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Covering of Spray Foam in a Heated Crawlspace?

moose_head27 | Posted in General Questions on

Hi, I’m looking to get some advice on what is required when spray foam is applied in a heated crawlspace( Ontario, Canada). More specifically the thermal barrier requirements. The entire home is planned to be heated with forced air electric, including the crawlspace (direct ducts, with supply and return plenum)

There’s a lot of information out there but a lot of resources say that all foamed plastics need to be covered regardless of it’s in a habitable space or not. 

Other resources say that since there is return air in the crawlspace  then the spray foam needs to be covered as fire in the crawlspace will release toxic fumes and be circulated to the living spaces.

Lastly a few resources say that since that there is a duct work(warm air plenum) then it needs to be covered.

Looking at the ontario code online I can’t find anything where it says it has to be covered in a crawlspace. Only exception is if the crawlspace has open registers to the main floor and the crawlspace is used as a plenum.

Your thoughts?

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  1. John Clark | | #1

    check your local codes but IIRC some sort of flame retardant coating is at a minimum required.

  2. GBA Editor
    Brian Pontolilo | | #2

    Hi Moose,

    Though it is based on IRC requirements, this article may be helpful:

  3. Ethan Foley | | #3

    If you're looking for strictly Ontario Building Code requirements, then see "Protection of Foamed Plastics".

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