metal deck

[DNBEA]

I am checking a built metal deck floor designed by someone else. for some reason it is a 2 1/2" 33ksi roof deck with 2" concrete on top (overall 4 1/2". The catolog does not give us the capacity of roof deck with concrete topping. and the manufacturer said the actually fy is 80ksi. I am hasitating to use the number in the catolog times 80/33. because I think the deck may fail in some way other than yeilding. and how do you consider the composite action for this kind of deck? I conservatively consider none. what do guys think? I May have to call the manufacurer anyway.

 

[DaveAtkins]

First of all, I think the deck may be 2", with 2-1/2" topping. I have not heard of 2-1/2" deck. Second of all, most deck is 33 ksi (I think only very thin gauge decks are 80 ksi, like metal wall and roof panels). Finally, I would say the deck is non-composite.

DaveAtkins

 

[DNBEA]

Sorry it's 1.5" roof deck with 2.5" topping. But that is not the point. it has been built and we found out it is a wrong deck. although the catologe shows it is 33ksi but the manufacturer says it is made of 80ksi. My concern actually is if we can use a high capacity for the deck due to the actual yield strength. but the deck may fail before it yields.

 

[miecz]

The deck manufacturer should provide the load rating for the 80ksi deck, taking into account deflection and buckling considerations.