If your garage door is a bit of a “draft magnet,” it’s probably doing more than letting in chilly air—it’s a major source of heat loss, and a burden to energy bills. While an uninsulated garage might be fine if you just use it to store your car, things change if you use it as a workshop, a gym, or a band rehearsal space. If you're going to hang out in there, adding insulation to your garage door can help keep the indoor space comfortable year-round and make a noticeable difference in your home's energy efficiency.

How much heat is lost out of your garage?

Temperatures in uninsulated spaces can fluctuate fast. Since garage doors are usually large and thin, they let a lot of heat through and it can be very hard to keep them at a comfortable temperature. For attached garages like with an uninsulated ceiling, or perhaps the drafty garages in colder climates, losing that much heat can impact not just your comfort but your energy bills. Managing that heat transfer with some insulation panels will keep your garage warmer to turn it into a useable space.

Option 1: Add Weatherstripping

Weatherstripping can be a great first step in sealing off the elements. If you live in a moderate climate, it may be all you need to limit cold transfer and energy loss. This affordable option is a relatively easy insulation project that is all about closing those little gaps and threshold seals around the garage door that let in drafts and let out warmth.

  • Choose a Quality Product: Look for rubber or vinyl strips designed to hold up in varying temperatures.
  • Clean the Surface: Wipe down the area where the weatherstripping will go, so it adheres well.
  • Cut to Fit: Measure, cut, and apply the strips around the edges of the door frame.
  • Press Firmly: Make sure it sticks properly for an airtight seal.
A rubber weatherstripping seal on the bottom of a garage door.
Weatherstripping on the bottom of a garage door. Credit: Emily Fazio

Option 2: Insulate with Foam Board Panels

These rigid insulation panels are a solid DIY option that adds an extra layer of insulation directly onto the garage door.

  • Choose the Right Thickness: Opt for foam panels about 1-inch thick for effective insulation.
  • Measure and Cut: Measure your garage door panels and cut the foam boards accordingly.
  • Adhesive is Key: Use a heavy-duty adhesive to secure each panel directly onto the door’s interior surface.
  • Cover All Panels: For uniform insulation, apply a piece of insulation to each section of your garage door. Use a spray foam as an air seal to close awkward corners and holes.

Option 3: Install Reflective Insulation

Reflective insulation, often made with foil, is perfect for garages that get too hot in the summer but need warmth retention in winter. It's a win-win for your energy savings.

  • Cut to Size: Measure the door panels and cut the insulation material to fit each one.
  • Adhere Securely: Attach the insulation with double-sided tape or adhesive spray, ensuring it stays flush.
  • Secure the Edges: Use foil tape around the edges to prevent air from sneaking in or out.
Use insulated foil to line the garage door.
Use reflective insulation to line the garage door. Credit: Boris SV / Getty Images

Option 4: Attach Fiberglass Insulation

Fiberglass insulation is one of the most common types and also often the cheapest option. It's flexible and can fit into irregular spaces, so it’s a great heat retention choice for garage doors with an uneven surface. It also acts as a good sound barrier against outdoor noise.

  • Wear Protective Gear: Fiberglass are notorious eye irritants, so gloves, long sleeves, and a mask are essential.
  • Measure & Trim: Cut the fiberglass insulation batts or rolls to match the size of your garage door panels. Cut excess insulation with a utility knife.
  • Attach Carefully: Use adhesive tape or fasteners designed for insulation to attach the fiberglass to the interior panels.
  • Cover It Up: Consider covering the layers of insulation with a vapor barrier to protect it and reduce dust.

New garage door panels enhance insulation.
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