Steel Deck

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Revision 9 · Oct 2, 2026 +1063 −1011

SynC Standards Team — Specifier (Platform Standards) ✓ OfficialDiscloses employment SynC (SynC Platform Team)

Remade for neutrality: every choice explained, project facts as parameters, scope boundaries linked both ways

Showing changes from Rev 8 to Rev 9 in Steel Deck.

−---

−title: Steel Deck

−category: Structural / Steel & Metal Fabrications

−toc_depth: 3

−description: >

− When to use: Cold-formed steel deck for floor and roof construction in commercial, institutional, industrial, and multi-family buildings. Covers composite floor deck (acting compositely with structural concrete topping), non-composite form deck (acting as a permanent stay-in-place form for a concrete slab), and roof deck profiles (Type B wide-rib, Type N deep-rib, Type A narrow-rib, Type F intermediate-rib). Addresses material grade and galvanized coating selection (G60, G90), deck profile and depth, gauge, attachment to supports (arc spot welds, powder-actuated fasteners, screws), side-lap fastening, diaphragm action, concrete fill for composite slabs, openings and reinforcement, accessories (closures, pour stops, ridge and valley plates), and field inspection.

−

− Not intended for: Hot-rolled structural steel framing — beams, girders, columns, and bracing (see [[sync/structural-steel-framing]]); open-web steel joists and joist girders (see [[sync/steel-joists]]); cast-in-place structural concrete slabs without permanent steel forming (see [[sync/cast-in-place-concrete]]); reinforcing steel within concrete fill or topping (see [[sync/concrete-reinforcement]]); spray-applied fireproofing applied to the underside of steel deck (see [[sync/fireproofing]]); cold-formed light-gauge stud framing or non-structural acoustical deck; cellular deck for in-floor electrical distribution; or stainless steel or aluminum decking systems.

−---

−

−# Scope {toc}

−

−## This specification covers the materials, fabrication, attachment, and installation of cold-formed steel deck used as a structural floor or roof element in buildings and structures. {note}

−## Steel deck under this specification serves one or more of three structural functions: as a permanent form and tensile reinforcement for a structural concrete slab (composite floor deck); as a permanent stay-in-place form for a concrete slab in which the deck is not relied upon for composite action (non-composite form deck); and as a roof deck supporting roofing membranes, insulation, and superimposed live and dead loads. {note}

−## In all three functions the deck may also act as a horizontal diaphragm transferring lateral loads to the building's vertical lateral force-resisting system.

−

−## Steel deck is procured by profile, depth, gauge, finish, and length, but it is structurally meaningful only when correctly attached. {note}

−## The same deck panel with two different fastening patterns produces dramatically different shear capacity, uplift resistance, and composite or diaphragm behavior. {note}

−## This specification governs both the deck product and the fastening pattern that makes the deck perform as designed; both shall be installed in accordance with the contract drawings and the approved shop drawings.

−

−## Design, materials, fabrication, and installation shall conform to the Steel Deck Institute (SDI) standards applicable to the deck function — SDI C-2017 (Standard for Composite Steel Floor Deck-Slabs), SDI NC-2017 (Standard for Non-Composite Steel Floor Deck), and SDI RD-2017 (Standard for Steel Roof Deck) — together with SDI MOC3 (Manual of Construction with Steel Deck), AISI S100 (North American Specification for the Design of Cold-Formed Steel Structural Members), and AISI S310 (North American Standard for the Design of Profiled Steel Diaphragm Panels).

−

−## Diaphragm design shall additionally comply with SDI DDM04 (Diaphragm Design Manual, 4th Edition) where the deck is relied upon for diaphragm action.

−

−## Deck profile, depth, gauge, finish, span direction, side-lap orientation, panel layout, support fastener pattern, side-lap fastener pattern, and the locations and details of openings, sumps, ridge plates, valley plates, and pour stops are [[drawing: as indicated on the structural framing plans, roof framing plans, deck layout drawings, and structural details]].

−

−## Where this specification and the contract drawings differ, the more stringent requirement governs; the Structural Engineer of Record (SER) shall resolve genuine conflicts in writing.

−

−## Exclusions {toc}

−

−### This specification does not cover hot-rolled structural steel framing (see [[sync/structural-steel-framing]]), open-web steel joists and joist girders (see [[sync/steel-joists]]), the design and placement of the concrete fill or topping placed over composite or non-composite deck (see [[sync/cast-in-place-concrete]]), reinforcement furnished within the concrete fill or topping (see [[sync/concrete-reinforcement]]), or spray-applied fireproofing applied to the underside of the deck (see [[sync/fireproofing]]). {note}

−### Roofing membranes, insulation boards, and roof cover boards installed above the roof deck are covered by the roofing specifications. {note}

−

−# Referenced Standards {toc}

−

−| Standard | Title |

−|----------|-------|

−| SDI C-2017 | Standard for Composite Steel Floor Deck-Slabs |

−| SDI NC-2017 | Standard for Non-Composite Steel Floor Deck |

−| SDI RD-2017 | Standard for Steel Roof Deck |

−| SDI MOC3 | Manual of Construction with Steel Deck (3rd Edition) |

−| SDI DDM04 | Diaphragm Design Manual (4th Edition) |

−| SDI T-CD | Test Standard for Composite Steel Deck-Slabs |

−| AISI S100-16 (R2020) | North American Specification for the Design of Cold-Formed Steel Structural Members |

−| AISI S310-20 | North American Standard for the Design of Profiled Steel Diaphragm Panels |

−| ANSI/AISC 360-22 | Specification for Structural Steel Buildings (composite slab provisions) |

−| AWS D1.3/D1.3M:2018 | Structural Welding Code — Sheet Steel |

−| AWS D1.1:2025 | Structural Welding Code — Steel (where structural welds to supports are involved) |

−| ASTM A653/A653M | Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip Process |

−| ASTM A1008/A1008M | Standard Specification for Steel, Sheet, Cold-Rolled, Carbon, Structural, High-Strength Low-Alloy, and High-Strength Low-Alloy with Improved Formability, Solution Hardened, and Bake Hardenable |

−| ASTM A370 | Standard Test Methods and Definitions for Mechanical Testing of Steel Products |

−| ASTM E108 | Standard Test Methods for Fire Tests of Roof Coverings |

−| ASTM E119 | Standard Test Methods for Fire Tests of Building Construction and Materials |

−| ACI CODE-318-19(22) | Building Code Requirements for Structural Concrete (composite slab and concrete fill) |

−| IBC 2021 | International Building Code (Chapter 22 — Steel; Chapter 17 — Special Inspections) |

−| FM 4451 | Approval Standard for Profile Roof Deck |

−| FM 4470 | Approval Standard for Single-Ply, Polymer-Modified Bitumen Sheet, Built-Up Roof (BUR), and Liquid Applied Roof Assemblies for use in Class 1 and Noncombustible Roof Deck Construction |

−| UL Fire Resistance Directory | UL fire-resistance designs for floor-ceiling and roof-ceiling assemblies |

−| ASNT SNT-TC-1A | Personnel Qualification and Certification in Nondestructive Testing (welding inspector qualification, where applicable) |

−

−## Materials, fabrication, and installation shall comply with the latest adopted edition of each standard listed above.

−

−## Where conflicts exist between referenced standards, the more stringent requirement shall govern unless the SER directs otherwise in writing.

−

−# Submittals {toc}

−

−## Action Submittals {toc}

−

−### The Contractor shall submit the following for review by the SER prior to fabrication and delivery.

−

−```datasheet

−label: Action Submittals Required

−type: checkbox

−options:

− - "Shop drawings — deck layout, fastener pattern, accessories"

− - "Mill test reports for base steel"

− - "AWS D1.3 welder qualification records"

− - "Fastener product data with ICC-ES evaluation reports"

− - "Diaphragm design calculations or SDI table reference"

− - "Manufacturer product data and load tables"

− - "Concrete fill mix design (composite and non-composite floor deck) — coordinate with [[sync/cast-in-place-concrete]]"

− - "Fire-rated assembly UL design references (where applicable)"

−default:

− - "Shop drawings — deck layout, fastener pattern, accessories"

−```

−

−### Fabrication shall not begin and material shall not be released for shipment until the corresponding submittals are reviewed and returned.

−

−### The Contractor shall allow a minimum of 10 working days for each review cycle.

−

−### Shop drawings shall be prepared in accordance with SDI MOC3 and shall show, for each deck area: deck profile and manufacturer's product designation; base steel gauge and design thickness; finish (galvanized coating designation, prime paint, or both); panel layout, including panel length, span direction, side-lap orientation, and end-lap conditions; support fastener type, pattern, and spacing keyed to each support condition; side-lap fastener type and spacing; locations, sizes, and reinforcement details for openings, drains, sumps, and penetrations; accessory locations including pour stops, edge angles, ridge plates, valley plates, closures, cant strips, and column closures; and erection sequence where the sequence affects stability of the partially completed deck.

−

−### Mill test reports (MTRs) or certified test reports shall be submitted for each heat or lot of base steel used in the project, confirming compliance with ASTM A653/A653M or ASTM A1008/A1008M as applicable, including yield strength, tensile strength, elongation, and the galvanized coating designation (G60, G90, or as specified).

−

−### Material shall not be installed without traceable certification.

−

−### Welder and welder operator qualification records shall be submitted in accordance with AWS D1.3/D1.3M for all personnel performing arc spot welds, arc seam welds, and other welded deck attachments.

−

−### Welder qualifications shall be current and shall cover the specific deck thickness, welding position, and joint configuration to be performed.

−

−### AWS D1.3 governs sheet steel welding; AWS D1.1 procedures alone are not sufficient for deck-to-support welding because of the thin-gauge sheet involved. {note}

−

−### Fastener product data shall be submitted for all powder-actuated fasteners (PAFs), screws, and other mechanical fasteners used to attach the deck to supports or to fasten side laps.

−

−### Fastener product data shall include ICC-ES evaluation reports or equivalent code-compliant evaluation, manufacturer's installation instructions, base-metal thickness ranges for which the fastener is qualified, allowable load tables, and installation tools and settings.

−

−### Each fastener product is qualified for a specific base-metal thickness range; substituting a fastener qualified for a different range is a nonconformance. {note}

−

−### Diaphragm design calculations or the SDI Diaphragm Design table reference used to select the support and side-lap fastener pattern shall be submitted where the contract drawings designate the deck as a diaphragm element.

−

−### The diaphragm submittal shall identify the published diaphragm shear capacity used and the deck-and-fastener configuration that achieves it.

−

−### Manufacturer's product data sheets shall be submitted for the deck profile, including section properties, allowable loads as a simple, two-span, or three-span condition (per SDI tables), maximum unshored construction span, and load-deflection tables.

−

−## Closeout Submittals {toc}

−

−### At substantial completion, the Contractor shall provide:

−

−- As-built deck layout shop drawings reflecting any field-approved deviations from the original layout, including locations of field-cut openings and added reinforcement

−- Field inspection reports for support fastening, side-lap fastening, and concrete placement (composite slabs), organized by floor or roof area

−- Touch-up coating documentation for damaged galvanized surfaces and field-cut edges

−- Certificate of compliance from the deck installer attesting that the work was performed in accordance with the contract documents, SDI standards, and AWS D1.3 (welding)

−- UL design number documentation for each fire-rated floor-ceiling or roof-ceiling assembly installed, including the deck designation in the UL design and any field-coordination evidence required by the UL design

−

−```datasheet

−label: Required Closeout Submittals

−type: checkbox

−options:

− - As-built deck layout shop drawings

− - Field inspection reports for support and side-lap fastening and concrete placement

− - Touch-up coating documentation for damaged galvanized surfaces and field-cut edges

− - Certificate of compliance from the deck installer

− - UL design number documentation for each fire-rated assembly

−default: [As-built deck layout shop drawings, Field inspection reports for support and side-lap fastening and concrete placement, Touch-up coating documentation for damaged galvanized surfaces and field-cut edges, Certificate of compliance from the deck installer, UL design number documentation for each fire-rated assembly]

−```

−

−# Quality Assurance {toc}

−

−## Installer Qualifications {toc}

−

−### Steel deck shall be installed by a contractor regularly engaged in the installation of structural steel deck and capable of executing the support and side-lap fastener patterns shown on the shop drawings.

−

−### The installer's foreman shall have a minimum of three years of documented experience installing structural steel deck on projects of comparable scope.

−

−### Welders performing arc spot welds and arc seam welds for deck attachment shall be qualified under AWS D1.3/D1.3M for the specific deck thickness and welding position.

−

−## Code Compliance and IBC Special Inspection {toc}

−

−```datasheet

−label: Special Inspection of Steel Deck Attachment

−type: radio

−options:

− - "Required — per IBC Chapter 17 and Statement of Special Inspections"

− - "Not required — confirmed in writing by SER and AHJ"

−default: "Required — per IBC Chapter 17 and Statement of Special Inspections"

−```

−

−### Steel deck shall be designed, fabricated, attached, and inspected in accordance with IBC 2021 Chapter 22 and the SDI standards referenced above.

−

−### Special inspections of steel deck construction shall be performed in accordance with IBC 2021 Chapter 17 and the project's Statement of Special Inspections (SSI) prepared by the SER.

−

−### Special inspection of deck attachment is required because the structural performance of the deck depends entirely on the quantity, pattern, and quality of the fasteners — the deck panel itself is the smaller part of the engineering decision. {note}

−

−## Welding Quality {toc}

−

−```datasheet

−label: Welding Inspector Qualification

−type: radio

−options:

− - "AWS Certified Welding Inspector (CWI) with documented AWS D1.3 sheet-steel experience"

− - "AWS CWI plus separate AWS D1.3 inspection authorization"

− - "Manufacturer-qualified inspector with documented sheet-steel inspection training"

−default: "AWS Certified Welding Inspector (CWI) with documented AWS D1.3 sheet-steel experience"

−```

−

−### Welds attaching deck to supports shall comply with AWS D1.3/D1.3M:2018.

−

−### The QA inspector shall be familiar with AWS D1.3 acceptance criteria specifically; an AWS Certified Welding Inspector (CWI) qualified only under AWS D1.1 may not correctly evaluate sheet-steel welds.

−

−### Arc spot welds (puddle welds) and arc seam welds are the deck attachment welds covered by AWS D1.3; they differ from the structural welds covered by AWS D1.1 because the sheet thickness controls weld geometry and acceptance criteria. {note}

−

−## Manufacturer Qualifications {toc}

−

−### Steel deck shall be supplied by a manufacturer that is a member of the Steel Deck Institute or that produces deck under a quality management system equivalent to the SDI requirements.

−

−### The manufacturer's published section properties, load tables, and diaphragm tables shall be based on testing or calculation methods conforming to AISI S100 and AISI S310; manufacturer load tables not traceable to the AISI specifications shall not be used for design.

−

−# Environmental and Service Conditions {toc}

−

−## Exposure and Atmospheric Conditions {toc}

−

−### Steel deck is a thin-gauge cold-formed product, and its service life depends on protecting the base steel from corrosion. {note}

−

−### The service environment shall be specified for each area of the deck so that the governing coating designation can be selected.

