Projects that have spray fireproofing that only protect the beams or joists, the overspray onto the metal deck needs to be cleaned off prior to the installation of the Head of Wall spray fire stopping.
When we install a fire rated wall directly under and parallel to a spray fireproofed beam (as shown below):We will likely need to install extra spray fireproofing on the web in order to comply with the UL Assembly for the Head of Wall.(not all Head of Wall assemblies are the same, so we must review the approved system in order to determine the actual thickness of material needed)
Fireproofing, either Spray Fire Resistive Materials (SFRM) or Intumescent Fire Resistive Materials (IFRM), is not a suitable substrate for air/vapor barrier or Spray Polyurethane Foam (SPF) insulation. This fact creates a challenging condition for the continuity of the AVB or SPF system(s) when fireproofed structural steel extends out of the exterior wall (line of AVB). The team will need to address how the air/vapor barrier (AVB) or SPF will be continuous.
According to UL and the NFCA ( National Fireproofing Contractors Association ): The flutes above the beam flange being sprayed is required to befull with spray fireproofing…