I use half of my two car garage as a garage and the other half as a gym. I am lucky enough that when the house was built they routed AC ducts to the garage but since the thermostat is inside (and I am thankful for that) it can still get pretty warm in the summertime (Texas).

To help it stay cooler I was thinking about adding an insulation kit to my garage doors, but I was unsure if it would actually be effective. The walls all have panels up so I can't tell for sure if there is insulation in them but from the looks of it, it was being used as a room in the past as carpet had been laid down at some point so I assume it would be insulated.

One other note, the garage door doesn't see a direct sun hit. The doors are closer to lining up north to south than east to west.

Does putting insulation on a garage door make a noticeable difference in maintaining cooler temperatures in the summer or are they still too leaky?

  • Have you lived in the house in the summer? In my west facing home, the garage door noticeably radiates heat from the sun when I'm in the garage.
    – JPhi1618
    Commented Mar 26, 2018 at 16:24
  • An eastern exposure is better than a western exposure. The solarization from a western exposure stacks on top of the normal heating from daylight air that happened all morning; solarization on an an eastern exposure only cancels out the chill of night. Commented Mar 26, 2018 at 16:49

1 Answer 1


Yes, insulation would help reduce heat transfer through the door enough to make it a worthwhile investment. Steel is a good heat conductor, so heat from the outside air is readily transmitted to the indoor air.

You wouldn't have to purchase a branded kit, however. Simply fitting 1" or 1-1/2" extruded foam (or even Styrofoam) will do. The one you linked seems priced competitively, though.

Make sure that you have good vinyl seals on the door as well. Airflow is much worse an energy waste than conduction.

  • Do you have numbers to back up the "worthwhile" part ? Amount of energy transfered, cost of cooling it down, versus cost of installation, time, maintenance, etc. ? Also, the number of times a day the door is opened should come into play to decide on it being worthwhile.
    – Jeffrey
    Commented Mar 26, 2018 at 16:43
  • No, but being in an extreme climate myself I certainly wouldn't want to pay to cool an uninsulated garage. Since the thermostat is in the home, cooling will be intermittent and the benefit to occupants minimal without good insulation.
    – isherwood
    Commented Mar 26, 2018 at 16:48
  • Thanks for your input, sounds like something I definitely want to pursue. I didn't even think about how the door would be a good heat conductor. Commented Mar 26, 2018 at 16:57
  • Since conduction is the only thing insulation resolves, you must have. :)
    – isherwood
    Commented Mar 26, 2018 at 17:48
  • 1
    An ugly but cheap way to do it is duct tape foil faced foam sheathing to the panels , This works well , It lasted several years before i moved. I may have put in a couple screws. My son has done it in TX and the sheathing has been up about 4 years . I now have insulated doors which is another way to go. Commented Mar 26, 2018 at 19:12

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.