How to Install a Radiant Barrier in 5 Easy Steps

Matt Marandola
Written by Matt Marandola
Updated October 5, 2021
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Keep the heat out of your home

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When a heatwave strikes, it can cause your home to feel like a sauna even with your HVAC system working hard. This is where radiant barriers come into play.

Radiant barriers are typically installed in the attic as a way to trap heat outside your home, saving you energy and keeping you cool. Installing radiant barriers does take a little bit of time to accomplish, so prepare to tackle this job over the weekend with a helping hand or two.

Difficulty: 3/5

Time: 6 to 10 hours

Tools and Materials Needed: 

  • Step ladder

  • Staple gun

  • Radiant barrier

  • Utility knife

  • Tape measurer

1. Declutter Your Attic

Attics are typically used for storage, so you’ll need to spend some time turning that storage space into a work zone. Any items you had pushed up against the walls will need to be removed or at least moved to the center of the attic. This way, you’re not making the job more difficult than it needs to be.

2. Measure

Measure the length of the roof on one side. You’ll want to start about 3 inches below the peak of the roof. From there, you’ll follow the roof’s angle until you’re about 3 inches from the floor. This will make measuring out the radiant barrier easier and so you’re not wasting the product.

3. Cut the Radiant Barrier

Using the utility knife, cut out the first piece of radiant barrier at the required length. Try not to step on or bunch up the radiant barrier while working it, as these little bunches can cause the sheet to shorten in length.

4. Staple the Top

Staple the radiant barrier to the top of the rafters where you measured 3 inches from the roof. Work your way across the attic as you staple.

5. Staple the Bottom

Once the radiant barrier is stapled to the top of the rafters, slowly move the bottom of the radiant barrier to the bottom of the rafter following the angle of the home. Staple the radiant barrier to the bottom.

In the event that you cut too short or you run out of the radiant barrier, overlap the material by about 2 inches and staple it into the rafters at that location. You may also want to do a second layer for optimal results.

Repeat these steps until you reach the wall plate (the vertical walls of the attic typically located at the front and back of the home). Continue the process on the other side until completed.

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Stapling the material to your walls isn’t the only way you can keep your home cool. 

Install on the Floor

Put the material on the floor rather than the roof. Though, this means you can’t use your attic as a living space or storage space anymore. 

All you need to do is lay the material over the insulation and floor joists and staple it down. Be sure to cut out any spots where a vent or ductwork is.

The Hybrid Method

There are situations where the attic has too little space to effectively install a radiant barrier in one location or the other. In these cases, you’ll want to install a radiant barrier on parts of the roof and parts of the floor.

For this method, you’ll install the radiant barrier about halfway down the roof—or, really, as low as you want to go. Then, starting from the spot where the roof radiant barrier ended, you’ll lay the flooring part until you hit the area where the roof and floor connect.

Should You Install a Radiant Barrier Yourself?

The project isn’t that hard to accomplish yourself, but it will require quite a few hands to get the job done—so you may need to call a friend or two.

If you want to save time and energy, it’s best if you have an attic insulation company near you come out and handle the job.

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