USACE / NAVFAC / AFCESA UFGS-05 30 00 (July 2006)
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Preparing Activity: NAVFAC Superseding
UFGS-05 30 00 (April 2006)
UNIFIED FACILITIES GUIDE SPECIFICATIONS
References are in agreement with UMRL dated January 2009
SECTION 05 30 00
STEEL DECKS
07/06
NOTE: This guide specification covers the requirements for steel floor and
roof decks, including accessories.
Edit this guide specification for project specific requirements by adding, deleting,
or revising text. For bracketed items, choose applicable items(s) or insert
appropriate information.
Remove information and requirements not required in respective project, whether
or not brackets are present.
Comments and suggestions on this guide specification are welcome and should
be directed to the technical proponent of the specification. A listing of technical
proponents, including their organization designation and telephone number, is
on the Internet.
Recommended changes to a UFGS should be submitted as a Criteria Change Request
(CCR).
NOTE: Determine which roof areas on the structure are considered by the structural
engineer as functioning as diaphragms for the lateral force resisting system.
Composite decks and diaphragm acting decks, including connections, should be
designed by the structural engineer according to the Steel Deck Institute.
Refer to the Uniform Building Code for diaphragm decks in seismic areas. All
connections must be shown. Drawings must show wind uplift loads for roof joist
design in addition to the items listed below.
For non-diaphragm acting, non-composite decks, the contractor may provide the
deck design and connections. In this case, the drawings must show roof live
loads, including snow loads, and wind loads, including internal and external
pressures and high intensity zones. Consider showing a roof uplift and snow
load plan on the drawings.
In addition to the above, show the following information on the project drawings:
1. Structural properties (height, sheet thickness, and section moduli or moment
of inertia).
2. Floor and roof deck penetrations.
3. Location, spacing, and size of hanger clips or loops.
4. Closure plates.
5. Location of cellular decking and whether it is to be used as electrical
raceway.
6. Weld or fastener spacing.
7. Whether construction is based on shored construction.
Design steel deck to carry the concrete and steel deck dead loads, and the live
loads during construction before the concrete sets. Additional concrete dead
load due to deflection of the deck shall be considered when necessary to prevent
excessive stresses or deflections in the deck.
PART 1 GENERAL
NOTE: The structural steel design must meet the requirements of OSHA Steel
Erection Standard, 29 CFR Part 1926, Subpart R-Steel Erection, Effective Date
January 18, 2002.
1.1 REFERENCES
NOTE: This paragraph is used to list the publications cited in the text of
the guide specification. The publications are referred to in the text by basic
designation only and listed in this paragraph by organization, designation,
date, and title.
Use the Reference Wizard's Check Reference feature when you add a RID outside
of the Section's Reference Article to automatically place the reference in the
Reference Article. Also use the Reference Wizard's Check Reference feature
to update the issue dates.
References not used in the text will automatically be deleted from this section
of the project specification when you choose to reconcile references in the
publish print process.
The publications listed below form a part of this specification to the extent referenced. The publications are
referred to within the text by the basic designation only.
[AMERICAN INSTITUTE OF STEEL CONSTRUCTION (AISC)AISC 360(2005) Specification for Structural Steel Buildings, with Commentary][AMERICAN IRON AND STEEL INSTITUTE (AISI)AISI SG-913(1991) LRFD Cold-formed Steel Design ManualAISI SG03-3(2002) Cold-Formed Steel Design Manual Set][AMERICAN WELDING SOCIETY (AWS)AWS D1.1/D1.1M(2008) Structural Welding Code - SteelAWS D1.3/D1.3M(2008; Errata 2008) Structural Welding Code - Sheet Steel][ASTM INTERNATIONAL (ASTM)ASTM A 1008/A 1008M(2008a) 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 HardenedASTM A 108(2007) Standard Specification for Steel Bar, Carbon and Alloy, Cold-FinishedASTM A 123/A 123M(2008) Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel ProductsASTM A 36/A 36M(2008) Standard Specification for Carbon Structural SteelASTM A 570/A 570M(1998) Standard Specification for Steel, Sheet and Strip, Carbon, Hot-RolledASTM A 653/A 653M(2008) Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip ProcessASTM A 780(2001; R 2006) Standard Practice for Repair of Damaged and Uncoated Areas of Hot-Dip Galvanized CoatingsASTM A 792/A 792M(2008) Standard Specification for Steel Sheet, 55% Aluminum-Zinc Alloy-Coated by the Hot-Dip ProcessASTM C 423(2008a) Sound Absorption and Sound Absorption Coefficients by the Reverberation Room MethodASTM D 1056(2007) Standard Specification for Flexible Cellular Materials - Sponge or Expanded RubberASTM D 1149(2007) Standard Test Method for Rubber Deterioration - Surface Ozone Cracking in a ChamberASTM D 746(2007) Standard Test Method for Brittleness Temperature of Plastics and Elastomers by ImpactASTM E 84(2008a) Standard Test Method for Surface Burning Characteristics of Building Materials][FM GLOBAL (FM)FM DS 1-28(2002) Design Wind LoadsFM P7825(2005) Approval Guide][NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)NFPA 70(2007; AMD 1 2008) National Electrical Code - 2008 Edition][STEEL DECK INSTITUTE (SDI)SDI 30(2001) Design Manual for Composite Decks, Form Decks, and Roof DecksSDI DDMO3(3rd Edition) Diaphragm Design ManualSDI DDP(1987; R 2000) Deck Damage and PenetrationsSDI MOC2(2006) Manual of Construction with Steel Deck][THE SOCIETY FOR PROTECTIVE COATINGS (SSPC)SSPC Paint 20(2002; E 2004) Paint Specification No. 20 Zinc-Rich Coating Type I Inorganic and Type II Organic][U.S. DEPARTMENT OF DEFENSE (DOD)UFC 3-310-01Load Assumptions for Buildings][UNDERWRITERS LABORATORIES (UL)UL 209(2005; Rev thru May 2007) Cellular Metal Floor Raceways and FittingsUL 580(2006) Tests for Uplift Resistance of Roof AssembliesUL Bld Mat Dir(2008) Building Materials Directory]1.2 SUBMITTALS
NOTE: Review Submittal Description (SD) definitions in Section 01 33 00 SUBMITTAL
PROCEDURES and edit the following list to reflect only the submittals required
for the project. Submittals should be kept to the minimum required for adequate
quality control.
