Insulating the space between the joists in a basement or crawlspace can help reduce your energy bills.
How to insulate basement floor joists.
Joist bays the open spaces between floor joists are prime hosts for insulation under specific circumstances.
Rigid foam is affordable.
Properly insulating and air sealing rim joists band joists takes patience so most builders simply stuff in some fiberglass and walk away.
Rim joists let in more than air.
Fiberglass insulation batts or rolls are the most economical and easiest diy choice for insulating between the floor joist in a crawl space.
If you need to insulate these rim joists it s best to hire a cellulose insulation contractor.
Hold the batts in place by stapling their paper faced vapor retarders to the lower edges of the joists.
Department of energy recommends r 11 3 insulation under floors in warm climates and an r 25 6 to 8 in cold climates.
Here s how to insulate under a floor.
Also insulate 4a any portion of the floor in a room that is cantilevered beyond the exterior wall below.
If you have an unfinished basement you can properly insulate the rim joists in two or three hours.
Cut the insulation to length using a square and sharp utility knife.
Once the ceiling is buttoned up insulate the rim joist the floor framing around the perimeter of the house directly above the foundation wall.
When the basement or crawl space has vents installed insulating joist bays.
If you re ready to insulate the rim joists in your basement or crawlspace you have to decide between rigid foam and spray foam.
Use a box cutter to cut the insulation to length.
Spiders bugs and even mice find the rim joist an attractive place to enter the home.
4d extend insulation into joist space to reduce air flows.
4c as an alternative to floor insulation foundation walls of unvented crawl spaces.
It s the simplest and least expensive basement area to insulate and will bring the highest return on your investment.