Ever wonder why your floors feel cold even with decent attic insulation? The culprit is likely your rim joists — those horizontal boards where your floor meets the foundation wall.
Rim joist insulation is one of the most overlooked energy upgrades in Northeast Arkansas homes. These exposed wood members create a thermal bridge that bleeds conditioned air year-round. In our humid summers and chilly winters, uninsulated rim joists can account for 10-15% of your total energy loss.
The fix? Closed-cell spray foam at R-6 per inch is ideal for rim joists. Unlike fiberglass batts that sag and leave gaps, spray foam air-seals while insulating. For a typical 1,800 SF home, expect 150-200 linear feet of rim joist at $8-12 per linear foot installed.
Here in Jonesboro, we see dramatic results: homeowners report 15-25% drops in heating and cooling costs after rim joist spray foam. The payback period is typically 3-4 years, and the comfort improvement is immediate — no more cold floors in January.
Bonus: properly sealed rim joists also reduce moisture infiltration, preventing the mold and rot issues common in our humid climate. It's a small investment that pays dividends in comfort, efficiency, and structural protection.
Thinking about tackling your rim joists this summer? Reply or DM us for a free estimate and thermal imaging assessment.