install radiant barrier in attic
initial requirements:
- The roof receives direct sunlight in summer and has a full attic underneath. The roof should have a ridge vent for ventilating hot air produced between itself and the radiant barrier. The attic should already have at least R-19 insulation. Radiant heat barriers are never a substitute for insulation.
materials needed:
- 1/4-inch staples for stapler
- An aluminum foil designed to be used as a radiant barrier. Any product should resist tearing and be fire resistant. One or both surfaces should reflect at least 95 percent of incoming radiant heat. Purchase enough to fit on the underside of all of the attic rafters.
tools needed:
- Carpenter’s tool belt
- Heavy-duty stapler
- Heavy-duty shears
- Drop lights and extension cords
- Tape rule
required skills: Simple handiwork
annual energy savings: Research has shown radiant heat barriers can reduce annual cooling bills around 10 percent if the attic has less than R-30 insulation.
average time required: 4 to 8 hours/1,000 sq ft
project steps:
- Set up the extension cord, lights, and walkboards in the attic.
- Most radiant barrier products come in a roll from 4 to 6 feet wide. Staple the foil either across the rafters or parallel to them, as specified by the manufacturer. The shiny side should face downward so it does not gather dust over time. As long as the surface remains shiny, it will block radiant heat whether facing upward or downward. Of course, it is best to have a reflective surface on both sides.
- Repeat step 2 for all sections of the attic.
