Ever wonder why your floors feel cold in January even after you've insulated the attic? The answer is probably your rim joist โ and most Northeast Arkansas homeowners have never heard of it.
The rim joist is the band of wood that sits right on top of your foundation wall, framing the edge of your first floor. It's full of gaps, cracks, and raw lumber exposed directly to outside air. In a typical 1,500 SF Jonesboro home, that adds up to 50โ80 linear feet of uninsulated edge just hemorrhaging conditioned air.
The fix is straightforward: cut-and-cobble rigid foam plus a flash of closed-cell spray foam. A 2" application of closed-cell hits R-13, and adding a 1" rigid board behind it pushes you past R-20 โ well above the IRC R402.1 minimum for Climate Zone 3 (that's us). Materials and labor usually run $1.50โ$2.50 per square foot of rim joist area, which on an average Trumann crawl space comes out to $400โ$900 total.
The payoff is real. Sealing and insulating the rim joist can cut basement and floor-level heat loss by 20โ30%, according to DOE data. With September already cooling off and October right around the corner, now is the ideal time to get this done before your heating bills spike.
Bonus: a properly air-sealed rim joist also keeps out moisture, insects, and that musty smell that creeps up from the crawl space every spring.
Reply or DM us for a free rim joist assessment โ we serve Jonesboro, Trumann, Paragould, and the surrounding area.