Ever wonder why your floors feel cold even after you've insulated the attic? The culprit is often the rim joist โ that narrow band of framing sitting right on top of your foundation wall. Most older homes in Jonesboro and Trumann have zero insulation there, and it's leaking conditioned air 24/7.
A rim joist is typically only 9โ11 inches tall, but it runs the entire perimeter of your house. Air infiltration there can account for 15โ25% of total heat loss, according to the Department of Energy. With overnight lows already dipping into the low 40s across Northeast Arkansas this week, you're feeling that loss right now on your utility bill.
The fix is straightforward: 2 inches of closed-cell spray foam applied directly to the rim joist delivers R-13 and completely air-seals in one step. No stapling, no cutting batts to fit around pipes and blocking โ just a clean, monolithic seal. Closed-cell is the right call here because it also acts as a vapor retarder, which IRC Section R702.7 requires in our mixed-humid Climate Zone 3A.
Cost-wise, rim joist work typically runs $1.50โ$2.50 per board foot installed, and most 1,500 SF ranch homes are done in two to three hours. Homeowners routinely report a 10โ18% drop in heating and cooling costs after this single upgrade โ not bad for a job most people never even think about.
If you're already planning a crawl space encapsulation or attic top-off this fall, bundling the rim joist saves you a mobilization charge. Smart sequencing, better savings.
Reply or DM us for a free rim joist assessment before the real cold hits.