The Best Way to Insulate Garage Doors
Kevin O’Connor hunts down an expert on garage doors to answer a homeowner’s insulation concerns
I’d like to make my attached garage more energy efficient by insulating the garage door. Lots of air comes in around it. Where should I start?
—Dottie Schickling, State College, PA
That’s a good question for Frank James, the owner of , who has 32 years of hands-on experience in the garage-door industry. Here’s what he had to say about your drafty door.
“First off, it’s not a good idea to add insulation to a garage door, which should be nicely balanced to roll up and down with minimal effort. The added weight of the insulation will throw off that balance, strain your door opener, reduce the door’s life span, and make it less safe. Even if you paid a pro to install new springs and rebalance your insulated door—an expensive proposition—it still isn’t likely to perform as well as you might expect, due to all the exposed, heat-conducting metal parts that haven’t been insulated.
“What you can do is stop the drafts. That will go a long way to keeping your garage warmer in the winter and cooler in the summer.
“Start by going outside and checking the seals on the sides and top of the door when it’s closed. You should see gently curved plastic fins that remain in contact with the door even when you press on it. Each seal should be continuous, without any cracks or cuts, and should return to its position after being flexed. If the existing seals have been damaged or are no longer flexible, order a new roll.
“Weatherseals are made of either PVC or EPDM, a synthetic rubber. EPDM is the more durable material, remaining flexible for decades, even in temperatures as low as −50 degrees F. It fits into sections of aluminum track (sold separately), so it’s fussier and more expensive to install than standard one-piece PVC seals. The one-piece seals are simply nailed in place with 11⁄4-inch ring-shanks spaced every 6 to 8 inches.
“Whichever material you use, put the top seal in first, then attach the sides, and caulk the seams between the seals and the jambs. Lots of air can sneak in through those seams.
“Next, fasten a seal to the top edge of the upper door section. Its fin presses against the header inside the garage, just above the door opening, when the door is closed. This is one of the best things you can do to block drafts.
“Finally, check the seal at the bottom of the door. If it’s not intact, or if you can see light coming in under it when the door is shut, consider replacing it. You’ll get the best performance from a U-shaped, bead-style seal made of EPDM. It slides onto an aluminum track held in place with stainless-steel screws. “Installing the tracks and bottom seal is straightforward, but you must take these precautions before you start the job to keep the door from accidentally dropping while you’re working on it: (1) Unplug the door opener. (2) Pull the emergency release cord to disengage the opener from the door. (3) Open the door manually and lock Vise-Grips to the track above and below one of the rollers.
“Give the seals about a week to settle into their final shape, then wait for a cold, windy day to feel for drafts. Hopefully, there won’t be any, and your garage will be much more comfortable.
“There is a chance you’ll feel air coming through the joints between the door sections. If so, you can add strips of adhesive-backed, open-cell foam weatherstripping to each section, as long as it’s no more than 1⁄4 inch thick. Anything thicker could interfere with the door’s operation. As you install it, be sure to follow the same safety guidelines for installing the bottom seal. Each of those joints is a pinch point that will leave you in a world of hurt if it closes down on your fingers.”