Although the emphasis on saving home heating and cooling energy has been on attic insulation, exterior walls have a similar surface area that transmits energy.
Homes built prior to 1960 had no insulation or at best R-5. Between 1960 and 1980’s average R values increased to about R-11.
Insulating wall cavities that were empty or under-insulated will save energy. A 2″ x 4″ stud framed wall filled with expanding foam insulation will provide an insulating value of R-22.
Before insulating side walls you need to find out what is in there. Visual inspection through openings may reveal what is already in place, if anything, or an infrared thermal imaging will reveal heat loss in areas that are hidden or have varying insulating value.
Garage insulation may seem optional, when other more obvious home improvements vie for limited dollars. But with rising fuel costs, it’s a good idea to take a close look at all the ways it could make good sense, and good cents, to insulate all or part of the garage.
This is particularly true for the attached garage. Insulation of common walls shared by the garage and the main living space is obviously of great importance. This includes the ceiling of the garage if there is living space above. All too often, there is great heat loss or gain through these walls, because the air in the garage can rise or fall to temperatures that are even more extreme than those outside. It is therefore almost more important to insulate the walls between the garage and the house as it is to insulate the house’s exterior walls.
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.