Heat from the house rises up to the attic but when there isn t one the heat rises up to the roof.
Foam roof vents.
Rigid foam and spray foam are two of them.
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.
In a vented roof foam can seal the openings and serve as an air barrier and a vapor retarder in addition to its insulating function.
This alternative to traditional building insulation fiberglass can be applied into wall cavities holes concrete slabs and even onto roof tiles and.
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.
Similarly not everyone can afford to spray nearly 10 in.
Unvented attic assemblies unvented attics rely on an air impermeable insulation installed to the roof deck s underside i e.
Of open or closed cell spray foam in their roof or to stack a half foot of rigid foam on the roof deck.
All insulation materials require proper venting.
In an un vented roof foam can serve as the air barrier and vapor retarder and prevent moisture from getting in to the roof.
Insulate above and below the roof not all homes have deepenough rafters to insulate to desired r values easily.