A Guide on How to Insulate Your Garage Effectively

With fall upon us and winter just around the corner, now is the time to check on the insulation of your garage. In this article, we will provide you with tips on how to save money on energy bills with our step-by-step guide on how to insulate your garage effectively before winter strikes.

When preparing your house for winter, there are many things you need to do to ensure a comfortable living environment for the season. Whether that is checking on your heating system, outdoor landscaping, or plumbing, there is no shortage of tasks that need to be complete before winterizing your home. One often-overlooked task is properly insulating your garage.

This garage door is an Eastman E-21 design, 9' x 7' size, Ice White doors and overlays, 8 lite Orion windows.

Do you like this look? These garage doors are in the Eastman E-21 Design, 9' x 7', Ice White doors and overlays, 8 lite Orion windows.

Take Care of Your Garage Door Before Cold Weather Arrives

This garage door is an Eastman E-21 design, 9' x 7' size, Ice White doors and overlays, 8 lite Orion windows.

Do you like this look? This single garage door is the North Hatley LP Design, 9’ x 7’ size, Desert Sand colour, windows with Richmond Inserts.

What You Need to Know About R-values

During the winter months, the temperature in your garage can fall if there are any cracks in the walls or garage door. To properly protect against cold winds, you're going to want good high-quality insulation to keep the warm air inside and the cold out.

Insulations are commonly measured by their R-value, which measures the resistance to the conductive flow of heat.

High R-values indicate superior insulation performance. If the R-value comes in high, your garage is more likely to stay warm. The correct R-value for a garage will largely depend on the square footage of your garage as well as the climate your garage is located in. Floor levels in a garage will usually require a lower R-value than an attic because attics are typically draftier and will need higher levels of insulation.

How Much Insulation Does It Take to Keep Your Garage Warm?

A garage door that isn’t properly insulated can lead to increased energy costs in your home. Drafts that penetrate your garage door can find their way into your home, causing the heat to need to work harder to maintain a comfortable temperature in your house.

With that in mind, you will need to determine the right level of insulation that will ensure that cold air doesn’t make its way into your house. Calculating the correct R-value for your garage will depend on these factors:

Insulation (Interior of the door)

A garage that is not very insulated should find R-12 to be a good level of insulation compared to a well-insulated one at an R-16 thermal resistance.

Attached vs. detached

An attached garage can increase the cost of your heating bills if the insulation does not have an R-value of at least 12. Detached garages aren’t usually heated and require a lower insulation level.

Usage and Living Space

If you have living space above your garage or want to convert your garage into a room, an R-16 level of insulation is recommended. Those planning on spending time in the garage will need a higher thermal resistance value to maintain a comfortable temperature in their space.

Garage Door Insulation Materials

The inside of the garage door is the most vital part when it comes to insulation. There are two distinct types of material that these doors are insulated with.

Polyurethane is a foam that can be applied between the door and interior garage door panels. Once applied, it will expand with heat to fill any gaps in your door. Because it expands quickly, the foam fills in all the gaps between the panels, which is an advantage over polystyrene. Polyurethane has a thick and solid consistency that is resistant to bending and has twice the strength of polystyrene.

Polystyrene, also known as Styrofoam, comes in large sheets that are affordable and easy to install. While it is less effective than polyurethane, it can still help keep cold air out to a certain degree.

See the difference between polyurethane (on the left) and polystyrene (on the right) insulation for garage doors

The difference between polyurethane (on the left) and polystyrene (on the right) insulation for garage doors.

Other Essential Elements you Don’t Want to Forget

Bottom garage door gap

Having a gap at the door threshold of your garage door can allow water, dirt, and unwanted pests to enter your garage. To prevent unwanted elements and pests from entering your space, you should check to see if the bottom garage door weatherstripping needs to be changed.

Garage door gap at sides and/or top

Garage doors with worn-out and cracked perimeter weatherstripping have a higher chance of having cold air penetrate the door. Replacing the weather stripping or applying a top molding piece can close these gaps and help you better insulate your space.

Areas You Might Easily Overlook

Garage Door Opener

Did you know your garage door opener can play a vital role in how well your garage is insulated? You should test the opener periodically to make sure it’s adjusted to a setting that efficiently closes the garage door.

Generally, you want the door to shut enough to allow for your fingers to barely slide underneath. You don’t want them to get stuck, but they should be fairly snug between the threshold and weatherstripping.

