Do Attics Require Ventilation With Spray Foam Insulation

Here s the answer to the question posed in my article title.

Do attics require ventilation with spray foam insulation.

Nope you absolutely do not need to ventilate a spray foam house and here s why. A lot of builders and homeowners are going with spray foam insulation because of the airtightness benefits. Unvented attics rely on an air impermeable insulation installed to the roof deck s underside i e. This spray foam is applied as a low or high pressure two component polyurethane spray foam that can be applied onto walls in unvented attics to ducts and ceilings and in vented attics and crawl spaces.

A well sealed home does a better job keeping conditioned air inside. Attic ceiling to stop airborne moisture from reaching a cold surface and condensing inside the building envelope. Spray foam insulation may prevent your home from getting enough ventilation. Nothing unusual about that.

Because basically now that attic is a conditioned space. They know roofing materials underlayments flashing and attic ventilation. The main aim of ventilating the attic space is to allow the air in the home to circulate. Generally speaking that s a good thing.

Therefore providing mechanical fresh air ventilation is especially important in spray foam houses. Spray foam provides an air seal. When we seal the attic with spray foam it s as tight as a butter tub. Yes using spray foam we have added your attic to the conditioned space.

I have a spray foamed attic. However in a traditionally insulated attic insulation on the ceiling the attic is vented. Earlier this year i got a question about a home that had spray foam insulation in the attic. It s terrific because it s pretty much the same temperature as the rest of the house all the time.

The basics ventilation is required but not all ventilation options are appropriate for the home or homes with spray foam insulation. Some know more than others of course but you should probably assume the worst any time a roofer comes to your spray foam insulated home. Tell them the attic is to have no ventilation of any type.