Spray Foam Insulation

There are multiple types of spray foam insulation. Most medium to large residential applications for spray foam are limited to new construction, renovation projects or insulating roof rafters. Unlike blown-cellulose or loose-fill fiberglass which can be added to improve existing attic floor insulation, spray-foam is not normally considered for attic floors, unless existing installation is completely removed. Two chemicals are usually mixed at the tip of a gun to form an expanding foam that is sprayed into unfinished wall cavities or the interior side of sheathing. Spraying foam into a finished wall lacking any insulation can occur by drilling holes in the drywall or sheathing.

The cost for spray foam insulation is higher than cellulose or loose-fill fiberglass. Most spray foams are made from petrochemicals and release toxic fumes when they burn, with the exception of cementitious foams. Spray foams, such as Polyurethane and Isocyanate insulation, contain hazardous chemicals such as benzene and toluene.

Like blown-cellulose insulation, spray foam insulation blocks airflow in gaps and penetrations. It works well in tight spaces and provides acoustical insulation similar to blown-cellulose and can be applied in small quantities.