Insulating the space between the joists in a basement or crawlspace can help reduce your energy bills. Here’s how to insulate under a floor:
- Cut the insulation to length using a square and sharp utility knife.
- In older homes, where the spacing of the floor joists varies, you may need to cut the insulation to width as well.
- Install the insulation with the vapor barrier facing up toward the heated living area of the house. If both floors of the house are heated, use unfaced insulation.
- Don’t compress the insulation when installing it, but allow it to expand to fill the cavity.
- Hold the insulation in place using support wires beneath it. Cut to length if needed using wire cutters.