B-deck or W-deck for concrete filled metal deck

[davab]

Have you guys used B-deck 1.5" + 2.5" LWC assembly before? I am designing a residential steel building and I am considering using B-deck instead of W3 or W2.
My past experiences with office buildings, we always used W2 or W3 deck for 2 hour fire ratings. For residential, I believe our building requires 1 hour fire rating, which is why I am looking to use B-deck as 4" LWC W2 deck doesn't have any fire rating.

Any insights as to whether anyone has used B-deck for concrete floor would be very helpful.

Thank you guys.

 

[msquared48]

Used it many times over the years for floors. No worries.

Mike McCann, PE, SE (WA, HI)

 

[davab]

Thanks for the response Mike. If you can expand on when you used it in the past, it would be so helpful. Is it strictly based on the fire rating and the limitations set by the architect in terms of floor assembly and ceiling space?

 

[msquared48]

Economy of structure with steel bar joists or steel purlins - we just fireproofed the bar joists or steel purlins and beams. Did not increase the slab thickness to increase fire rating, but that is possible.

Mike McCann, PE, SE (WA, HI)

 

[wannabeSE]

The concrete above the deck determines the fire rating, not the depth of the deck. 3” deck is more efficient for longer spans with more loads than 1-1/2” deck.