−

−```datasheet

−label: Service Environment

−type: select

−options:

− - "Concealed interior — covered by ceiling, fireproofing, or finishes; controlled humidity"

− - "Exposed interior — visible in conditioned space, low to moderate humidity"

− - "Roof deck — typical commercial roofing, single-ply or built-up membrane above"

− - "Exposed exterior or high-humidity (parking garage, natatorium, food processing, marine)"

−default: "Roof deck — typical commercial roofing, single-ply or built-up membrane above"

−```

−

−```datasheet

−label: Galvanized Coating Designation

−type: radio

−options:

− - "G60 (ASTM A653, 0.60 oz/ft² total both sides) — standard for concealed and typical roof applications"

− - "G90 (ASTM A653, 0.90 oz/ft² total both sides) — exposed, high-humidity, or aggressive environments"

− - "A60 (ASTM A653 zinc-iron alloy, 0.60 oz/ft²) — paintable surfaces requiring better paint adhesion"

− - "Phosphatized and primed — to be field painted; coordinate with paint system"

−default: "G60 (ASTM A653, 0.60 oz/ft² total both sides) — standard for concealed and typical roof applications"

−```

−

−### Galvanized coating designation shall be selected based on the service environment of the deck.

−

−### G90 (0.90 oz/ft² total both sides) shall be specified for deck exposed to view in parking garages, natatoriums, food and beverage facilities, marine air, or any condition where chloride or moisture exposure is elevated.

−

−### Prime paint or phosphatized finishes shall be used only where the deck will be field painted, because the manufacturer's primer is a thin shop coating intended for field-painting compatibility, not a long-term protective coating.

−

−### G60 is the standard finish for concealed locations and typical roof deck under a continuous roofing system and is the most economical and most commonly procured finish; G90 provides 50% more zinc coating at a modest cost premium (typically 5–10%). {note}

−

−## Construction-Phase Exposure {toc}

−

−### Steel deck shall be protected from prolonged exposure to standing water, snow accumulation, and aggressive substances during construction.

−

−### Deck stored on the ground shall be elevated on dunnage and covered to shed water; bundled deck shall not be stored in direct contact with mud or vegetation.

−

−### Water trapped at side laps and end laps can produce white rust (zinc hydroxide bloom) on galvanized surfaces; this is cosmetic in moderate cases but indicates that the zinc is being consumed, and shall be cause for corrective coating in severe cases.

−

−## Fire-Resistance Considerations {toc}

−

−```datasheet

−label: Fire-Rated Assembly Required

−type: radio

−options:

− - "Not applicable — no fire-resistance rating required for this assembly"

− - "Yes — UL design number indicated on contract drawings"

− - "Yes — Engineer to designate UL design"

−default: "Yes — UL design number indicated on contract drawings"

−```

−

−### Steel deck used in fire-rated floor-ceiling or roof-ceiling assemblies shall be installed in accordance with the specific UL design listed on the contract drawings.

−

−### The deck manufacturer's product designation shall match the design as listed.

−

−### Substituting a deck not listed in the referenced UL design voids the fire rating; UL fire-resistance designs specify the deck profile, gauge, finish, concrete topping (where applicable), and any required fireproofing application. {note}

−

−# Base Steel {toc}

−

−```datasheet

−label: Base Steel Specification

−type: radio

−options:

− - "ASTM A653/A653M Structural Steel (SS) Grade 33 minimum — non-composite form deck and roof deck"

− - "ASTM A653/A653M Structural Steel (SS) Grade 50 — composite floor deck and high-strength applications"

− - "ASTM A653/A653M Structural Steel (SS) Grade 80 — high-strength roof deck where designed"

− - "ASTM A1008/A1008M cold-rolled, with separate galvanizing or finishing"

−default: "ASTM A653/A653M Structural Steel (SS) Grade 33 minimum — non-composite form deck and roof deck"

−```

−

−## ASTM A653 covers hot-dip galvanized and zinc-iron alloy coated sheet steel and is the standard specification for nearly all steel deck supplied in North America. {note}

−## Structural Steel (SS) Grade 33 (33 ksi minimum yield) is the default for roof deck and non-composite form deck profiles in the most common gauges. {note}

−## Composite floor deck profiles typically use Grade 50 (50 ksi minimum yield) to achieve the section capacity needed for the composite-slab span and load tables. {note}

−## Grade 80 may be used for roof deck where higher strength reduces required gauge, but the section properties of the cold-formed profile, not the base material strength alone, control the design.

−## ASTM A1008 cold-rolled sheet without integral galvanizing is used only where the deck will receive a separately applied finish; nearly all commercial deck production uses A653 because it incorporates galvanizing in the same continuous process. {note}

−

−# Deck Profile {toc}

−

−## Steel deck is classified by its function and its profile geometry. {note}

−

−## Where composite floor deck is used, the deck depth shall be specified to match the required span and loading.

−

−```datasheet

−label: Composite Floor Deck Depth

−type: select

−unit: in.

−drawing_ref: true

−options:

− - "Not applicable — non-composite or roof deck"

− - "1-1/2 in. composite deck (light-duty composite slab, short spans)"

− - "2 in. composite deck (most common — typical office and commercial spans)"

− - "3 in. composite deck (longer spans or heavier loads)"

−default: "2 in. composite deck (most common — typical office and commercial spans)"

−```

−

−## Where non-composite form deck is used, the deck depth shall be specified to match the required span and slab loading.

−

−```datasheet

−label: Non-Composite Form Deck Depth

−type: select

−unit: in.

−drawing_ref: true

−options:

− - "Not applicable — composite or roof deck"

− - "9/16 in. form deck (very short spans, light slabs)"

− - "1 in. form deck (typical non-composite floor slabs)"

− - "1-1/2 in. form deck (longer spans or heavier slabs)"

−default: "1 in. form deck (typical non-composite floor slabs)"

−```

−

−## The structural drawings shall identify the deck function (composite, non-composite, or roof) and either the SDI profile classification or the manufacturer's product designation.

−

−```datasheet

−label: Deck Function

−type: select

−drawing_ref: true

−options:

− - "Composite floor deck (acts compositely with concrete topping)"

− - "Non-composite form deck (concrete slab carries gravity load; deck is permanent form)"

− - "Roof deck (Type B, Type N, Type A, or Type F)"

− - "Combination — composite floor deck and roof deck on same project"

−default: "Composite floor deck (acts compositely with concrete topping)"

−```

−

−```datasheet

−label: Roof Deck Profile (SDI Classification)

−type: select

−drawing_ref: true

−options:

− - "Not applicable — floor deck only"

− - "Type A — narrow-rib, 1-1/2 in. depth (legacy profile, limited current production)"

− - "Type F — intermediate-rib, 1-1/2 in. depth (legacy profile, limited current production)"

− - "Type B — wide-rib, 1-1/2 in. depth (industry standard for typical commercial roofing)"

− - "Type N — deep-rib, 3 in. depth (long-span roof deck)"

− - "Deep deck — 4-1/2 in. to 7-1/2 in. depth (very long span or low-slope long-span roofs)"

−default: "Type B — wide-rib, 1-1/2 in. depth (industry standard for typical commercial roofing)"

−```

−

−## The Contractor shall not substitute a different profile, even from the same manufacturer, without written approval of the SER, because section properties and load tables differ.

−

−## Type A and Type F narrow- and intermediate-rib profiles have largely been displaced by Type B in current production and should not be specified for new construction unless a specific reason exists.

−

−## Type B (1-1/2 in. wide-rib) is the dominant roof deck profile in current commercial construction, pairs well with rigid insulation board over single-ply and built-up membrane roofing, and is universally available; Type N (3 in. deep-rib) is specified for longer spans (typically 12 ft to 18 ft), and deep deck profiles (4-1/2 in. to 7-1/2 in.) for very long spans (20 ft to 35 ft or more) in warehouses, distribution centers, and large arenas. {note}

−

−## Composite floor deck is supplied in three predominant depths: 2 in. (most common, spanning typical 8 ft to 12 ft bays with a finished slab thickness of 4-1/2 in. to 6-1/2 in.), 1-1/2 in. (shorter spans, lower loads, or constrained floor depth), and 3 in. (longer spans of 12 ft to 16 ft and heavier loads, reducing concrete fill volume). {note}

−

−## Non-composite form deck does not contribute to the structural capacity of the slab and is designed only to resist the wet weight of the concrete plus construction loads as a permanent form; the slab is reinforced as a conventional reinforced concrete slab (see [[sync/concrete-reinforcement]]), and form deck depth is selected primarily for the construction-phase span between supports. {note}

−

−# Gauge and Design Thickness {toc}

−

−## Steel deck gauge is identified by gauge number (16, 18, 20, 22) where lower gauge numbers indicate thicker steel. {note}

−## Each gauge corresponds to a design thickness used in cold-formed steel calculations per AISI S100; the design thickness is approximately 95% of the minimum delivered base-steel thickness, reflecting the AISI convention that excludes coatings from the structural calculation. {note}

−

−## The deck gauge shall be specified for each deck type based on the required section capacity, diaphragm capacity, and fastener pull-out resistance.

−

−```datasheet

−label: Deck Gauge

−type: select

−drawing_ref: true

−options:

− - "22 gauge (0.0295 in. design thickness, light-duty roof deck only)"

− - "20 gauge (0.0358 in. design thickness, common roof and form deck)"

− - "18 gauge (0.0474 in. design thickness, typical composite and heavy roof deck)"

− - "16 gauge (0.0598 in. design thickness, heavy composite or long-span deck)"

−default: "20 gauge (0.0358 in. design thickness, common roof and form deck)"

−```

−

−## The Contractor shall not substitute a lighter gauge than specified, because gauge directly controls section capacity, diaphragm capacity, and fastener pull-out resistance.

−

−## 22 gauge is the lightest gauge in common production (short-span roof deck under light loads, rarely specified except for re-roof matching); 20 gauge is standard for typical Type B roof deck and non-composite form deck; 18 gauge is standard for composite floor deck and heavier roof loads; 16 gauge is specified for composite deck at longer spans (12 ft or greater), heavy floor loads, or high-diaphragm-capacity roof deck. {note}

−

−# Deck Length and End-Lap Conditions {toc}

−

−```datasheet

−label: Deck End-Lap Detail

−type: radio

−options:

− - "Lapped at supports per SDI MOC3 (minimum 2 in. end lap, attached at support)"

− - "Butted at supports with attachment to support per SDI MOC3"

−default: "Lapped at supports per SDI MOC3 (minimum 2 in. end lap, attached at support)"

−```

−

−## Deck panels shall be furnished in lengths that minimize the number of end laps and maximize the use of the deck's continuous-span capacity.

−

−## The Contractor shall lay out panels per the shop drawings to achieve continuous-span behavior wherever the structural design relies on it.

−

−## SDI tables present allowable loads for single-span, two-span continuous, and three-span continuous conditions; three-span and two-span continuous conditions produce significantly higher capacity than single-span because of moment redistribution at the interior supports. {note}

−

−## End laps shall occur at a support and shall not be floated between supports.

−

−## Lapped end joints are the standard SDI detail for roof deck and non-composite form deck and shall have a minimum lap of 2 in. with the lap attached to the support through both layers.

−

−## Butted end joints are common for composite floor deck where end-lap leakage of fresh concrete would be problematic; butted joints shall have attachment to the support of both panels and shall be backed by a butt strip where required by the manufacturer or by the contract drawings.

−

−# Attachment to Supports {toc}

−

−## The attachment of steel deck to its supporting structure is the most consequential decision in deck specification, because it controls gravity load capacity (resistance to uplift, side-bending, and panel buckling), diaphragm shear capacity, and panel stability under construction loads. {note}

−## The structural drawings shall specify the support fastener type, the fastener pattern (number of fasteners per panel width at each support), and the spacing of fasteners along supports.

−

−## Support Fastener Type {toc}

−

−```datasheet

−label: Primary Support Fastener Type

−type: select

−drawing_ref: true

−options:

− - "Arc spot welds (puddle welds) per AWS D1.3 — most common for floor deck and heavy roof deck"

− - "Arc seam welds per AWS D1.3 — used where greater shear capacity per fastener is needed"

− - "Powder-actuated fasteners (PAFs) — common for roof deck and non-composite form deck"

− - "Self-drilling, self-tapping screws — light loads, retrofit, or where welding/PAFs are restricted"

−default: "Powder-actuated fasteners (PAFs) — common for roof deck and non-composite form deck"

−```

−

−### The Contractor shall verify that the proposed PAF is qualified for the gauge of the supporting steel; typical PAFs require a minimum support thickness of 1/8 in. or 3/16 in. flange, and thinner supports require a different fastener type or welding.

−

−### Arc spot welds (puddle welds) made through the deck are the historical standard and remain common for composite floor deck and heavy roof deck; each develops substantial shear and pull-out capacity that can be tuned to match diaphragm demand, but they require qualified welders, calibrated equipment, weld washers for thinner deck (22 gauge and sometimes 20 gauge) to prevent burn-through, and the deck in firm contact with the support and free of paint or galvanized buildup at the weld location. {note}

−

−### Powder-actuated fasteners (PAFs) — pins driven through the deck into the support flange by a powder-charge tool — have largely displaced welds for roof deck attachment because they are faster, require no certified welders, and introduce no localized heat into the galvanized coating; PAF capacity is governed by ICC-ES evaluation reports for each specific fastener and supporting-steel thickness combination. {note}

−

−### Self-drilling, self-tapping screws are used where welding and PAFs are restricted (hospitals, schools, or operating facilities where weld spatter or PAF noise is unacceptable) and for attaching deck to thin secondary supports such as cold-formed steel framing; screws have lower per-fastener shear capacity than welds and most PAFs and are typically required in higher quantities, while combination patterns suit support members of differing thicknesses. {note}

−

−## Support Fastener Pattern {toc}

−

−### SDI uses a "X/Y" notation to describe the support fastener pattern, where X is the number of fasteners across the panel width at the support and Y is the panel width in flute units. {note}

−### For example, "36/4" means four fasteners across a 36 in. wide panel at each support (one fastener per 9 in. of panel width). "36/7" means seven fasteners across a 36 in. wide panel at each support (one fastener per ~5 in. of panel width, achieved by placing a fastener in each rib valley plus additional fasteners in the flat). {note}

−### Heavier patterns produce higher diaphragm capacity but require more fasteners and more labor. {note}

−

−### The support fastener pattern shall be [[drawing: as indicated on the structural framing plans and deck attachment schedule]].

−

−```datasheet

−label: Support Fastener Pattern

−type: select

−drawing_ref: true

−options:

− - "36/4 — every third valley (light pattern, typical roof deck)"

− - "36/5 — every other valley (moderate pattern)"

− - "36/7 — every valley (typical heavy roof deck or composite floor deck)"

− - "36/9 — every valley plus intermediate (high diaphragm capacity)"

−default: "36/7 — every valley (typical heavy roof deck or composite floor deck)"

−```

−

−### Deck designed as a diaphragm element shall use the pattern specified on the drawings without substitution, because the diaphragm shear capacity is computed from the specific pattern and fastener type.

−

−### Substituting a lighter pattern or a different fastener type reduces diaphragm capacity and is a nonconformance. {note}

−

−## Arc Spot Weld Requirements {toc}

−

−```datasheet

−label: Arc Spot Weld Diameter Requirement

−type: select

−unit: in.

