Ever wonder why your floors feel cold in January even though your furnace is running fine? The rim joist โ that band of framing sitting right on top of your foundation wall โ is almost certainly the culprit. It's the most overlooked air-leak point in Northeast Arkansas homes, and most people have never heard of it.
A typical uninsulated rim joist loses as much conditioned air as leaving a window cracked open all winter. In Climate Zone 3 (where Jonesboro and Trumann sit), the IRC R402.1.2 table calls for a minimum R-15 in this cavity. Most older homes have zero โ just bare wood facing a cold concrete foundation.
The fix is straightforward: two inches of closed-cell spray foam applied directly to the rim joist delivers about R-14 to R-16 and โ more importantly โ seals the air gap in the same step. One pass, two problems solved. Closed-cell is the right call here because it also acts as a vapor barrier, which matters when you have humid Arkansas summers pushing moisture toward that wood framing.
Cost-wise, rim joist work typically runs $1.50โ$2.50 per board foot depending on accessibility and linear footage. A standard 1,500 SF ranch home might have 150โ180 linear feet of rim joist, so most jobs land in the $400โ$700 range โ a one-time fix that pays back in lower Entergy bills every single month.
With nighttime lows already dropping into the low 50s this last week of September, now is the perfect time to get this done before heating season hits full swing. Crews are still scheduling efficiently before the holiday rush.
Reply here or DM us for a free rim joist estimate โ we serve Jonesboro, Trumann, Paragould, and surrounding communities.