Vented Attic With Spray Foam

Both low density open cell and medium density closed cell spray foam can be used in an unvented attic to provide the needed thermal resistance and airtightness.

Vented attic with spray foam.

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. Rigid foam and spray foam are two of them. 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. 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.

Cathedral roofs especially need a lot more insulation between the ceiling and the rafters because there usually isn t any attic space. An unvented attic system relies on an air seal and no vents to make the attic a conditioned space. Nothing unusual about that. By using an air impermeable insulation like spray foam on the roof deck will.

Heat from the house rises up to the attic but when there isn t one the heat rises up to the roof. Earlier this year i got a question about a home that had spray foam insulation in the attic. When we seal the attic with spray foam it s as tight as a butter tub. All insulation materials require proper venting.

The unvented attic space is considered the most effective and up to date building practice particularly by the spray foam industry. In a vented attic all of that expensive airflow is lost to the environment. This alternative to traditional building insulation fiberglass can be applied into wall cavities holes concrete slabs and even onto roof tiles and. Unvented attic assemblies unvented attics rely on an air impermeable insulation installed to the roof deck s underside i e.

Unvented attics sometimes called sealed enclosed or encapsulated attics feature insulation on the underside of the roof decking rather than on the attic floor. Image courtesy of d7 spray foam insulation houston tx using spray foam insulation in an unvented attic application.