note}
+
+### A screen, rated unit, or cover furnished as fall protection shall support without failure the load indicated in the datasheet applied perpendicular to its surface at any point, and not less than twice the maximum intended load the federal rule at 29 CFR 1910.29 requires of a cover.
+
+```datasheet
+label: Fall-Protection Rated Load
type: range
unit: lb
min: 200
−max: 400
−step: 50
−default: 200
+max: 1000
+setpoints: [200, 300, 400, 500, 800, 1000]
+constraint: min
```
−# Tubular Daylighting Devices {toc}
+### The 200 lb figure is the legacy screen criterion from the rule the current one replaced, and it is still the figure most screen catalogs quote. The current rule asks for twice the maximum intended load, which for a worker with tools is 400 lb or more, and a unit rated as a cover is commonly tested at several times that to cover a fall rather than a step. {note}
−## A tubular daylighting device captures daylight at a roof dome, transmits it down a reflective tube, and distributes it through a ceiling diffuser; TDDs serve spaces where a framed skylight opening cannot be created. {note}
+### A guardrail furnished as fall protection shall have its top rail at 42 in above the walking surface, plus or minus 3 in, shall resist a 200 lb force applied in any outward or downward direction at any point along the top rail, and shall be furnished under [[sync/metal-fabrications]] or [[sync/miscellaneous-metals]] as the Contract Documents assign it.
−## TDDs shall be installed with the manufacturer's flashing matched to the roof type and slope.
+### The fall-protection element at each opening shall be in place before the roof is released to any trade other than the skylight installer and the roofing Contractor.
−## The reflective tube shall be sealed and insulated where it passes through conditioned and unconditioned spaces to limit condensation and heat transfer.
+### Anchors for personal fall arrest and travel restraint near a skylight are governed by [[sync/fall-protection-anchorage]], and nothing in this standard furnishes them.
−## The ceiling diffuser shall be selected for the required light distribution and, where specified, integral ventilation or electric-light kits.
+# Tubular Daylighting Devices {toc}
+## Tube, Dome, and Diffuser {toc}
+
+### A tubular daylighting device captures light at a roof dome, carries it down a highly reflective tube through the attic or plenum, and releases it through a ceiling diffuser. It lights a corridor, a toilet room, or an interior office that a framed skylight cannot reach, at a roof penetration a roofer can flash like a vent. Its performance is set by the tube: a longer tube, a bend, or a less reflective lining each cost a fraction of the light. {note}
+
+### Tubular daylighting devices shall be of the tube diameter indicated in the datasheet.
+
```datasheet
−label: TDD tube diameter
−type: select
+label: Tube Diameter
+type: range
unit: in
−options:
− - "10"
− - "14"
− - "18"
− - "22"
−default: "14"
+min: 10
+max: 22
+setpoints: [10, 13, 14, 18, 21, 22]
+drawing_ref: "the reflected ceiling plan and skylight schedule"
+default: deferred
+constraint: exact
```
+### The tube shall be of the type indicated in the datasheet.
+
```datasheet
−label: TDD dome glazing
+label: Tube Type
type: radio
options:
− - Clear impact-rated dome
− - Diffusing dome
− - Low-e coated dome
−default: Clear impact-rated dome
+ - "Rigid reflective tube with adjustable elbows"
+ - "Flexible reflective tube"
+default: "Rigid reflective tube with adjustable elbows"
```
+### The tube shall be lined with a specular reflective surface of not less than 95 percent reflectance, sealed at every joint against dust, and insulated where it passes through unconditioned space.
+
+### The ceiling diffuser shall be as indicated in the datasheet.
+
```datasheet
−label: TDD accessories
+label: Ceiling Diffuser
+type: select
+options:
+ - "Prismatic lens"
+ - "Frosted lens"
+ - "Open lens with a decorative trim ring"
+```
+
+### A prismatic lens spreads the light widest and hides the tube; a frosted lens gives a softer, dimmer field and shows a bright disk; an open lens shows the tube and delivers the most light directly below. {note}
+
+### Tubular daylighting devices shall be furnished with the accessories indicated in the datasheet.
