A musty smell in rooms above a crawl space is a classic sign that your crawl space vapour barrier isn’t working. When ground moisture rises through bare soil or a torn barrier, it feeds mould and mildew on joists and subfloor, and that damp air drifts up through gaps in the floor. A properly sealed barrier stops most of that moisture at the source and helps keep your indoor air fresher through BC’s long, wet winters. Read about what causes a musty crawl space.