Ever wonder why your floors feel cold in January even after you've insulated the attic? The culprit is probably your rim joist โ the band of framing that sits right on top of your foundation wall. It's one of the most overlooked air-leakage points in any Northeast Arkansas home.
A typical 1,500 SF ranch has roughly 150โ200 linear feet of rim joist. Left uninsulated, that's essentially a continuous crack running around the entire perimeter of your house. In Climate Zone 3 (that's us โ Jonesboro, Trumann, Paragould), the IRC R402.1 table calls for a minimum R-15 in wood-framed floors, but most older homes have zero.
The go-to fix is 2-inch closed-cell spray foam applied directly to the rim joist cavity. Two inches gets you to about R-14, seals the air gap simultaneously, and acts as a vapor retarder โ all in one pass. Installed cost typically runs $2.50โ$4.00 per square foot of rim joist face, and most jobs are done in under a day. For a 1,500 SF house that's usually a $600โ$900 investment.
Homeowners who've had this done consistently report their first-floor rooms feeling noticeably warmer in winter and cooler in August โ without touching the HVAC. It's also one of the fastest payback insulation upgrades you can make, often recouping cost in two to three heating seasons.
If you're in the Jonesboro area and your heating bills have been climbing, a rim joist inspection is a smart first call. Reply or DM us for a free estimate โ we can usually get eyes on it within the week.