eyden
Member
We are renovating an old warehouse into a commercial building. Two of the walls are on the property line and were not previously fire rated at all. We grabbed an assembly from the GA Fire Resistance Manual to keep the existing framing. 3/4" stucco over 5/8" type X gyp, 2x4 wood studs, 2 layers of 5/8" type X gyp. The building has open web trusses, and in some places we are framing in a ceiling as well. The contractor is claiming that after framing, it will be difficult to get into some spaces between the ceiling framing and trusses to run the drywall up to the roof sheathing with the required screw spacing and asking us for alternatives. It was suggested that that part of the wall be sprayed with intumescent paint instead of the 2 layers of gyp to get the required rating. This raised some red flags for me.
1) CBC 706.6 Vertical Continuity - fire walls shall extend from the foundation to a termination point not less than 30" above both adjacent roofs.
This says nothing about the assembly materials being continuous, so as long as I can maintain 2-hr with the intumescent, can I use that for a section of it?
2) As a fire wall, it needs to be rated from both directions. Will removing the 2 layers of gyp negate the rating on the exterior side, or does that stop at the studs?
3) If it is allowable, how would I transition between the two? Just cap the wall with 2 layers of gyp and overlap the intumescent?
Thank you
1) CBC 706.6 Vertical Continuity - fire walls shall extend from the foundation to a termination point not less than 30" above both adjacent roofs.
This says nothing about the assembly materials being continuous, so as long as I can maintain 2-hr with the intumescent, can I use that for a section of it?
2) As a fire wall, it needs to be rated from both directions. Will removing the 2 layers of gyp negate the rating on the exterior side, or does that stop at the studs?
3) If it is allowable, how would I transition between the two? Just cap the wall with 2 layers of gyp and overlap the intumescent?
Thank you