Do Attics Require Ventilation With Spray Foam Insulation

Spray polyurethane foam is a chemical product that is created by two materials isocyanate and polyol resin that will react with each other when they are mixed and will expand up to 30 to 60 times its liquid volume as it is sprayed in place.

Do attics require ventilation with spray foam insulation.

When we seal the attic with spray foam it s as tight as a butter tub. I have read two articles by allision bailes that seem to contradict one another concerning whether or not a home or building that has spf should be ventilated or not. This alternative to traditional building insulation fiberglass can be applied into wall cavities holes concrete slabs and even onto roof tiles and. Earlier this year i got a question about a home that had spray foam insulation in the attic.

Nothing unusual about that. But with spray foam ventilation is not an issue. One huge benefit of the spray foam insulated attic is that conditioned air leakage from the ac furnace duct system is contained and used to condition the attic. Spray foam insulation will not prevent ventilation and so there s no need to avoid it thinking that it will result in mould and mildew from building up inside the attic space.

I am planning to use open cell spray foam insulation in my metal building and then build out the interior. You may not have heating ducts up there but it does not need to be ventilated. Now we use attic ventilation when we use products like fiberglass because we have to manage the moisture. The most important thing to remember is to use the correct type of insulation and to ensure it is installed correctly.

A lot of builders and homeowners are going with spray foam insulation because of the airtightness benefits but then the questioner mentioned that the spray foam contractor had intentionally left big holes to the outside by not sealing the gable vents.