Ceiling mounted Electric Heater

[AdamB7]

Hi,

I have a 5kw electric unit heater. It is an Ouellett ODS model. The ceiling is just vapor barrier with fiberglass batt insulation above it. I had OSB cut a little larger than the heater, and screwed that to the ceiling to mount the heater to. After the first winter I noticed that some of the vapor barrier looked a little wavy like it was starting to melt which obviously got me concerned.

From what I could find, it doesnt take much heat for vapor barrier to do this, and if concerned I should just put a bigger piece of OSB behind it, possibly with some spacers to get it a little further from the ceiling. Any opinions on if that is good enough? Should I maybe treat the wood with some flame resistant coating? Possibly replace OSB with cement board? All probably overkill, but better safe than sorry. Thanks!

 

[The Cobbler]

what are the specs from the heater manufacturer telling you to do

 

[AdamB7]

Oddly enough the instructions don't really specify any recommendations. I contacted them and they said it can go right on the vapor barrier or on OSB like I had it. Just to ease my nerves I thought maybe going on a larger piece of cement board would be best, I was just wondering if anyone has done this or knows a reason this might be a bad idea.

 

[BrandonV]

Oddly enough the instructions don't really specify any recommendations. I contacted them and they said it can go right on the vapor barrier or on OSB like I had it. Just to ease my nerves I thought maybe going on a larger piece of cement board would be best, I was just wondering if anyone has done this or knows a reason this might be a bad idea.

Probably hard for them to account for everything.

Concrete board would be a good choice.