+
+```datasheet
+label: Tubular Daylighting Device Accessories
type: checkbox
options:
− - Daylight dimmer
− - Integral electric light kit
− - Integral ventilation
−default: []
+ - "Daylight dimmer at the tube"
+ - "Integral electric light at the diffuser"
+ - "Integral exhaust fan at the diffuser"
+ - "Fire-rated ceiling assembly closure"
+constraint: all_of
```
−# Size and Configuration {toc}
+### The roof dome and flashing of a tubular daylighting device shall be rated and labeled as a unit skylight under this standard, and the dome shall be impact-resistant where the datasheet requires impact resistance.
−## Standard catalog sizes carry the shortest lead time; custom and non-catalog units require 8 to 16 weeks of fabrication and shall be identified during procurement planning so they do not delay the schedule.
+### Where the tube passes through a fire-resistance-rated ceiling or floor assembly, the penetration shall be protected by a listed assembly that maintains the rating, furnished with the device.
−## Custom or non-catalog unit sizes and shapes shall be flagged during procurement so their fabrication lead time is incorporated into the construction schedule.
+# Testing {toc}
−## Unit locations, quantities, and layout are shown on the drawings. [[drawing: roof plan skylight layout]]
+## Field Water Testing {toc}
+### Installed units shall be field tested for water penetration by the method indicated in the datasheet.
+
```datasheet
−label: Unit configuration
+label: Field Water Test Method
type: radio
options:
− - Single unit
− - Gang (abutting units on common curb)
− - Continuous row
− - Custom (pyramid / barrel-vault / polygonal)
−default: Single unit
+ - "Hose test per AAMA 501.2 at each unit tested"
+ - "Static pressure test per ASTM E1105 at each unit tested"
+ - "Hose test per AAMA 501.2 on a sample and static pressure test per ASTM E1105 on the first unit of each type"
+ - "No field water test"
```
+### The hose test is a nozzle at a set pressure and distance, run along every joint for five minutes each, and it finds the open joint and the blocked weep; it takes one person and a hose. The static pressure test seals a chamber over the unit and pulls the test pressure across it, reproducing wind-driven rain, and it finds the leak the hose cannot drive; it takes a chamber, a crew, and the unit's design pressure. Running the pressure test on the first unit of each type and the hose test on the rest buys the harder test where the detail is being proved and the cheaper one where it is being repeated. {note}
+
+### The proportion of units tested shall be not less than that indicated in the datasheet.
+
```datasheet
−label: Curb opening size
−type: select
−unit: in
−options:
− - 24 × 24
− - 24 × 48
− - 48 × 48
− - Custom
−drawing_ref: "roof plan skylight schedule"
−default: deferred
+label: Proportion of Units Field Water Tested
+type: range
+unit: '%'
+min: 0
+max: 100
+setpoints: [0, 10, 25, 50, 100]
+constraint: min
```
+### Where a static pressure test is indicated, the test pressure shall be two thirds of the laboratory water test pressure for the unit's performance class, and the unit shall show no water penetration at the interior face.
+
+### Field tests shall be performed after the unit is set and the flashing and counterflashing are complete, and before the ceiling or light well below the unit is closed.
+
+### A unit that fails a field test shall be corrected and retested, and the cost of retesting shall be borne by the Contractor.
+
+### Where the Engineer of Record and the Contractor disagree whether water observed at a unit is penetration or condensation, the Engineer of Record shall make the initial determination.
+
+## Operational Testing {toc}
+
+### Each operable unit shall be cycled through its full travel after installation, and shall open, close, latch, and seat on its weatherstripping without binding.
+
+### Each electrically operated unit shall be tested from every control location, and each rain sensor shall be tested by wetting it.
+
+### Each unit opened by the fire alarm system shall be tested on a signal from the fire alarm control panel in the presence of the fire alarm Contractor, and shall be shown to open fully and to hold open with its power removed.
+
# Installation {toc}
−## Skylights shall be installed in accordance with the manufacturer's printed instructions and ASTM E2112.
+## Setting the Unit {toc}
−## Units shall not be installed on slopes flatter than the manufacturer's certified minimum; glazed skylights without a curb shall be installed on slopes of not less than 1:4 per IBC Section 2405.3.
+### Units shall be installed in accordance with the manufacturer's printed instructions and ASTM E2112.
−## Curb-mounted units shall be set on a continuous bed of the manufacturer's specified sealant and fastened to the curb at the spacing shown on the shop drawings.
