How To Insulate The Floor Of Your Crawl Space

No insulation on the ceiling of the crawl space.

How to insulate the floor of your crawl space.

The best method is to insulate crawlspace walls with rigid insulation. My house has an x board support in the floor joists for support. It is my understanding the insulation goes on the walls of the crawl space as well as the floor of crawl space. When you re using fiberglass batting insulation material run it about 6 inches or so onto the crawl space floor.

However the insulation needs to be treated with a fire retardant. The idea is to condition the crawl space much in the same way that you might condition other parts of your home. Install an air and vapor barrier over the floor and tape it to the insulation. Pairing silverglo with our terrablock padded floor insulation will keep out all outdoor air so your crawl space can stay warm in the winter and cool in the summer.

This type of crawl space also allows insulation with an r value of 19 installed in the floor joist if the crawl space and has a permanently installed dehumidifier. In a cold climate the most efficient technique is to insulate the walls of your crawl space and close it off from the elements by sealing all air leaks. The sill plate is the first piece of framing lumber and it runs on top of the crawl space wall. Fiberglass insulation batts or rolls are the most economical and easiest diy choice for insulating between the floor joist in a crawl space.

Department of energy recommends r 11 3 insulation under floors in warm climates and an r 25 6 to 8 in cold climates. That way plumbing pipes and hvac ducts are protected from freezing temps helping to conserve energy. Only use mold resistant waterproof insulation such as ridge board spray foam and cellulose instead of fiberglass. Cover the walls with insulation from the sill plate to the plastic covered dirt floor.

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. 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. John a cervo january 5 2018 at 8 08 am. 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.