The Rim Joist Problem Most Hudson Valley Homes Have — And Don't Know About

If you've never heard of a rim joist, you're not alone — and there's a good chance yours have never been insulated.

The rim joist is the perimeter framing at the top of your foundation wall, where the floor structure meets the exterior of the house. In most homes built before 1990, it's either uninsulated or has a piece of fiberglass batt stuffed in loosely. Neither approach does much. Cold air moves through wood easily, and fiberglass batts without an air seal don't stop infiltration.

The result is a band of cold that runs around the base of your ground floor all winter. If you've ever noticed that your floors are cold near exterior walls, or that certain rooms on the ground floor are harder to heat, rim joists are a likely contributor.

Closed-cell spray foam is the standard fix. Applied directly to the rim joist cavity, it insulates and air-seals in one step, and it adds a vapor barrier that protects the wood from moisture. It's a relatively fast job — most rim joist applications take a few hours — and the impact on comfort and heat loss is noticeable.

It's also one of the more overlooked items on a home energy audit. If you've already addressed your attic and crawl space but still have heat loss issues, rim joists are the next place to look.

Call Innovative Insulation at (845) 319-9169 for a free assessment.

Based in Hopewell Junction, serving all of Dutchess, Putnam, Ulster, Orange, and Westchester County.