Cut the strips to fit between floor joists using a box cutter. How to Finish a Basement: Framing and Insulating Run a bead of acrylic caulk around each section of foam to form an airtight barrier.

Check out our guide to waterproofing basement ... joists, but it’s a good idea if you plan to run ductwork or plumbing in the walls. If your floor is horribly out of level, or if you’re ...