How To Install A Radiant Barrier On Garage Door

Do you dread driving your car into a hot and uncomfortable garage? If so, you may have thought of installing a radiant barrier to protect your garage and everything you have stored in there from the sweltering heat, but you're not sure how to go about the process. Worry no more! We have researched on your behalf to furnish you with the best answers below.

Follow these steps to install a radiant barrier on your garage door for a cool garage during the hot season:

  • Measure the rectangular sections on the garage door.
  • Cut out the radiant barrier according to the measurements.
  • Pop each section onto the garage door.

Keep reading to gain insight on insulating your garage door with a radiant barrier, not forgetting the attic, if you have one above the garage. To complement the insulation, we'll also discuss tips on improving ventilation in your garage. Also, learn more about how you will benefit from installing a radiant barrier in your garage.

Insulating of attic with fiberglass cold barrier and reflective heat barrier used as baffle between the attic joists to increase the ventilation to reduce humidification - How To Install A Radiant Barrier On Garage Door

Installing A Radiant Barrier On Your Garage Door

Insulating of attic with fiberglass cold barrier and reflective heat barrier used as baffle between the attic joists to increase the ventilation to reduce humidification

Significant damage can occur to the operating system of your garage door during the summer. Furthermore, the items stored in the garage and the structural composition of the garage are at risk of being damaged.

Taking precautions early enough will not only keep your garage cool but save you from hefty repair costs.

To begin this project, you will need four sheets, 8 inches long, 4 inches wide, and ½ inch thick of polystyrene foam board with a layer of illuminated film on one side.

However, you can make your own if you cannot find any. And if you don't know how to go about it, ask for guidance from a professional.

Check out this reflective garage door foam insulation kit on Amazon.

The following are the steps to take to install a radiant barrier on your garage door:

Tools Needed:

  • Blade/knife
  • Measuring tape
  • Foam board with foil on one side


  1. Measure the length and width of one of the pockets on the inside of the garage. There are between 12 and 16 pockets on a single garage door. However, you may have to measure each pocket, because the sizes may be different from one another.
  2. Cut out the sections after adding 1 inch to the height of each section.
  3. An air gap will be created between the garage door and the foam board, making the radiant barrier more efficient at reflecting the heat away from the garage.
  4. Fix or pop the foam boards onto all the pockets or rectangle sections until you complete the installation on both garage doors.

Below is a video that explains in-depth how to install a radiant barrier inside your garage door:

Installing A Radiant Barrier On The Attic Above The Garage

Have a look at this foil insulation on Amazon.

If you have an attic above the garage, you could add extra comfort to the garage, by insulating the attic with foil.

Measure the floor and purchase the correct size of foil needed. Staple the foil to cover the floor and other surfaces with foil, not forgetting to wrap around every stumbling block like the support beams.

The foil will reflect the heat away to create a cool environment in the attic and garage.

Ensuring Your Garage Has Enough Ventilation

Construction of roof. View from the inside.

After installing the radiant barrier in your garage and insulating your attic with foil, open up all the ventilations available.

For example, open the side windows and doors if there are any. Also, remove debris on the scuttle hole, and open the pull-down staircase at the ceiling to let in air.

In addition, open the garage door, such that there is some space between the ground and the door.

Is It Worth Insulating Your Garage Door With Radiant Barrier?

silver foil insulation on ceiling roof house

Generally, insulation is an excellent move to condition your home adequately. But, is it worth installing a radiant barrier inside a garage door, yet you don’t use the garage that much?

Yes, it is worth all the effort to insulate the garage door because you will enjoy a cool, and comfortable garage for the few minutes you’ll be parking your car or driving out.

Besides, you may unexpectedly end up spending a few hours in your garage doing some chore such as arranging the items you’ve stored in it.  

Let us explore other advantages of installing a radiant barrier in your garage.

Protection Of Your Car

You can avoid the problems that cars experience when they are exposed to too much heat, such as the following:

  • Shortened Battery Life - The life of a car battery can be shortened by too much heat causing it to erode faster. Moreover, it can interfere with the electrical system of the car. Nevertheless, radiant heat will help your battery last longer.
  • Faster Tear And Wear Of Your Car Tires - Heat causes tires to expand and subsequently affects the pressure in them. That is why you have to check your tire pressure often during the hot season.
  • Reduced Strength Of Oil - The oil in your car is essential for lubricating the parts that run. Too much heat can deplete its strength or cause it to evaporate.
  • Evaporation Of Water - Your car can overheat and break down if the required water level is not maintained, at any given time, especially during summer when evaporation happens much faster.

Protection Of Stored Items

Sometimes we store things like paint, oils, lubricants, and other chemical-based products in the garage. They can deteriorate faster when exposed to heat.

So, to keep these items within the recommended temperatures according to the manufacturer's manual, a radiant barrier will provide the solution. 

Protection Of The Garage

The very construction of the garage comprising the walls, floor, and roof or ceiling needs to be protected to ensure its longevity. 

Enhanced Energy Efficiency

Since a radiant barrier helps to cool down the air inside your garage, the overall conditioning system of your home will not have to work as hard. It significantly reduces the energy bills. 

A More Functional Garage

Insulating your garage will allow you to add a conditioning system that will influence you to have new ideas on making it more functional such as using it as a recreational or workshop area.

Increased Value Of Your Home

Generally, insulating your home, including your garage, will improve the value of your home. It will give you better returns when you decide to put it up for sale. 

What Is The Best R-Value For Your Garage Door?

In addition to insulating your garage door, you may decide to insulate the walls and ceiling of the garage. These areas need a very high R-value: 13 to 15 for the walls and 30 for the ceiling. 

The R-value required for a garage door is usually between 8 and 12. This is because there isn’t much space behind the door to add a thick layer of insulation that would otherwise hamper the proper functioning of the door.

If you need a garage door with a higher R-value, you could buy a pre-insulated garage door with an R-value of 14, though the costs are high. 

How Much Does It Cost To Install A Radiant Barrier?

Insulating Board Into Roof Of House - Image

Installing a radiant barrier is a DIY project that would cost around $200 for two 9 feet wide garage doors. 

Foam board insulation costs between 30 cents to $1 per square foot, depending on the thickness and type of board. Thickness ranges from ½ inch to 2 inches, and sometimes more. 

And, if you hire a professional to install the insulation, it will cost you between $1.50 to $5.50 per square foot for both material and labor. 

In Closing

Installing a radiant barrier on your garage door helps to cool down your garage to protect your car and all the stored items in it. Furthermore, it helps preserve the construction of your garage for increased durability. 

The R-value of the garage door radiant insulation is not usually very high, ranging between 8 and 12. However, you could insulate the whole garage for a higher R-value.

Radiant barrier has immense benefits including reduction of your home’s energy bills, improving the value of your home, and creating a more functional garage.

You may want to read our previous posts on how to close open gaps on the sides of your garage door, and how to insulate the walls of your garage:

How To Insulate Garage Door Sides

Insulating Finished Garage Walls

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