Unvented Attic Foam Insulation

Only spray polyurethane foam can be used for this application as batt insulation will end up sagging and blown insulation simply can t adhere to the roof decking.

Unvented attic foam insulation.

How unvented assemblies work a properly constructed unvented attic is. Spray foam in unvented attics spray foam in unvented attics allows homeowners to convert the area into a liveable space. Any hvac equip ment located in the attic is within the conditioned shell of the house which also cuts energy losses. Unvented attics sometimes called sealed enclosed or encapsulated attics feature insulation on the underside of the roof decking rather than on the attic floor.

Common problems found with traditional insulation in an unvented attic assembly can be mitigated with spray foam insulation like icynene. The insulation extends down the roofline to the rim joists and soffit areas as well as on gable wall ends. The foam insulation used for unvented attics stops air movement and with it the transport of moisture. This is done by using what is referred to as air impermeable insulation such as rigid foam board or spray foam.

Two acceptable methods for insulating an unvented attic assembly in all climates are as follows. Using spray foam insulation in an unvented attic application 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. Spray foam in unvented attics intended for regular use helps.