Cellar insulation

Dear Mr. Gocze,
I believe that I may have missed the article that you suggested you were going to write regarding insulating basements without causing an issue with mold and mildew. We insulated one area of our basement last year with 3" aluminum coated styrofoam insulation. We also taped all of the seams with aluminum tape. Since this area is a
storage area, we have not had it finished with sheet rock. In addition, we insulated the sill with paper-backed fiberglass insulation, then applied the same styrofoam insulation that was used to cover the walls and taped
the seam where it joined. We are concerned already that we may have issues with mold and mildew! Could the way that we insulated this area have created a problem? Your comments would be greatly appreciated before we
continue to insulate the rest of the basement.
Thank you.
Best regards,
Lisa Colburn

Hi,
Do you smell mildew? If not, probably you are on the right track. The material you used is unlikely to cause an issue. This is the time that you might have a problem given the humidity in the summer. The foam should be right up against the wall, leaving no space for humid air to get up to it. Spray foam is the ideal material for this application, but other materials can work well, if you can seal off the masonry surfaces.
Tom