Spray Foam Insulation in Galveston, TX

Spray foam insulation is sprayed as a liquid that expands and hardens in place. It fills gaps around framing, wiring and plumbing that batts and loose fill miss, so it insulates and air seals at the same time. In Galveston County, where OpenEI places the county in Climate Zone 2A and cooling runs most of the year, foam is especially useful on roof decks over attics with ducts, under raised floors, in walls of new homes and additions, and inside metal buildings.

Open-cell foam

Open-cell foam is light and spongy, rated about R-3.5 to R-3.7 per inch by HomeGuide. It expands a lot, fills cavities completely and costs less. It lets water vapor pass, so it is a good fit in interior walls, many exterior walls and some roof decks, but not where it could get wet from flooding or wind-driven rain.

Closed-cell foam

Closed-cell foam is dense and rigid, rated about R-5 to R-7 per inch. A couple of inches slows vapor, sheds water and stiffens the surface. On the coast it is the usual choice under raised floors, on surfaces below base flood elevation, inside steel buildings and on roof decks where a vapor retarder makes sense. It costs more per square foot, but it holds up where other insulation fails.

Signs foam is the right choice

A hot upstairs with ducts in the attic, a cold or clammy floor in a raised home, a metal shop that drips, a bonus room that never cools, or new framing that you want sealed tight are all good reasons to look at spray foam. If the only issue is a thin attic floor, sealing and blowing insulation may be cheaper, and we will tell you so.

Code and safety

The Insulation Institute's Texas summary lists R-38 ceilings and R-13 wood-frame walls in Zone 2. Foam in living spaces is covered by a thermal barrier such as drywall; attics and crawl areas may need an ignition barrier depending on use. HomeGuide advises staying out of the house for 24 hours or more after spraying, and we ventilate the area during and after the work.