Electrical Outlets

According to Conservation Mart, between 2 and 5% of comes outdoor air through the electrical outlets. Unfortunately, most homeowners don’t pay attention to this area when they’re winterizing.

Because light switches and outlets have small openings, cold air can easily rush in, while precious warm air is filtered out. Using tape or coverings is a great way to prevent losing heat.

If you’re interested in learning more about insulating your switches Refer to this guide for 7 easy ways to insulate your garage switches.

Are Your Walls Well Insulated?

Walls and ceilings

How much you have to pay to upgrade your insulation will mostly depend on the level of insulation that will be required for your space. It is important to know that walls don’t have the same R-value as ceilings because warm air rises and is released through the roof. If you’re unsure about your insulation needs, consulting a professional could be a great way to assess what insulation solution is best for you.

If you want to insulate your garage yourself, you can follow these 4 easy steps from Dumpsters.com.

They also propose different types of insulation with pros and cons. Follow their blog to get insightful tips on preventing cold air from coming through your garage walls, ceilings, and door.

The guide goes more into detail, but the process is fairly simple. It’s as easy as clearing your walls and patching any small holes and cracks on the surface. You can use mud or a plaster to fill these in. Spread the insulation generously on the installation area, making sure to keep it as even as possible. Finally, you hang your drywall and allow 24 hours for finishing time.

Insulate your walls to save energy costs with foam.

Insulate your walls and ceilings adequately, and you will save energy! Image from Pixabay.


Windows can be an excellent addition to any garage if you’re looking to add more natural light to your space. However, it is important to know how to install them properly to ensure that you keep your garage well insulated. Thankfully there are many options out there to choose from that can accommodate any budget.


An easy way to keep the cold out is to use weatherstrip tape. To install it, just cut the tape to your desired length and place it around your window frame. You’d be surprised at how much this tape will keep the cold air out!


If you’ve caulked your window in the past, it is important to know that window caulking cracks over time. With that in mind, you should inspect it every year to check if it has separated from the seam. Refer to this article to learn which caulk is best for you.

Window treatments

Thermal curtains are an excellent option for maintaining a comfortable temperature during the winter months. This thick material can reduce energy costs by increasing the level of insulation of your windows while preventing heat loss.

Reduce Condensation in Your Garage

Condensation can occur when water comes in contact with a cold garage floor or door. Water that reaches a cold surface can result in moisture which is the last thing you want in your garage. While garage doors today are usually well insulated, there are still other spots where you should be aware of potential leaks.

Preventing Water from Accumulating on your Garage Floor

To prevent water from entering your garage, the ground near your garage door should have a sloped angle that directs the water away from the door. The interior of the door threshold should also be slightly sloped to prevent water from accumulating inside.

Water that pools up on your garage floor can create humidity. And this can prevent a garage from heating. Additionally, it is important to understand that excess condensation can damage a garage floor over the long term.

A garage door that keeps rainwater from running in your garage.

This garage has the proper garage door seal, and floor finishes to prevent water from leaking.

If you’re looking for the most effective way to keep your garage’s humidity levels low, a floor coating and dehumidifier are two simple solutions to keep your garage dry.

Do you Still Have Questions Regarding Your Garage Door Insulation?

Now that we’ve gone over the major considerations on how to properly insulate your garage from top to bottom, you will now be able to winterize your space. However, if you’re still looking for a professional opinion, you should consider contacting the professionals at Soo Overhead Doors Inc.

Before replacing your garage door, consider letting our specialists at Soo Overhead Doors Inc come to your house to inspect your garage door and garage door parts. Our experts will be sure to catch any weaknesses in your insulation. Whether you’re looking for new springs, rollers, or lift cables, we have all the hardware accessories you would ever need.

Replacing and properly insulating a garage door is not a simple repair. Why go through the hassle when you can have one of our certified and experienced experts perform your garage door maintenance? With many qualified technicians, you can have the peace of mind that your garage door replacement or insulation job is done right.

If your garage door is what prevents you from having effective insulation in your garage and needs to be replaced, contact us at 1-877-794-4223!

When choosing a garage door, you have no shortage of design and color options to choose from. By contacting one of our qualified team members, we can help you navigate the process and find a design choice that fits your home’s style.

If you want to get an idea of what your garage door will look like, check out our image gallery of residential garage doors to find houses that look like yours. You can also try out Design Centre App to get an idea of what your door will look like after installation.

If you’re interested in our services, get a free quote by email today. With years of experience, our team will be sure to guide you in the right direction.

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