Not only will insulating your attached garage save money, it can help make your home a safer place to live.
Garage insulation is probably not something you think about. Most homeowners keep their attics and walls well insulated because they know it saves on energy costs. However, since garages are unconditioned spaces; not heated or cooled; most people don’t consider insulating them.
An uninsulated garage can become as hot or cold as it is outside. This may not be a problem in the garage itself, but, with uninsulated walls and a ceiling shared between the garage and your home, it can become a costly source of energy loss. In addition, harmful fumes in your garage; from car exhaust, fertilizers, paints, etc., can seep into your home.
The best way to keep the harmful elements in your garage from entering your home is to insulate the walls and ceiling that is shared between the garage and the house. However, you have a number of options for insulating your garage and choosing the right one can make a big difference.
Batt insulation, long a popular choice for insulating attics and walls, is often the first type of insulation homeowners think of. While the R-values (the rating of insulation performance) for batt insulation may be similar to other insulating materials, it is not necessarily the best choice for garages.
Batt insulation is installed in rolls, or batts. The batts do not seal spaces between the wall and ceiling and gaps can form between insulation rolls. The gaps allow energy to escape from your home and fumes to enter. Batt insulation is also susceptible to damage from moisture, further reducing its insulating ability.
Foam-board insulation, solid sheets of molded polystyrene, offers similar R-values as batt insulation, but is less bulky. However, foam-board insulation also does not fill all the gaps in your wall and there can be gaps between the sheets of insulation.
To reduce energy loss and fume seepage from your garage as much as possible, you should consider insulation that fills every gap and covers your garage walls and ceiling with a tight seal. Spray foam insulation spreads and fills all the gaps. R-values are the same or better than other types of insulation and spray foam insulation is resistant to moisture damage.
If you have a door in your garage that leads into your home, a properly sealed, self-closing, fire rated door is a must to help protect your home and your family from fire, toxic fumes and heat loss.