Insulation in the Garage: One Area That Has a Surprising Impact on Home Comfort

InsulationDon’t overlook garage insulation when you’re planning ways to make your Macon area home more comfortable and energy efficient. Many garages are finished without insulation in order to reduce construction costs, on the assumption that the garage will be used for nothing more than parking cars at night. But, many area homeowners use the garage space as a workshop, play area, storage facility or a place for the dog to sleep at night. Whatever you use your garage for, adding insulation to it might be an easy weekend do-it-yourself project. Even if you decide to hire a professional to do the work, upgrading insulation is a good investment.

Good Reasons for Garage Insulation

You might be surprised at the positive impacts that garage insulation can have on your home comfort:

  • Insulating a garage gives you an inexpensive addition to your home’s living space. Instead of being oppressively hot in the summer and uncomfortably cold in the winter, you’ll be able to use the space all year round. Garage insulation will make it possible to heat or cool the space with a portable electric heater or a window air conditioner.
  • Air sealing the common walls between the garage and living spaces will minimize conditioned air losses from your house while also reducing the danger of noxious fumes garage entering your home from the garage. Auto exhaust fumes and vapors from paint, insecticides and other products you may store in the garage are potential health hazards that you don’t want inside the house. Blocking them will improve your home’s indoor air quality.
  • Turning your garage into an insulated space will save energy when you’re heating or cooling your home. Insulating a garage will effectively increase the R-value of the walls that separate your living space from the garage space.
  • Garage insulation will reduce noise transmission into your house. While insulation won’t completely sound-proof the walls, it will reduce the annoyance factor to your family when you use power tools in your garage.
  • An insulated garage will make driving your car more pleasant on cold mornings. Instead of having to heat your car up from freezing on a cold day, you’ll start out with it already at the moderate temperature of your insulated garage.

Understanding R-Value

R-value is a measure of the thermal resistance offered by a material under standard laboratory conditions. It’s also a measure of the total thermal resistance of a structural member, such as a wall or ceiling that results from the combined effect of all of the materials in the member. This can include paint, drywall, insulation, studs or rafters and external siding. The higher the R-value, the harder it is for heat to flow through the material or structural member.

When you shop for insulation at your local home improvement store, the R-value of each material will be indicated on the packaging, so you can estimate how much fiberglass batting, loose-fill insulation or rigid foam insulation you’ll need to achieve the levels of garage insulation that you want.

Here in the Macon area, the Department of Energy (DOE) recommends a minimum R-value of 49 for attics and 18 for walls in residential construction.

Windows are always a weak point in a building’s thermal envelope, so plan to do some work to reduce energy losses from garage windows at the same time you’re upgrading garage insulation in the walls and attic.

Insulating Garage Walls

Before you add insulation to garage walls, take the time to air seal the common walls between the garage and house. Sealing air leaks will reduce energy losses and keep hazardous fumes from entering your house from the garage. Use silicone caulk to seal small cracks and holes where wiring or pipes penetrate the walls. Seal the space at the bottom and top of walls with expanding foam insulation.

You can add insulation to garage walls using several different approaches. Walls with exposed studs are the easiest to insulate, but you can also work with walls that are already finished with drywall.

If your wall studs are exposed, the best way to insulate the wall is to add batts of fiberglass insulation between the studs. A home improvement store will have batts pre-cut to fit the space between 2×4 studs or 2×6 studs spaced on 16 inch or 20 inch centers. Get the batts that fit the space correctly, so you don’t leave gaps from using material that’s too small nor have to compress material that’s too big for the space.

Once the insulation is in place, you can cover it by finishing the wall with drywall or sheets of plywood, depending upon the appearance you want to achieve. For even better insulation, cover the insulation with rigid foam insulation boards before you add the final wall finish. Be aware that local fire codes may require that rigid foam boards be covered with drywall or otherwise made fire resistant for safety reasons.

If your walls are already finished with drywall, drill a small hole in each wall and check to be sure they’re not already insulated. If the space behind the drywall is empty, you can blow loose-fill cellulose or fiberglass insulation into the wall cavity using equipment that you can rent at your home improvement store. This will require cutting holes in the drywall large enough to accommodate the blower hose, which you can cover up after the job is finished.

Insulating the Garage Attic

Insulating the garage attic is one of the most cost-effective ways to make the space more comfortable in hot and cold weather. If the garage ceiling is finished with drywall, you can install insulation between the ceiling joists. If it’s not finished but has the ceiling joists exposed, the best way to insulate might be to spray foam insulation onto the inside surface of the roof decking, a job that might be best left to a professional insulation contractor.

For adding insulation to the floor of the garage attic, if the garage ceiling is finished, you can either lay fiberglass batts between the joists or blow in loose-fill cellulose or fiberglass insulation. Fiberglass batts are easy to work with and come in sizes ready to fit between the joists. Blown-in insulation has the advantage of uniform coverage without having to cut material to fit tight spaces and corners.

Insulating the Garage Door

Garage insulation won’t be very effective if you neglect the garage door. It’s probably not cost effective to replace the entire door with a new door that has a higher R-value, but you can improve the door’s energy efficiency significantly by add insulating gaskets between the joints and replacing the weatherstripping at the bottom of the door. When the door is closed, it should seal tightly to keep drafts to a minimum.

Don’t Forget the Windows

If your garage has windows, be sure to do what you can to make them more energy efficient. Use expanding foam insulation to seal gaps around the window frames. Replace worn weatherstripping so the windows seal tightly when they’re closed. Storm panels or sheets of clear plastic taped to the window frames can reduce heat transfer across the window panes. If you use a window air conditioner in hot weather, be sure to cover it in cold weather to prevent drafts.

For help with your garage insulation project and for more tips for making your Macon area home more comfortable and energy efficient, contact at Wilson Bryant Air Conditioning. Our expert technicians can help you with design, installation and maintenance of all of your home’s heating and air conditioning systems.