I have a Ranch home with a finished rec room in the basement. It is our second year in the house. We had no mold/mildew problems last year. I put new carpet in the family room above basement and I filled in and covered a cold air return vent. The basement door is now very tight because the new carpeting is very thick. I also put two new glass block windows in the basement. Now I have mold/mildew showing up on most of the lower paneling in the basement.
Is it because of lack of air flow? How can I fix it?