rigid foam board

Homeowner installing rigid foam insulation board into a basement rim joist cavity and sealing edges with spray foam.

How to Air Seal and Insulate Rim Joists for Basement Energy Savings

August 17, 202616 min read

Eliminate cold floor drafts and cut heating expenses with our hands-on DIY guide. Learn how to accurately cut rigid foam boards, detail sill plate connections, and apply canned spray foam for superior basement rim joist air sealing and energy performance.