Spray-on Foam & Home Insulation

Spray-on insulation is a powerful and relatively recent plastic material, with an insulating efficiency (rated in R-values) that amounts to the double of traditional insulation products like fiberglass batts/rolls.

Most of spray-on insulation is made of liquid polyurethane or polystyrene, also found in small aerosol cans and used in refrigerators and water heaters (see also, for elements on the environmental impact of this type of insulation: Insulation materials and the environmental issue).

Home sprayed foam insulation is an alternative to consider to traditional insulation materials.

See:

Insulation materials
Fiberglass, mineral wool & Home insulation
Cellulose insulation.

Uses

Spray foam materials are excellent for home cathedral ceilings, side walls and basement wall insulation. They are also excellent for filling window jambs, rim joist areas, small stud bays, and other penetrations where traditional insulation materials (e.g. fiberglass batt insulation) are difficult to use.

How spray-on foam insulation works

The spray foam liquid is pumped through pressurized spray nozzles on the surface of cathedral ceilings or sidewalls and basement walls, forming a continuous insulating barrier.

After applied, the material expands and conforms to the shape of the cavities, filling and sealing them thoroughly.

The pros of spray-on foam insulation

Unlike fiberglass, cellulose or rock wool insulating materials, spray foam insulation fills and seals all the miniscule cracks and seams in walls and other surfaces, eliminating any energy loss by air filtration.

Because it provides a particular high performance (R-value) per inch, it makes possible to use 2x4 exterior walls (instead of the 2x6), with the correspondent savings on framing costs.

Foam insulation is also fire and insect resistant and a powerful mean to control moisture condensation.

The cons

Foam insulation is difficult to apply in existing homes, besides being pricey in many applications than traditional fiberglass, cellulose and mineral wool insulation.

Costs-benefits analysis

The installed cost for sprayed foam insulation may cost about 2-3 times more per inch/square foot than traditional insulating materials: something around $1.25 to $2.25 per square foot, depending on wall thickness or type of foam...

But since most foam insulation products dispense with sealing and have a much higher R-value per inch than traditional insulation materials, its higher initial cost it's rather relative.

Installation

Sprayed foam installation demands special equipment and requires skill and knowing to spray the materials into cavities… It's not a common do-it-yourself work.

Warranties

Some sprayed foam insulation manufacturers provide a lifetime limited warranty.

Sprayed Foam insulation and environment

Against the expected, most today’s foam insulation products aren't environmentally-unfriendly. See Insulation Materials & Environment.