Garage Door Insulation
Garage Door Insulation | Get It Done At The Factory
DEAR TIM: I live in a condo with an attached garage. The current garage door insulation is rated at R-4. Even with that it's cold in the winter and hot as Hades in the summer. Local companies have given me estimates to increase the insulation by installing a new door. This would cost over $1,000. I've seen kits that allow you to add insulation to the inside of the door for one-tenth the cost of a new door. Are they worth the price? Will the kit last? Will it fall off the door onto my new car when the door is in the up position? What would you do? Darla J., Findlay, OH
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DEAR DARLA: I know all about cold and hot garages. My current home has a larger three-car garage that's attached to the house with a small connector hallway.
My previous home had a very large garage that was ninety-five percent detached from my home. Even though the walls and ceilings of both are insulated, they still aren't comfortable when the temperatures get extreme.
Garage Door Insulation Helps But...
I think many people expect too much from insulation. Based on the constant flow of emails I get, it seems that many feel if something is insulated, then that means the space will be comfortable almost all the time.
What you, and others, need to know about insulation is that it simply slows the transfer of heat. Heat wants to travel rapidly from where it's hot to where it's cold. This is one of the simple laws of thermodynamics you may have studied in high school physics.
Insulation Slows The Transfer Of Heat
The rate of heat transfer is the R number you referenced. The higher that number, the better the insulating material performs at slowing down the heat transfer. A product with a rating of R-38 will retain heat much longer than a product that has a rating of R-5.
The issue with most garages is they're not heated or cooled. Very few people can afford to spend the money to pump heat or air conditioning into a garage to keep them the same temperature as the inside of a house.
Most Garages Are Like Sheds
Because of this, garages tend to act much like outdoor sheds. What little heat there is in a garage, it eventually starts to transfer through the walls and ceiling to where it's cooler.
This means as you go from summer to winter and your garage is not heated at some point your garage is just a few degrees warmer than the outside air temperature.
The actual temperature of your garage in the winter depends on so many things. For example, how well is the garage door weatherstripped? Are there other air leaks around the walls or ceiling of the garage?
How much heat from your house or condo leaks into your garage? How often do you drive your car and do you park it right away in your garage so the heat from the car and engine help heat the garage space?
Garage Temperature Starts To Equal Outdoors
Here's the bottom line. If you don't supply heat or cooling into your garage, the garage space temperature will eventually start to be quite close to whatever the outdoor air temperature is no matter how well insulated the garage walls, ceiling and garage door are.
DIY Garage Door Insulation Kits
All that said, the insulation kit you saw at the home center or hardware store could be a great value. It all depends on how well the rest of your garage is insulated.
If your garage door is the weak link in your insulation with respect to the walls and ceiling, and the kit allows the door to now have as much insulation as the rest of the space, then you're headed in the right direction.
However, if the kit simply increases the R-factor of the door so that its R-factor is much higher than the walls and ceiling, then the heat in the garage will transfer faster out of the walls and ceiling and you'll still have a cold garage in the winter.
I know all this is confusing but think of your garage like your body. If you have a warm coat and pants on but no hat, then you'll probably lose lots of heat out of your head and feel colder faster.
Use Common Sense With The Kit
If you decide to purchase the kit, you need to employ some common sense with respect to making sure the insulation stays on the door. You're very smart to have connected that when your garage door is in the open position and your car is in the garage, the new insulation can detach and tumble onto your car.
That's a very valid concern. It's up to you to determine how well the new insulation bonds and is connected to the existing insulation.
If the new kit is relying on some sort of adhesive, be sure your new and old insulation is dust free before applying the adhesive. Perhaps do a test. Just glue on one piece of insulation, allow the adhesive to dry and cure and then raise the garage door to see if the insulation stays put.
The issue with this is that an open garage door is an invitation for bad people to enter your garage, snoop around and possibly abscond with some of your possessions. Who thought that trying to insulate a simple garage door could be so complex? Jeeesh!