Crawl Space Floor Joist Insulation

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.

Crawl space floor joist insulation.

Crawl space insulation basics. Where winter temperatures are extreme opt for insulating the walls and sealing off the crawl space entirely. Don t compress the insulation as it requires its loft in order to maintain its rated r value. Stapling fiberglass batts between joists to the underside of your home s floor presents a number of problems.

Insulating and air sealing this perimeter zone is important because it s a major source of air infiltration and conductive heat loss. However the insulation needs to be treated with a fire retardant. Floor insulation for moderate climes popular reads. While this method does work in the very short term moisture eventually builds in the crawl space and grows on this highly porous surface.

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. Instead install fiberglass batting between the joist bays which are the spaces between each set of floor joists. 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. In moderate or dry climates without the threat of sustained subfreezing temperatures insulation between floor joists makes sense.