Vented Attic With Spray Foam

Heat from the house rises up to the attic but when there isn t one the heat rises up to the roof.

Vented attic with spray foam.

Rigid foam and spray foam are two of them. By using an air impermeable insulation like spray foam on the roof deck will. Nothing unusual about that. 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.

All insulation materials require proper venting. Cathedral roofs especially need a lot more insulation between the ceiling and the rafters because there usually isn t any attic space. Using foam insulation for vented attics thanks to its air sealing properties foam insulation for vented attics particularly in cold and dry climates helps curb a stack effect where heated air escapes through the ceiling and eventually the attic and is replaced in lower levels of the home by drawn in outdoor air. This alternative to traditional building insulation fiberglass can be applied into wall cavities holes concrete slabs and even onto roof tiles and.

In a vented attic all of that expensive airflow is lost to the environment. An unvented attic system relies on an air seal and no vents to make the attic a conditioned space. Unvented attic assemblies unvented attics rely on an air impermeable insulation installed to the roof deck s underside i e. Spray foam insulation in vented attics will resist any heat transfer from that airflow so you don t have to worry about the rest of your house getting hot as well.

When we seal the attic with spray foam it s as tight as a butter tub. 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. 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. Image courtesy of d7 spray foam insulation houston tx using spray foam insulation in an unvented attic application.

Earlier this year i got a question about a home that had spray foam insulation in the attic. Unvented attics sometimes called sealed enclosed or encapsulated attics feature insulation on the underside of the roof decking rather than on the attic floor.