Gainesville, GA considering spray foam insulation often encounter the question of whether or not a vapor barrier is needed. Vapor barriers are used to prevent water vapor from moving through walls and into the rest of a house. This can lead to rot and mold problems. In many climates a vapor barrier is recommended to help limit moisture intrusion.

Vapor barriers have long been a popular way to control energy costs. However, on average 99% of moisture intrusion in homes is the result of air leakage and not vapor movement. For this reason it is important to seal leaks before insulating a home or pole barn.

Attic Insulation for Old Homes: Challenges and Solutions

Closed cell spray foam, sprayed in a thickness of 1.5″ or more, acts as an air barrier, a vapor retarder and an insulation. This makes closed cell insulation the ideal choice for eliminating the need for separate vapor barriers in cold climates.

Open cell spray foam, sprayed in fewer than 1.5″ thick, is considered an air impermeable insulation and does not act as a vapor barrier. Open foam does not block the passage of vapor from warmer to cooler air and this can contribute to condensation issues in attics. It is important to consult local codes or work with a professional when insulating an attic with open cell spray foam.

For basement and crawl space applications, closed cell spray foam is the best option for creating a vapor barrier. Closed cell spray foam will lock out the damp, musty vapors that cause rot in basements and crawl spaces. It will also keep the air dry, preventing humid warm air from increasing humidity in the basement and promoting condensation and rot.

Georgia Insulation
2092 Crow Rd, Gainesville, GA 30501
(770)758-4459