This is one of those projects that we should have done years ago, but for some reason, I always thought it would be a lot more painful to do than it actually was. Even after building a detached garage (workshop) and seeing how much its insulated door helped, I still waited another four years to do this. As it turns out, it was extremely simple and only took a couple of hours to do both a single and double-bay door.

An insulated 2-car garage door.

There are several types of garage door insulation kits, but the ones we ordered were rigid polystyrene panels that have grooves cut along their lengths. This allows them to bend slightly along their width which makes it easier to insert them in the garage door.

The tools that were required included a 2′ straight edge, a utility knife, and a small tape measure. A socket wrench may also be needed to temporarily remove one of the door’s metal cross supports depending on where they are located.

A garage door insulation kit.

After measuring the length of the panel, they can be scored with a knife using the straight edge as a guide.

Scoring a piece of garage door insulation with a knife

Then the panels can be easily snapped along the cut line. This part can be a little messy as it results in quite a bit of Styrofoam snow blowing around.

Snapping a scored piece of garage door insulation.

A small piece needs to be cut and inserted behind the metal frame as the panels will not flex along their length.

Inserting the initial small piece of garage door insulation.

The rest of the panel just slides into place (with a little help at times). I was able to install the insulation for the single bay door without having to take the cross supports off, but I did end up needing to remove one for the double door.

Several pieces of insulation installed in a garage door.

That’s really all there is to it. A single-bay door will require one kit usually (depending on its height), and a double-bay door will require at least two kits.

A single bay garage door with insulation.

The most immediate difference was the reduction in outside noise. Since we have both a single and double-bay door that face a highway, it seemed eerily quiet once all the insulation was installed. Opening and closing the doors was also noticeably more quiet with the insulation in place. The kits have a rated R-value of around 4.5 and the temperatures in the garage definitely seemed more comfortable and fluctuated less overnight.

So it may not be the most impressive home improvement project, but it certainly seems to have been worth it. I only wish that I’d gotten around to it sooner!