How To Insulate Dirt Crawl Space Floor

Here s how to insulate under a floor.

How to insulate dirt crawl space floor. Insulating the space between the joists in a basement or crawlspace can help reduce your energy bills. Applying spray foam to the dirt floor of your crawlspace may be one of the easiest and most effective solutions and if so then you would be best not to insulate the joists over your head and just heat that space instead. The idea is to condition the crawl space much in the same way that you might condition other parts of your home. Cut the insulation to length using a square and sharp utility knife.

It is important to secure insulation and cover it with a vapor barrier in order to prevent moisture and the mold that often follows close behind. The sill plate is the first piece of framing lumber and it runs on top of the crawl space wall. In this video home renovation brothers dave and rich demonstrate how to insulate a crawl space. This will give you the thermal barrier between the crawl space and your living space as well as help keep the air from getting from the crawl space into the living space.

Department of energy recommends r 11 3 insulation under floors in warm climates and an r 25 6 to 8 in cold climates. When you re using fiberglass batting insulation material run it about 6 inches or so onto the crawl space floor. If you would like to keep your crawl space vented because you live in a low humidity environment we recommend insulating the crawl space floor with fiberglass or rock wool mixed with spray foam for air sealing. Fiberglass insulation batts or rolls are the most economical and easiest diy choice for insulating between the floor joist in a crawl space.

If the crawl space is ventilated which is ideal because it aids in the elimination of moisture then fiberglass insulation can be easily installed under the subfloor between the floor joists. Cover the walls with insulation from the sill plate to the plastic covered dirt floor. Instead a better method is the multi pronged approach of insulating the inside walls of the crawl space with rigid foam laying down a plastic vapor barrier over the dirt floor then joining the two items with tape.