How To Install A Radiant Barrier In A Attic | Do It Yourself

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How To Install A Radiant Barrier In A Attic

Earl W. from Dallas, TX wrote:

How's it going Itchy?

I just had R-40 insulation installed into the attic. It's still hot up there. I am thing about installing one of those reflective radiant barriers in the attic. How do I go about installing a radiant barrier?

There are a couple of ways to do it. You can lay it directly on top of the existing insulation, but I wouldn't recommend it if you live in a hot climate. The other method of installing a radiant barrier in the attic is to staple it to the roof rafters, assuming your roof isn't too high above the attic floor.

I would recommend buying the radiant barrier in widths or 3 or 4 feet. Grab a drop light, staple gun, utility knife, the roll(s) of radiant barrier and a helper and get on up into that attic. Don't forget to wear protective clothing and a dust mask and try to do this in the morning before the attic heats up.

If your attic is not platformed you're going to have to walk the ceiling joists so be careful not to fall through the drywall. You're going to attach the radiant barrier to the roof rafters. Roll out the radiant barrier the entire length of the rafters and cut it with your utility knife. Starting at the bottom, near the eaves, begin stapling it to the face of the rafters. Make sure the shiny foil surface is facing the open attic - not the roof. Watch for electrical wiring and don't staple into it. You should be using 1/2" staples.

Continue going across the attic, stapling the reflective radiant barrier as you go to the rafters. Don't let your helper goof off. Have him hold the radiant barrier up so you don't get all wrapped up in it. Once you have the bottom attached you should give your back a break. I know it's not easy bellying through tight areas of an attic.

Next, attach the opposite end in the same manner, stapling across the rafters and down each rafter every 8". Once you have that length of foil barrier installed, roll out another length of it and install it in the same manner, making sure you overlap the previous piece about 2". Don't install it completely up to the roof ridge because you'll need a opening for the heat to escape. Leave the rafters open at least 6" from the roof top.

The gable ends should also have radiant barrier installed. Staple the barrier to the studs, but make sure to leave room at the top for the hot air to escape through the roof vents.

Okay, now you have the radiant barrier installed in the attic. You have another problem if your attic was insulated with loose fill insulation. You've walked on it and smashed it down in areas. Use a rake and try to fluff it back into it's untouched condition. If you're unable you should consider blowing new insulation over it as it has lost some of its r-value.

Related Tips and Advice:

How To Insulate Garage Walls
How To Install Blown In Insulation In Your Attic
How To Insulate A Concrete Wall
How To Insulate Ducts

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