Do Attics Require Ventilation With Spray Foam Insulation

Unvented attic assemblies unvented attics rely on an air impermeable insulation installed to the roof deck s underside i e.

Do attics require ventilation with spray foam insulation.

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. However in a traditionally insulated attic insulation on the ceiling the attic is vented. When we seal the attic with spray foam it s as tight as a butter tub. Oh and when you put it in your attic spray foam insulates the attic itself.

It is also known to act as an air barrier however unfortunately it will not protect against vapor and moisture intrusions. Do attics with spray foam insulation need ventilation. Nope you absolutely do not need to ventilate a spray foam house and here s why. Yes using spray foam we have added your attic to the conditioned space.

It s terrific because it s pretty much the same temperature as the rest of the house all the time. Attic ceiling to stop airborne moisture from reaching a cold surface and condensing inside the building envelope in this design insulation effectively separates the interior and exterior spaces while slowing down moisture flow so the dewpoint is not achieved within. Compared to traditional insulation whether fiberglass or cellulose spray foam has the potential to provide better performance via its air sealing properties high r values per inch of thickness and in the case of closed cell spray foam ability to repel moisture. Here s the answer to the question posed in my article title.

They need the right level of ventilation but they also require insulation in order to help improve the energy efficiency of the property.