Crawl Space Insulation: What You Should Know

Insulation in your basement crawl space can make your whole house more efficient. Here's how to install it in your space.

Crawl Space

Crawl space insulation, as a part of overall home air sealing and insulation, helps maintain your entire home's energy efficiency. Without insulation, heat and cool air are easily lost through the floor. Insulation also helps to preserve the air quality and reduce energy costs. There are two types of crawl spaces - ventilated and unventilated - and each requires its own form of insulation. The goal, however, is the same: to enclose the space in a thermal envelope.

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.

If your crawl space isn't ventilated, insulate the walls of the crawl space rather than the subfloor of the room above. This requires less insulation and will eliminate the need to insulate ducts and pipes, separately.

You may also want to install a polyurethane vapor barrier over the dirt floor for further protection. The barrier may be covered with sand to keep it from getting damaged.

While crawl space insulation may be installed by a handy homeowner, you might consider using a professional. They'll clean up and properly dispose of old insulation and often spray the space with bacteria - and fungicides.

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