−options:

− - "5/8 in. visible diameter — minimum per AWS D1.3 for typical deck"

− - "3/4 in. visible diameter — heavy patterns and thicker deck"

− - "Per AWS D1.3 Table 5.4 based on deck thickness"

−default: "Per AWS D1.3 Table 5.4 based on deck thickness"

−```

−

−```datasheet

−label: Weld Washer Required

−type: radio

−options:

− - "Not required — deck design thickness ≥ 0.028 in."

− - "Required for deck thinner than 22 gauge or where specified by manufacturer"

−default: "Not required — deck design thickness ≥ 0.028 in."

−```

−

−### Arc spot welds shall be made in accordance with AWS D1.3/D1.3M:2018.

−

−### The minimum arc spot weld visible-diameter shall be 5/8 in. for deck up to 0.06 in. design thickness, increasing per AWS D1.3 for thicker deck.

−

−### Welds shall be made in firm contact with the supporting steel; the deck shall not be bridged or warped at the weld location.

−

−### Where deck is thinner than 22 gauge (0.028 in.) the welder shall use a weld washer (a flat steel washer placed on top of the deck through which the weld is made) to prevent burn-through; weld washers shall conform to the deck manufacturer's specification.

−

−### Welds shall be visually inspected after cooling for full perimeter fusion, absence of porosity at the visible surface, no burn-through, and no cracks.

−

−### The weld shall completely fuse the deck to the support; welds that show only surface adherence (a "lollipop" with no fusion) shall be rejected and remade.

−

−### The visible diameter on the top of the deck shall be measured; welds smaller than the minimum specified diameter shall be remade or supplemented with an additional weld immediately adjacent.

−

−## Powder-Actuated Fastener Requirements {toc}

−

−```datasheet

−label: PAF Verification Method

−type: checkbox

−options:

− - "Verify fastener model is listed for support thickness in ICC-ES report"

− - "Verify operator certification card current"

− - "Visual inspection of installed fastener for flush seating"

− - "Random pull-out testing per manufacturer recommendation"

−default: "Verify fastener model is listed for support thickness in ICC-ES report"

−```

−

−### Powder-actuated fasteners shall be installed in accordance with the manufacturer's instructions and within the range of supporting steel thicknesses covered by the fastener's ICC-ES evaluation report.

−

−### The Contractor shall verify the actual flange thickness of the supporting steel before installation; PAFs driven into supports thinner than the qualified range are not properly anchored and shall be supplemented or replaced.

−

−### The tool operator shall be trained by the fastener manufacturer or distributor and shall hold a current operator's card or certification card.

−

−### Powder charges shall be selected to drive the fastener fully without overdriving (overdriving creates a depression and reduces shear capacity by deforming the deck and reducing the effective contact area) and without underdriving (underdriving leaves a gap between fastener head and deck and reduces shear capacity).

−

−### The installed fastener head should be flush with the deck surface or recessed not more than 1/16 in.

−

−## Self-Drilling Screw Requirements {toc}

−

−```datasheet

−label: Self-Drilling Screw Specification

−type: select

−options:

− - "Not applicable — screw attachment not used"

− - "#12 self-drilling screw with hex washer head — typical light-duty attachment"

− - "#14 self-drilling screw with hex washer head — typical structural attachment"

− - "1/4 in. self-drilling screw with hex washer head — heavy patterns"

−default: "Not applicable — screw attachment not used"

−```

−

−### Where deck is attached with self-drilling, self-tapping screws, the screw shall be a structural-grade screw listed for steel-to-steel attachment with adequate point and thread design for the supporting steel thickness.

−

−### Screws shall be installed perpendicular to the deck and shall be driven until the head is firmly seated against the deck without overtorquing (which strips the threads and dramatically reduces pull-out capacity).

−

−### Screw guns shall be set with depth control or torque control to prevent overdriving.

−

−# Side-Lap Fastening {toc}

−

−## Side-lap fasteners connect adjacent deck panels along their longitudinal edges, between supports. {note}

−## Side-lap fastening is structurally important for diaphragm action because it forces adjacent panels to act as a continuous diaphragm rather than as independent strips; without adequate side-lap fastening, the panels can slip relative to each other under diaphragm shear and the diaphragm capacity drops dramatically. {note}

−## Side-lap fastening is also important for keeping wet concrete from leaking through side-lap gaps during composite-slab placement. {note}

−

−## Side-Lap Fastener Type {toc}

−

−```datasheet

−label: Side-Lap Fastener Type

−type: select

−drawing_ref: true

−options:

− - "Button punch (mechanical interlock) — common for non-composite form deck and light roof deck"

− - "Self-drilling, self-tapping screws (#10 or #12) — typical for diaphragm-rated deck"

− - "Arc seam welds per AWS D1.3 — high-shear diaphragm applications"

− - "Pneumatic-driven pins — proprietary, manufacturer-specified"

− - "No side-lap fastener — short spans, low diaphragm demand only"

−default: "Self-drilling, self-tapping screws (#10 or #12) — typical for diaphragm-rated deck"

−```

−

−### Button-punch side-lap fasteners are formed in the field by a tool that crimps the upper and lower sides of the lap together into a mechanical interlock; they have moderate shear capacity and are used on roof deck and form deck where diaphragm demand is light. {note}

−### Screws (typically #10 or #12 self-drilling, self-tapping) are the most common side-lap fastener for diaphragm-rated deck because their capacity is established in the SDI diaphragm tables and is reproducible and inspectable in the field. {note}

−### Arc seam welds along the side lap are used for the highest-shear-demand diaphragms (large multi-story buildings in high seismic zones) but require more skilled labor and produce more localized heat in the galvanized coating. {note}

−### Pneumatic-driven pins (proprietary fastener systems) are used by some installers under their own manufacturer's published diaphragm tables. {note}

−

−## Side-Lap Fastener Spacing {toc}

−

−```datasheet

−label: Side-Lap Fastener Spacing

−type: select

−unit: in. on center

−drawing_ref: true

−options:

− - "No side-lap fastener (button-punch optional)"

− - "36 in. (one fastener at mid-span only)"

− - "24 in."

− - "18 in."

− - "12 in."

− - "Per SDI diaphragm table — varies by zone"

−default: "Per SDI diaphragm table — varies by zone"

−```

−

−### Side-lap fastener spacing shall be [[drawing: as indicated on the structural deck attachment schedule]].

−

−### Tighter side-lap spacing shall be provided at locations of high diaphragm demand — around large openings, at exterior walls in seismic zones, and where the deck transfers significant lateral load to the lateral force-resisting system — because tighter spacing increases diaphragm shear capacity.

−

−### The Contractor shall not space side-lap fasteners further apart than specified, even where the spacing appears redundant.

−

−## Side-Lap Installation {toc}

−

−### The lap shall be fully engaged before the fastener is installed; the upper lip shall be seated firmly against the lower lip with no visible gap.

−

−### Where the lap has been crushed, twisted, or deformed during handling or installation traffic, the deformation shall be corrected before fastening or the affected panel shall be replaced.

−

−### Screws installed at side laps shall pass through both deck plies fully and shall not be installed through only one ply or through one ply with the second ply pushed aside.

−

−# Composite Slabs (Composite Floor Deck) {toc}

−

−## Where the deck acts compositely with a concrete topping to form the structural floor slab, the requirements of SDI C-2017 and ANSI/AISC 360-22 Chapter I apply. {note}

−## The composite action depends on the embossment pattern in the deck flutes engaging the concrete, the bond between deck and concrete, and the integrity of the slab as a flexural element. {note}

−

−## Concrete Topping {toc}

−

−```datasheet

−label: Composite Slab Concrete Compressive Strength (f'c)

−type: select

−unit: psi

−drawing_ref: true

−options:

− - "Not applicable — non-composite or roof deck"

− - "3,000 psi"

− - "3,500 psi"

− - "4,000 psi"

− - "5,000 psi"

−default: "4,000 psi"

−```

−

−```datasheet

−label: Composite Slab Total Thickness (deck depth + topping)

−type: select

−unit: in.

−drawing_ref: true

−options:

− - "Not applicable — non-composite or roof deck"

− - "4-1/2 in. (2 in. deck + 2-1/2 in. topping) — typical office and commercial"

− - "5 in. (2 in. deck + 3 in. topping) — fire-rated or heavier loads"

− - "5-1/2 in. (2 in. deck + 3-1/2 in. topping)"

− - "6-1/2 in. (3 in. deck + 3-1/2 in. topping) — longer spans"

−default: "4-1/2 in. (2 in. deck + 2-1/2 in. topping) — typical office and commercial"

−```

−

−```datasheet

−label: Concrete Aggregate Type

−type: radio

−options:

− - "Normal-weight concrete (145 to 150 pcf)"

− - "Lightweight concrete (110 to 115 pcf) — reduces dead load, may extend span"

−default: "Normal-weight concrete (145 to 150 pcf)"

−```

−

−### The concrete topping shall be designed and placed in accordance with [[sync/cast-in-place-concrete]].

−

−### The structural drawings shall specify the concrete compressive strength, slump or slump flow range, normal-weight or lightweight aggregate, and total slab thickness (deck depth plus topping thickness above the top of the deck).

−

−### Typical composite slabs use 3,000 psi to 5,000 psi concrete with a total slab thickness of 4-1/2 in. to 6-1/2 in. {note}

−

−## Construction Loads and Unshored Spans {toc}

−

−```datasheet

−label: Composite Slab Construction Method

−type: radio

−drawing_ref: true

−options:

− - "Unshored construction — deck supports wet concrete and construction loads alone"

− - "Shored construction — temporary supports installed prior to concrete placement"

−default: "Unshored construction — deck supports wet concrete and construction loads alone"

−```

−

−### Composite floor deck shall be installed and concreted as either an unshored or shored construction.

−

−### The Contractor shall verify the unshored span capacity from the manufacturer's published tables for the specific deck profile, gauge, and span condition (single, two-span, or three-span).

−

−### Where the support spacing on the drawings exceeds the published unshored span, shoring shall be installed prior to concrete placement.

−

−### In unshored construction the deck alone must carry the wet concrete plus minimum construction live loads (typically 20 psf per SDI C-2017) without exceeding allowable bending stress or deflection limits, whereas shored construction places temporary supports during concreting (removed after cure) and is required where the span exceeds the unshored capacity. {note}

−

−## Composite Slab Reinforcement {toc}

−

−```datasheet

−label: Composite Slab Reinforcement Above Deck

−type: select

−drawing_ref: true

−options:

− - "Welded wire reinforcement only (typical 6×6 W2.9×W2.9 or 6×6 W4.0×W4.0)"

− - "WWR plus negative-moment rebar over interior supports"

− - "Deformed bars throughout — no WWR"

−default: "WWR plus negative-moment rebar over interior supports"

−```

−

−### Reinforcement shall conform to [[sync/concrete-reinforcement]] and shall be installed in accordance with the contract drawings.

−

−### Composite slabs require reinforcement above the deck for shrinkage and temperature control, for negative-moment resistance over interior supports, and for distribution of concentrated loads; welded wire reinforcement (WWR) is the most common, supplemented with deformed bars at supports and around openings. {note}

−

−## Concrete Placement on Deck {toc}

−

−### Concrete shall be placed without overloading the deck.

−

−### Concrete buggies, pumps, and discharge hoses shall not concentrate load at a single panel that exceeds the deck's construction-load capacity.

−

−### Pour direction shall progress from one support toward the next; concrete shall not be discharged in piles that exceed the slab thickness, because the resulting weight concentrates load between supports.

−

−### Vibrating the concrete shall be performed to consolidate the concrete and engage the embossments in the deck flutes; the embossments are the mechanical key for composite action.

−

−### However, internal vibrators shall not be used in contact with the deck face, because contact can damage the galvanized coating and is not effective at consolidating the deck-concrete interface.

−

−### Vibrators shall be inserted vertically into the slab and shall consolidate the slab thickness as a whole.

−

−# Roof Deck {toc}

−

−## Where the deck is used as a roof deck, the deck supports the weight of the roofing system, insulation, mechanical equipment supports (curbs and rails), and live loads (snow, rain, and live load per ASCE 7-22), and resists wind uplift from the roofing membrane and parapet conditions. {note}

−

−## Roof deck shall be installed in accordance with SDI RD-2017 and with the manufacturer's roof-deck product data.

−

−## Insulation and Roofing Coordination {toc}

−

−### Roof deck is the structural substrate for the roofing assembly but is not the roofing system itself. {note}

−

−### The roof insulation, cover board, membrane, fasteners, and flashings are governed by the roofing specifications and shall be coordinated with the deck profile and the deck's ability to receive roofing fasteners.

−

−```datasheet

−label: Roof Deck Top Surface

−type: radio

−options:

− - "G60 or G90 galvanized only — to receive insulation board above"

− - "Galvanized with shop primer for paint compatibility"

−default: "G60 or G90 galvanized only — to receive insulation board above"

−```

−

−### Single-ply membrane systems require an insulation or cover board substrate over the deck flutes; the deck flutes themselves are not a usable substrate for membrane bonding. {note}

−

−## Wind Uplift {toc}

−

−```datasheet

−label: Wind Uplift Zones (Roof Deck)

−type: radio

−drawing_ref: true

−options:

− - "Single uniform fastener pattern across entire roof"

− - "Zoned per ASCE 7-22 (corner, edge, field) — patterns shown on drawings"

−default: "Zoned per ASCE 7-22 (corner, edge, field) — patterns shown on drawings"

−```

−

−### Roof deck shall be attached to resist the design uplift pressures derived from ASCE 7-22 wind loading.

−

−### The Contractor shall execute the zoned pattern shown without substitution.

−

−### Uplift is resisted by the support fastener system (fastener pull-out from the supporting steel and pull-over of the deck around the fastener head); wind uplift is highest at the roof corners and edges, so the contract drawings typically show zoned patterns with denser fastening at corners and edges and lighter fastening in the field. {note}

−

−## FM Approval {toc}

−

−```datasheet

−label: FM Global Compliance Required

−type: radio

−options:

− - "Not required — code-compliant design only"

− - "FM 4470 Class 1 roof assembly required"

− - "FM 4470 Class 1 plus specific windstorm rating (1-60, 1-90, 1-120, etc.)"

−default: "Not required — code-compliant design only"

−```

−

−### Where the project specifies FM Global insurance compliance, the roof deck and roof assembly shall be tested and approved per FM 4451 (Profile Roof Deck) and the roof assembly shall be approved per FM 4470 (Single-Ply, Modified Bitumen, and BUR systems on noncombustible deck).

−

−### Where FM approval requirements and the structural-only design both apply, the more stringent shall govern, because FM approval imposes specific deck-to-support attachment requirements that may exceed the structural-only design.

−

−# Diaphragm Action {toc}

−

−## A horizontal diaphragm is the floor or roof element that collects lateral loads (wind and seismic) and transfers them to the vertical lateral force-resisting system (shear walls, braced frames, or moment frames). {note}

−## Steel deck acts as a diaphragm by virtue of its in-plane shear stiffness and strength; the diaphragm capacity depends on the deck profile, deck gauge, support fastener type and pattern, side-lap fastener type and spacing, and the span of the diaphragm between vertical elements. {note}

−

−## Diaphragm Design Source {toc}

−

−```datasheet

−label: Diaphragm Design Source

−type: radio

−options:

− - "SDI Diaphragm Design Manual (DDM04) tables — most common"

− - "AISI S310 design calculations — engineered diaphragm"

− - "Manufacturer's proprietary diaphragm test data and tables"

− - "Not applicable — deck is not relied upon for diaphragm action"

−default: "SDI Diaphragm Design Manual (DDM04) tables — most common"

−```

−

−### The SDI DDM04 diaphragm tables provide allowable diaphragm shear capacity for combinations of deck profile, deck gauge, support fastener type and pattern, and side-lap fastener type and spacing. {note}

−### The SER selects the table entry that meets or exceeds the demand and the deck shall be installed with the exact configuration listed.

