Depending on where you live, critters from snakes and rodents to spiders, bugs, may have taken up residence in your crawl space. Add a little water—or even a lot when flooding occurs—and mould and rot create indoor air quality problems and structural deterioration. Oh, and did I mention that soil gases like radon can find their way into your house through the crawl space? Research has shown that whenever it’s warmer inside your house than outside, the buoyancy of the rising warm air in the house sucks air into your home from the lowest point, often that's the crawl space.
In cold climates like Manitoba—closed crawl spaces are the best option. Under hot-humid conditions, warm, moist air enters the vented crawl space from outside and can condense on the cooler surfaces. Even when condensation doesn’t take place, relative humidity (RH) above 80% for an extended period can support mold growth and eventually rot wooden structural materials. Add A/C to the house, and the floor above the crawl space becomes even cooler—and any ducts in the crawl space creates an added risk of condensation. In Winter other elements come in to play Cold air makes its way in to the space and dramatically cools the floor and living space above greatly effecting living conditions and energy consumption.
At RRSO we specialize in closed crawlspaces. In closed conditioned crawl spaces insulation is normally placed around the perimeter and not in the floor. With perimeter insulation the house is coupled to the cooler temperatures of the ground, and this can reduce the overall amount of A/C needed to cool the space above. When closed conditioned crawlspaces are used in heating-dominated climates like Manitoba, this same ground coupling can actually increase the heating load of a house, but that may cost very little compared to the cost of damage done by moisture brought in by an unsealed crawlspace envelope.
