How To Insulate Garage Doors: A Guide

Did you know your garage door is a significant source of heat loss in your home? In fact, it can account for up to 40% of the heat lost from your house. This means if you insulate your garage doors correctly, you could have a big impact on heating costs and energy efficiency.

Most of us, myself included, get tired of paying so much for heating. But, because they already take up so much time and energy as it is, I don’t want to waste any more time worrying about reducing these expenses!

My good friend, Sean, suggested I fix the insulation on my garage doors, and boy has it been a game changer! There are insulation kits available to help keep warm air inside and cold air out by filling gaps between your garage door panels with insulation foam strips or polystyrene beads.

This article will share how you can insulate your garage doors and have a warmer, cozier home while hopefully bringing down your heating bills.

Step by Step Guide to Insulating Your Garage Door

1. The first step is to find out what type of insulation you need for your garage door


Various insulation materials can be used to insulate garage doors, including fiberglass bats, blankets, foam board sheets, and vinyl or cloth coverings.

The first step is to determine the type of doors being used, which may or may not be wood. If the door uses fiberglass, insulating materials made from fiberglass like blanket insulators and batts can be used. A blanket insulator is made from a piece of fiberglass that insulates and covers the door. A bat is a hollow tube of poly-fiberglass, similar to foam insulators but lighter and far more expensive (batts are used in walls).

If vinyl or cloth insulators are being used, it may be necessary to use an extra insulator at the bottom of the door to insulate it from the ground. This insulator should be made from foam boards with a width that is wide enough to insulate the bottom of your garage door.

2. Next, measure the height and width of your garage door

Measure the height and width of your garage door before you buy insulating equipment. Some sizes require special orders, which may cost more than other items, so measuring will save time and money. 

Measure the height of your door from the bottom to the middle of the top. The average garage door is roughly 8 feet high, but yours may be taller or shorter depending on many factors. Whatever you do, don’t just guess here!

Measure the width of your doors from one side to another. Or install a measuring tape along with each panel while it’s opened. This is also important to get a precise measurement because garage doors can have different widths depending on many factors, such as the size of your vehicle, for example.

3. Calculate how much insulation you’ll need

Take the Height and Width (in feet) and multiply them together. You will obtain the area in square feet. This is the surface area of your garage door.

Next, take the area measurement of one insulation sheet you’re looking to apply on the garage door.

Divide the total surface area of your garage door by the surface area of one insulation board/panel.

You have now obtained the number of panels or foam boards you will require to insulate your garage door. Well done!

4. Purchase insulation that’s suitable for the climate where you live 

R-Value is the measure of how good a material is at keeping the heat in. The higher the R-Value, the better it can keep heat inside.

R-value is calculated as –

R = thickness of material in meters ÷ thermal conductivity in W/mK

If you think there’s no way for you to do the math to figure out if your garage doors have the right R-value, don’t worry. It’s enough for you just to know that they are not too low or too high.

You should look for a garage door insulation kit that has a decent R-value. This will keep the amount of heat going out through your garage doors down to a minimum, thus making your house warmer and more energy efficient.

The top kits are usually those which have foam boards with an R-value between 6 and 10. If you live in the northern states of America or Canada, you should use a thick foam board with an R-value of about 15. If you live in a southern state where the temperature is lower, look for an insulating kit with an R-Value around 11.

You should make the decision based on your region. However, aiming for R-value of 11 or 15 is usually a safe bet.

5. Apply your insulation kit

  • Start from the bottom of your garage door and apply the boards one by one. Smooth these into place as you proceed up. This is to avoid air pockets.
  • Apply a generous amount of glue or cement over each seam between panels to ensure they stick together properly – usually about an inch in length for each piece that goes together. Use a Trowel to spread the glue/cement in a thin layer.
  • You may also want to double-check your R-value – is it what you were hoping for? If not, try again with the next best thing. Caulking can be used at this point if there are any holes where the foam panels meet up (like between them and around the edges).
  • Finally, screw the insulation kits onto the garage doors using screws in each corner. Other options are to use metal clamps if you have them available or strong adhesives. The key here is to ensure that the panels stay put since they will be placed under pressure from weather and temperature changes for many years to come!
  • Also, consider keeping the area around your doors dry and warm. This is crucial to keep moisture out of your garage door insulation kit for as long as possible, increasing lifespan and ensuring that your efforts aren’t wasted in vain. In addition, keeping moisture out will ensure that no mold or fungus is growing inside your insulation panels. 
  • You can also choose to add an extra layer of protection around the edges by installing metal siding, plywood, or even a vinyl board that’s strong enough to withstand the elements.