−### AISI S310 provides the analytical method underlying the SDI tables and may be used for configurations outside the tabulated range.

−### Manufacturer proprietary tables (typically based on full-scale cantilever diaphragm tests) may be used where the proprietary fastener system is specified.

−

−## Diaphragm Special Inspection {toc}

−

−```datasheet

−label: Diaphragm Verification at Special Inspection

−type: checkbox

−options:

− - "Deck profile and depth match drawings"

− - "Deck gauge match drawings (mill marking or microcalliper measurement)"

− - "Support fastener type and pattern match drawings"

− - "Side-lap fastener type and spacing match drawings"

− - "Deck attachment to perimeter shear collectors verified"

−default: "Deck profile and depth match drawings"

−```

−

−### Where the deck is relied upon for diaphragm action, the IBC special inspector shall verify that the actual installed deck profile, gauge, support fastener type and pattern, and side-lap fastener type and spacing match the configuration on the drawings exactly.

−

−### A substitution that appears equivalent on inspection (for example, screws of one size for screws of a different size) may produce a different diaphragm capacity and is a nonconformance. {note}

−

−# Openings, Penetrations, and Reinforcement {toc}

−

−## Small Openings {toc}

−

−```datasheet

−label: Maximum Field-Cut Opening Size Without Engineer Review

−type: select

−unit: in.

−options:

− - "6 in. in any dimension"

− - "8 in. in any dimension"

− - "12 in. in any dimension"

− - "Per Engineer of Record"

−default: "8 in. in any dimension"

−```

−

−### Small penetrations through the deck (single small ducts, pipes, conduits, smaller than approximately 8 in. in any dimension) may be cut in the field by the trades requiring the penetration, but shall be cut cleanly using a metal hole saw or other clean-cut method; torch cutting is not permitted because it damages the galvanized coating and produces a notch geometry that initiates cracking.

−

−### Cut edges shall be touched up with a zinc-rich coating to restore corrosion protection.

−

−## Larger Openings {toc}

−

−### Openings larger than the field-cut threshold above shall be detailed on the contract drawings or designed by the SER and shall be reinforced with structural framing — typically L-shaped or channel-shaped angle frames welded or bolted to the deck supports and to the deck — to transfer the deck loads around the opening.

−

−### The Contractor shall not cut large openings in the field without written direction from the SER.

−

−### Reinforcement for large openings shall be coordinated with [[sync/structural-steel-framing]] where the reinforcement attaches to the primary steel.

−

−## Sumps and Drains {toc}

−

−### Roof deck areas at drains, scuppers, and sump locations shall be installed with the deck profile sloped or with manufactured sump pans set into the deck per the contract drawings.

−

−### Sump pans shall be of the same gauge and finish as the deck and shall be welded or fastened to the surrounding deck and supports to maintain diaphragm continuity.

−

−# Accessories {toc}

−

−```datasheet

−label: Deck Accessories Required

−type: checkbox

−options:

− - "Pour stops at slab edges (composite and non-composite floor deck)"

− - "Edge angles at deck terminations"

− - "Ridge plates at roof ridges"

− - "Valley plates at roof valleys"

− - "Cant strips at parapet and curb transitions"

− - "Column closures at column penetrations"

− - "Cell closures at deck ends (open-rib roof deck above heated space)"

− - "Sump pans at roof drains and floor drains"

−default: "Pour stops at slab edges (composite and non-composite floor deck)"

−```

−

−## Steel deck installations require numerous accessory components, all of which shall be furnished by the deck manufacturer or by an approved supplier and shall match the deck finish and gauge unless otherwise specified.

−

−## Pour Stops {toc}

−

−### Pour stops are vertical plates installed at the edge of a composite or non-composite slab to retain the wet concrete during placement. {note}

−

−### Pour stops shall be sized to extend from the top of the deck to the top of the concrete slab and shall be attached to the deck and to the perimeter steel framing per the contract details.

−

−### The pour-stop gauge shall be heavier than the deck gauge to resist concrete pressure without bowing; 16 gauge or 14 gauge is typical even where the deck itself is 18 gauge or 20 gauge.

−

−## Roof-Deck Accessories {toc}

−

−### Ridge and valley plates, cant strips, and closures are roof-deck accessories used at geometry transitions and at the perimeter of the roof. {note}

−### Cell closures (sometimes called rib closures or vent closures) are installed in the open ribs of roof deck at the deck ends or at deck terminations to prevent the open ribs from acting as paths for unconditioned air infiltration into the building; they are particularly important where roof deck extends over heated, conditioned space. {note}

−

−# Installation {toc}

−

−## Storage and Handling {toc}

−

−### Deck shall be delivered to the project site in bundles labeled with the manufacturer's product designation, gauge, finish, and quantity.

−

−### Bundles shall be stored on dunnage above grade, protected from standing water, and covered to shed precipitation.

−

−### Bundles shall not be stacked higher than the manufacturer's published maximum stack height, because excess stack height can produce permanent set in the lower panels.

−

−### Deck bundles shall not be stored directly on the partially erected structural steel where their concentrated weight could overload an erector's bay; the deck contractor shall coordinate with the erector for staging locations.

−

−## Erection Sequence {toc}

−

−### Deck shall be erected in accordance with the approved erection sequence and the SDI MOC3.

−

−### Deck shall not be placed onto a portion of the structural steel that has not been bolted and welded in accordance with the contract documents; deck shall not be relied upon to brace the structural steel during erection unless the structural steel design specifically permits it.

−

−### The deck installation shall follow behind the structural steel erection by an appropriate interval.

−

−### Deck shall be tack-welded or temporarily attached at each support immediately upon placement to prevent panels from being displaced by wind or by foot traffic.

−

−### Final attachment (per the support and side-lap fastener pattern) shall be completed before any concentrated load is applied to the deck.

−

−## Construction Loads on Deck {toc}

−

−### Construction loads (material storage, scaffolding bases, equipment) shall not be concentrated on the deck at locations where the load exceeds the deck's published unshored construction load capacity.

−

−### Material pallets, conduit reels, and equipment bases shall be distributed across multiple panels and shall be placed near supports rather than at mid-span.

−

−### Concentrated wheel loads (such as small equipment carts or buggies) shall be coordinated with the deck manufacturer's published wheel-load tables.

−

−## Field Cutting and Notching {toc}

−

−```datasheet

−label: Field Touch-Up Coating

−type: radio

−options:

− - "Zinc-rich cold galvanizing compound — match galvanized finish"

− - "Organic zinc-rich primer"

− - "Manufacturer-recommended touch-up coating"

−default: "Zinc-rich cold galvanizing compound — match galvanized finish"

−```

−

−### Field cutting of the deck shall be done with a hole saw, jigsaw with metal-cutting blade, shears, nibblers, or other clean-cut method.

−

−### Plasma torches and oxyacetylene torches shall not be used to cut deck because they destroy the galvanized coating at the cut edge and produce ragged edges that initiate cracking.

−

−### Cut edges and any field-damaged galvanized surfaces shall be touched up with a zinc-rich coating (organic or inorganic zinc primer) within 24 hours of exposure.

−

−## Coordination with Fireproofing {toc}

−

−### See [[sync/fireproofing]] for fireproofing requirements, bond strength testing, and patch and repair after deck cutting. {note}

−

−### Where spray-applied fireproofing is to be applied to the underside of the deck — typically for composite floor deck in a fire-rated assembly — the deck galvanized finish shall be compatible with the fireproofing bond requirements.

−

−### The Contractor shall verify fireproofing compatibility against the specific UL design listed; most spray-applied cementitious fireproofing is qualified for application directly to G60 galvanized deck.

−

−### Where prime paint or other shop coatings are applied to the deck, the fireproofing manufacturer shall confirm bond compatibility prior to application.

−

−## Coordination with Reinforcement Placement {toc}

−

−### Reinforcement placed above composite floor deck or above non-composite form deck shall be installed and supported in accordance with [[sync/concrete-reinforcement]].

−

−### Bar chairs shall be selected for compatibility with the deck profile; chair feet shall bear on the deck flat top surface (not on the open rib) wherever possible to prevent the chair from puncturing or distorting the deck.

−

−# Field Inspection {toc}

−

−## Pre-Pour Inspection (Composite and Non-Composite Floor Deck) {toc}

−

−```datasheet

−label: Pre-Pour Inspection Documentation

−type: radio

−options:

− - "Contractor checklist plus Special Inspector observation report"

− - "Special Inspector observation report only"

− - "Contractor checklist only (where no special inspection required)"

−default: "Contractor checklist plus Special Inspector observation report"

−```

−

−### Before concrete is placed on any deck area, the Contractor shall perform and document an inspection confirming: deck profile and gauge match the shop drawings; support fastener type and pattern match the drawings (visual count and weld/PAF/screw inspection); side-lap fastener type and spacing match the drawings; deck panel laps and end-lap details are correct; pour stops, edge angles, and closures are installed; openings and penetrations are reinforced where required; field-cut edges and damaged areas are touched up.

−

−### For composite slabs, the inspection shall additionally confirm that the deck embossments are clean and free of mud, ice, or coatings that would prevent composite action.

−

−## Weld Inspection {toc}

−

−```datasheet

−label: Welded Deck Attachment Inspection Rate

−type: select

−options:

− - "100% visual inspection (typical for diaphragm-rated deck)"

− - "Representative sample inspection per Statement of Special Inspections"

− - "Per Statement of Special Inspections"

−default: "100% visual inspection (typical for diaphragm-rated deck)"

−```

−

−### Where the deck is attached by arc spot welds or arc seam welds, the QA inspector shall visually inspect a representative sample of welds at each support condition for visible diameter, fusion, absence of cracks, absence of burn-through, and absence of porosity at the visible surface.

−

−### The weld inspection rate shall be as required by the project SSI; typical practice is 100% visual inspection of welded attachments because the deck-to-support weld is structurally critical and the inspection is rapid.

−

−## Fastener Inspection (PAF and Screw) {toc}

−

−### Powder-actuated fasteners and screws shall be inspected for proper seating (head flush or slightly recessed, no overdrive or underdrive), correct quantity at each support, and conformance with the specified pattern.

−

−### Visual inspection alone is normally adequate; where doubt exists, random pull-out testing per the manufacturer's procedure may be performed.

−

−## Concrete Placement Observation (Composite Slabs) {toc}

−

−### During concrete placement on composite floor deck, a qualified individual shall monitor the deck for deflection, lap separation, and any sign of overload.

−

−### If excessive deflection is observed, placement shall be stopped at the location of concern, the deck condition shall be evaluated, and placement shall not resume until the cause is identified and corrected (typically by adding shoring or by re-distributing the concrete buggy traffic).

−

−## Nonconformance Reporting {toc}

−

−```datasheet

−label: Maximum Time to Receive Engineer Disposition on Deck Nonconformance

−type: select

−drawing_ref: "project schedule"

−options:

− - "24 hours"

− - "48 hours"

−default: "24 hours"

−```

−

−### Any deck installation that does not conform to the contract documents, the approved shop drawings, or the requirements of the SDI standards shall be documented as a nonconformance by the Special Inspector and reported to the SER, the Contractor, and the Owner in writing before subsequent work proceeds.

−

−### For composite floor deck, concrete shall not be placed over a documented nonconformance until the SER has issued a written disposition.

−

−### For roof deck, the roofing system shall not be installed over a documented nonconformance.

−

−# Delivery, Storage, and Handling {toc}

−

−## Steel deck shall be delivered to the project site in clearly labeled bundles identified by deck product designation, profile, gauge, finish (G60 or G90), and quantity.

−

−## Bundles shall carry certification tags traceable to the mill test reports submitted under the Action Submittals section.

−

−## Material shall not be accepted without traceable certification.

−

−## Bundles shall be stored above grade on timber or other dunnage, protected from standing water, and covered with weatherproof tarps that allow air circulation.

−

−## Bundles shall not be stored in direct contact with mud, vegetation, or chemicals that could accelerate corrosion of the galvanized coating.

−

−## Where deck is stored on the partially erected structural steel for ease of placement, the storage location shall be coordinated with the steel erector to avoid overloading any single bay.

−

−## Deck shall be handled with nylon slings, padded chokers, or other methods that do not score, dent, or damage the galvanized coating.

−

−## Wire rope slings shall not be used directly on galvanized deck.

−

−## Bundles dropped from height or stacked improperly may develop permanent set in the lower panels; such panels shall be inspected and rejected if their profile deviates from the specified geometry.

−

−## Galvanized deck stored for prolonged periods in damp or poorly ventilated conditions may develop white rust (zinc hydroxide), which is a cosmetic and minor structural concern that indicates the zinc coating is being consumed.

−

−## Light white rust may be wiped off and the surface allowed to dry before installation; heavy white rust requires the panels to be cleaned and the coating restored, or the panels rejected.

−

−# Warranty {toc}

−

−```datasheet

−label: Installation Warranty Period

−type: select

−options:

− - "1 year from substantial completion"

− - "2 years from substantial completion"

−default: "1 year from substantial completion"

−```

−

−## The Contractor shall warrant the steel deck installation against defects in workmanship — including incorrect deck profile, gauge, or finish; incorrect or missing support fasteners; incorrect or missing side-lap fasteners; damaged galvanized coating not touched up; and any deviation from the approved shop drawings — for the project warranty period.

−

−## Material warranties provided by the deck manufacturer shall be passed through to the Owner.

−

−## Where the deck is part of a fire-rated assembly, the Contractor shall additionally warrant that the deck-and-coating-and-fireproofing combination matches the UL design listed on the contract drawings; deviation from the listed design voids the fire rating and constitutes a warranty defect.

−

−## The Contractor's warranty shall not limit the SER's right to require corrective work for nonconforming conditions discovered during the warranty period, including conditions concealed by subsequent work that are exposed during routine maintenance or alteration.

+---

+title: Steel Deck

+category: Structural / Steel & Metal Fabrications

+description: >

+ When to use: Cold-formed steel floor and roof deck furnished and installed under the Steel Deck Institute standards: composite floor deck acting with the concrete slab above it, non-composite form deck serving as a permanent form, roof deck carrying the roofing assembly, and acoustical roof deck. Covers the division of design responsibility for the deck and its diaphragm, manufacturer and installer qualification, sheet steel and metallic coating selection, the basis for profile, depth, gauge, and section properties, diaphragm design basis, attachment to supports by arc spot welds, arc seam welds, powder-actuated fasteners, and screws, side-lap fastening, the deck's role in a composite slab including shoring, concrete placement loads, and the sequence for shear studs welded through the deck, roof deck uplift attachment and FM Approval, openings and their reinforcement, pour stops, closures, and sump pans, placement and OSHA decking requirements, field cutting and coating repair, field inspection under the SDI quality standard, delivery and storage, and the warranty for the deck work.

