It’s simple, right?! Buildings being constructed must maintain a structural stability at all times during the steel erection process. That’s according to OSHA Federal Register Subpart R 1926. OSHA also reminds us that “Since structural collapse is second only to falls as a cause of fatalities in the construction industry, stability is essential to the successful erection of any steel structure, including single- story, multi-story, bridges, etc.” Let’s further examine what goes into the erection and installation practice for roof or floor metal decking as a safe working platform.
The Steel Deck Institute (SDI) “Manual of Construction with Steel Deck” (MOC2) offers some information that is intended to be an aide and general guide for the safe and proper erection of metal deck. Here are just some selections from SDI:
Metal Deck Erection
- During hoisting, landing, and placing of metal decking bundles, it is essential that any loose items being carried by a deck bundle be secured to that bundle. An erector should never use the bundle packaging and strapping to lift loads unless specifically designed for that purpose.
- When deck bundles are placed on joist, all bridging components must be installed and anchored and all joist bearing ends permanently attached to the structure.
- Metal decking bundles must be placed on framing members with sufficient support to allow unbanding of the bundles without dislodging from the supports. Metal deck must be secured against displacement or when environmental or jobsite conditions require.
- Installation of metal decking must be immediately secured to prevent accidental movement or displacement by qualified and experienced workers in accordance with the “Approved for Construction” drawings. The beginning point should be carefully selected for proper deck orientation and edge of roof or floor slab location.
- Maintaining rib or flute alignment across the structure is very important to assure proper alignment of deck panels. Proper alignment is achieved by adjusting each deck panel as it is placed.
- The side lap connections (stitch) sheet to sheet are required to stabilize the panels and reduce differential vertical displacement at the joints. The deck should be inspected for adequate attachment at all supports and side laps.
- For floor deck receiving concrete, side laps must be tightly connected to prevent opening during concrete pouring. The installer must be sure that the underlying sheet is drawn tightly against the top sheet.
- Self drilling screws, welds or button punches are the typical stitch connections. Good metal to metal contact is necessary for good side lap connections.
Metal Decking as Safe Working Platform
- For roof and floor holes and openings, metal decking must be installed to allow continuous deck installation. The openings must be decked over and where larger size openings (e.g. elevator shafts, stair wells, etc.) fall protection must be provided.
- Roof and floor holes and openings that are cut in the field must be adequately supported and guarded. The openings must be immediately and permanently filled with the intended equipment or structure and covered.
- Roof and floor opening covers must be designed to support without failure twice the weight of a person, equipment and materials imposed on them. All covers must be securely installed to prevent accidental displacement by wind, equipment or people.
- Areas must be painted with high-visibility paint or marked with the word “HOLE” or “COVER” indicating the presence of a hazard.
- Deck suppliers have established shipping practices and manufacturing processes so that as shipped deck products will be free of visible liquid lubricants and minimized dry residues for the purpose of reducing the slipping hazard of the walking surfaces of decking products.
- Deck installations are done on elevated structure and the danger of falling is always present. Alertness is essential. Ladders should be securely tied to the structural frame or the scaffolding. Stairs, if available, should be rigidly attached to the building frame.
- Deck edges are sharp. Workers should take precautions to protect themselves from sharp edges or projecting corners.
For metal deck to perform its design functions and serve as a working platform, it must be adequately and properly aligned and attached. Often deck is used as part of the horizontal bracing system and the fastening methods and attachment patterns have been selected to provide certain strength and stiffness in the plane of the deck. A rule of thumb is for a minimum of 1 ½” of end bearing be provided at all times. For deck that is intended to end lap (roof deck), the end lap location should be adjusted so the center of the lapped portion occurs over the support or, when supported by bar joists, over a top chord member to prevent an unstable condition. Therefore, metal decking provides structural stability for the erected building components and doubles as a safe working platform during and after the deck erection process. For a full description of recommended installation practices please refer to The Steel Deck Institute (SDI) “Manual of Construction with Steel Deck” (MOC2) or visit the official SDI website at www.sdi.org. Likewise, https://www.osha.gov/pls/oshaweb provides applicable guidelines from OSHA Federal Register Subpart R 1926.
Allan Abbata is a senior consulting engineer at Warren and a licensed professional engineer in South Carolina, North Carolina, New York, New Jersey, Pennsylvania, Massachusetts, Missouri, Texas, Alabama, Maryland, Minnesota and Virginia. Allan holds a Bachelor of Science in Civil Engineering. He has more than 40 years of applied engineering expertise to include in-depth knowledge of building codes, rules and regulations that guide design. Allan has also prepared construction drawings and specifications, provided on-site supervision and inspection of construction projects, and. has overseen project management and responsibility for overall performance of building contracts while also serving as the client’s liaison with local, state and federal agencies and municipalities.