A “G” following a submittal item indicates that the submittal requires Government
approval. Some submittals are already marked with a “G”. Only delete an existing
“G” if the submittal item is not complex and can be reviewed through the Contractor’s
Quality Control system. Only add a “G” if the submittal is sufficiently important
or complex in context of the project.
For submittals requiring Government approval on Army projects, a code of up
to three characters within the submittal tags may be used following the "G"
designation to indicate the approving authority. Codes for Army projects using
the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO"
for District Office (Engineering Division or other organization in the District
Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project
Office. Codes following the "G" typically are not used for Navy, Air Force,
and NASA projects.
Choose the first bracketed item for Navy, Air Force and NASA projects, or choose
the second bracketed item for Army projects.
Government approval is required for submittals with a "G" designation; submittals not having a "G" designation
are [for Contractor Quality Control approval.][for information only. When used, a designation following the
"G" designation identifies the office that will review the submittal for the Government.] Submit the following
in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:
SD-02 Shop Drawings
Fabrication Drawings
Metal Floor Deck Units
Cant Strips
Ridge and Valley Plates
Metal Closure Strips
SD-03 Product Data
Accessories
Deck Units
Galvanizing Repair Paint
Joint Sealant Material
[Mechanical Fasteners]
Metal Floor Deck Units
Piston Tool Operator
Repair Paint
Sound Absorbing Material
Welder Qualifications
Welding Equipment
Welding Rods and Accessories
SD-04 Samples
Metal Roof Deck Units
Flexible Closure Strips
[Accessories]
SD-05 Design Data
Deck Units
Submit manufacturer's design calculations, or applicable published literature for the structural
properties of the proposed deck units.
SD-07 Certificates
.Welding Procedures
Fire Safety
Wind Storm Resistance
1.3 QUALITY ASSURANCE
1.3.1 Deck Units
Furnish deck units and accessory products from a manufacturer regularly engaged in manufacture of steel decking.
[Provide a 0.19 sq meter 2 sq ft. sample of decking material and each accessory to be used.] [Provide a sample
of acoustical material to be used.] Provide manufacturer's certificates attesting that the decking material
meets the specified requirements.
1.3.2 Certification of Piston Tool Operator
Manufacturer's certificate attesting that the operators are authorized to use the low velocity piston tool.
1.3.3 Qualifications for Welding Work
[Follows Welding Procedures in accordance with AWS D1.1/D1.1M. Test specimens shall be made in the presence
of Contracting Officer and shall be tested by an approved testing laboratory at the Contractor's expense.
Submit qualified Welder Qualifications in accordance with AWS D1.1/D1.1M, or under an equivalent approved qualification
test. Perform tests on test pieces in positions and with clearances equivalent to those actually encountered.
If a test weld fails to meet requirements, perform an immediate retest of two test welds until each test weld
passes. Failure in the immediate retest will require the welder be retested after further practice or training,
performing a complete set of test welds.]
Submit manufacturer's catalog data for Welding Equipment and Welding Rods and Accessories.
1.3.4 Regulatory Requirements
NOTE: For roofing systems with insulation/ underlayment applied directly to
deck, include applicable paragraph/sentence for fire rated and/or windstorm
resistance. Specify roof assemblies that are in consonance with other roof
components (Supports, deck, adhesives, bitumen, fasteners and attachments, vapor
retarders, insulation, membrane, and surfacing) so that the roof construction
assembly results in UL or FM fire-resistance and windstorm resistance classification
required by project criteria.
1.3.4.1 Fire Safety
Test roof deck as a part of a roof deck construction assembly of the type used for this project, listing as fire
classified in the UL Bld Mat Dir, or listing as Class I construction in the FM P7825, and so labeled.
1.3.4.2 Wind Storm Resistance
NOTE: Select the appropriate wind uplift pressure based on wind speeds used
by the structural designer in accordance with UFC 3-310-01, "Load Assumptions
for Buildings".
Provide roof construction assembly capable of withstanding an uplift pressure of [3] [5] [_____] kPa [60] [90]
[_____] pounds per square foot when tested in accordance with the uplift pressure test described in the FM DS 1-28
or as described in UL 580 and in general compliance with UFC 3-310-01.
1.3.5 Fabrication Drawings
Show type and location of units, location and sequence of connections, bearing on supports, methods of anchoring,
attachment of accessories, adjusting plate details, size and location of holes to be cut and reinforcement to
be provided, the manufacturer's erection instructions and other pertinent details.
1.4 DELIVERY, STORAGE, AND HANDLING
Deliver deck units to the site in a dry and undamaged condition. Store and handle steel deck in a manner to
protect it from corrosion, deformation, and other types of damage. Do not use decking for storage or as working
platform until units have been fastened into position. Exercise care not to damage material or overload decking
during construction. Must not exceed the design live load. The maximum uniform distributed storage load. Stack
decking on platforms or pallets and cover with weathertight ventilated covering. Elevate one end during storage
to provide drainage. Maintain deck finish at all times to prevent formation of rust. Repair deck finish using
touch-up paint. Replace damaged material.
1.5 DESIGN REQUIREMENTS FOR ROOF DECKS
1.5.1 Properties of Sections
Properties of metal roof deck sections must comply with engineering design width as limited by the provisions
of AISI SG-913.
1.5.2 Allowable Loads
Indicate total uniform dead and live load for detailing purposes.
PART 2 PRODUCTS
2.1 MATERIALS
2.1.1 Steel Sheet
NOTE: Minimum metal thickness should be 0.35 mm 0.014 inch for form decks and
0.75 mm 0.028 inch for roof and composite decks. However, for corrosive exposures,
consider 0.92 mm 0.034 inch minimum thickness.
NOTE: Include requirements for acoustical steel deck when required by the design,
otherwise delete. Acoustical steel deck is designed to serve as a sound absorbing
ceiling as well as a structural deck. Acoustical noncellular steel roof deck
is identical in appearance to standard steel roof deck (noncellular) except
that the webs of the ribs are perforated to receive fiber glass sound absorbing
material, in roll form, placed between the perforated ribs. Acoustical noncellular
roof deck should not be used without modifying FM or UL requirements for roof
decks in Division 07. Acoustical cellular steel deck is identical in appearance
to cellular steel deck, except that the steel bottom plate (ceiling) is perforated.
