If you are looking at insulation for your home, there are more choices than blown cellulose and pink fiberglass. Expanding spray foam insulation is increasingly popular due to its many benefits.
Expanding spray foam insulation is made of polyurethane or acrylic latex. The foam has been used in refrigerators and water heaters for many years.
Liquid polyurethane is pressurized and released through spray nozzles. When the spray lands on surfaces it expands and foams up, then hardens to a aerated material. Traditional insulation such as cellulose wool or spun fiberglass leave gaps and voids when applied as ceiling and wall insulation. Expanding spray foam insulation fills out to all cracks and into seams even if they are hidden from view. The sealing ability can practically eliminate air flow and energy transfer.
The resulting expanded polyurethane foam has a high R-value, which is the measure of resistance to energy flow relative to its thickness, when compared to other insulation materials. This high R-value feature can allow 4″ wall construction to achieve the same energy rating as a 6″ wall, providing improved performance at a substantial savings in construction materials and even increased floor area.
Because expanding spray foam insulation is dimensionally stable it does not settle or compress, and maintains its high performance characteristics. It does not absorb or transfer moisture, preventing humidity, condensation, and mold problems. It is also insect and flame resistant.
Although there are retail products for small crack filling tasks, expanding spray foam insulation for large areas is best left to professionally trained contractors who have the necessary equipment and expertise to apply this material effectively and economically.
There are hazardous materials handling issues when the polyurethane is in the liquid and aerosol state that require special precautions. Proper application and cavity filling requires experience and care to achieve the desired outcome and prevent damage or distortion of structural elements by over-expansion.
Coordination with plumbing and electrical installation is critical since the foam insulation encloses these utilities and makes it difficult to change or reinstall.
Expanding foam insulation costs about three times more than traditional materials to install initially. Some of this cost will be offset by savings in other areas and materials as mentioned above. However the longterm payback is increased energy savings year after year, with improved comfort and air quality, that justifies the investment in using expanding spray foam insulation.
8 responses so far ↓
1 Expanding Foam Wall Insulation | Expanding Foam Insulation // Apr 17, 2008 at 1:15 pm
[...] exterior walls are opened for remodeling consider in place expanding spray foam insulation for best R-value and reduced air [...]
2 Expanding Spray Foam Insulation Installation | Expanding Foam Insulation // Apr 17, 2008 at 1:22 pm
[...] contemporary best practice is expanding spray foam insulation installation. Foam fills the cavities in between the framing studs of the walls and attic. Spray-on [...]
3 Derek // Oct 29, 2009 at 11:45 am
What is R value of spray in foam insulation?
4 admin // Oct 29, 2009 at 5:25 pm
Thank you for your question. Expanding foam wall insulation in a 2″ x 4″ stud wall provides about R22, or about R7 per inch of thickness.
5 Les // Jan 2, 2010 at 4:20 am
Can you spray foam insulation in crawl and if so where and how?
6 admin // Jan 5, 2010 at 12:08 pm
Yes, foamed in insulation works well in crawl spaces. Expanding foam insulation can be sprayed in between the floor joists above and between studs of the walls. Install a vapor barrier over the finished foam to reduce condensation. Consult a professional installer for best results in your particular circumstances and application.
7 Carol // Jan 29, 2010 at 2:44 pm
I live on the first floor of a condo. The garage is directly below my condo. The floor underneath is cement. There is about a 5 ft. crawl space between the ceiling in the garage and the floor of my condo. I’m thinking about spraying the underneath side of my floor with urethane foam to help insulate it. Will spray foam adhere to the concrete? There is a cold draft between my garage ceiling and the floor of my condo. This results in a very cold floor in the condo.
8 admin // Jan 29, 2010 at 3:20 pm
Hi Carol,
Yes, expanding foam insulation adheres to just about any surface.
Insulation is material to impede conductive energy transfer and is dependent on it’s thickness, and rated by R-value. Foam has a high R-value and can provide excellent insulation with less thickness than other materials.
If there is a draft there will also be convective losses; therefore, be sure to seal any gaps and cracks that allow air to pass between the spaces. Properly installed spray foam insulation does an excellent job of sealing these gaps and cracks.
Depending on the temperature difference between the living space and external space, a radiant heat barrier can be also be helpful.
A qualified contractor should be able to provide a cost benefit analysis.
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