DIY Home Improvement Forum banner
1 - 1 of 1 Posts

Registered User
11,730 Posts
No air should be allowed on the f.b./concrete joint. Air brings moisture form outside/inside (humidity). Foamboard installed air-tight to concrete will insulate and vapor retard any cold moisture coming through the concrete. If you air-seal the f.b. and glue as mentioned; with the "closed grid pattern" (horizontally and vertically) which limits the surface area of the air movement and wetness to diffuse through-- rather than drain-down to collect/pool at the bottom- possibly wetting wood framing (to mold, being organic) or cavity insulation from wicking- degrading it's R-value- if fiberglass;

Seal the perimeter edges (canned foam) when installing against the closed-grid adhesive pattern. Mastic/tape the seams between panels, keep in mind f.b. will shrink over time (reason I typed mastic first);

Rim, as said already;

Thanks, Canucker, I was busy cut/paste my other links from other threads....!
  • Like
Reactions: Mijotter
1 - 1 of 1 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.