In addition, acoustical deck serves as both a deck and acoustical ceiling (in
lieu of a separate finished acoustical ceiling) where noise levels are to be
controlled. Include cover plates when cellular deck is specified. Include
50 mm 2 inch end laps for non-cellular deck.
Flat rolled carbon steel sheets of structural quality, [thickness not less than [indicated] [0.75] [_____] mm
[0.028] [_____] inch before coating,] meeting the requirements of AISI SG03-3, except as modified herein. [For
acoustical steel deck units, provide perforated sheets with 4 mm 5/32 inch diameter holes staggered 10 mm 3/8
inch on-centers.]
2.1.2 Steel Coating
NOTE: Specify coated steel for most floor decks and all roof decks. Use Z275
G90 galvanized coating or galvalume ASTM A 792/A 792M for severe corrosive
conditions. Galvanize Z275 G90 deck used with concrete or spray applied fire
protection. Use Z180 G60 when severe conditions do not exist. Prime painted,
not coated, should be specified only for low-budget jobs where deck is not critical.
Include sentence in brackets when applicable. Coordinate cellular deck wire
raceways with appropriate sections in Division 16 and add information where
needed.
ASTM A 653/A 653M designation [Z275] [_____] [G90] [_____] galvanized, or ASTM A 792/A 792M designation AZ165
AZ55, aluminum-zinc alloy. Apply coating to both sides of sheet. Conform to UL 209 for coating on decking
provided as wire raceways.
2.1.3 Mixes
2.1.3.1 Galvanizing Repair Paint for Floor Decks
Provide a high-zinc-dust content paint for regalvanizing welds in galvanized steel conforming to ASTM A 780.
2.1.4 Galvanized Steel Angles for Roof Decks
Provide hot-rolled carbon steel angles conforming to ASTM A 36/A 36M, merchant quality, Grade Designation SAE/AISI
1023 or SAE/AISI 1025, and hot-dip galvanized in accordance with ASTM A 123/A 123M.
2.1.5 Joint Sealant Material for Roof Decks
Provide a nonskinning, gun-grade, bulk compound material as recommended by the manufacturer.
2.1.6 Galvanizing Repair Paint for Roof Decks
Provide a high zinc-dust content paint for regalvanizing welds in galvanized steel and shall conform to ASTM A 780
.
2.1.7 Flexible Closure Strips for Roof Decks
NOTE: Delete paragraph heading and following paragraphs when fire-resistance-rated
construction is required.
Provide strips made of elastomeric material specified and premolded to the configuration required to provide
tight-fitting closures at open ends and sides of steel roof decking.
Provide a vulcanized, closed-cell, expanded chloroprene elastomer having approximately 25 kilopascal 3.5 psi
compressive-deflection at 25 percent deflection (limits), conforming to ASTM D 1056, Grade No. SCE 41, with the
following additional properties:
Brittleness temperature of minus 40 degrees C minus 40 degrees F when tested in accordance with ASTM D 746
.
Flammability resistance with a flame spread rating of less than 25 when tested in accordance with ASTM E 84
.
Resistance to ozone must be "no cracks" after exposure of a sample kept under a surface tensile strain
of 25 percent to an ozone concentration of 100 parts per million of air by volume in air for 100 hours
at 40 degrees C 104 degrees F and tested in accordance with ASTM D 1149.
Provide a elastomeric type adhesive with a chloroprene base as recommended by the manufacturer of the
flexible closure strips.
[2.1.8 Sound Absorbing Material
NOTE: Include requirements for acoustical steel deck when required by the design,
otherwise delete. Acoustical steel deck is designed to serve as a sound absorbing
ceiling as well as a structural deck. Acoustical noncellular steel roof deck
is identical in appearance to standard steel roof deck (noncellular) except
that the webs of the ribs are perforated to receive fiber glass sound absorbing
material, in roll form, placed between the perforated ribs. Acoustical noncellular
roof deck should not be used without modifying FM or UL requirements for roof
decks in Division 07. Acoustical cellular steel deck is identical in appearance
to cellular steel deck, except that the steel bottom plate (ceiling) is perforated.
In addition, acoustical deck serves as both a deck and acoustical ceiling (in
lieu of a separate finished acoustical ceiling) where noise levels are to be
controlled. Include cover plates when cellular deck is specified. Include
50 mm 2 inch end laps for non-cellular deck.
Provide [glass fiber in roll or premolded form for acoustical noncellular steel roof deck] [and] [glass fiber
rigid strip for acoustical cellular steel deck] in accordance with the manufacturer's standards.
]2.2 ACCESSORIES
Provide accessories of same material as deck, unless specified otherwise. Provide manufacturer's standard type
accessories, as specified.
2.2.1 Adjusting Plates
Provide adjusting plates, or segments of deck units, of same thickness and configuration as deck units in locations
too narrow to accommodate full size units. Provide factory cut plates of predetermined size where possible.
2.2.2 End Closures
Fabricated of sheet metal by the deck manufacturer. Provide end closures minimum 0.75 mm 0.028 inch thick to
close open ends at [exposed edges of floors,] [parapets,] [end walls,] [eaves,] [and] openings through deck.
2.2.3 Partition Closures
NOTE: Coordinate options in paragraphs entitled "Partition Closures" and "Closures
Above Partitions." When a suspended acoustical ceiling is provided below the
metal deck, the closures above partitions may be eliminated for acoustical purposes
provided the acoustical properties of the ceiling are adequate to restrict sound
transmission to a level consistent with the facility design criteria.
Provide closures for closing voids above interior walls and partitions that are perpendicular to the direction
of the configurations. [Provide rubber, plastic, or sheet steel closures above typical partitions.] [Provide
minimum one inch thick soft composition rubber closures above walls and partitions contiguous to acoustical steel
deck.] [Provide sheet steel closures above fire-resistant interior walls and partitions located on both sides
of wall or partition.] [Provide glass fiber blanket insulation in the space between pairs of closures at acoustical
partitions.]
NOTE: Drawings shall show closures above interior partitions where required.
On fire partitions, metal closures will be shown on both sides of the wall.
2.2.4 Closure Plates for Composite Deck
Support and retain concrete at each floor level. Provide edge closures at all edges of the slab of sufficient
strength and stiffness to support the wet concrete. Provide metal closures for all openings in composite steel
deck 6 mm 1/4 inch and over.