+### Curb-mounted units shall be set on a continuous bed of the manufacturer's specified sealant or gasket on the curb top and shall be fastened to the curb through the frame at the spacing shown on the accepted shop drawings.
−## Flashing shall be lapped to shed water over the downslope roofing and integrated continuously with the roofing system.
+### Fasteners into the curb shall be of a material compatible with the frame and the curb, shall not penetrate the condensation gutter, and shall be sealed at the frame.
−## Operable units shall be adjusted after installation so they open, close, latch, and weatherseal without binding.
+### Deck-mounted units shall be set over the roof underlayment with the integral flange lapped into the roof covering so that the upslope and side flanges are under the covering and the downslope flange is over it.
−## Glazing and frames shall be protected from construction traffic and from sealant, mortar, and roofing-bitumen contamination until final acceptance.
+### Units shall be set on a roof slope not flatter than the manufacturer's certified minimum for the unit and the mounting, and glass units set without a curb shall be set on a slope not flatter than the slope IBC Section 2405 permits.
−## Each installed unit shall be tested for water resistance by a controlled water test where required by the Contract Documents, with no water penetration to the interior.
+### Units shall not be set until the roofing on the surrounding area has reached the point in its sequence that the pre-installation conference agreed, so that the base flashing is carried up the curb before the unit covers it.
+## Flashing Interface {toc}
+
+### The membrane base flashing carried up a curb on a membrane roof is furnished under [[sync/membrane-roofing]], the panel closure and counterflashing at a curb on a metal panel roof under [[sync/metal-roof-panels]], the step flashing and underlayment at a deck-mounted unit on a shingle roof under [[sync/asphalt-shingle-roofing]], and any separate sheet metal counterflashing or curb cap under [[sync/sheet-metal-flashing-and-trim]]. {note}
+
+### The factory flashing kit furnished with a deck-mounted unit, and the counterflashing or curb cap furnished as part of a factory curb, shall be furnished and installed under this standard.
+
+### Flashing furnished under this standard shall lap over the roofing below it and under the roofing above it in the direction of water flow, and shall not block the weeps of the unit.
+
+### Where the roofing manufacturer's warranty requires a detail at the curb that differs from the skylight manufacturer's instructions, the Contractor shall obtain both manufacturers' written acceptance of one detail before the unit is set.
+
+### A cricket or diverter shall be provided on the upslope side of every curb wider than 24 in across the slope, furnished under the roofing work for the roof type, and the Contractor shall confirm at the pre-installation conference that the roofing work includes it.
+
+## Protection During Construction {toc}
+
+### Glazing shall be protected from construction traffic, from dropped tools, and from sealant, mortar, bitumen, and solvent contamination from the time the unit is set until final acceptance.
+
+### Protective film on plastic glazing shall remain in place until the roofing adjacent to the unit is complete, and shall be removed before it bonds to the glazing under sun exposure.
+
+### Workers shall not stand, sit, or place material on any glazing at any time, and the Contractor shall cover each unit that is not rated as a fall-protection cover whenever other trades work on the roof around it.
+
# Delivery, Storage, and Handling {toc}
−## Units shall be delivered in the manufacturer's packaging with the NAFS label and glazing identification intact.
+## Units shall be delivered in the manufacturer's packaging with the certification label, the NFRC label, and the glazing identification intact.
−## Units shall be stored upright and protected from impact, ultraviolet exposure, and ponded water until installation.
+## Units shall be stored upright on the frame, off the ground, under cover, and protected from impact, ultraviolet exposure, and ponded water until installation.
−## Plastic-glazed domes shall be handled to avoid scratching and shall not have protective films removed until after installation.
+## Plastic domes shall be handled by the frame, never by the glazing, and shall not be stacked on one another.
−## Damaged units, units with broken seals, or units with delaminated glazing shall be rejected and replaced.
+## Units with a broken insulating glass seal, a cracked or crazed dome, a bent frame, or a damaged finish shall be rejected and replaced at no change in Contract Sum.
# Warranty {toc}
−## The manufacturer shall warrant each unit against defects in materials and workmanship for the period specified, and shall warrant insulating-glass and dome assemblies against seal failure and internal condensation.
+## Manufacturer Warranty {toc}
−## The installer shall warrant the installation, including flashing integration and water resistance, for the period specified.
