Foam board or spray foam also is the best ... It is difficult to secure and seal a long piece of fiberglass insulation to the outside rim joists without damaging the insulation.

Installing insulation at the rim joists enhances energy efficiency and ... The next level up: Rigid foam boards, used in conjunction with caulk or a spray foam sealant offer better air sealing ...

The insulation will fit into the cavity of the rim joists and will be ... some builders either leave the rim joists uninsulated or use a piece of rigid foam board, cut to fit into each opening.

Q: Should we insulate the rim ... rim-joist cavity. Custom-cutting the panels takes time, and if the fit is not exact, a small amount of spray foam can seal the edges of the foam board.

If you don't have any insulation at your rim space, add this project to your list of 'to-do' projects. It's not as critical as attic insulation and it takes more time, but it's a good thing to do.

Q: Should we insulate the rim-joist cavities of a crawlspace foundation? I am a builder, and where I live the codes require insulation, but I have discovered that the insulation causes decay and ...

but it’s a classic example of what happens when you combine the ability to seal out air movement along with high insulation values. Rim joists are another area where spray foam is king.

with expanding foam sealant. 19 Tips for Finishing Basements Use a box cutter to cut the insulation to length. Properly insulating and air-sealing rim joists (band joists) takes patience ...