jdgengineer
Structural
We are working on a small commercial TI for a building that was constructed in the mid 60s (I think). The existing roof framing is W12x steel beams at 7'-0" oc with 1 1/2" roof deck with a 1 1/2" rigid insulation above (no concrete topping). I don't know the specifics of the exact deck but assuming it is a 22 gauge 1 1/2" roof deck at a 7'-0" span a current Verco catalog would give a 45 PSF single span rating (L/180), or 77 PSF double span rating (stress).
As part of the project the architect is looking at putting in 2 skylights which we will provide new channels framing between the existing beams for support. Additionally, they are looking at putting in a suspended gypsum ceiling (US Gypsum or similar suspended product. It is similar to an accoustical ceiling grid with wire ties @ 4'-0" oc max each direction). Each wire tie would have approximately 40# of load on it (2.5 PSF).
Would it be typical to try and hang this directly from the metal deck (assuming it has the capacity)? I'm not thrilled about using a TEK screw in withdrawal for the condition. Would there be other alternatives (some sort of toggle bolt?) Or would it be more common to frame out the supports with light gauge steel framing?
As part of the project the architect is looking at putting in 2 skylights which we will provide new channels framing between the existing beams for support. Additionally, they are looking at putting in a suspended gypsum ceiling (US Gypsum or similar suspended product. It is similar to an accoustical ceiling grid with wire ties @ 4'-0" oc max each direction). Each wire tie would have approximately 40# of load on it (2.5 PSF).
Would it be typical to try and hang this directly from the metal deck (assuming it has the capacity)? I'm not thrilled about using a TEK screw in withdrawal for the condition. Would there be other alternatives (some sort of toggle bolt?) Or would it be more common to frame out the supports with light gauge steel framing?