Sub Panel Surface Mount Backer

[MikeWI]

Hi All,

This seems like an easy question but my research is turning up conflicting answers.

I want to surface mount a 100A sub panel in garage. The spot has drywall up.

What is best to mount panel to? I’ve read that people like to put plywood backer board behind panel. If I do this, does it need to be fire rated or will any plywood do the trick?

Or should I run shallow strut across the studs and mount to that? Or directly to drywall and maybe hit a stud on one side?

 

[dcg9381]

Here's a good post on it below. Note there are location specific requirements that may not apply to your case. Best solution seems to be 3/4 fire-retardant plywood.

Another option, if you need to mount between studs would be to put in a backer board larger than the panel, but have it hit studs on both sides.


ref: https://diy.stackexchange.com/questions/41236/is-a-plywood-backer-required-for-all-breaker-panels

 

[Terry D]

Check we you local codes. We mount them right to the drywall. Use a decent anchor, a metal zip it or a toggle style anchor. There are some areas when they are mounted on a concrete wall , they would require a wood backer board.

 

[nadogail]

The requirements in my city are probably not relevant to you and your location.

A brief conversation with your local Building Department, Electrical Inspector, or a local Electrical Contractor will be a wise investment of your time.

 

[u2slow]

Current code (in my area) requires fire-retardant plywood for that purpose. That said, my place is from 1973 with the only further documented renovations 25+ years ago - preceding this requirement - so I do not care about the fire rating.

I quite like the utility factor of at least 1/2" plywood surrounding a panel for fastening of cables, conduit, etc.

EDIT: I probably wouldn't bother with strut unless I had an uneven surface, or needed to pass conduit or cable behind the panel.