Do You Need to Insulate Your Garage Walls and/or Ceiling?
That depends on what you plan to do in your garage. If you have a living space above the garage or you plan to heat and cool your garage in the summer and winter, then YES. Depending on what you are trying to achieve you may not need to insulate the entire garage.
If your garage is connected to your home, Spray Polyurethane Foam (SPF) insulation will protect your home against toxic air flow, odors, temperature difference and noise coming from the garage. SPF insulation also provides a water-resistive barrier. Moisture from rain or snow on vehicles will not compromise the SPF insulation.
The amount of SPF insulation will depend on the use of the garage. This can be discussed with a KSFI SPF Advisor. Commonly we install an average of 1.5”-2” of closed cell foam (compared to 3-4” in new homes). Reasonably priced, this will insulate enough to heat the garage temporarily with an electric heater or wood stove. This is a great system when you want to keep your cars thawed out and above freezing temperatures when it is very cold outside. If your garage is permanently heated or cooled with your HVAC system, then you will need to step up the amount of SPF insulation to be installed.
Should You Insulate Garage Doors?
Installing well-sealed and well-framed insulated doors in your garage is highly recommended whether or not you insulate your garage walls or ceiling. This will allow at least some of the outside extreme temperatures to be resisted from the inside space. If your garage is attached to your home, insulated doors are absolutely necessary. Not only will you be insulating the space from the outside elements, but also preventing unconditioned air from entering into your home and up through the space above the garage.
Attics & Living Spaces Above the Garage:
If the space above your garage is used for storage or is a living space, you will need to insulate the ceilings in the garage to prevent the temperatures in the garage from affecting the conditioned space above. We have had many customers with problems in spaces above garages becoming very difficult to cool down or heat up depending on the time of year.
If the ceiling is adjacent to an attic space with open rafters, then SPF insulation can be applied to the attic floor. You can then install a floor in the space above. Let us know your plans, and we can provide you with some options.
If the ceiling rafters support an outside roof only, SPF insulation would be installed to the underside of the roof.