    Yes, these options will indeed cost you a little more money than installing regular insulation panels, but they are worth it in the long run. They also improve the look of your garage doors!

When Should You Insulate Your Garage Doors?

Insulating your garage doors is a great way to save on energy costs, but you need to know when it’s best to do the job.

If you live in a cold climate, it’s always best to do the job as soon as possible after construction. Before that, your garage door may suffer from condensation build-up and other moisture-related problems even if you heave insulated it.

If you live in an area with moderate climates, then there are different opinions on this because it all comes down to how long you intend to stay at your current location. 

For example, some people argue that it’s better not to do the job until you’re about to sell your home or move because garage doors can sometimes become more attractive for buyers if they are well insulated.

However, no matter where you are or when you choose to do it, always be sure to buy the very best insulation kit for your particular situation! The extra money you spend now will pay off many times over in the long run!

Since cold weather will complicate the process, most people recommend installing insulation before winter arrives.

It’s also important not to wait too long after installation because the colder and more humid months can cause mold or fungus growth in your insulation panels.

Your insulation’s performance may also be affected by local weather patterns. For example, if your area is prone to hurricanes or tornadoes, you may want to install something stronger than foam panels that can withstand a bit of a beating. Remember: You need something that you’ll feel comfortable with for years and years to come!

Tips to Insulate a Garage Door

  • First, mount the door opener before starting your insulation project, as it can be difficult once you’ve already applied the insulation panels. It is also easier if you find that door only opens in one way and not both ways.
  • Use a hacksaw to cut the insulation sheets into appropriate sizes for your door. Each sheet will probably need to be cut in half or thirds depending on the width of your garage door.
  • Secure each insulation piece with screws onto your garage door by drilling them directly through hole punches that are part of the panel. This will also require you to screw into the back panel of your garage door. You will need to do this every foot or so in order to have one continuous surface for air seal.
  • Drill through holes in the insulation to secure it on the front side (measure first to ensure correct placement).
  • Use slit foam pieces to fill in the gaps. Any gaps less than 1/2 an inch wide should be filled with slit foam and then covered with insulation panels.
  • Apply shingles to the top of the garage door insulation kit to keep out moisture and dust. It also reduces the chances that bird droppings, dirt, or debris will get caught from underneath and build upon the top surface.
  • Leave extra space along the bottom edge so that you can fit it with foam panels later. This will also help with noise control – remember, each additional layer of insulation will bring you one step closer to a quieter garage door.

How Much Do Garage Door Insulation Kits Cost?

The cost of insulation kits will depend on several factors: type, size, and location. It’s challenging to give specific figures here since each company has its unique prices for its products. One thing is sure, though: the good ones are not cheap by any stretch of the imagination!

If you’re on a budget, the best way to go would be to find something that’s affordable and effective. In other words: avoid vinyl or low-grade foam insulation kits at all costs! They will do nothing but give false hope by making you believe they work as advertised.

Reputable companies have a higher chance of being well worth the extra money. Go for a company that has been in business for many years. Their products should be high-quality while offering great insulation, excellent durability, and maximum protection against moisture!

Can You Do It Yourself?

This is a general question that you will get no matter where you look! 

So the short answer to this question is yes! It’s entirely possible to do the job yourself, but it does require a bit of extra strong-back and forearm muscles.

The most important thing when installing garage door insulation is laying down the panels correctly.

What Can I Expect from Insulating My Garage Door?

If you have properly installed insulation, one of the most noticeable changes you’ll see is that your garage door will stay cooler during hot weather. The panels will absorb and evaporate heat faster than if it wasn’t insulated at all!

This also means that your home will be more comfortable during those sweltering summer days. Adding insulation to your garage door will also help you save money on your energy bills!


Garage doors are a major source of heat loss in your home and should be prioritized when insulating. If you do not have a garage door, it is important to make sure that the windows in any adjacent room will provide adequate insulation as well. It’s also worth noting that if possible, this project may take time- so plan accordingly before winter sets in!