Insulation Crawl Space Floor Joists

Cover the walls with insulation from the sill plate to the plastic covered dirt floor.

Insulation crawl space floor joists.

Fiberglass insulation batts or rolls are the most economical and easiest diy choice for insulating between the floor joist in a crawl space. 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. Joist bays the open spaces between floor joists are prime hosts for insulation under specific circumstances. If vents are not present in your crawl space insulate the walls instead of the joist bays.

In moderate or dry climates without the threat of sustained subfreezing temperatures insulation between floor joists makes sense. When the basement or crawl space has vents installed insulating joist bays. In those days common building practice was to insulate the floor above the crawl space and to leave the crawl space s wall vents open so any moisture buildup would vent to the outside a. Where winter temperatures are extreme opt for insulating the walls and sealing off the crawl space entirely.

The sill plate is the first piece of framing lumber and it runs on top of the crawl space wall.