+ Not intended for: Hot-rolled beams, girders, and columns and the headed shear studs welded to them (see [[sync/structural-steel-framing]]); bolted and welded connections between hot-rolled members (see [[sync/structural-steel-connections]]); open-web steel joists and joist girders (see [[sync/steel-joists]]); cold-formed steel studs, joists, and trusses (see [[sync/cold-formed-metal-framing]]); the concrete slab placed on the deck, its mixture, strength, and placement (see [[sync/cast-in-place-concrete]]); reinforcement within that slab (see [[sync/concrete-reinforcement]]); bar supports and embedded items set in the slab (see [[sync/concrete-accessories]]); the design, erection, and removal of shoring (see [[sync/concrete-formwork]]); applied fireproofing on the underside of the deck (see [[sync/fireproofing]]); the roofing membrane, insulation, cover board, and their attachment (see [[sync/membrane-roofing]]); deck furnished as part of a manufacturer's pre-engineered metal building (see [[sync/metal-building-systems]]); the project welding program for hot-rolled steel (see [[sync/welding-requirements]]); cellular raceway deck for in-floor electrical distribution; and stainless steel or aluminum deck.

+---

+# Scope {toc}

+## Work Covered by This Standard {toc}

+### This standard governs the cold-formed steel deck that forms the floors and roofs of a steel-framed building: what sheet it is rolled from and how that sheet is coated, which profile and gauge go where, how the deck is fastened to its supports and to itself, how it works as a diaphragm and as the form and tensile element of a composite slab, how it is cut, closed, and repaired, and how the installed deck is verified before concrete or roofing covers it. {note}

+### Steel deck is bought by profile, depth, gauge, finish, and length, but it carries load only through its attachment. The same panel fastened two different ways has two different diaphragm capacities, two different uplift resistances, and two different composite behaviors, so this standard treats the fastening as part of the product rather than as a field detail. {note}

+### Steel deck shall be designed, fabricated, and installed in accordance with ANSI/SDI C for composite floor deck, ANSI/SDI NC for non-composite floor deck, ANSI/SDI RD for roof deck, and the trade practice of the SDI Manual of Construction with Steel Deck.

+### Steel deck shall comply with the cold-formed steel deck provisions of IBC Chapter 22 as adopted in [[parameter: adopted-building-code]].

+### This standard governs how the deck is procured, attached, and verified; the contract documents define what deck goes where. {note}

+### Where this standard and the structural drawings differ, the more stringent requirement shall govern until the Engineer of Record resolves the difference in writing.

+### Steel deck placed on a metal building frame, where the deck is not part of the manufacturer's package, is governed by this standard. {note}

+## Work Governed by Companion Standards {toc}

+### The following are governed elsewhere and are outside this standard: {note}

+- the hot-rolled members the deck bears on, the headed shear stud connectors, their diameter, layout, welding, and acceptance, and hot-rolled frames at deck openings, which are governed by [[sync/structural-steel-framing]]

+- the connections between hot-rolled members, which are governed by [[sync/structural-steel-connections]]

+- open-web steel joists and joist girders, including the bridging and end anchorage that stabilize them before the deck arrives, which are governed by [[sync/steel-joists]]

+- cold-formed steel studs, joists, rafters, and trusses, which are governed by [[sync/cold-formed-metal-framing]]

+- the concrete slab on the deck, its mixture, strength, placement, consolidation, curing, and finishing, which are governed by [[sync/cast-in-place-concrete]] and [[sync/concrete-curing-and-finishing]]

+- the reinforcement within the slab and the bar supports that hold it, which are governed by [[sync/concrete-reinforcement]] and [[sync/concrete-accessories]]

+- the design, erection, and removal of shoring beneath the deck, which are governed by [[sync/concrete-formwork]]

+- applied fireproofing on the underside of the deck, its thickness, and its bond verification, which are governed by [[sync/fireproofing]]

+- the listed fire-resistance-rated assemblies of which the deck is a component, which are governed by [[sync/fire-rated-wall-and-floor-assemblies]]

+- the roofing membrane, insulation, cover board, vapor retarder, and their attachment to the deck, which are governed by [[sync/membrane-roofing]]

+- sheet metal flashing, copings, and roof edge metal above the deck, which are governed by [[sync/sheet-metal-flashing-and-trim]] and [[sync/roof-specialties-and-copings]]

+- procedure and welder qualification for welds on hot-rolled members, which are governed by [[sync/welding-requirements]]

+- the administration of the special inspection program, which is governed by [[sync/special-inspections-and-testing]]

+- hangers and supports suspended from the deck after it is installed, which are governed by [[sync/hangers-and-supports]]

+### Deck-to-support welds and side-lap welds are made under D1.3, the welding code for thin-gauge steel, and are excluded from the program that [[sync/welding-requirements]] establishes; their procedures, welder qualification, and acceptance are governed by this standard. {note}

+### Deck furnished and installed as part of a manufacturer's pre-engineered metal building is governed by [[sync/metal-building-systems]]. {note}

+# Referenced Standards {toc}

+## Materials, fabrication, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.

+## Where the contract documents, the Authority Having Jurisdiction, or two referenced standards impose conflicting requirements, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.

+| Standard | Title |

+|----------|-------|

+| ANSI/SDI C | Standard for Composite Steel Floor Deck-Slabs |

+| ANSI/SDI NC | Standard for Non-Composite Steel Floor Deck |

+| ANSI/SDI RD | Standard for Steel Roof Deck |

+| ANSI/SDI QA/QC | Standard for Quality Control and Quality Assurance for Installation of Steel Deck |

+| SDI MOC | Manual of Construction with Steel Deck |

+| SDI DDM | Diaphragm Design Manual |

+| AISI S100 | North American Specification for the Design of Cold-Formed Steel Structural Members |

+| AISI S310 | North American Standard for the Design of Profiled Steel Diaphragm Panels |

+| ANSI/AISC 360 | Specification for Structural Steel Buildings (Chapter I, Composite Members) |

+| ANSI/AISC 341 | Seismic Provisions for Structural Steel Buildings |

+| AWS D1.3/D1.3M | Structural Welding Code - Sheet Steel |

+| AWS D1.1/D1.1M | Structural Welding Code - Steel |

+| AWS QC1 | Standard for AWS Certification of Welding Inspectors |

+| ASTM A653/A653M | Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip Process |

+| ASTM A792/A792M | Steel Sheet, 55% Aluminum-Zinc Alloy-Coated by the Hot-Dip Process |

+| ASTM A1008/A1008M | Steel, Sheet, Cold-Rolled, Carbon, Structural, High-Strength Low-Alloy, High-Strength Low-Alloy with Improved Formability, Solution Hardened, and Bake Hardenable |

+| ASTM A924/A924M | General Requirements for Steel Sheet, Metallic-Coated by the Hot-Dip Process |

+| ASTM A780/A780M | Repair of Damaged and Uncoated Areas of Hot-Dip Galvanized Coatings |

+| ASTM A370 | Standard Test Methods and Definitions for Mechanical Testing of Steel Products |

+| ASTM C1513 | Steel Tapping Screws for Cold-Formed Steel Framing Connections |

+| ASTM E119 | Standard Test Methods for Fire Tests of Building Construction and Materials |

+| UL 263 | Fire Tests of Building Construction and Materials |

+| UL 1256 | Fire Test of Roof Deck Constructions |

+| UL Fire Resistance Directory | Listed fire-resistance-rated floor-ceiling and roof-ceiling assemblies |

+| FM 4451 | Approval Standard for Profiled Steel Panels for Use as Decking in Class 1 Insulated Roof Construction |

+| FM Global Data Sheet 1-29 | Roof Deck Securement and Above-Deck Roof Components |

+| ICC-ES AC70 | Acceptance Criteria for Fasteners Power-Driven into Concrete, Steel, and Masonry Elements |

+| ASCE/SEI 7 | Minimum Design Loads and Associated Criteria for Buildings and Other Structures |

+| IBC | International Building Code (Chapter 16, Structural Design; Chapter 17, Special Inspections and Tests; Chapter 22, Steel) |

+| OSHA 29 CFR 1926 Subpart R | Safety Standards for Steel Erection |

+| ANSI A10.3 | Safety Requirements for Powder-Actuated Fastening Systems |

+# Submittals {toc}

+## Action Submittals {toc}

+### The deck supplier and the Contractor shall submit the following to the Engineer of Record before deck is released for fabrication:

+- Erection drawings, called the deck placement plan, showing for every deck area the profile, the manufacturer's designation, depth, gauge, finish, span direction, panel lengths, end and side lap conditions, bearing at each support, the support and side-lap fastener type, pattern, and spacing by zone, every opening with its reinforcement, and every accessory with its location and attachment

+- Product data for each deck profile, including section properties computed under AISI S100, the yield strength on which they are based, the uniform load tables for single, double, and triple spans, the maximum unshored clear span for composite and form deck, and the diaphragm capacity tables where proprietary tables are relied on

+- Diaphragm design calculations sealed by the deck supplier's specialty engineer, where the diaphragm design is delegated under the datasheet

+- Evaluation reports and installation instructions for powder-actuated fasteners, screws, and proprietary side-lap fasteners, covering the deck thickness and support thickness combinations on the project

+- Product data for weld washers where the deck thickness requires them

+- Product data for pour stops, closures, sump pans, cover plates, and other accessories

+- Evidence that each deck designation used in a listed fire-resistance-rated assembly is a designation the listing names

+```datasheet

+label: Action Submittals Required

+type: checkbox

+options:

+ - "Deck placement plan"

+ - "Product data with section properties and load tables"

+ - "Delegated diaphragm design calculations"

+ - "Fastener evaluation reports and installation instructions"

+ - "Weld washer product data"

+ - "Accessory product data"

+ - "Fire-resistance listing evidence for the deck designation"

+default:

+ - "Deck placement plan"

+ - "Product data with section properties and load tables"

+ - "Fastener evaluation reports and installation instructions"

+ - "Accessory product data"

+```

+### The deck placement plan is where the structural drawings become orderable panels, and it is the document on which a missing closure, an unframed opening, or a fastener pattern that cannot be executed around a column surfaces while it is still a drafting change. It does not reproduce the structural drawings and does not supersede them. {note}

+### Fabrication shall not begin on any deck area until the submittals covering it have been reviewed and returned.

+### The Contractor shall allow ten working days for each review cycle, measured from receipt of a complete submittal.

+### The Contractor shall not substitute a deck profile, gauge, finish, or fastener for the one shown without the Engineer of Record's written approval.

+### A substitute that matches the uniform load capacity can still change the diaphragm capacity, the fire-resistance listing, the stud geometry at composite beams, and the withdrawal resistance of the roofing fasteners, so equivalence in one table is not equivalence in the building. {note}

+## Informational Submittals {toc}

+### The deck supplier shall submit the following before or with the first shipment of deck:

+- Certified mill test reports or certificates of conformance for the sheet steel, traceable by coil or heat, stating the ASTM specification, yield strength, tensile strength, elongation, and coating designation

+- Welding procedure specifications under AWS D1.3 for arc spot welds, arc seam welds, and side-lap welds

+- Welder qualification records under AWS D1.3 for each welder who will attach deck

+- Training records for each powder-actuated tool operator

+- Documentation of Steel Deck Institute membership, or of the quality program under which the deck is produced

+```datasheet

+label: Informational Submittals Required

+type: checkbox

+options:

+ - "Mill test reports or certificates for the sheet steel"

+ - "AWS D1.3 welding procedure specifications"

+ - "AWS D1.3 welder qualification records"

+ - "Powder-actuated tool operator training records"

+ - "SDI membership or quality program documentation"

+default:

+ - "Mill test reports or certificates for the sheet steel"

+ - "AWS D1.3 welding procedure specifications"

+ - "AWS D1.3 welder qualification records"

+ - "Powder-actuated tool operator training records"

+```

+## Closeout Submittals {toc}

+### At substantial completion the Contractor shall submit the following:

+- An as-built deck placement plan recording every field change, every field-cut opening, and the reinforcement added at each

+- Field inspection reports for support fastening, side-lap fastening, and the verification performed before concrete placement, organized by deck area

+- A record of coating repair, stating the material used and the areas treated

+- A certificate of compliance from the deck installer

+```datasheet

+label: Closeout Submittals Required

+type: checkbox

+options:

+ - "As-built deck placement plan"

+ - "Field inspection reports by deck area"

+ - "Coating repair record"

+ - "Certificate of compliance from the deck installer"

+default:

+ - "As-built deck placement plan"

+ - "Field inspection reports by deck area"

+ - "Certificate of compliance from the deck installer"

+```

+### The submittal workflow common to the project is established in [[sync/submittal-and-quality-procedures]], and the coordination envelope shared by every structural steel package is established in [[sync/structural-steel-common-results]].

+# Quality Assurance {toc}

+## Deck Manufacturer Qualification {toc}

+### The deck manufacturer shall meet the qualification indicated in the datasheet.

+```datasheet

+label: Deck Manufacturer Qualification

+type: radio

+options:

+ - "Steel Deck Institute member manufacturer"

+ - "Manufacturer accepted by the Engineer of Record on demonstration of AISI-based load tables and an audited quality program"

+default: "Steel Deck Institute member manufacturer"

+```

+### Steel Deck Institute membership obliges a manufacturer to publish section properties and load tables computed under AISI S100 and diaphragm values under AISI S310, which is what lets the Engineer of Record design to a catalog rather than to a test report; a manufacturer outside that framework is accepted on the strength of its own documentation, which is an engineering judgment about that manufacturer. {note}

+### Published section properties, uniform load tables, and diaphragm tables shall be computed under AISI S100 and AISI S310, or established by testing under those standards.

+### Load tables not traceable to AISI S100 or AISI S310 shall not be used for design.

+### Where a manufacturer outside the Steel Deck Institute is proposed, the party proposing it shall bear the cost of the Engineer of Record's review.

+## Installer Qualification {toc}

+### The deck installer shall have at least the experience indicated in the datasheet installing steel floor and roof deck on work comparable in scope to this project.

+```datasheet

+label: Minimum Installer Experience with Steel Deck

+type: range

+unit: years

+options:

+ min: 0

+ max: 10

+ setpoints: [0, 2, 3, 5, 10]

+default: 3

+```

+### Where the parties disagree whether an installer's experience is comparable in scope to the work of this project, the Engineer of Record shall make the initial determination.

+### Deck installation is a fastening trade: the panel arrives finished, and nearly every defect that reaches an inspector is a weld that did not fuse, a pin driven into a flange too thin to hold it, a side lap left open, or a pattern thinned out across a bay. Experience with the specific fastening systems on the project matters more than years with steel generally. {note}

+## Welding of Deck Under AWS D1.3 {toc}

+### Arc spot welds, arc seam welds, and side-lap welds attaching deck shall be made under welding procedure specifications prequalified or qualified under AWS D1.3.

+### Welders attaching deck shall be qualified under AWS D1.3 for the sheet thickness range, the weld type, and the position in which they will weld.

+### Qualification under AWS D1.1 alone does not qualify a welder for deck attachment, because sheet steel welding is governed by burn-through rather than by fusion, and the arc spot weld's capacity depends on a visible diameter and a fused perimeter that AWS D1.1 procedures do not control. {note}

+### Welder qualification shall be current at the time the production weld is made.

