Spray Foam Insulation in Greenwood, IN

Spray foam insulation goes on as a liquid, expands in place and hardens, so it fills gaps that batts and loose fill leave open. That makes it both an air seal and an insulation layer. Around Greenwood, where Johnson County sits in Climate Zone 5A with cold winters and humid summers, foam is the strongest choice for surfaces that leak a lot of air or see moisture: rim joists, crawl space and basement walls, cathedral ceilings, kneewalls, bonus room floors and metal buildings.

Two kinds of foam

Open-cell foam is soft and expands a lot. HomeGuide rates it around R-3.5 to R-3.7 per inch. It fills stud bays well, quiets sound between rooms and costs less per square foot, but it lets vapor through, so it is not the right choice where it will get wet. Closed-cell foam is dense and rigid, rated about R-5 to R-7 per inch. A couple of inches of it acts as a vapor retarder and adds stiffness to the surface it is sprayed on. It costs more, but it is the right material against concrete, steel, a roof deck with no attic, or a rim joist.

How to tell if you need it

Signs that foam belongs in your house: cold floors over a crawl space, a bonus room over the garage that never gets comfortable, frost or damp on the rim joist in winter, a cathedral ceiling with no room for batts, or a garage or barn you want to use year round. If the only issue is a thin attic floor, loose fill after air sealing is often cheaper, and we will tell you that.

What the code asks for

The Insulation Institute's summary of the 2020 Indiana Residential Code lists Zone 5 minimums of R-20 or R-13 plus R-5 for wood-frame walls and R-13 or R-10 continuous for basement and crawl space walls. Closed-cell foam reaches those values in less thickness, which helps in 2x4 walls and tight spaces.

Safety and curing

Foam is applied by trained installers wearing respirators, and the space is ventilated during and after the work. HomeGuide advises that occupants stay out for 24 hours or more. In living spaces foam is covered with a thermal barrier such as drywall; in attics and crawl spaces an ignition barrier may be required depending on how the space is used. We explain what your project needs before we start.