Crawl Space Floor Joist Insulation

While this method does work in the very short term moisture eventually builds in the crawl space and grows on this highly porous surface.

Crawl space floor joist insulation.

Don t compress the insulation as it requires its loft in order to maintain its rated r value. Insulating and air sealing this perimeter zone is important because it s a major source of air infiltration and conductive heat loss. In moderate or dry climates without the threat of sustained subfreezing temperatures insulation between floor joists makes sense. Crawl space insulation basics.

If your space has them avoid adding insulation to the crawl space walls. Silverglo rigid foam insulation won t absorb water or support mold growth and does not allow air infiltration making it the perfect insulation product for use on crawl space walls. 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. Instead install fiberglass batting between the joist bays which are the spaces between each set of floor joists.

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. However the insulation needs to be treated with a fire retardant. 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. Where winter temperatures are extreme opt for insulating the walls and sealing off the crawl space entirely.