Money is rarely wasted on insulation – that is unless if you don’t need it. What need to be considered are your needs are & how much insulation do you need. Here is your ultimate quick cheat sheet guide to insulated garage doors.
What Is The Concept Of How Insulation Works?
In the real world heat is transferred in different ways.
- Conduction – touch a cup of hot coffee.
- Convection – heat transfer through moving gasses, fluids, liquids etc.
- Radiation – the sun on your face is a good example.
Insulation of course slows down the transfer of heat. Insulation like fiberglass works by isolating air pockets. Fiberglass works excellent in your walls. 5 1/2″ is up to R-21. A garage door may be 2″ thick so ideally if we can match the R-value of the wall this is good.
Garage Door Contractor Insulation Speak: One Layer, Two Layer, Three Layer
This will help you in the future be a smarter buyer.
- One layer: or a pan door as understood in-between all garage door contractors. No insulation. Just a steel garage door.
- Two layer: The same as a one layer but with insulation. You will see exposed insulation on the inside of the garage.
- Three layer: Insulated & has steel on the inside & outside of the door. This will make for a stronger longer lasting door. If you choose to upgrade to polyurethane AKA intellicore you will have a rock solid panel.
Types Of Garage Door Insulation Materials
- Polyurethane – This is the ultimate in insulation. Two inches will give you about the same R-value of 5 1/2″ of fiberglass bat in your standard 2×6 wall. R-18.4. This is also VERY strong. It is injection molded into the door & fills all the voids & shape of the door. It is a big seller in Mexico for security reasons.
- Polystyrene – This is AKA Styrofoam. In a typical 2″ door you will have R-6.3. This is not all bad. R-value wont tell you the whole story of how insulation will help to keep your garage climate controlled. More on this below.
- Aftermarket kits may use fiberglass or polystyrene. See below.
R-Value? U-Value? & Other Esoteric Terms Explained Simply
Explained simply without the math or engineering speak.
- R-Value: This is a familiar term. This is thermal resistance to heat being transferred. The higher the better.
- U-Value: This is used for windows. This is the inverse of R-value. It isn’t a value of insulation but heat transmission. Just simply think of a piece or copper vs a piece of wood for heat being transferred . A lower U-value is better.
- There are other terms like K-value (basically U-value) & C-value (relates to insulation thickness). You wont see these on any ratings at Home Depot so unless your a pointy headed engineer we don’t need to concern ourselves with this.
So, keep in mind that R-value & U-value are kind of the same but in the opposite ways but because we are dealing with different materials, the engineers figure it is practical to use different terms for ratings.
- E-Value: The ability to resist radiant heat transfer like the sun. You may not see this term used often but in windows sometime.
- Radiant Barriers: Imagine in the summer & your under a hot tin roof. Anything you can put between the roof & you is a good thing! This is the same for your steel garage door. See below!
About radiant barriers, forget the numbers (R-value) for a moment. If you insulate your garage door with even a minimal polystyrene R-6.3 insulation. When you have the hot sun on your door in the afternoon you will have an exceptional radiant barrier! This will make a BIG difference for making the space cooler (conversely to a lesser degree in the winter, but also true).
Also an advantage of any insulation is a cleaner garage. The voids on the inside of the door will be filled so there will be no place for the dust, dirt, spider webs & the to collect.
Do I Need Insulation?
Consider your needs.
Maybe not if:
- Is your garage only a place to park your car or maybe has become like a lot of people’s & has transformed into a storage area?
- The home & garage is a rental unit.
- Your budget. There is nothing wrong with allocating your money for other things. What would Dave Ramsey say? 🙂
- You have an non-insulated utility detached garage.
Maybe Yes & You Get What You Pay For:
- Like mentioned above, even a minimal R-6.3 polystyrene insulation as a radiant barrier will cool your garage in the summer & keep the bugs & dirt off the inside of your door. Figure to add about $90 for a single wide & $150 for a double wide for a two layer door cost.
- The space is going to be climate controlled. If your spending a lot of time in your garage during the summer & winter 2″ of polyurethane is a wise choice.
- Consider how the rest of the space is insulated. The door’s R-value should be similar to the walls. If there is not much point in most cases in going above the R-value of the walls when buying a garage door. As an extreme example if you have a steel shed you would be wasting your money on a intellicore polyurethane R-18.4 door on this structure.
- Strength & Quality! I have been in this business for over 25 years. I have seen what the real world does to a door panel. There is a big difference in the life of a one layer pan door VS a three layer door! – forget warranty sheets!! A three layer panel just makes a stronger garage door.
Here is a well written resource covering insulating garages & garage doors. Why Insulating a Garage Should Top Your Home Improvement List
After-Market Insulation Kits
Some of these aren’t to bad, a few a waste of money. The best option is to get a kit from the manufacturer’s dealer if possible. It will fit the inside of the door better. Keep in mind an aftermarket kits on a double door could be adding at least 30 lbs to the weight of the door. This will make a problem with the torsion spring that lifts the door. You can maybe add a 1/2 or 3/4 turn to the spring or purchase new springs. See my post on torsion & extension springs.
There are fiberglass & other garage door insulation kits. These are not perfect & sometimes they have problems staying attached to the door. Some ingenuity you can make these work.
1 Comment. Leave new
Awesome post! Thanks for sharing the knowledge and keep up the good work.