Crawl Space Insulation
If you properly insulate your crawl space—in addition to air sealing and controlling moisture, you will save on energy costs and increase your home’s comfort.
Before insulating or deciding whether to add insulation to your crawl space, first see our information about adding insulation to an existing house or selecting insulation for new home construction if you haven’t already.
How to insulate a crawl space depends on whether it’s ventilated or unventilated. Traditionally, crawl spaces have been vented to prevent problems with moisture; most building codes require vents to aid in removing moisture from the crawl space. However, many building professionals now recognize that building an unventilated crawl space (or closing vents after the crawl space dries out following construction) is the best option in homes using proper moisture control and exterior drainage techniques. There are two main reasons for this line of thinking:
* Ventilation in the winter makes it difficult to keep crawl spaces warm
* Warm, moist outdoor air brought into the crawl space through foundation vents in the summer is often unable to dehumidify a crawl space. In fact, this moist outdoor air can lead to increased moisture levels in the crawl space.
Source: EERE, U.S. Department of Energy