A customer from Campbell River, BC ask Chris if the musty smells coming into the living area from the crawl space under her home are a reason for concern. He explains that the musty smells are usually a product of mold and decay that is happening in the crawl space due to high relative humidity levels.
It is a sign that moist air from the outside is coming into the space through the vents and ground moisture is evaporating into the crawl, and condensing over wooden structures and insulation, causing mold and dry rot to appear.
“We can show you some really ugly pictures of crawl spaces, that have rats in them, mold and all kinds of gross stuff. People are breathing that air.”
Chris explains that, due to a physics phenomenon present in every building and known as “the stack effect”, the air in the house always rises and escapes through the upper levels. As a result, air is sucked in from the bottom of the house into the living space. That means that at least 1/3 of the air you breathe in your house is coming straight from your crawl space, carrying all the moisture, dirt and pollutants into your living areas.