Light gauge steel for roof deck bearing support
Light gauge steel for roof deck bearing support
(OP)
We have been asked to review and engineer a steel roof deck support detail proposed by the steel truss fabricator as an alternate to the detail provided by the EOR. The original detail by the EOR is a continuous 1/4" bent steel plate welded to a continuous embed pate with headed studs. The proposed detail is a post-installed light gauge bent plate (similar to a hat channel) attached to the concrete beam using Tapcons. The wind loads are 150 lb/ft uplift (net) and 285 lb/ft diaphragm. We are assuming the wall is braced by the tie beam (not the deck) at this time so no wind loads perpendicular to the deck (we need the EOR to verify this). Has anyone used light gauge steel for steel roof deck bearing or have any other ideas on how the deck support could be post-installed? Sketches of the current detail and proposed detail are attached for clarification.






RE: Light gauge steel for roof deck bearing support
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Light gauge steel for roof deck bearing support
First, I don't like to use Tapcons in tension for a structural application. Here you have the highest portion of your wind uplift applied to an easily compromised connection. In addition, you will have a shear component applied to those fasteners as well.
The second issue I have is light gage material sitting flat on concrete. That can easily be a corrosion issue, again with compromised uplift resistance.
The third issue is that of compatible strengths between the 5/8" puddle weld as compared to Teks screws...check it carefully.
RE: Light gauge steel for roof deck bearing support
I appreciate any argument points - pro or con (such as the light gauge sitting on the concrete). My client is a light gauge steel truss and sheet metal fabricator and they can only bend up to 14 gauge steel in house.
RE: Light gauge steel for roof deck bearing support
RE: Light gauge steel for roof deck bearing support
RE: Light gauge steel for roof deck bearing support
I was hoping to see if anyone has used a light gauge steel detail for this application; it doesn't sound like it. I think I have enough argument points now for my client to tell the GC the detail will not work (atleast if my client fabricates it in house).
Thank you all for your input!
RE: Light gauge steel for roof deck bearing support
If not, the original one is my choice. Tapcons can easily be installed wrong.
RE: Light gauge steel for roof deck bearing support
How about fastening clips on the sides of the wall and running a regular shaped member between glulam beams? This member could be fastened to the clips on the wall and glulam at the ends. This would avoid fabricating and analyzing odd ball shaped hat channel.
Can the deck span as a cantilever from the last truss to the end of the wall?
RE: Light gauge steel for roof deck bearing support
RE: Light gauge steel for roof deck bearing support