mtlogcabin
SAWHORSE
I have a steel beam supporting a one hour occupancy seperation between a merchantile and 2 floors of R-2 above. 2009 IBC full nfpa 13 system V-B construction. The beams are below the floor ceiling assembly. The architect wrapped 2x4 around the sides and bottom of the beam at 24" OC and wants to attach 2 layers of 5/8 type X and is calling this a one-hour assembly under Section 721. I have never seen a steel beam listed assembly that included wood for attaching the gypsum board to. I understand the assembly is to limit the tempature rise of the steel beam. I am wondering if the gypsum board will provide enough thermal protection to keep the wood from igniting. Any thoughts, do I have legitimate concerns or am I being over cautious here.