Residential Application

Radiant Barrier Installation Over Attic Floor

Least Ideal Installation - Attic Rafters

Although this method of laying over the attic floor won't lower the temperature of your overall attic space, it will still block up to 95% of the radiant heat from transferring into the rooms below. To compensate for the exposed AC duct work, you can easily lay a blanket of radiant barrier over the ducts to protect them from the heat.

CAUTION: If you choose to install over the attic floor, keep in mind that condensation may form under the radiant barrier based on sudden extreme temperature differences between the air below the barrier and above the barrier typically found in colder climates in the winter. Read more about condensation buildup).

Looking for the best way to install a radiant barrier in an attic?

Step-by-Step Instructions

Upon delivery of your radiant barrier, store in a dry space with no contact to the ground or sources of water.

Read through all instructions below before proceeding to ensure proper installation.

Suggested Product: RadiantGUARD® Xtreme breathable radiant barrier

Materials Needed:

Utility knife or scissors
Measuring tape
Staple gun and 5/16-inch staples
Gloves (optional)
Step ladder or scaffolding (if necessary)
Safety googles and protective headgear is encouraged to avoid injury from roofing nails protruding from roof decking.

Steps to Install:

Starting at one end of your attic, install Xtreme breathable radiant barrier over attic floor joists, plywood decking or existing insulation. Use a stick (furring strip with nail secured to the end works well) to help push the barrier into the tight spaces of your attic.
Continue covering the attic floor by overlapping each section of radiant barrier by 2 inches.
Is not necessary to make the radiant barrier lie smooth or flat. It is also not necessary to tape the seams. You can staple the barrier in place if you wish but it's not necessary.
Cover all knee walls located in the attic overlapping each piece of radiant barrier by 2 inches and stapling.
Cut out any material around appliances that produce heat and/or protrude through the attic floor (canister lights) and mark any electrical junction boxes that are covered by the radiant barrier.

A great tip related to laying the radiant barrier directly on the attic floor is to tape an outline of any underlying decking pieces you use to walk on to access various storage areas or equipment in your attic. By outlining these decking pieces with a brightly colored tape, you, and contractors or repairmen who access your attic in the future, will easily be able to see where it's safe to walk eliminating the risk of stepping in the wrong place through the ceiling drywall.