Would you please offer your expert opinion on a potential moisture issue I’m concerned with?
I’m planning to install Rockwool R-23 (5.5” thick) between floor joists under my radiant floor quik-trak panel. This is my middle level floor, see attached picture. I’m installing Rockwool R-23 for both the floor and the 2x6 wall in this picture.
The bedroom floor is raised 10” from the concrete slab. There will be 5” high cavity between the R-23 floor insulation (in pink) and the concrete slab. This cavity is bordered on the west and south side by exterior walls with steel I-beams (impossible for vent), east side is the unheated garage, north side is conditioned living space.
Do you see any potential condensation/mold problem under (in the cavity itself) or above (in the layers of subfloor/quik-trak/engineered wood floor)? Rockwool itself is water repellent. Would installing vapor retarder (CertainTeed MemBrain) on the warm side help further reducing any mold problem?
I live in Seattle WA, next to a lake (don’t know if humidity is more or less of an issue here).