Ever wonder why your floors feel cold even after you've insulated the attic? Blame the rim joist โ that band of wood sitting right on top of your foundation wall, right where your floor framing begins. It's one of the most overlooked air-leak spots in Northeast Arkansas homes, and fixing it pays off fast.
Rim joist insulation is a topic a lot of Jonesboro and Trumann homeowners don't search for until they've already wasted a winter with cold feet and high gas bills. Here's the real problem: most rim joists are bare wood, fiberglass batt stuffed loosely (which does almost nothing for air sealing), or just open to the crawl space or basement. Cold October air โ and we know NE Arkansas temps swing hard this month โ pours straight in.
The right fix is 2 inches of closed-cell spray foam applied directly to the rim joist cavity. That gives you roughly R-13, plus a complete air seal in one step. At $1.50โ$2.25 per board foot installed, a typical 1,500 SF home with an 8-inch rim joist runs $300โ$600 total. That's one of the best dollar-for-dollar upgrades in the building envelope.
IRC Section R402.4 requires air sealing at rim joists in new construction for Climate Zone 3 (that's us), but existing homes are rarely up to that standard. A quick blower-door test will confirm what we already suspect: your rim joist is bleeding conditioned air year-round.
We can usually knock out a rim joist job in two to three hours. Before the first cold front hits Craighead County, it's worth a look. Reply or DM us for a free estimate โ we'll tell you exactly what you're losing and what it'll cost to stop it.