2.2.5 Sheet Metal Collar
Where deck is cut for passage of pipes, ducts, columns, etc., and deck is to remain exposed, provide a neatly
cut sheet metal collar to cover edges of deck. Do not cut deck until after installation of supplemental supports.
2.2.6 Cover Plates
Sheet metal to close panel edge and end conditions, and where panels change direction or butt. Polyethylene-coated,
self-adhesive, 50 mm 2 inch wide joint tape may be provided in lieu of cover plates on flat-surfaced decking
butt joints.
Fabricate cover plates for abutting floor deck units from the specified structural-quality steel sheets not less
than nominal 1.3 millimeter 18 gagethick before galvanizing. Provide 150 millimeter 6 inch wide cover plates
and form to match the contour of the floor deck units.
2.2.7 Roof Sump Pans
NOTE: Coordinate sump pans with type of roof drain specified.
Sump pans must be provided for roof drains and must be minimum 2 mm 0.075 inch thick steel, [flat] [recessed]
type. Shape sump pans to meet roof slope by the supplier or by a sheet metal specialist. Provide bearing flanges
of sump pans to overlap steel deck a minimum of 75 mm 3 inch. Shape, size, and reinforce the opening in bottom
of the sump pan to receive roof drain.
2.2.8 Column Closures
Sheet metal, minimum 0.85 mm 0.0358 inch thick or metal rib lath.
2.2.9 Access Hole Covers
Sheet metal, minimum 1.2 mm 0.0474 inch thick.
2.2.10 Hanger
NOTE: Location, spacing, and size of hangar clips or loops must be indicated
or specified, as applicable to the project.
Provide clips or loops for [utility systems] [and] [suspended ceilings] of one or more of the following types:
a. Lip tabs or integral tabs where noncellular decking or flat plate of cellular section is
1.2 mm 0.0474 inch thick or more, and a structural concrete fill is used over deck.
b. Slots or holes punched in decking for installation of pigtails.
c. Tabs driven from top side of decking and arranged so as not to pierce electrical cells.
d. Decking manufacturer's standard as approved by the Contracting Officer.
2.2.11 Shear Connectors
NOTE: Designer shall determine the necessity for shear connectors as per AISC
ASD Spec S335. Designer shall show the size, spacing, and location of the shear
connectors.
Provide shear connectors as [headed stud type, ASTM A 108, Grade 1015 or 1020, cold finished carbon steel with
dimensions complying with AISC 360] [and] [or] [strap type, ASTM A 570/A 570M, Grade D, hot-rolled carbon steel].
[2.2.12 Mechanical Fasteners
NOTE: Delete this paragraph when only welding is allowed.
Provide mechanical fasteners, such as powder actuated or pneumatically driven fasteners, for anchoring the deck
to structural supports and adjoining units that are designed to meet the loads indicated. Provide positive locking-type
fasteners standard with the Steel Deck Institute and the steel deck manufacturer, as approved by the Contracting
Officer.
]2.2.13 Miscellaneous Accessories
NOTE: Ensure that items listed in this paragraph are indicated on the project
drawings.
Furnish the manufacturer's standard accessories to complete the deck installation. Furnish metal accessories
of the same material as the deck and with the minimum design thickness as follows: saddles, 1.204 mm (0.0474
inch); 0.0474 inch; welding washers, 1.519 mm 0.0598 inch cant strip, 0.749 mm 0.0295 inch other metal accessories,
0.909 mm 0.0358 inch unless otherwise indicated. Accessories must include but not be limited to saddles, welding
washers, fasteners, cant strips, butt cover plates, underlapping sleeves, and ridge and valley plates.
2.3 FABRICATION
Furnish one sample of each type of Metal Floor Deck Units used to illustrate the actual cross section dimensions
and configuration.
Furnish sample of Metal Roof Deck Units used to illustrate actual cross section dimensions and configurations.
Furnish one sample of each type Flexible Closure Strips, 300 millimeter 12 inch long.
2.3.1 Deck Units
NOTE: Cellular and noncellular decking may or may not be combined into one
deck system. If only one type is used, delete the other type. Where deck design
is based on shored construction, edit and include requirements in the last bracketed
sentence and indicate on structural drawings that decking must be shored during
placement and curing of concrete.
NOTE: The steel deck shall be designed according to SDI Pub No. 30 Verify grades
of steel are appropriate for design. SDI allows ASTM A 653/A 653M, Grade 230
Grade 33; ASTM A 1008, Grades C and D; or ASTM A 792/A 792M. Phosphatized
and painted coating is not recommended for the majority of applications. The
steel deck specified in this guide specification will be used in conjunction
with insulation and built-up roofing in accordance with TM 5-805-14, Roofing
and Waterproofing, or will be used as a permanent form for concrete or as part
of a composite deck assembly. Steel deck for lightweight concrete roofs is
specified in Section 03340 ROOF DECKING, CAST-IN-PLACE LOW DENSITY CONCRETE.
Drawings should show location and extent of steel deck, complete structural
support including openings greater than 300 mm 12 inch, type and location of
accessories, uniformly distributed live loads (positive and negative) in kPa
(psf), thickness, and required values for section modulus and moment of inertia
per mm foot of width. Moments of inertia and section modulus values will be
designed based on procedures set forth in SDI Pub No. 30. Steel decks used
as diaphragms must meet the requirements of TM 5-809-10, Chapter 5. Subsystems
for fire-rated construction, including roof deck, joists, insulation, built-in
roofing, and ceiling material will be indicated. When the finished installations
will be exposed to high humidity, seacoast atmosphere or corrosive chemical
fumes special care in specifying the finish should be used and individual manufacturers
should be consulted for the specific application. Where sprayed-on fireproofing
is used only galvanized decking with a G90 coating will be allowed. ASTM A
653/A 653M, G90 coating should be specified in paragraphs Roof Deck, Composite
Deck, and Form Deck. Notes on the drawings should indicate the attachment method
to be used, and should give the size and spacing for perimeter, side lap, intermediate
supports, and end lap attachments.
2.3.1.1 Cellular Metal Floor Deck Units
Provide decking as wire raceways conforming to NFPA 70. Fabricate units from the specified structural-quality
steel sheets. Provide nominal thickness of the steel sheets, before galvanizing, a minimum 1.3 millimeter 18-gage
for the upper element of the floor deck unit, and a minimum 1.6 millimeter 16-gage for the lower element of
the floor deck unit.
