How To Insulate The Floor Of Your Crawl Space

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.

How to insulate the floor of your crawl space.

Use caulk or foam sealant to seal the joint between the top of the crawl space wall and the sill. 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. No insulation on the ceiling of the crawl space. Cover the walls with insulation from the sill plate to the plastic covered dirt floor.

Seal all vents and openings in your crawl space. John a cervo january 5 2018 at 8 08 am. Install an air and vapor barrier over the floor and tape it to the insulation. My house has an x board support in the floor joists for support.

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. 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 idea is to condition the crawl space much in the same way that you might condition other parts of your home. It is my understanding the insulation goes on the walls of the crawl space as well as the floor of 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. However the insulation needs to be treated with a fire retardant. Only use mold resistant waterproof insulation such as ridge board spray foam and cellulose instead of fiberglass. That way plumbing pipes and hvac ducts are protected from freezing temps helping to conserve energy.

This type of insulation allows for conditioned air to be introduced into the crawl space. 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.