New Posts  All Forums:Forum Nav:

Backer box material

post #1 of 4
1/21/13 at 6:25pm
Thread Starter 
Is it OK to build recessed light backer boxes from OSB+drywall, or is OSB+cement board necessary for fire safety?

I'm using the 4" remodel cans from Lowe's (the ones that come with a housing and white baffle for ~$16), non IC, but have a thermal cutoff switch. There are no real guidelines in the product documentation about clearances between the housing and any other materials- just 3" min from insulation.
Reply
Reply

AVS Top Picks

post #2 of 4
1/22/13 at 8:21am
Drywall is fine, It is what is used for firecode backer-boxes

http://intranet.progresslighting.com/firebox/Firebox.html

I like using the cement board because I can cut all the pieces on my table saw for a quick assembly. (Special blade required)
Reply
Reply
post #3 of 4
1/22/13 at 8:43am
Many years ago, and engineer from USG told me that Type-X paper can delaminate with successive heating and cooling, and the paper is combustible, so that's when we started recommending cement board.

In reality, I have no idea how much of a liability (if any) the drywall is as a liner for these boxes.
Reply
Reply
post #4 of 4
1/22/13 at 12:31pm
I would be a little leary of using OSB for the actual box. Mainly because of it's density and attaching the components to each other when you screw them together (making a air tight seal).

I used 3/4 MDF for the box and cement siding board to line it. The cement siding worked great, was inexpensive and I only needed one stick of it to do my 6 cans. The MDF (as you know) is very dense and made very tight seals when screwed together.

Just a thought...
Reply
Reply
New Posts  All Forums:Forum Nav:
  Return Home

AVS Top Picks