Provide sufficient welds, forming the steel sheets into the cellular floor deck unit, to develop the full horizontal
shear at the plane where the steel sheets are joined.
NOTE: Delete inapplicable paragraphs. When fire-resistance-rated construction
is required, the fire rating agency's specifications for the applicable floor
or roof and ceiling construction must be consulted.
Cellular metal floor deck units must be fluted section cells combined on a flat plate having interlocking type
sidelaps. Provide depth, width of unit, number of cells per unit, and width of cells as follows:
NOTE: Delete the following cellular floor deck units that are not required.
DEPTH WIDTH OF UNIT NUMBER OF CELLS WIDTH OF CELLS
MINIMUM NOMINAL PER UNIT NOMINAL
(millimeter) (millimeter) _______________ (millimeter)
38 600 4 92
38 600 2 245
38 300 1 245
75 600 3 143
75 600 2 245
75 300 1 245
115 600 4 67
115 600 2 245
115 300 1 245
150 600 2 245
150 300 1 245
190 600 2 245
190 300 1 245
DEPTH WIDTH OF UNIT NUMBER OF CELLS WIDTH OF CELLS
MINIMUM NOMINAL PER UNIT NOMINAL
(inch) (inch) (inch)
1-1/2 24 4 3-5/8
1-1/2 24 2 9-5/8
1-1/2 12 1 9-5/8
3 24 3 5-5/8
3 24 2 9-5/8
3 12 1 9-5/8
4-1/2 24 4 2-5/8
4-1/2 24 2 9-5/8
4-1/2 12 1 9-5/8
6 24 2 9-5/8
6 12 1 9-5/8
7-1/2 24 2 9-5/8
7-1/2 12 1 9-5/8
Cellular metal floor deck units must be fluted section cells combined with a matching fluted bottom section having
interlocking type sidelaps. Provide depth, width of unit, number of cells per unit, and width of cells as follows:
NOTE: Delete the following floor deck units that are not required.
DEPTH WIDTH OF UNIT NUMBER OF CELLS WIDTH OF CELLS
MINIMUM NOMINAL PER UNIT NOMINAL
(millimeter) (millimeter) _______________ (millimeter)
75 600 4 92
75 300 1 245
150 600 3 143
DEPTH WIDTH OF UNIT NUMBER OF CELLS WIDTH OF CELLS
MINIMUM NOMINAL PER UNIT NOMINAL
(inch) (inch) _______________ (inch)
3 24 4 3-5/8
3 12 1 9-5/8
6 24 3 5-5/8
Conform to SDI 30 for deck units. Conform to [ASTM A 653/A 653M, SQ, Grade 230, Grade 33]; [ASTM A 1008/A 1008M
Coated Carbon Steel Sheets, Grade C, 228 mPa, 33, 000 psi minimum yield strength]; or [ASTM A 792/A 792M Coated
Steel Sheets, Grade 33] for formed [cellular] [and] [non-cellular] decking and accessories. Use panels of maximum
possible lengths to minimize end laps. Fabricate deck units in lengths to span 3 or more supports with flush,
telescoped, or nested 50 mm 2 inch laps at ends, and interlocking, or nested side laps, unless otherwise indicated.
Deck with cross-sectional configuration differing from the units indicated may be used, provided that the properties
of the proposed units, determined in accordance with AISI SG03-3, are equal to or greater than the properties
of the units indicated and that the material will fit the space provided without requiring revisions to adjacent
materials or systems. [Factory apply a standard, phosphatized and painted, baked-on enamel finish to underside
of steel decking.] [[Floor] [and] [Road] deck system design is based on shared construction.]
2.3.2 Open Beam, Metal Floor Deck Units
NOTE: Delete paragraph heading and following paragraphs when a combination
of cellular and open beam metal floor deck units are not required.
Fabricate open beam metal floor deck units of the specified structural-quality steel sheets. Provide nominal
thickness of the steel sheets before galvanizing of minimum 1.3 millimeter 18-gage.
Provide open beam metal floor deck units with a fluted section having interlocking type sidelaps. Provide depth,
width of unit, number of flutes per unit, and width of flutes as follows:
NOTE: Delete the following open beam floor deck units that are not required.
Open beam floor deck units must match the depth and fluted section of the adjacent
cellular floor deck units as specified.
DEPTH WIDTH OF UNIT NUMBER OF CELLS WIDTH OF CELLS
MINIMUM NOMINAL PER UNIT NOMINAL
(millimeter) (millimeter) _______________ (millimeter)
38 600 4 92
38 600 2 245
38 300 1 245
75 600 3 143
75 600 2 245
75 300 1 245
115 600 4 67
115 600 2 245
115 300 1 245
150 600 2 245
150 300 1 245
190 600 2 245
190 300 1 245
DEPTH WIDTH OF UNIT NUMBER OF CELLS WIDTH OF CELLS
MINIMUM NOMINAL PER UNIT NOMINAL
(inch) (inch) _______________ (inch)
1-1/2 24 4 3-5/8
1-1/2 24 2 9-5/8
1-1/2 12 1 9-5/8
3 24 3 5-5/8
3 24 2 9-5/8
3 12 1 9-5/8
4-1/2 24 2 9-5/8
4-1/2 12 2 2-5/8
4-1/2 12 1 9-5/8
6 24 2 9-5/8
6 12 1 9-5/8
7-1/2 24 2 9-5/8
7-1/2 12 1 9-5/8
2.3.3 Length of Floor Deck Units
Provide floor deck units of sufficient length to span three or more spacings where possible.
2.3.4 Roof Deck
NOTE: The epoxy coating is expensive and should only be considered for corrosive
environments where justified by a cost analysis.
Conform to ASTM A 792/A 792M or ASTM A 1008/A 1008M for deck used in conjunction with insulation and built-up
roofing. Fabricate roof deck units of [[0.75] [_____] mm [0.0295] [_____] inch design thickness or thicker steel]
[the steel design thickness required by the design drawings] and [shop painted] [galvanized] [painted with an
epoxy coating or equivalent applied to prime-coating in accordance with manufacturer's standard] [zinc-coated
in conformance with ASTM A 653/A 653M, G90 coating class or aluminum-zinc coated in accordance with ASTM A 792/A 792M
Coating Designation AZ55].
