Insulation is used to improve energy efficiency and the comfort level in a home. When it comes to the garage, however, many homeowners are unsure if insulation is needed; others may not know how to install it effectively. There are a variety of ways to insulate a garage depending on the needs and budget of the homeowner.
Though many garages are not heated, it is still important to insulate them properly. Because they are attached to the home, hot or cold air from the garage can pass through the walls of your house. This not only makes your heating, ventilating and air conditioning (HVAC) system work harder to maintain the desired temperature, but can also increase monthly heating and cooling costs. This increased HVAC use also shortens the life of your equipment while increasing greenhouse gas emissions.
Adding insulation can help keep your home more comfortable and can even allow you to use your garage as an additional living space. A well-insulated garage can become a playroom for kids, a work space or a controlled storage area.
Insulating Walls and Ceilings
To get the most bang for your buck when insulating a garage, only add insulation to shared walls between the garage and the house. If your garage seems to be a significant source of air leaks, consider insulating all four walls and the ceiling.
Add fiberglass batts or rigid foam between studs and joists. According to the Department of Energy's Energy Star website, rigid foam offers about twice the insulating effectiveness per inch as fiberglass, though foam is much more expensive. You can combine these materials or use multiple layers, but avoid packing insulation too tightly--this reduces the effectiveness.
If the studs are covered by drywall, consider using spray foam or loose fill cellulose. These materials are professionally installed by contractors who create small holes in the drywall to provide room for installation. Liquefied foam is sprayed into the walls, where it expands to fill the cavity. Cellulose is made from shredded newspaper that is blown into a ceiling or roof structure. The walls and ceilings can be repaired after installation is complete to conceal holes.
Insulating Garage Doors
Garage doors provide another opportunity to add insulation and improve thermal resistance. For entry doors between the garage and home, choose a steel door filled with foam insulation. Add stick-on seals around the door and a nylon brush sweep to block air flow beneath the door.
If your coiling or overhead garage door is not already insulated, look for garage door insulation kits at your local home improvement store. These kits feature pre-cut panels designed to fit specific door models. Another alternative is to buy sheets of rigid foam insulation and use adhesive to fasten them to the door. Adding multiple layers can increase the effectiveness of the installation. Be sure to add a neoprene or rubber seal to the bottom of the door.