+### The manufacturer's unit warranty covers the frame, the glazing retention, the operator, and the factory curb against defects in material and workmanship and against water penetration through the unit itself. It stops at the curb top on a site-built curb and at the flange edge on a deck-mounted unit; below that line the roofing warranty governs. Where the two meet, a leak at the joint is the one each warrantor attributes to the other, which is why this standard requires the boundary to be settled in writing before the unit is set. {note}
−## Warranty periods shall not be reduced by accessory operators, sensors, or shades furnished with the unit.
+### The manufacturer shall warrant each unit against defects in materials and workmanship and against water penetration through the unit for the term indicated in the datasheet, running from the date of substantial completion.
```datasheet
−label: Manufacturer unit warranty
−type: select
+label: Manufacturer Unit Warranty Term
+type: range
unit: years
−options:
− - "5"
− - "10"
− - "20"
−default: "10"
+min: 1
+max: 20
+setpoints: [1, 2, 5, 10, 15, 20]
+constraint: min
```
+### The manufacturer shall warrant each insulating glass unit against seal failure, internal condensation, and interlayer delamination for the term indicated in the datasheet.
+
```datasheet
−label: Glazing seal warranty
−type: select
+label: Insulating Glass Seal Warranty Term
+type: range
unit: years
−options:
− - "5"
− - "10"
− - "20"
−default: "10"
+min: 5
+max: 20
+setpoints: [5, 10, 15, 20]
+default: 10
+constraint: min
```
+### The manufacturer shall warrant plastic glazing against breakage under the design load, yellowing beyond the limit stated in the warranty, and loss of transmittance beyond the limit stated in the warranty, for the term indicated in the datasheet.
+
```datasheet
−label: Installation warranty
−type: select
+label: Plastic Glazing Warranty Term
+type: range
unit: years
−options:
− - "1"
− - "2"
− - "5"
−default: "2"
+min: 5
+max: 25
+setpoints: [5, 10, 15, 20, 25]
+constraint: min
```
−# Spare Parts {toc}
+### The manufacturer shall warrant the frame finish against chalking, color change beyond the limit stated in the warranty, peeling, and cracking for the term indicated in the datasheet.
−## The Contractor shall furnish the spare parts and maintenance materials specified for operable units and accessories.
+```datasheet
+label: Frame Finish Warranty Term
+type: range
+unit: years
+min: 1
+max: 20
+setpoints: [1, 2, 5, 10, 15, 20]
+constraint: min
+```
−## Spare parts shall be furnished in the manufacturer's original packaging and labeled with the unit type they serve.
+### The warranty boundary between the unit and the roofing at each roof type shall be stated on the accepted shop drawings and in the executed warranties, and the Contractor shall obtain the skylight manufacturer's and the roofing manufacturer's written agreement to that boundary before any unit is set.
+### The Contractor shall confirm with the manufacturer, before the action submittal is submitted, every condition the manufacturer places on issuing the warranty terms indicated in the datasheet, and shall report in writing any project condition that would prevent their issuance.
+
+### The Contractor shall not substitute a warranty of shorter term or narrower coverage than that indicated in the datasheet without the Owner's written acceptance.
+
+## Installer Warranty {toc}
+
+### The installer shall provide a written warranty against defects in workmanship and against leaks attributable to the setting, fastening, and flashing furnished under this standard, for the term indicated in the datasheet, running from the date of substantial completion.
+
```datasheet
−label: Spare parts and maintenance materials
−type: checkbox
−options:
− - Spare operator / motor (each operable type)
− - Spare crank handles
− - Spare insect screens
− - Touch-up finish kit
− - Replacement gaskets / weatherstripping
−default:
− - Spare crank handles
− - Touch-up finish kit
+label: Installer Warranty Term
+type: range
+unit: years
+min: 1
+max: 10
+step: 1
+default: 2
+constraint: min
```
+
+### The installer warranty shall cover the labor and materials required to correct the defect and to repair damage the defect caused to the roofing, the light well, and the building interior below the unit.
+
+### The installer warranty shall be in addition to, and shall not be reduced by, the manufacturer's warranties.
+
+### Where a warranty repair is performed, the repaired work shall carry a fresh warranty term running from the date of the repair, or the remainder of the original term, whichever is longer.