Q. Every time I come home I smell a damp musty odour. I think the smell is coming from my crawl space. I especially notice the musty odour on clothes or anything that has been stored down there. The perimeter drains were cleaned out last winter and I have laid down a moisture barrier on the crawl space floor. The crawl space is below grade with no windows. What can be done to address the ventilation?
A. What you smell is mildew caused by high humidity (over 55% relative humidity) in the crawl space area. The high moisture in the crawl space will eventually work its way up to the living space. You need to lower the humidity level in the crawl space by fixing any groundwater, plumbing or other leaks and de-humidifying the air. You are taking correct steps by addressing the perimeter drainage and adding a moisture barrier to the crawl space floor but simply adding ventilation to this space may not rectify the problem especially in the winter months when the vents in the crawl space should get closed up and insulated. You may require a dehumidifier/air purifier System. The folks at “Basement Systems Winnipeg” specialize in crawl space problems and you can call 204-339-7219 for more information on this system.