Unvented Attic Spray Foam Insulation

Insulating unvented attics with spray foam figure 1 spray foam is a good choice for roofs that are difficult to vent like a turret with converging rafters left or a flat roof with its rafters hung between flush beams right.

Unvented attic spray foam insulation.

This is done by using what is referred to as air impermeable insulation such as rigid foam board or spray foam. If you want you can even transform a spray foamed attic into a finished space. Fibrous insulation e g batt or blown in can be installed under the roof deck in the hot dry climate zone but this will cause moisture problems in all other climates straube and grin 2010. Spray foam insulation in an unvented attic assembly has been one of the most researched and widely implemented innovations of recent years.

Over time feedback from builders and building owners has been and continues to be overwhelmingly positive especially in the areas of moisture performance energy efficiency and building durability. Common problems found with traditional insulation in an unvented attic assembly can be mitigated with spray foam insulation like icynene. Insulation approaches for unvented attics vary by climate. This allows you to install your bulkheads above the ceiling plane without the need for spray foam insulation.

Two acceptable methods for insulating an unvented attic assembly in all climates are as follows. The unvented attic space is considered the most effective and up to date building practice particularly by the spray foam industry. Air impermeable insulation typically spray foam installed to the underside of the roof sheathing. The insulation extends down the roofline to the rim joists and soffit areas as well as on gable wall ends.

Humid or cold climates require either rigid foam insulation above the roof deck to keep its temperature above 45 f. When you insulate the top of your attic with spray foam you re bringing your attic into your home s envelope. Spray foam in unvented attics intended for regular use helps. Unvented attics sometimes called sealed enclosed or encapsulated attics feature insulation on the underside of the roof decking rather than on the attic floor.

Spray foam in unvented attics spray foam in unvented attics allows homeowners to convert the area into a liveable space.