Recently, savvy homebuyers have become aware of the advantages, payback times, and investment value of home energy efficiency measures, especially those improving the efficiency of the building envelope. The spray foam industry has made major advances in the chemical composition and durability of the foam. Moreover, improvements in spray foam application technology have decreased installation costs, bringing this type of insulation system within the reach of the residential homeowner.
Resistance Value ("R-Value")
The higher the R-value, the greater the insulating power. Spray foam has double the R-Value of fiberglass (3.5) and nearly five times the R-Value of fiberboard sheathing (1.32).
Spray foam insulation boasts high insulation value with the best R-value per inch of any readily available insulation. It allows for more insulation in a tighter space than conventional batt insulations, and performs well in controlling hot or cold temperatures. The spray foam is good at keeping heat out as well as in, giving homeowners additional savings on their air conditioning bills which are usually higher than their heating bills.
Spray foam also reduces drafts by cutting convection looping. Temperature differences between the outside and inside walls cause warm air to rise and cold air to sink in the cavity between the studs. This action initiates a convection current flowing up and down the walls, especially with fiber batt insulation. Spray foam insulation applied to the interior walls reduces the temperature differences of the air current activity.
Spray foam insulates hard-to-reach areas and provides a seamless layer of insulation.
Air Filtration and Vapor Barrier Advantages
Spray foam reduces air infiltration by conforming to cavity shapes and sealing around wall features. In the presence of air leakage, fiberglass batts can act more as a filter than as insulation. Since batt does not fully conform to all cavity shapes in corners and walls, especially at the top and bottom plates, cold spots may appear in these areas.
Air leakage can also occur around outlets, window and door trim. Spray foam insulation adheres and seals tightly in the cavity and reduces air leakage caused by irregularities in surfaces.
Spray foam resists moisture due to its closed cell seal ability and dries with minimum insulation value loss.
Properties of Spray Foam Insulation