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Cape Cod - Spray Foam Insulation?

I am currently researching using icynene spray foam insulation for the upstairs of my cape cod. The level is currently unfinished and will house a bedroom and bathroom.

I have been told no ridge vents or other ventilation is needed, and others say spray the foam then install a ridge vent for moisture control and ventilation.

Do I need additional ventilation with a spray in insulation? If so, what should I plan on getting into?

Kyle - Columbus, Ohio

Eric Anderson
Re: Cape Cod - Spray Foam Insulation?

It's been a while since I researched it, but I found conflicting statements in Icynene product literature in regard to moisture transfer. One report stated that the product is a vapor barrier, and another that it allows a gradual transfer of moisture through the foam. To my eye, the surface of the cured insulation seems fairly inpenetrable, in contrast to the interior. In any case, I'd play it safe and install the Icynene with the same ventilation allowances you'd give to any other kind of insulation, which in the roof structure means two out of three of: gable vents, soffit vents, and ridge vents. If soffit vents, don't let the insulation block the air flow from the soffit up to the gable or ridge vents.

Re: Cape Cod - Spray Foam Insulation?

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Re: Cape Cod - Spray Foam Insulation?

I've read that closed cell foam does act as a vapor barrier and probably wouldn't require venting.

Open cell applications like the insulation used in the New Orleans project are going to let moisture through so venting would seem to be necessary to keep it dry.

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