Roll out the insulation with the foil face down on a unfinished floor or plywood base. Measure the length of insulation needed with a tape measure and place a straight board across the insulation at that point. Press the insulation down with the straight board and cut along the edge of the board with a sharp utility knife. Cut through the foil face of the insulation and into the unfinished floor or plywood.
Place the cut piece of insulation into the wall cavity. The foil face should be toward the living area of the home. The insulation should fit by friction between the studs. The insulation must reach all the corners of the wall space. Do not compress or stretch the fiberglass insulation while installing. Either process changes the insulation's effectiveness.
Fold the foil or paper flanges over the wall studs. Staple in place with 1/2-inch staples. The friction should hold the insulation in place; the staples only hold the facing in place to increase its effectiveness as a vapor barrier.
Things You Will Need
- Tape measure
- Straight board
- Sharp utility knife
- Staple gun with 1/2-inch staples
- Wear a breathing mask while working with fiberglass insulation.
- Cut the packaging material on the sides rather than across the roll to avoid cutting the foil insulation face.