+### Welds attaching support angles, opening frames, and other hot-rolled members to the frame shall be made under D1.1 within the welding program established in [[sync/welding-requirements]].

+### Welding inspection of deck attachment shall be performed by an AWS Certified Welding Inspector qualified under AWS QC1, or by an inspector whose equivalent qualification the Engineer of Record has accepted in writing.

+### The welding inspector shall be familiar with the AWS D1.3 acceptance criteria for arc spot and arc seam welds before inspecting deck attachment.

+## Special Inspection of Deck {toc}

+### Special inspection of steel deck shall be performed as [[parameter: adopted-building-code]] requires under IBC Chapter 17 and ANSI/SDI QA/QC, under the program administered in accordance with [[sync/special-inspections-and-testing]].

+### The Statement of Special Inspections shall designate each deck inspection task as continuous or periodic.

+### Special inspection of deck work shall cover at least the items indicated in the datasheet.

+```datasheet

+label: Special Inspection Scope for Deck Work

+type: checkbox

+options:

+ - "Deck profile, gauge, and finish verified against the placement plan"

+ - "Support fastener type, pattern, and spacing verified"

+ - "Side-lap fastener type and spacing verified"

+ - "Welds visually inspected under AWS D1.3"

+ - "Mechanical fasteners inspected for seating and listing"

+ - "Attachment at collectors, chords, and perimeter members verified"

+ - "Opening reinforcement verified"

+default:

+ - "Deck profile, gauge, and finish verified against the placement plan"

+ - "Support fastener type, pattern, and spacing verified"

+ - "Side-lap fastener type and spacing verified"

+ - "Welds visually inspected under AWS D1.3"

+ - "Mechanical fasteners inspected for seating and listing"

+```

+### The inspection agency shall have no business, financial, or organizational relationship with the deck supplier or the deck installer.

+### The panel is the smaller part of the engineering decision. A diaphragm capacity is computed from a specific fastener in a specific pattern at a specific spacing, and a floor that looks finished can be missing half of what the calculation assumed, which is why deck inspection is about counting and not about appearance. {note}

+# Deck Types and Profiles {toc}

+## Deck Types in Scope {toc}

+### The deck types used on the project shall be as indicated in the datasheet.

+```datasheet

+label: Deck Types in Scope

+type: checkbox

+options:

+ - "Composite floor deck"

+ - "Non-composite form deck"

+ - "Roof deck"

+ - "Acoustical roof deck"

+```

+### Composite floor deck is a permanent form that becomes the tensile reinforcement of the slab cast on it, bonding to the concrete through embossments rolled into its webs or flanges; it is designed under ANSI/SDI C and the composite slab provisions of ANSI/AISC 360 Chapter I. {note}

+### Non-composite form deck is a permanent form only: it carries the wet concrete and the construction loads, and the hardened slab is designed as a reinforced concrete slab that gets no strength from the deck; it is designed under ANSI/SDI NC. {note}

+### Roof deck carries the roofing assembly, the superimposed roof loads, and the net uplift, and on most steel-framed roofs it is also the diaphragm; it is designed under ANSI/SDI RD. {note}

+### Acoustical roof deck is roof deck with perforated webs or flanges and a sound-absorbing insert in the rib, used where the underside of the roof is the finished ceiling of a space that needs sound absorption. {note}

+## Profile, Depth, and Gauge by Area {toc}

+### Deck profile, depth, gauge, span direction, panel layout, and the support and side-lap fastener pattern and spacing for each deck area shall be as indicated on [[drawing: the structural framing plans and deck attachment schedule]].

+### Where the structural drawings identify a profile by an SDI classification rather than by a manufacturer's designation, the deck supplier shall propose the specific product on the placement plan.

+### Roof deck profiles are classified by rib geometry: 1-1/2 in. deep narrow-rib, intermediate-rib, and wide-rib profiles, 3 in. deep profiles, and 4-1/2 in. to 7-1/2 in. deep long-span profiles; the wide-rib 1-1/2 in. profile dominates current production because its wide top flange carries roofing fasteners and insulation board, while the deeper profiles buy span at the cost of a narrower flat for roofing attachment. {note}

+### Composite floor deck is produced in 1-1/2 in., 2 in., and 3 in. depths, with the 2 in. and 3 in. profiles on a 12 in. rib pitch and the 1-1/2 in. profile commonly on a 6 in. pitch; the 2 in. profile covers the span range of most framed bays, the 1-1/2 in. profile is reached for where floor depth is tight, and the 3 in. profile extends the span or reduces the concrete volume on long bays. {note}

+### Non-composite form deck is produced from 9/16 in. to 3 in. deep and in lighter gauges than composite deck, because it is designed only for the construction condition; the shallowest profiles are the ones most likely to need weld washers at their support welds. {note}

+### Where composite beams or girders carry the deck, the deck profile shall satisfy the rib depth, rib width, and slab thickness limits of ANSI/AISC 360 Chapter I for the stud diameter and slab shown on the structural drawings.

+### Where CJ-series composite joists carry the deck, the deck profile, gauge, and rib orientation shall be coordinated with the composite joist design under [[sync/steel-joists]].

+### Composite action between the slab and a steel beam is transferred through studs welded in the deck ribs, so the rib width, the rib depth, and the stud's projection above the deck are design inputs; a deck profile that differs from the one the beam design assumed changes the beam's capacity even when the slab itself is unaffected. {note}

+## Acoustical Roof Deck {toc}

+### Requirements in this article apply where acoustical roof deck is selected in the datasheet field for the deck types in scope.

+### The perforation pattern, the insert material, and the noise reduction coefficient required for acoustical deck shall be as indicated on [[drawing: the roof deck schedule]].

+### Section properties and load tables for acoustical deck shall be those published for the perforated section, not for the solid profile.

+### Perforating the webs or flanges removes material from the section, and a manufacturer publishes separate, lower section properties for the perforated profile; the solid-profile tables overstate it. {note}

+### Sound-absorbing inserts shall be furnished by the deck supplier, sized for the rib, and protected from water from delivery until the roof is closed.

+### Where acoustical deck participates in the diaphragm, the diaphragm capacity used in design shall be that established for the perforated profile.

+# Sheet Steel and Finish {toc}

+## Sheet Steel {toc}

+### Deck shall be formed from sheet steel conforming to ASTM A653 for zinc-coated and zinc-iron alloy-coated sheet, ASTM A792 for 55% aluminum-zinc alloy-coated sheet, or ASTM A1008 for uncoated sheet that will be shop primed, as the finish selected in the datasheet requires.

+### Metallic-coated sheet shall meet the general requirements of ASTM A924.

+### The minimum yield strength of the sheet steel shall be as indicated in the datasheet.

+```datasheet

+label: Minimum Sheet Steel Yield Strength

+type: range

+unit: ksi

+options:

+ min: 33

+ max: 80

+ setpoints: [33, 40, 50, 80]

+```

+### Where no yield strength is selected in the datasheet, the yield strength on which the manufacturer's published load tables are based shall govern, and the manufacturer shall state it in the product data.

+### Structural-quality sheet is produced at 33 ksi, 40 ksi, 50 ksi, and 80 ksi minimum yield; the load table, not the grade, is what the Engineer of Record designs to, and most manufacturers publish composite deck at 50 ksi and roof deck at 33 ksi or higher. An 80 ksi sheet is designed under AISI S100 at a reduced yield strength because its elongation is low, so the extra grade buys less capacity than the number suggests. {note}

+### Sheet steel shall be reported by coil or heat in the certified mill test reports.

+### The uncoated base steel thickness delivered shall be not less than 95 percent of the design thickness, as AISI S100 requires.

+## Floor Deck Finish {toc}

+### The finish of composite floor deck and non-composite form deck shall be as indicated in the datasheet.

+```datasheet

+label: Floor Deck Finish

+type: select

+options:

+ - "Hot-dip galvanized G60 (ASTM A653)"

+ - "Hot-dip galvanized G90 (ASTM A653)"

+ - "Galvannealed A60 (ASTM A653)"

+ - "55% aluminum-zinc alloy-coated AZ50 (ASTM A792)"

+ - "Shop primer over G60 galvanized sheet"

+ - "Shop primer over uncoated sheet (ASTM A1008)"

+default: "Hot-dip galvanized G60 (ASTM A653)"

+```

+### G60 is the coating most composite and form deck is produced in and is what the fire-resistance listings and fireproofing bond tests for deck are run on; G90 carries half again as much zinc and is reached for where the underside of the deck stays exposed in a humid or chloride-bearing space; galvannealed sheet trades some corrosion resistance for a surface that holds paint; an aluminum-zinc coating outlasts zinc in an atmospheric exposure but is less forgiving at cut edges and welds; and a shop primer is a shipping coat that protects the sheet until it is covered and is selected where the deck will be painted or where a listing calls for it. {note}

+## Roof Deck Finish {toc}

+### The finish of roof deck shall be as indicated in the datasheet.

+```datasheet

+label: Roof Deck Finish

+type: select

+options:

+ - "Hot-dip galvanized G60 (ASTM A653)"

+ - "Hot-dip galvanized G90 (ASTM A653)"

+ - "Galvannealed A60 (ASTM A653)"

+ - "55% aluminum-zinc alloy-coated AZ50 (ASTM A792)"

+ - "Shop primer over G60 galvanized sheet"

+ - "Shop primer over uncoated sheet (ASTM A1008)"

+default: "Hot-dip galvanized G60 (ASTM A653)"

+```

+### Roof deck under a membrane and insulation is concealed from weather but not from the building's air, and a roof over a conditioned space sees condensation on its underside in cold weather; a galvanized finish rides that out where a bare primer does not. A primed finish is selected where the underside is exposed and will be painted, or where the regional market produces painted roof deck as its stock item and the deck will be covered by a ceiling. {note}

+## Service Exposure {toc}

+### Deck exposed to weather in service, deck over a parking level, natatorium, kitchen, wash-down area, or other space with sustained high humidity or chloride exposure, and deck within 1 mile of a salt water coast shall be galvanized G90 at minimum, unless the Engineer of Record directs otherwise in writing.

+### A shop primer is a short-term coating that keeps the sheet from rusting between the mill and the building, not a corrosion protection system, and primed deck left exposed to weather on site begins to rust at the laps within weeks. {note}

+### Where applied fireproofing will be applied to the underside of the deck, the finish selected shall be one for which the fireproofing material is listed, and the fireproofing applicator shall confirm compatibility under [[sync/fireproofing]] before the deck is released for fabrication.

+### Most cementitious fireproofing is listed over galvanized deck and bonds poorly to a primed surface, so a primed finish chosen for a floor deck that will be fireproofed is the usual reason a deck bond test fails. {note}

+### Where the deck is a component of a listed fire-resistance-rated assembly, the finish shall be one the listing permits.

+# Gauge and Section Properties {toc}

+## Design Thickness {toc}

+### Section properties and load tables shall be computed on the design thickness of the uncoated base steel under AISI S100.

+### The gauge designations in common deck production correspond to the following design thicknesses: {note}

+| Gauge | Design thickness |

+|-------|------------------|

+| 22 | 0.0295 in. |

+| 20 | 0.0358 in. |

+| 18 | 0.0474 in. |

+| 16 | 0.0598 in. |

+### A lighter gauge than the one shown shall not be furnished for any deck area.

+### Gauge controls the section capacity, the diaphragm capacity, the pull-over resistance at every fastener, and the withdrawal resistance of the roofing screws, so a lighter gauge is four substitutions at once. {note}

+### Each bundle shall be tagged with the manufacturer's designation, the gauge, and the finish, and the gauge shall be verifiable on the delivered sheet by measurement.

+## Span Condition {toc}

+### Deck shall be laid out so that each panel spans the number of supports the design assumed.

+### Load tables give a different capacity for a panel on two supports, on three, and on four or more, because continuity over interior supports redistributes moment; a layout that turns the three-span panel the design assumed into single spans at a column line hands the deck a capacity it does not have. {note}

+### Where panel lengths available from the manufacturer cannot achieve the span condition assumed, the deck supplier shall report the shortfall on the placement plan for the Engineer of Record's disposition.

+# Diaphragm Design {toc}

+## Diaphragm Design Responsibility {toc}

+### The diaphragm design shall be performed by the party indicated in the datasheet.

+```datasheet

+label: Diaphragm Design Responsibility

+type: radio

+options:

+ - "Engineer of Record designs the diaphragm and specifies the fastening"

+ - "Delegated to the deck supplier's specialty engineer for the diaphragm shears stated by the Engineer of Record"

+default: "Engineer of Record designs the diaphragm and specifies the fastening"

+```

+### The Engineer of Record keeps the diaphragm design on most projects because the diaphragm shears, the chord and collector forces, and the deck attachment are one calculation with the lateral system; delegation is reached for where a proprietary fastener system with its own tested tables is the basis, or where the deck supplier is selected early enough to design around its own products. {note}

+### Where the diaphragm design is delegated, the Engineer of Record shall state the diaphragm shear along each line, the deck profile and gauge, and the attachment required at collectors, chords, and perimeter members.

+### A delegated diaphragm design shall be sealed by an engineer licensed in the jurisdiction of the project and submitted for the Engineer of Record's review before deck is released for fabrication.

+### The diaphragm design shall be based on the source indicated in the datasheet.

+```datasheet

+label: Diaphragm Design Basis

+type: radio

+options:

+ - "SDI Diaphragm Design Manual tabulated capacities"

+ - "AISI S310 calculation"

+ - "Manufacturer's tested capacities under a current evaluation report"

+ - "Deck not relied on for diaphragm action"

+default: "SDI Diaphragm Design Manual tabulated capacities"

+```

+### The SDI Diaphragm Design Manual tabulates capacities for generic profiles with welds, screws, and button punches, which covers the majority of designs; AISI S310 is the calculation behind those tables and is used where a configuration falls outside them; a proprietary fastener system has no entry in the generic tables, so its tested capacities under an evaluation report are the only basis for it; and a deck that is not relied on for diaphragm action still needs the minimum attachment the SDI standards require, but the fastener pattern is no longer a lateral design input. {note}

+### Where the deck is not relied on for diaphragm action, the lateral system that replaces it shall be identified on the structural drawings.

+## Lateral System Coordination {toc}

+### The diaphragm design shall address the seismic load effects of ASCE/SEI 7 Chapter 12 for [[parameter: seismic-design-category]].

+### Deck attachment along collectors, chords, shear walls, and braced frame lines, where it differs from the field pattern, shall be as indicated on [[drawing: the lateral force resisting system plans]].

+### Within a protected zone designated on the structural drawings, deck shall be attached only by arc spot welds, and powder-actuated fasteners and screws that penetrate the member flange shall not be used, in accordance with ANSI/AISC 341.

+### The protected zone is the length of a seismic member where plastic hinging is expected, and a fastener hole through its flange is a crack starter in the one place the design cannot tolerate one. {note}

+### The installed deck profile, gauge, support fastener, side-lap fastener, pattern, and spacing shall match the configuration the diaphragm design is based on without substitution.

+# Attachment to Supports {toc}

+## Support Fastener Type {toc}

+### Composite floor deck and non-composite form deck shall be attached to their supports with the fastener indicated in the datasheet.

