Spray Foam Insulation in Biloxi, MS

Spray foam insulation is sprayed as a liquid that expands and hardens, sealing gaps as it insulates. On the Gulf Coast its main jobs are keeping attic heat away from the ducts and living space, sealing raised floors and crawl spaces against humid air, and stopping condensation in metal buildings.

Open-cell foam

Open-cell foam is soft, about R-3.5 to R-3.7 per inch in HomeGuide's figures, and runs $1.50 to $3.50 per square foot installed. It is commonly sprayed on the underside of the roof deck to create a sealed, conditioned attic, so ductwork and the air handler sit inside the insulated space instead of in a superheated one.

Closed-cell foam

Closed-cell foam is dense, about R-5 to R-7 per inch, and slows water vapor at normal thickness. It costs $3.00 to $5.00 per square foot. We use it under raised floors, on crawl space walls, in metal buildings, and anywhere moisture resistance matters.

Roof decks and the ducts

In a typical Coast house with ducts in the attic, a sealed attic can make a big difference: the ducts no longer sit in air that gets far hotter than outdoors. HomeGuide lists roof-deck foam at $1,500 to $9,000. If the ducts are not in the attic, sealing and blowing in the attic floor is usually the better value.

Termites

Mississippi State University Extension notes that spray foam can conceal leaks and termite infestations, and Formosan subterranean termites are established in all three Coast counties. We discuss inspection access with you and your pest control company before foaming sills, foundation walls or crawl space walls.

Curing

HomeGuide advises staying out 24 hours or more while foam cures. We plan the schedule around that.

Sealed attics and humidity

A sealed, foamed attic is part of the conditioned space. In a humid climate it needs to be dried by the air conditioning like any other room; some systems add a small supply of conditioned air to the attic. We explain what your system needs.