IBC 2012, Washington, D.C. I have a 2-hr rated wall that is curved in two locations. The radii for the curves are approximately 15'-0" for one and 40'-0" for the other. My standard partition construction for this wall without the curve is a 6" metal stud with (2) layers 5/8" drywall on both sides. My boss has told me that the 5/8" drywall cannot be curved because it's too thick, and has suggested that I used multiple layers of 1/2" drywall that can be wetted and curved, AND add a 1/2" of plywood between the metal studs and the drywall in order to give the wet drywall a solid surface to form to.
So, my questions are:
1) Is it possible, or better said, realistic, to curve two layers of 5/8" drywall to radii of these dimensions? If not,
2) Does it make sense to do 3 layers of 1/2" drywall on both sides? And if so,
3) Is it allowable (or even needed) to have a 1/2" of plywood backing between the stud and drywall, in a 2-hr rated wall? Seems like the plywood would have to be fire-treated if so...
Thanks!
So, my questions are:
1) Is it possible, or better said, realistic, to curve two layers of 5/8" drywall to radii of these dimensions? If not,
2) Does it make sense to do 3 layers of 1/2" drywall on both sides? And if so,
3) Is it allowable (or even needed) to have a 1/2" of plywood backing between the stud and drywall, in a 2-hr rated wall? Seems like the plywood would have to be fire-treated if so...
Thanks!