2.3.4.1 Cant Strips for Roof Decks
NOTE: When cant strips exceeding the dimensions specified in the following
paragraph are required, the steel sheet quality and thickness must be revised
as required.
Fabricate cant strips from the specified commercial-quality steel sheets not less than nominal 0.91 millimeter
0.0359 inch thick before galvanizing. Bend strips to form a 45-degree cant not less than 125 millimeter 5 inch
wide, with top and bottom flanges a minimum 75 millimeter 3 inch wide. Length of strips 3000 millimeter 10
feet.
2.3.4.2 Ridge and Valley Plates for Roof Decks
Fabricate plates from the specified structural-quality steel sheets, not less than nominal 0.91 millimeter 0.0359
inch thick before galvanizing. Provide plates of minimum 120 millimeter 4-1/2 inch wide and bent to provide
tight fitting closures at ridges and valleys. Provide a minimum length of ridge and valley plates of 3000 millimeter
10 feet.
2.3.4.3 Metal Closure Strips for Roof Decks
Fabricate strips from the specified commercial-quality steel sheets not less than nominal 0.91 millimeter 0.0359
inch thick before galvanizing. Provide strips from the configuration required to provide tight-fitting closures
at open ends and sides of steel roof decking.
2.3.5 Form Deck
Conform to ASTM A 653/A 653M or ASTM A 1008 for deck used as formwork for concrete. Fabricate form deck of[
[0.38] [____] mm [0.015] [____] inch design thickness or thicker steel.] [the steel design thickness required
by the design drawings.] [Paint with one coat of manufacture's standard paint.] [Zinc-coat in conformance
with ASTM A 653/A 653M,[ G60][ G90] coating class.]
2.3.6 Composite Deck
[Conform to ASTM A 653/A 653M or ASTM A 1008/A 1008M for composite deck assembly. Fabricate deck used as the
tension reinforcing in composite deck if [0.75][____] mm [0.0295] [____] inch design thickness or thicker steel.]
[The steel design thickness required by the design drawings. Zinc-coat in conformance with ASTM A 653/A 653M
, [G60][G90] coating class.
In addition to resisting shear, provide devices to resist vertical separation between the steel deck and the
concrete. Provide one of the following types of shear devices:
a. Mechanically fixed shear devices such as embossments, holes, or welded buttons.
b. Mechanically fixed shear devices such as inverted, triangular-shaped ribs.
][2.3.7 Acoustical Steel Deck
NOTE: A noise reduction coefficient of 0.70 is a commonly used coefficient.
The coefficient can also be obtained from manufacturer's literature. However,
specific design requirements must be considered and the appropriate value inserted.
The manufacturer's standard acoustical steel deck shall be provided where indicated.
Provide a Noise Reduction Coefficient (NRC) rating of not less than [0.70] [_____], when tested in accordance
with ASTM C 423, Standard Mounting No. 6. Provide sound absorbing materials with either [glass fiber in roll
or premolded form for acoustical steel deck (noncellular)] [and] [or] [glass fiber rigid strip for acoustical
steel deck (cellular)] in accordance with manufacturer's standards.
][2.3.8 Venting
NOTE: Include this paragraph on projects where lightweight insulating concrete
roof systems are used. Verify that deck size specified is available as vented.
To ensure positive venting from the underside, provide slotted or perforated steel deck to receive concrete fill,
overlay, or a poured concrete deck.
][2.3.9 Shop Priming
NOTE: Specify shop priming when decking will receive field applied finish painted.
Paint will not adhere to passivating or stabilizing treatment commonly used
on galvanized steel surfaces to prevent "white rust." Coordinate requirements
for finishes with requirements for fireproofing and field finish painting.
Shop prime accessories and [underside of] deck at the factory after coating. Clean surfaces in accordance with
the manufacturer's standard procedure followed by a spray, dip or roller coat of rust-inhibitive primer, oven
cured.
]2.3.10 Touch-Up Paint
Provide touch-up paint for shop-painted units [of the same type used for the shop painting] [_____], and touch-up
paint for zinc-coated units of [an approved galvanizing repair paint with a high-zinc dust content] [_____].
Touch-up welds with paint conforming to SSPC Paint 20 in accordance with ASTM A 780. Maintain finish of deck
units and accessories by using touch-up paint whenever necessary to prevent the formation of rust.
For floor decking installation, wire brush, clean, and touchup paint the scarred areas on the top and bottom
surfaces of the metal floor decking and on the surface of supporting steel members. Include welds, weld scars,
bruises, and rust spots for scarred areas. Touched up the galvanized surfaces with galvanizing repair paint.
Touch up the painted surfaces with paint for the repair of painted surfaces.
After roof decking installation, wire brush, clean, and touchup paint the scarred areas on top and bottom surfaces
of metal roof decking. The scarred areas include welds, weld scars, bruises, and rust spots. Touchup galvanized
surfaces with galvanizing repair paint. Touchup painted surfaces with repair paint of painted surfaces.
PART 3 EXECUTION
3.1 EXAMINATION
Prior to installation of decking units and accessories, examine worksite to verify that as-built structure will
permit installation of decking system without modification.
3.2 INSTALLATION
NOTE: Use SDI Pub No. 30 for all decks except those designed for diaphragm
action. Use SDI DDM O2 for diaphragm-action decks. Indicate cellular deck
to be used as wiring raceways on the project drawings if included below.
NOTE: The designer must determine if there are shoring requirements for composite
decks. For most applications the design is selected so that shoring is not
required. Shoring requirements shall be detailed on the design drawings.
Install steel deck units in accordance with [SDI 30][SDI DDMO3 and] approved shop drawings. Place units on structural
supports, properly adjusted, leveled, and aligned at right angles to supports before permanently securing in
place. Damaged deck and accessories including material which is permanently stained or contaminated, deformed,
or with burned holes shall not be installed. Extend deck units over three or more supports unless absolutely
impractical. Report inaccuracies in alignment or leveling to the Contracting Officer and make necessary corrections
before permanently anchoring deck units. Locate deck ends over supports only. [Ends of floor deck may be lapped
or butted.] Do not use unanchored deck units as a work or storage platform. [Do not fill unanchored deck with
concrete.] Permanently anchor units placed by the end of each working day. Do not support suspended ceilings,
light fixtures, ducts, utilities, or other loads by steel deck unless indicated. Distribute loads by appropriate
means to prevent damage. Prepare [shoring in position before concrete placement begins in composite or form
deck. ][Size cellular decking provided as electrical raceways to accommodate indicated wiring systems. Chip
off burrs and eliminate sharp edges which may damage wiring. Mesh decking panels accurately and place in accordance
with UL 209.] Neatly fit [acoustical material into the rib voids.]