+```datasheet

+label: Floor Deck Support Fastener

+type: select

+drawing_ref: "the deck attachment schedule"

+options:

+ - "Arc spot welds under AWS D1.3"

+ - "Arc seam welds under AWS D1.3"

+ - "Powder-actuated fasteners"

+ - "Self-drilling screws"

+default: deferred

+```

+### Roof deck shall be attached to its supports with the fastener indicated in the datasheet.

+```datasheet

+label: Roof Deck Support Fastener

+type: select

+drawing_ref: "the deck attachment schedule"

+options:

+ - "Arc spot welds under AWS D1.3"

+ - "Arc seam welds under AWS D1.3"

+ - "Powder-actuated fasteners"

+ - "Self-drilling screws"

+default: deferred

+```

+### The fastener type is an input to the diaphragm design and to the uplift design, so it is set by whoever performs those designs and reaches the field on the attachment schedule; the datasheet selection governs where the schedule is silent. {note}

+### An arc spot weld, the puddle weld, is the historical standard: it develops the most shear per fastener, it needs no fastener inventory, and it is what the generic diaphragm tables are built on, but it needs a qualified welder, a dry deck in firm contact with the flange, and a weld washer on the thinnest sheet, and it burns the coating at every location. An arc seam weld is a longer weld used where a single spot weld cannot develop the required shear. {note}

+### A powder-actuated fastener is driven through the deck into the flange by a tool operator rather than a welder, leaves the coating intact, and is unaffected by water on the deck, which is why it has displaced welding on much roof deck; its capacity is published per fastener per flange thickness in an evaluation report, and a flange thinner than the report covers is the common defect. {note}

+### A self-drilling screw develops less shear than a weld or a pin, so it is used in greater numbers, and it is reached for where the support is too thin for a pin, where welding is barred by the building's use or by a coating that has to stay continuous, and on cold-formed supports. {note}

+## Fastener Placement at Supports {toc}

+### Deck shall be fastened to every support it bears on, including perimeter members, members at openings, and the members at each end lap.

+### Fasteners at an end lap shall pass through both sheets into the support.

+### Support fasteners shall be placed at the spacing shown and in no case at a spacing greater than ANSI/SDI C, NC, or RD permits for the deck type.

+### The SDI pattern notation states the number of fasteners across a panel width at each support, so a 36/4 pattern places four fasteners across a 36 in. panel and a 36/7 pattern places one in every rib; the heavier pattern buys diaphragm capacity and uplift resistance with more fasteners and more labor. {note}

+### Where a support flange is too thin or too narrow to receive the fastener shown, the installer shall report the condition to the Engineer of Record before the deck is attached there.

+## Arc Spot and Arc Seam Welds {toc}

+### Arc spot welds shall have a visible diameter of not less than 5/8 in., or the larger diameter shown on the attachment schedule.

+### Arc seam welds shall have the length and width shown on the attachment schedule.

+### A weld washer shall be used at every arc spot weld where the deck design thickness is less than 0.028 in.

+### A weld washer is a flat steel washer the arc is struck through so the thinnest sheet is fused to the support instead of burned away around the weld; the 0.028 in. threshold is the SDI boundary below which a bare puddle weld cannot be made reliably. {note}

+### The deck shall be in firm contact with the support at every weld location, with no gap between the sheet and the flange.

+### Deck shall not be welded through standing water, ice, mud, or a coating or debris that prevents fusion.

+### Welds shall be visually inspected after cooling under the AWS D1.3 acceptance criteria for fused perimeter, visible diameter, cracks, porosity at the surface, and burn-through.

+### A weld that does not meet the acceptance criteria shall be supplemented by an acceptable weld placed adjacent to it, and the original shall be left in place unless the Engineer of Record directs its removal.

+### Grinding out a rejected puddle weld removes more sheet than the weld did, so the repair for a bad weld is a good weld beside it. {note}

+## Powder-Actuated Fasteners {toc}

+### Powder-actuated fasteners shall be listed in a current evaluation report under ICC-ES AC70 for the deck thickness and the support flange thickness at each location they are used.

+### The installer shall verify the actual flange thickness of each support before fasteners are driven into it.

+### Fasteners shall not be driven into a support thinner than the minimum the evaluation report covers.

+### Each tool operator shall be trained in accordance with ANSI A10.3 and the fastener manufacturer's program and shall carry evidence of that training on site.

+### The powder charge and tool setting shall drive the fastener so that its head bears on the deck without a gap and without a depression that deforms the sheet.

+### An underdriven fastener leaves a gap under the head and carries shear through the gap; an overdriven one crushes the sheet and reduces the bearing that resists pull-over, and both read as a pin in the right place at a glance. {note}

+### An underdriven, overdriven, or misplaced fastener shall be supplemented by a fastener placed adjacent to it, with the original left in place.

+## Self-Drilling Screws {toc}

+### Screws attaching deck to supports shall conform to ASTM C1513, with a drill point rated for the combined thickness of the deck and the support.

+### Screws attaching deck to supports shall be not smaller than #12, and side-lap screws not smaller than #10, unless the diaphragm design is based on a different size.

+### Screws shall be driven perpendicular to the deck until the head seats on the sheet, without stripping the threads in the support.

+### Screw guns shall have depth or torque control set for the screw and the material.

+### A stripped screw shall be removed and replaced by a screw of the next larger diameter in the same hole, or by a screw placed adjacent to it.

+# Side-Lap Fastening {toc}

+## Side-Lap Fastener Type {toc}

+### Side laps shall be fastened with the fastener indicated in the datasheet.

+```datasheet

+label: Side-Lap Fastener Type

+type: select

+drawing_ref: "the deck attachment schedule"

+options:

+ - "Button punch"

+ - "Self-drilling screws"

+ - "Top arc seam side-lap welds under AWS D1.3"

+ - "Arc seam welds through the lap under AWS D1.3"

+ - "Proprietary mechanical side-lap fasteners under an evaluation report"

+default: deferred

+```

+### A side lap joins two panels between supports, and it is what makes a floor of separate strips act as one plate; side-lap fastening governs the diaphragm capacity on most roof decks, because the panels slip along their laps long before the support fasteners fail. {note}

+### A button punch is a crimp made with a hand tool that interlocks the nesting edges of a standing-seam side lap; it costs no material and develops modest shear, which suits form deck and lightly loaded roof deck. A screw is the most common diaphragm side-lap fastener because its capacity is tabulated and each one can be counted. A top arc seam weld is made on the standing seam of a roof deck lap without burning through the flat, and an arc seam weld through a nested lap is reached for on the highest-shear diaphragms. A proprietary mechanical fastener is used under its own tested tables and only where those tables are the diaphragm basis. {note}

+## Side-Lap Spacing and Engagement {toc}

+### Side-lap fasteners shall be placed at the spacing shown and in no case at a spacing greater than ANSI/SDI C, NC, or RD permits for the deck type and span.

+### The side lap shall be fully nested or fully engaged before it is fastened, with the upper edge seated on the lower edge without a visible gap.

+### A side lap that has been crushed, spread, or twisted shall be straightened before it is fastened, or the panel shall be replaced.

+### Side-lap screws and welds shall pass through both sheets of the lap.

+### On composite and form deck, the side laps shall be closed tightly enough that concrete paste does not leak through them during placement.

+### Tighter side-lap spacing is typically shown along collectors, around large openings, and at the perimeter, because that is where the diaphragm shear concentrates; a spacing opened up in the field anywhere in those zones is a capacity reduction where it matters most. {note}

+# Composite Floor Deck Slabs {toc}

+## Composite Action and the Slab {toc}

+### Requirements in this section apply where composite floor deck is selected in the datasheet field for the deck types in scope, and the shoring and concrete placement articles apply to non-composite form deck as well.

+### The slab on the deck, its thickness, compressive strength, placement, consolidation, and curing are governed by [[sync/cast-in-place-concrete]] and [[sync/concrete-curing-and-finishing]], and the reinforcement within it by [[sync/concrete-reinforcement]].

+### The slab thickness above the top of the deck shall be not less than ANSI/AISC 360 Chapter I requires for a composite slab, and not less than the listed fire-resistance-rated assembly requires where the slab is part of one.

+### Composite action is developed by the embossments in the deck engaging the concrete, so the deck surface at the time of placement is part of the structural system: mud, oil, ice, or a release agent on the deck is a bond breaker in a member designed for bond. {note}

+### The deck shall be clean of mud, oil, ice, loose rust, and debris, and free of any coating not shown on the placement plan, at the time concrete is placed.

+## Shoring and Construction Loads {toc}

+### Composite and form deck shall be placed under the construction condition indicated in the datasheet.

+```datasheet

+label: Deck Construction Condition

+type: radio

+options:

+ - "Unshored, with the deck carrying the wet concrete and construction loads"

+ - "Shored in the bays the Engineer of Record designates"

+default: "Unshored, with the deck carrying the wet concrete and construction loads"

+```

+### Unshored deck shall be designed under ANSI/SDI C or ANSI/SDI NC to carry the wet concrete and the construction loads those standards define for the span condition shown, within the deflection limit those standards set.

+### The deck is an unshored form on nearly every project because shoring under a steel-framed floor costs more than a heavier gauge or a shorter span, and because an unshored floor frees the levels below for other trades; shoring is reached for where a bay exceeds the longest unshored span any available gauge offers, or where the slab is thick enough that the wet weight governs the whole deck selection. {note}

+### Where the clear span between supports exceeds the maximum unshored span published for the deck profile and gauge, shoring shall be provided at the locations indicated on [[drawing: the structural framing plans]].

+### The design, erection, and removal of shoring, and the slab strength at which it is removed, are governed by [[sync/concrete-formwork]].

+### The deck supplier shall identify every bay that requires shoring on the placement plan.

+### Concrete shall be placed to the basis indicated in the datasheet.

+```datasheet

+label: Composite Slab Placement Basis

+type: radio

+options:

+ - "Level top surface, with additional concrete for deck deflection"

+ - "Constant slab thickness following the deflected deck"

+default: "Level top surface, with additional concrete for deck deflection"

+```

+### A deck deflects under the wet concrete, and the two bases differ in what fills the sag: a level top surface takes extra concrete, which the deck and the frame carry as dead load, while a constant thickness follows the deflected profile and leaves a floor that dips at midspan; a level surface is the basis where the floor will receive a flatness-controlled finish, and a constant thickness is reached for where the added dead load governs the framing. {note}

+### Where a level top surface is the basis, the additional concrete weight from deck deflection shall be included in the deck design and in the design of the supporting members.

+## Concrete Placement Loads on the Deck {toc}

+### Concrete shall not be discharged in piles on the deck, and placement shall proceed from the supports toward midspan so that no area of deck carries more than the design construction load.

+### Concrete buggies and pumps shall operate on runways that distribute wheel loads across several panels, and runways shall be placed over supports where practicable.

+### Concentrated loads from pump lines, hoppers, and equipment shall not exceed the published construction load capacity of the deck at the location they bear.

+### Internal vibrators shall not be rested on or dragged across the deck.

+### A qualified individual designated by the Contractor shall monitor the deck during placement for deflection, lap separation, and leakage, and shall stop placement at any location showing distress until the cause is corrected.

+## Shear Studs Welded Through the Deck {toc}

+### Headed shear studs, their diameter, layout, welding procedure, and acceptance are furnished under [[sync/structural-steel-framing]]; this article governs the deck condition and sequence at stud locations.

+### The deck shall be fastened to its supports before studs are welded through it.

+### Studs shall be welded through a single thickness of deck, and the deck shall be laid out so that no end lap falls over a beam that receives studs, unless the stud welding procedure has been qualified for the lap condition.

+### A stud welded through two sheets at a lap fuses through twice the thickness the procedure was qualified for, and a lap that falls on a stud beam is a layout problem on the placement plan, not a welding problem in the field. {note}

+### At each stud location the deck shall bear tight on the beam flange, and standing water shall be removed from the deck before stud welding begins.

+### Coating burned away by stud welding shall be repaired under the coating repair article of this standard.

+# Roof Deck {toc}

+## Roofing Substrate {toc}

+### Requirements in this section apply where roof deck or acoustical roof deck is selected in the datasheet field for the deck types in scope.

+### Roof deck shall be installed in accordance with ANSI/SDI RD.

+### The roofing membrane, insulation, cover board, vapor retarder, and their attachment to the deck are governed by [[sync/membrane-roofing]], and the deck type, profile, and gauge installed shall be those the roofing assembly's uplift listing and fire classification name.

+### The deck installer shall complete attachment, closures, opening reinforcement, and coating repair in each roof area before that area is offered for the deck acceptance [[sync/membrane-roofing]] requires.

+### The roofing fasteners draw their withdrawal resistance from the deck top flange, so the roofing assembly is listed for a deck type and gauge, and a wide-rib profile is the common roof deck in part because its flat is wide enough to receive the roofing fastener plates. {note}

+## Wind Uplift {toc}

+### Roof deck attachment shall resist the net uplift pressures of ASCE/SEI 7 Chapter 30 for each roof zone.

+### Uplift is resisted by the support fasteners in pull-out from the flange and by the sheet in pull-over around the fastener head, and the pressures are highest at corners and edges, which is why the attachment schedule typically shows a denser pattern in those zones than in the field. {note}

+### The zoned attachment shown shall be executed without substitution, and the zone boundaries shall be laid out on the deck before fastening begins.

+### Roof deck shall be FM Approved as indicated in the datasheet.

+```datasheet

+label: FM Approval of Roof Deck

+type: radio

+options:

+ - "FM Approved profile under FM 4451 required"

+ - "FM Approval not required"

+default: "FM Approval not required"

+```

+### FM Approval is a requirement of the Owner's property insurer rather than of the building code, and it brings the FM Global data sheets on deck securement into the contract; where the insurer requires it, the deck profile and its attachment are governed by FM 4451 and FM Global Data Sheet 1-29 wherever those are more stringent than the structural design. {note}

+### Where FM Approval is required, the roof deck profile shall be listed in the current FM Approval Guide, and deck securement shall comply with FM Global Data Sheet 1-29.

+## Sumps and Drains {toc}

+### Sump pan locations shall be as indicated on [[drawing: the roof framing plans and plumbing drawings]].

+### Sump pans shall be furnished by the deck supplier, of not less than 14 gauge sheet in the roof deck finish, formed to the drain shown.

+### Sump pans shall be fastened to the deck around their perimeter and to the supports they bear on, so that diaphragm continuity is maintained across the sump.

+### A sump pan is a recessed plate that replaces the deck flat at a drain so the drain bowl sits below the insulation; an unattached pan is a hole in the diaphragm and a loose plate under the membrane. {note}

+# Openings and Penetrations {toc}

+## Openings Cut Without Added Reinforcement {toc}

+### Openings not exceeding the dimension indicated in the datasheet in any direction may be cut through the deck without added reinforcement, provided the opening does not interrupt a support fastener line or a side-lap fastener.

+```datasheet

+label: Maximum Opening Dimension Without Added Reinforcement

+type: range

+unit: in.

+options:

+ min: 4

+ max: 12

+ setpoints: [4, 6, 8, 10, 12]

+default: 6

+```

+### The SDI standards treat a hole of about 6 in. as one the deck carries around without help; the dimension is set lower where the deck is lightly gauged or heavily loaded and higher where the Engineer of Record has checked the profile for it. {note}

+### Openings within that limit shall be cut by the trade requiring them, cleanly, with the cut edge repaired under the coating repair article.

