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jonny1982
Guest
Is it necessary to install plywood behind an electrical panel if it is on an outside wall? If so, where in codebook?
- Status
JDB3
Senior Member
- Location
- San Antonio, Texas
I see no reason for it. The main thing is to have the panel securely fastened to whatever material is there. In some cases where I am in doubt about the strength of the surface, I install kendorf behind the panel, & fasten that to the framing members of the structure & go from there.
Are you talking inside a basement?
In the old days when foundations were built in field stone you would put up plywood, today you can use plywood and studs or unistrut, but it's not required in the code. But mounting a panel direct on a concrete wall and you will get condensation in the panel and that is not too good.
gadfly56
Senior Member
- Location
- New Jersey
- Occupation
- Professional Engineer, Fire & Life Safety
This is why, if fire alarm panels have to be mounted to an outside wall, we put up a couple Unistrut rails and a plywood panel and mount the FACP to the plywood.
K8MHZ
Senior Member
- Occupation
- Electrician
It's not in the NEC, but it is in our state electrical code that we shall not mount panels to concrete. If wood is used, it has to be pressure treated and marked as such, and of course we have to use fasteners that won't be affected by the chemicals in the wood.
I totally understand why our state requires this, as being surrounded by the Great Lakes provides for some horrendous humidity. There are times when it literally drips off basement walls.
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