What if we told you one of the biggest energy leaks in your home is a six-inch band of wood you've probably never thought about? Rim joist insulation is one of the most cost-effective upgrades a Northeast Arkansas homeowner can make โ and almost nobody talks about it.
The rim joist (also called the band joist) runs along the perimeter of your floor framing, right where it sits on the foundation wall. In summer, unconditioned outside air pushes straight through those gaps into your crawl space and floor system. In a Jonesboro or Trumann home, that means hot, humid air infiltrating every day from June through September.
Closed-cell spray foam is the go-to fix here. At 2 inches thick you hit roughly R-13, and at 3 inches you're at R-19 โ meeting IRC R402.2.1 requirements for Climate Zone 3. Material and labor typically runs $1.50โ$2.50 per square foot for a standard rim joist treatment. A 1,500 SF ranch home might have 150โ200 SF of rim joist, so total cost usually lands between $225โ$500. That's a small number for a problem that quietly inflates your Entergy bill every month.
Closed-cell also acts as an air AND moisture barrier in one shot โ critical in our humid Arkansas summers. No separate vapor retarder needed. The foam bonds directly to the wood and concrete, sealing every gap that batts would leave behind.
If your floors feel warm in July or cold in January, or your energy bills creep up with no obvious reason, your rim joists are a smart first place to look. We do free assessments and can usually knock out a rim joist job in a single morning.
Reply here or DM us for a free estimate โ we serve Jonesboro, Trumann, Paragould, and the surrounding NEA area.