3.2.1 Attachment
NOTE: Use of powder actuated or pneumatically driven fasteners is limited to
Seismic Zone 1 and areas with wind design velocity of less than 160 km/h 100
mph. However, based upon the submittal of supporting calculations and data
to substantiate that such fasteners can resist the design loads, and approval
of the Contracting Officer, fasteners may be used in all seismic areas and in
areas with the wind velocity to 160 km/hr (100 mph) or more. Refer to COE Technical
Instruction (TI) 809-04, "Seismic Design for Buildings".
NOTE: Refer to UFC 1-200-01 for shear capacity, flexibility, connection details,
size and spacing of welds and attachments, and concrete fill requirements.
For diaphragm acting decks, refer to Steel Deck Institute's "Diaphragm Design
Manual" (First and Second Editions).
Where welding only is allowed, delete the first two bracketed phrases and include
the last bracketed phrase.
Immediately after placement and alignment, and after correcting inaccuracies, permanently fasten steel deck units
to structural supports and to adjacent deck units by welding with normal 16 mm 5/8 inch diameter puddle welds
[or fastened with screws, powder-actuated fasteners, or pneumatically driven fasteners] as indicated on the design
drawings and in accordance with manufacturer's recommended procedure[ and SDI 30]. Clamp or weight deck units
to provide firm contact between deck units and structural supports while performing welding [or fastening].
[Anchoring the deck to structural supports with powder-actuated fasteners or pneumatically driven fasteners is
prohibited.] Attachment of adjacent deck units by button-punching is prohibited.
The fasteners shall provide minimum required pull-out, pull-over and shear resistance
based upon test results of the specific steel deck and fastener as listed in
the current edition of the Factory Mutual Approval Guide and Factory Mutual
Data Sheet 1-28 or manufacturer's data sheets. If studs are being welded to
the top flanges of beams, the deck ends should be butted. If not, deck ends
should be lapped. Welding washers shall be used at welded connections when
deck thickness is less than 0.711 mm 0.028 inch. Fasteners for roof insulations
are specified in Section 07220 ROOF AND DECK INSULATION.
3.2.1.1 Welding
NOTE: Show location, size, and spacing of attachments on the drawings for composite
and diaphragm-acting decks. If they are not shown, delete the first phrase
and include the second. Coordinate finish repair with finish requirements.
Perform welding in accordance with AWS D1.3/D1.3M using methods and electrodes recommended by the manufacturers
of the base metal alloys being used. Ensure only operators previously qualified by tests prescribed in AWS D1.1/D1.1M
and AWS D1.3/D1.3M make welds. Immediately recertify, or replace qualified welders, that are producing unsatisfactory
welding. [Indicate] [Conform to the recommendations of the Steel Deck Institute and the steel deck manufacturer]for
location, size, and spacing of fastening. [Do] [Do not] use welding washers at the connections of the deck to
supports. Do not use welding washers at sidelaps. Holes and similar defects will not be acceptable. [Lap 50
mm 2 inch] [butted] deck ends. Attach all partial or segments of deck units to structural supports in accordance
with Section 2.5 of SDI DDMO3. Attach [shear connectors as shown and welded as per AWS D1.1/D1.1M [through the
steel deck to the steel member] [directly to the steel member]]. Immediately clean welds by chipping and wire
brushing. Heavily coat welds, cut edges and damaged portions of [coated finish with zinc-dust paint conforming
to ASTM A 780] [shop [primed] [painted] finish with the manufacturer's standard touch-up paint].
[3.2.1.2 Fastening
NOTE: Delete this paragraph when only welding is allowed.
Anchor deck to structural supports and adjoining units with mechanical deck fasteners as recommended by the Steel
Deck Institute and the steel deck manufacturer, as approved by the Contracting Officer. Drive the [powder-actuated
fasteners with a low-velocity piston tool by an operator authorized by the manufacturer of the piston tool.
Drive pneumatically fasteners with a low-velocity fastening tool and comply with the manufacturer's recommendations.]
]3.2.1.3 Fastening Floor Deck Units
NOTE: When fire-resistance-rated construction is required, the fire rating
agency's specifications for the applicable floor or roof and ceiling construction
must be consulted.
Fasten floor deck units to the steel supporting members at ends and at all intermediate supports, both parallel
and perpendicular to deck span, by welds. Do not exceed spacing of welds of 300 millimeter 12 inch on center,
with a minimum of two welds per floor deck unit at each support. Provide 20 millimeter 3/4 inch minimum diameter
fusion welds. Coordinate welding sequence and procedure with the placing of the floor deck units. Blow holes
shall be cause for rejection.
Lock sidelaps between adjacent floor deck units together at intervals not exceeding 1220 millimeter 48 inch on
center by welding or button punching for all spans.
[Free the interior of cells that will be used for electrical raceways of welds having sharp points or edges.]
3.2.2 Openings
NOTE: Include bracketed phrases when design is based on seismic requirements.
When cells of cellular steel floor decking will be used for air ducts, the cutting
of decking units for connections to air distribution ductwork, outlets, and
system accessories must be coordinated with and specified in applicable sections
of the mechanical specifications.
When cells of cellular metal floor decking will be used for electrical raceways,
the inspection of these cells, cutting for inserts, and installation of electrical
outlets, fittings, or grounding of the metal floor decking, be coordinated with
and specified in applicable sections of the electrical specifications.
Cut or drill all holes and openings required and be coordinated with the drawings, specifications, and other
trades. Frame and reinforce openings through the deck in conformance with SDI DDP. Reinforce [holes and openings
150 to 300 mm 6 to 12 inch across by 1.204 mm (0.0474 inch) 0.0474 inch thick steel sheet at least 300 mm 12
inch wider and longer than the opening and be fastened to the steel deck at each corner of the sheet and at a
maximum of 150 mm 6 inch on center. Reinforce holes and openings larger than 300 mm 12 inch by steel channels
or angles installed perpendicular to the steel joists and supported by the adjacent steel joists. Install steel
channels or angles perpendicular to the deck ribs and fasten to the channels or angles perpendicular to the
steel joists. ][Deck manufacturer shall approve holes or openings larger than 150 mm 6 inch in diameter prior
to drilling or cutting. ] [Openings must not interfere with seismic members such as chords and drag struts.]
