Metal Decking
in Houston, TX

What is metal decking, and what is the difference between roof deck and floor deck?

Metal decking is corrugated sheet steel that spans between joists or beams and forms the roof or floor surface. The two families do different jobs.

• Roof deck carries the roof assembly and ties the building together as a diaphragm. Wide-rib Type B is the most common profile on Houston warehouses.
• Floor deck holds concrete. Composite deck has embossments that bond to the slab, so the deck and the concrete slab work together. Form deck just holds the concrete until it cures.

How is metal deck attached, and when do you weld instead of screw?

Support attachment is either puddle welds, self-drilling screws or power-actuated pins, and the structural drawings name the method and the pattern. Welds are still common on heavier gauges and on jobs where the diaphragm values were taken from welded tables. Screws and pins suit thin 22 gauge deck, galvanized finishes and work where a burn permit is a problem. Sidelaps get button punches, screws or welds at the spacing on the plan, and those sidelaps carry a real share of the diaphragm strength. We fasten to the approved schedule and let the special inspector verify it.

Does roof deck have to meet windstorm requirements in the Houston area?

It does in the designated catastrophe area. That covers Harris County east of SH 146 along with Galveston, Brazoria and Chambers counties, where TDI windstorm rules apply and a WPI-8 certificate depends on inspected work. Roof deck attachment is a big part of that, because uplift pulls the sheets off the supports before it does anything else. We build the fastener pattern from the engineered drawings and keep the inspection records for the certificate. See bar joists and roof framing for how the deck and the joists share that load path.

What deck gauge and finish should I use in Houston humidity and salt air?

Gauge comes from the span and the load. Most roof deck here runs 22 to 18 gauge, and floor deck is often 20 to 16 gauge. Finish is the local decision.

• G60 galvanized is standard for enclosed, conditioned buildings.
• G90 galvanized is the safer call near the Ship Channel and the bay, where salt air and humidity work on the underside of the deck.
• Wash areas, plants and open canopies may need heavier coatings called out by the engineer.

Who places the concrete on composite deck, and how does the handoff work?

We can carry both scopes. Our steel crew lays the deck, welds the shear studs and sets the pour stops and edge closures, then our concrete crew places the fill. Doing it under one contract removes the argument over deflection, pour stop height and slab thickness. If your own concrete contractor is placing the fill, we hand over an inspected deck with the studs done and the openings framed. Details on the slab side are on our concrete slabs page.

Can you repair or add to an existing metal deck?

Yes. Common work is patching corroded deck, adding new openings for rooftop units and stairs, framing the reinforcing angles around them, and re-fastening a diaphragm that an engineer found short. We also deck new mezzanines inside existing buildings and tie new framing into old. Older roofs may have thin or rusted sheet that will not hold a weld, so we check the deck before we quote. Call (832) 576-3278 and we will get up there and look at it. Related field work is covered on our steel repair and field modifications page.