Spray Foam Insulation in Montgomery, AL

Spray foam insulation is a two-part liquid that expands as it is sprayed, fills the cavity and cures in place. Unlike batts or loose fill, it stops air from moving through the spot it covers, so it insulates and air seals in one step. In a Montgomery summer that matters, because most of the heat and humidity entering a house rides in on leaking air through attic penetrations, open wall cavities and crawl space gaps.

Open-cell foam

Open-cell foam is light, soft and spongy. It expands a lot, fills irregular cavities and blocks air well. HomeGuide lists it at about R-3.5 to R-3.7 per inch and $1.50 to $3.50 per installed square foot. Because water vapor can move through it, it works best where the assembly can dry, and where a vapor retarder is not needed. Around Montgomery, common uses are the underside of the roof deck when the attic is being sealed and brought inside the cooled space, and interior walls or floors where it also cuts sound.

Closed-cell foam

Closed-cell foam is dense and hard. HomeGuide puts it at R-5 to R-7 per inch and $3.00 to $5.00 per square foot. At typical thickness it slows vapor, does not soak up water and adds stiffness to what it bonds to. In this climate it is the usual choice under floors above damp crawl spaces, on crawl space walls, on rim joists, on metal buildings that sweat and anywhere that might get wet.

Who needs it, and who does not

Foam makes the most sense where air sealing is hard to do any other way: a roof deck over an attic full of ductwork, a cathedral ceiling with no room for vents, a crawl space you want dry, or a steel building. It makes the least sense on a wide, easy attic floor, where sealing the leaks and blowing loose fill on top often gives similar comfort for less money. We tell you which approach fits each area, and if two would work, the quote shows both.

Signs your house needs attention

Upstairs rooms several degrees hotter than downstairs, an air conditioner that runs all afternoon in July, sweating ductwork, a musty smell, dust lines on carpet edges (a sign of air leaking through the gap) and high summer power bills are all clues. We find where the air is getting in before suggesting any material.