Can you insulate a concrete block basement walls with only rockwool?

Aarne Valikangas
Updated: Jan. 8, 2021


We are redoing our basement ourselves (zone 5, Toronto) and on a budget after gutting the entire finished basement due to extensive moisture penetration and mold issues. The foundation/walls are concrete block and we have 2 sides done with interior plastic membrane to french drain and sump pump, one side exterior waterproofing, and one side with no waterproofing but also no moisture penetration issues. Our plan after consulting several sources was to frame with 2x4s painted with mold resistant primer (pressure treated and sill gasket for anything touching concrete), with 1 inch air gap between block wall (or waterproofing membrane) and framing, then install mineral wool and mold resistant drywall and paint with latex paint. Floor would be dimpled mat over concrete slab and vinyl plank flooring. No current plan to seal walls and we are leaving plenty of air gaps near unfinished ceiling where floor joists are. We would have a dehumidifier. Anything in here that jumps out as potential for renewed mold growth? Thanks in advance!

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