||11-21-2010 03:37 PM
Foam board and electrical boxes
I am curious, is it safe/legal/whatever to mount a metal electrical box directly to blue foam board?
Reason I ask is I am working on a box out in my kitchen that has a small shed style roof. In order to gain some R-value to the ceiling I am installing 1" blue foam board to the joists, then I'm going to cover the foam with drywall. The junction box for the light is a 4" diameter 1/2" thick shallow fixture metal box. In order to get the box flush with the drywall, I'm wanting to mount the box directly to the foam board, but I question if that is ok to do. The specs on the foam say protect from high heat.
I am wondering if instead of mounting the box to the foam, I need to go get a thicker box and cut the foam away and mount the thicker box directly to the 2x nailer I put in place to secure the box to.
Any suggestions?? Thanks!!