Spray Foam Insulation In Vented Attic

Because basically now that attic is a conditioned space.

Spray foam insulation in vented attic. An open cell foam low density spray polyurethane is a spray applied to provide continuous insulation and an air sealing barrier. 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. It s terrific because it s pretty much the same temperature as the rest of the house all the time. I have a spray foamed attic.

The two products most often used in an unvented attic assembly are medium and low density sprayed polyurethane foam spf. 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. If the atmospheric combustion appliances start off in a vented attic the building code doesn t require those vents because the appliances are already connected to the outside and should get plenty of air. Most unvented attics incorporate spray polyurethane foam spf on the underside of the roof deck and attic walls.

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. However in a traditionally insulated attic insulation on the ceiling the attic is vented. Nope you absolutely do not need to ventilate a spray foam house and here s why. Whether the home is old or new however anyone considering spray foam insulation would be wise to ask this question.

This construction approach was first used in the 1970s and it has been implemented much more widely since it was first included in the international code council s icc model building code in 2007 irc section 806 4. When we seal the attic with spray foam it s as tight as a butter tub. An unvented attic system relies on an air seal and no vents to make the attic a conditioned space.