+### Openings in composite deck that are not shown on the placement plan shall be cut after the slab has reached its specified strength, unless the Engineer of Record approves cutting before concrete placement.

+### Cutting a hole in composite deck before the slab is placed leaves a form with a hole in it; cutting after the slab is cured removes a piece of a slab that is already carrying its load as a composite member, which the concrete around the hole is able to do. {note}

+## Reinforced and Framed Openings {toc}

+### Openings larger than the limit above shall be reinforced as indicated on [[drawing: the deck opening details]].

+### Sheet steel reinforcement that attaches only to the deck, including plates, bent plates, and angles fastened to the sheet, shall be furnished by the deck supplier and shown on the placement plan.

+### Opening frames that attach to the primary framing are furnished under [[sync/structural-steel-framing]] where the structural drawings show them, and their location shall be coordinated with the deck layout on the placement plan.

+### An opening larger than the limit shall not be cut until its reinforcement or frame is installed.

+### Deck around a reinforced opening shall be fastened to the reinforcement or frame at the spacing shown, so that the diaphragm shear path continues around the opening.

+### Where an opening is added after the deck is installed, the Contractor shall obtain the Engineer of Record's written direction for its reinforcement before cutting, and the party whose work required the opening shall bear the cost of that engineering and reinforcement.

+## Cutting and Coating Repair {toc}

+### Deck shall be cut with shears, saws, nibblers, or hole saws that leave a clean edge.

+### Where torch or plasma cutting is used, the cut edge shall be cleaned of slag and dross before coating repair.

+### Cut edges, burned coating at welds and studs, and coating damaged in handling or installation shall be repaired within seven days of the exposure that caused them and before the deck is concealed.

+### Repair of a galvanized or aluminum-zinc coating shall be performed under ASTM A780 with a zinc-rich coating.

+### Repair of a shop primer shall be performed with a primer compatible with the shop primer and with any finish or fireproofing to be applied over it.

+### White rust on galvanized deck, the loose white deposit that forms where water is held against the zinc without air, is wiped and dried where it is light; where it has gone to a dark or pitted surface the zinc beneath is gone and the area is repaired as damaged coating. {note}

+### Where the parties disagree whether a coating defect is light enough to clean rather than repair, the Engineer of Record shall make the initial determination.

+# Accessories {toc}

+## Accessories Furnished With the Deck {toc}

+### The deck supplier shall furnish the accessories indicated in the datasheet.

+```datasheet

+label: Deck Accessories Furnished by the Deck Supplier

+type: checkbox

+options:

+ - "Pour stops at slab edges"

+ - "Column closures"

+ - "Rib closures at deck ends"

+ - "End closures at walls and slab edges"

+ - "Sump pans"

+ - "Ridge and valley plates"

+ - "Cover plates at changes in deck direction and elevation"

+ - "Sheet steel opening reinforcement"

+default:

+ - "Pour stops at slab edges"

+ - "Column closures"

+ - "Rib closures at deck ends"

+ - "Sump pans"

+ - "Cover plates at changes in deck direction and elevation"

+```

+### Accessories shall be furnished in the same finish as the deck they serve.

+### Accessory gauge shall be not lighter than the gauge the SDI Manual of Construction with Steel Deck gives for the accessory and its span, and not lighter than the deck it attaches to.

+### Accessories shall be fastened to the deck and to the supports at not more than 12 in. on center, unless the placement plan shows closer fastening.

+## Pour Stops {toc}

+### A pour stop is a vertical sheet steel edge form at the slab edge that holds the wet concrete and projects past the edge member as far as the slab does. {note}

+### The pour stop height and overhang at each slab edge shall be as indicated on [[drawing: the slab edge details]].

+### Pour stop gauge shall be as indicated in the datasheet.

+```datasheet

+label: Pour Stop Gauge

+type: select

+derived: "the slab thickness above the deck and the pour stop overhang, per the SDI Manual of Construction with Steel Deck pour stop table"

+options:

+ - "16 gauge"

+ - "14 gauge"

+ - "12 gauge"

+ - "10 gauge"

+default: derived

+```

+### Pour stops shall be fastened to the deck and to the edge member at not more than 12 in. on center, with the fastening shown on the placement plan.

+### Where the structural drawings show a bent plate or angle slab edge as part of the structural steel, that edge form is furnished under [[sync/structural-steel-framing]], and the deck supplier furnishes pour stops only where the drawings show them.

+### A pour stop sized for the slab depth but not the overhang bows outward under the wet concrete and leaves a slab edge that is out of line and thicker than designed, which is why the SDI table reads the gauge from both dimensions. {note}

+## Closures {toc}

+### Rib closures shall be installed in the open ribs of roof deck at deck ends and terminations over conditioned space, so that the ribs do not carry unconditioned air into the building.

+### Rib and end closures shall be installed at every edge where composite or form deck ends, so that concrete does not leak from the ribs during placement.

+### Column closures shall be installed at every column the deck passes, and the opening around the column shall be covered before the deck is left at the end of a shift.

+### Closures within a listed fire-resistance-rated assembly shall be the closures the listing names.

+### Closures at walls that form part of a smoke or fire barrier shall be coordinated with the head-of-wall joint system under [[sync/fire-rated-wall-and-floor-assemblies]].

+# Installation {toc}

+## Bearing and Laps {toc}

+### Deck shall bear not less than 1-1/2 in. on each steel support, or the greater length ANSI/SDI requires for the deck type.

+### Bearing length on masonry and concrete supports shall be as indicated on [[drawing: the bearing details]].

+### End laps of roof deck and non-composite form deck shall occur over a support and shall be not less than 2 in.

+### End joints of composite floor deck shall be butted over a support, unless the placement plan shows lapped joints, and the butt joint shall be closed as the manufacturer's installation instructions require.

+### Composite deck is normally butted rather than lapped because a lap stacks two embossed sheets at the beam that most often receives shear studs, and because the lap edge projects into the concrete where the slab is thinnest. {note}

+### Panels shall be placed with the side laps nesting in one direction across each deck area and with panel ends aligned along each support.

+### Deck shall be placed with the span direction and the panel layout shown, and a panel shall not be turned, shortened, or placed to a different span condition to fit a bay.

+## Placement and Securing {toc}

+### Deck shall be placed in accordance with the reviewed placement plan and OSHA 29 CFR 1926 Subpart R.

+### Deck shall not be placed on framing that the erector has not released for loading under [[sync/structural-steel-framing]], or on joists whose bridging and end anchorage are not complete under [[sync/steel-joists]].

+### Deck bundles shall be landed only at the locations and on the members the erection plan identifies, within the limits [[sync/structural-steel-framing]] and [[sync/steel-joists]] set for landing bundles.

+### Each panel shall be laid tight to its neighbor and secured against displacement immediately upon placement.

+### Deck placed during a shift shall be fastened to its supports before the end of that shift, and no panel shall be left unattached overnight.

+### Loose deck is a sail, and a panel lifted by wind off a frame several stories up is the decking accident that OSHA's securing requirement exists to prevent. {note}

+### Openings in the deck, and the gaps between the deck and the columns it passes, shall be covered or guarded as soon as they are created and before the area is left.

+### Fall protection anchorage for decking operations is established under [[sync/fall-protection-anchorage]].

+### Final attachment to the pattern shown shall be complete in each area before concrete, roofing materials, or stored materials are placed on it.

+## Construction Loads on Installed Deck {toc}

+### Construction loads placed on the deck shall not exceed the published construction load capacity of the deck profile, gauge, and span condition at the location they bear.

+### Stored materials, equipment, and scaffold bases on the deck shall be placed over or adjacent to supports and distributed across several panels.

+### Wheeled equipment shall not be operated on the deck except on runways or where the manufacturer's published wheel load capacity covers it.

+### Roof deck shall not be used to store materials beyond the roof design loads after the roofing is installed.

+## Attachments to the Deck by Other Trades {toc}

+### Hangers for ceilings, piping, ductwork, and equipment shall not be supported from the deck unless the deck profile has a published hanger load that covers them and the hanger attachment is shown on the contract documents.

+### Suspended loads that the deck is permitted to carry shall be attached in accordance with [[sync/hangers-and-supports]].

+### Other trades shall not weld to, cut, or drive fasteners into the deck except as the contract documents show or the Engineer of Record approves in writing.

+### A deck flat is a thin sheet between ribs, and a hanger clip or a conduit strap fastened to it carries its load through that sheet rather than through the structure; deck profiles with a published hanger tab capacity are the exception, and the capacity is small. {note}

+## Fire-Resistance-Rated Assemblies {toc}

+### Required fire-resistance ratings and the listed assemblies that satisfy them shall be as indicated on [[drawing: the fire-resistance-rated assembly schedule]].

+### Where the deck is a component of a listed assembly, the deck profile, depth, gauge, finish, and closures installed shall be those the listing names.

+### The rating belongs to the whole assembly, which includes the deck, the slab or roofing above it, the fireproofing or ceiling below it, and the framing, so a deck that carries the same load as the listed one does not carry the same rating. {note}

+### Substituting any deck component of a listed assembly shall not be done without either selecting a different listed assembly or obtaining a written engineering evaluation acceptable to the Authority Having Jurisdiction.

+### The assemblies themselves are specified under [[sync/fire-rated-wall-and-floor-assemblies]], and the applied fireproofing under [[sync/fireproofing]].

+# Field Inspection {toc}

+## Verification Before Concrete or Roofing {toc}

+### Before concrete is placed on any deck area, and before roofing is installed on any roof deck area, the Contractor shall verify and record that the deck profile, gauge, and finish match the placement plan, that the support and side-lap fastening match the attachment schedule, that laps, bearing, closures, pour stops, and opening reinforcement are complete, and that cut edges and damaged coating are repaired.

+### For composite deck, the verification shall additionally record that the deck is clean of the bond breakers named in the composite action article.

+### The verification record for each area shall be available to the special inspector before concrete or roofing covers that area.

+### Deck is inspected before it is covered because nothing about it can be verified afterward: the fastener count under a slab or a membrane is the count on the record. {note}

+## Fastener Inspection {toc}

+### Special inspection of deck attachment shall be performed to the extent indicated in the datasheet.

+```datasheet

+label: Special Inspection Extent for Deck Attachment

+type: radio

+options:

+ - "Periodic sampling at each support condition and in each zone, under the Statement of Special Inspections"

+ - "Continuous during attachment of every deck area"

+default: "Periodic sampling at each support condition and in each zone, under the Statement of Special Inspections"

+```

+### IBC Chapter 17 assigns periodic inspection to deck welding and mechanical fastening, and periodic sampling across every zone and support condition is the norm; continuous inspection is reached for on a diaphragm whose capacity is close to its demand, or where an installer's early work has shown a pattern of defects. {note}

+### Welds shall be inspected visually under AWS D1.3 for visible diameter or length, fused perimeter, cracks, surface porosity, and burn-through.

+### Powder-actuated fasteners and screws shall be inspected for seating, for the fastener listed in the evaluation report, for the correct count at each support, and for conformance to the pattern and spacing shown.

+### Where the parties disagree whether a fastener is properly seated, the Engineer of Record shall make the initial determination, and the Engineer of Record may require pull-out or shear testing of representative fasteners to resolve it.

+### The cost of testing ordered to resolve a dispute shall be borne by the Contractor where the fasteners fail, and by the Owner where they pass.

+## Nonconforming Deck Work {toc}

+### Deck work that does not conform to the contract documents, the reviewed placement plan, or the ANSI/SDI standards shall be documented as a nonconformance and reported in writing to the Engineer of Record, the Contractor, and the Owner.

+### Concrete shall not be placed, and roofing shall not be installed, over a documented nonconformance until the Engineer of Record has issued a written disposition.

+### Each disposition shall be one of the following: reject and correct; accept as-is supported by a written engineering evaluation; or accept with a stated compensating measure such as added fasteners or added reinforcement.

+### The cost of evaluating and correcting a nonconformance shall be borne by the party whose work produced it.

+### The cost of re-inspection following a rejection shall be borne by the party whose work was rejected.

+# Delivery, Storage, and Handling {toc}

+## Delivery and Site Storage {toc}

+### Deck shall be delivered in the manufacturer's bundles, each tagged with the manufacturer's designation, profile, gauge, finish, panel length, quantity, and the deck area it is for.

+### Site storage shall satisfy the requirements indicated in the datasheet.

+```datasheet

+label: Deck Storage Requirements

+type: checkbox

+options:

+ - "Store bundles on dunnage clear of the ground"

+ - "Slope bundles to drain"

+ - "Cover bundles with a ventilated waterproof cover"

+ - "Separate bundles from mud, vegetation, and chemicals"

+ - "Limit stack height to the manufacturer's published maximum"

+default:

+ - "Store bundles on dunnage clear of the ground"

+ - "Slope bundles to drain"

+ - "Cover bundles with a ventilated waterproof cover"

+ - "Limit stack height to the manufacturer's published maximum"

+```

+### Water held between nested sheets in a bundle is the condition that produces white rust on galvanized deck, and a bundle under an unventilated tarp holds water as well as an uncovered one does; the cover keeps rain off and the ventilation lets the sheets dry. {note}

+### Bundles shall be lifted with slings and spreaders that do not crush the ribs or score the coating, and wire rope shall not bear directly on the sheet.

+### Bundles stored on the erected frame shall be placed at locations the erector has approved and shall not exceed the load the supporting members carry at that stage of erection.

+## Damaged Panels {toc}

+### Panels that arrive bent, crushed, kinked, with ribs out of profile, or with coating damage beyond the repair ASTM A780 permits shall be reported to the Engineer of Record before they are installed.

+### The Engineer of Record shall direct repair, acceptance, or replacement of a damaged panel in writing.

+### A panel with a crushed rib or a permanent set shall not be straightened and installed without the manufacturer's written direction.

+### The section properties of a cold-formed profile depend on the ribs holding their shape, and a crushed rib straightened in the field is a different section from the one in the load table. {note}

+# Warranty {toc}

+## Correction Period {toc}

+### The deck installer shall warrant the deck work for the period indicated in the datasheet, measured from the date of substantial completion.

+```datasheet

+label: Correction Period for Deck Work

+type: range

+unit: years

+options:

+ min: 1

+ max: 5

+ setpoints: [1, 2, 3, 5]

+default: 1

+```

+### The warranty shall cover the deck furnished against defects in material and workmanship, and the installation against incorrect profile, gauge, or finish, missing or defective support and side-lap fasteners, incomplete closures and accessories, and coating damage not repaired.

+### Where a warranted defect is corrected, the corrected work shall carry a fresh correction period of the same length measured from the date of correction, or the remainder of the original period, whichever ends later.

+### The party performing a warranty correction shall bear the cost of removing and replacing other work that must be disturbed to reach the defect.

+## Warranty Exclusions {toc}

+### The warranty does not cover loading beyond the design loads stated in the contract documents.

+### The warranty does not cover openings cut, attachments made, or fasteners driven by other trades after the deck installer has completed and turned over the deck.

+### The warranty does not cover corrosion of deck in an environment more aggressive than the one the specified finish addresses.

+### The deck manufacturer's material warranty shall be assigned to the Owner and included in the closeout submittals.

+### Bonds and the form of the warranty documents are established under [[sync/warranties-and-bonds]].

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