Foam Board Insulation Floor Joists

A do it yourself friendly method for sealing and insulating the rim joist or band joist area is to use rigid foam up against the rim joist.

Foam board insulation floor joists.

You can insulate second floor rim joists following the same steps shown here if you happen to tear out a ceiling during remodeling. 4b slab floors built directly on the ground. Foam board insulation is used on attics and walls yet it can also be used to insulate your floors. Unlike fiberglass rigid foam insulation does not absorb water support mold or allow air to pass through.

4c as an alternative to floor insulation foundation walls of unvented crawl spaces. To prevent these problems only air impermeable insulation either rigid foam or spray polyurethane foam should be used to insulate the interior of a rim joist. If you need to insulate these rim joists it s best to hire a cellulose insulation contractor. The best insulation material for crawl spaces is rigid foam insulation board.

Fill gaps and penetrations greater than 2 quickly and affordably with the froth pak spray foam sealant kit. 4d extend insulation into joist space to reduce air flows. This method can be hundreds of dollar less than the cost of using the commercially applied spray foam. Instead of installing the foam insulation between floor joists in the crawl space the foam board is installed against the crawl space foundation walls.

Unsealed rim joists rob homeowners of money energy efficiency and comfort. Most people do not think about insulating their floors unless perhaps it s their attic floor. You want it snug but not to. Rigid foam is the best insulation for rim joists.

But insulating your floors is a good idea for many reasons including energy efficiency and height adjustments. Seal and insulate using rigid foam board insulation. Two story homes usually have another ring of rim joists above the first floor ceiling.