5A Beam Protection

[Frank Karp]

First time doing a 3-story, 5A hotel - wow. We have most of it figured out, but can't find a 1 hour assembly to protect a primary steel beam. All 3 UL assemblies show steel/conc composite deck. We have plywood floor sheathing with 3/4" concrete topping using UL No. L570. Where else can I search? Or am I missing something? Must be fairly common. Thanks.

 

[Builder Bob]

IS the structural steel inside the envelope of the rated assembly??

 

[mtlogcabin]

GA BM 1137 How about some intumescent paint products

 

[Frank Karp]

Most of the steel fit within the floor/ceiling assembly Builder Bob - a few deeper beam do not. I'm looking at Table 601 differently now after your question. If my floor assembly is 1 hour rated, is all the structure (primary and secondary) protected? I was thinking we needed to protect primary beams separately within the envelope. Thanks.

 

[AegisFPE]

Individual encasement of the primary structural beams would be if required by 704.3.

 

[Frank Karp]

So my challange remains finding a 1 hour rated assembly/encasement for a steel beam (usually with a 2x nailer for the joist hangers and subfloor support/attachment) under plywood subfloor having a 3/4" concrete topping. Nothing in UL (that I found.) GA BM 1137 comes a bit closer, but still a ways off. Maybe AWC's National Design Standard for some type of equivilency guidance? Anywhere other sources out there?

 

[Builder Bob]

calculated fire resistance guidelines in the IBC