3.2.3 Deck Damage
SDI MOC2, for repair of deck damage.
3.2.4 Accessory Installation
3.2.4.1 Adjusting Plates
Install as shown on shop drawings.
3.2.4.2 End Closures
Provide end closure to close open ends of cells at columns, walls, and openings in deck.
3.2.4.3 Closures Above Partitions
NOTE: Coordinate options in paragraphs entitled "Partition Enclosures" and
"Closures Above Partitions." When a suspended acoustical ceiling is provided
below the metal deck, the closures above partitions may be eliminated for acoustical
purposes provided the acoustical properties of the ceiling are adequate to restrict
sound transmission to a level consistent with the facility design criteria.
Provide for closing voids between cells over partitions that are perpendicular to direction of cells. Provide
a one-piece closure strip for partitions 100 mm 4 inch nominal or less in thickness and two-piece closure strips
for wider partitions. [Provide sheet metal closures above fire-rated partitions at both sides of partition with
space between filled with fiberglass insulation.] [Provide flexible rubber closures above acoustic-rated partitions
at both sides of partition with space between filled with blanket insulation.]
3.2.4.4 Cover Plates
[Provide metal cover plates, or joint tape, at joints between cellular decking sheets to be used as electrical
raceways.] [Where concrete leakage would be a problem, provide metal cover plates, or joint tape, at joints
between decking sheets, cellular or noncellular, to be covered with concrete fill.]
[3.2.4.5 Column Closures
NOTE: Delete this paragraph if steel floor decks are not included.
Provide for spaces between floor decking and columns which penetrate the deck. Field cut closure plate to fit
column in the field and tack weld to decking and columns.
]3.2.4.6 Access Hole Covers
Provide to seal holes cut in decking to facilitate welding of decking to structural supports.
3.2.4.7 Hangers
NOTE: Location, spacing, and size of hanger clips or loops must be indicated
or specified, as applicable to the project.
Provide as indicated to support [utility system] [and] [suspended ceilings]. Space devices [as indicated] [so
as to provide one device per 0.60 square meters 6.25 square feet].
[3.2.5 Sound Absorbing Material
NOTE: Include this paragraph when required by the design for acoustical deck.
Install sound absorbing [glass fiber roll or premolded form, neatly in voids between perforated webs of acoustical
noncellular steel deck] [and] [glass fiber rigid strip, in cells of acoustical cellular steel deck]. Keep sound
absorbing material dry before, during and after installation.
][3.2.6 Concrete Work
NOTE: Ensure that admixtures containing chloride salts are not used in concrete
placed on steel deck. Coordinate with Section 03300 CAST-IN-PLACE CONCRETE.
Delete this paragraph if concrete is not cast on metal decking.
Prior to placement of concrete, inspect installed decking to ensure that there has been no permanent deflection
or other damage to decking. Replace decking which has been damaged or permanently deflected as approved by the
Contracting Officer. Place concrete on metal deck in accordance with Construction Practice of SDI 30.
]3.2.7 Preparation of Fire-Proofed Surfaces
Provide deck surfaces, both composite and noncomposite, which are to receive sprayed-on fireproofing, galvanized
and free of all grease, mill oil, paraffin, dirt, salt, and other contaminants which impair adhesion of the fireproofing.
Complete any required cleaning prior to steel deck installation using a cleaning method that is compatible with
the sprayed-on fireproofing.
3.3 JOINT SEALING FOR ROOF DECKS
Seal sidelaps and endlaps with manufacturer's recommended joint sealing material. Shop or field apply the material.
Before applying the sealing material, completely remove dust, dirt, moisture, and other foreign material from
the surfaces to which the sealing material is to be applied. Apply sealing material in strict accordance with
the sealing material manufacturer's printed instructions.
3.4 ROOF SUMP PANS
Place sump pans over openings in roof decking and fusion welded to top surface of roof decking. Do not exceed
spacing of welds of 300 millimeter 12 inch with not less than one weld at each corner. Field cut opening in
the bottom of each roof sump pan to receive the roof drain as part of the work of this section.
3.5 CANT STRIPS FOR ROOF DECKS
Provide strips to be fusion welded to surface of roof decking, secured to wood nailers by galvanized screws or
to steel framing by galvanized self-tapping screws or welds. Do not exceed spacing of welds and fasteners of
300 millimeter 12 inch. Lap end joints a minimum 75 millimeter 3 inch and secure with galvanized sheet metal
screws spaced a maximum 100 millimeter 4 inch on center.
3.6 RIDGE AND VALLEY PLATES FOR ROOF DECKS
Provide plates to be fusion welded to top surface of roof decking. Lap end joints a minimum 75 millimeter 3
inch. For valley plates, provide endlaps to be in the direction of water flow.
3.7 CLOSURE STRIPS FOR ROOF DECKS
Provide closure strips at open, uncovered ends and edges of the roof decking and in voids between roof decking
and top of walls and partitions where indicated. Install closure strips in position in a manner to provide a
weathertight installation.
3.8 ROOF INSULATION SUPPORT FOR ROOF DECKS
Provide metal closure strips for support of roof insulation where rib openings in top surface of metal roof decking
occur adjacent to edges and openings. Weld metal closure strips in position.
3.9 CLEANING AND PROTECTION FOR ROOF DECKS
Upon completion of the deck, sweep surfaces clean and prepare for installation of the roofing.
[3.10 FIELD QUALITY CONTROL
NOTE: Include this paragraph when roof decks that are not receiving concrete
are in the project. Coordinate paragraph with requirements for roofing membrane.
3.10.1 Decks Not Receiving Concrete
Inspect the decking top surface for distortion after installation. For roof decks not receiving concrete, verify
distortion by placing a straight edge across three adjacent top flanges. The maximum allowable gap between the
straight edge and the top flanges is 2 mm 1/16 inch; when gap is more than 2 mm 1/16 inch, provide corrective
measures or replacement. Reinspect decking after performing corrective measures or replacement.
]