Even though crawlspaces are closed off from the rest of the home the moisture problems they present aren’t. Crawlspaces, especially ones with dirt floors, are highly susceptible to water and dampness during times of rain and high humidity.
Crawlspaces are already dark and warm, but the addition of moisture creates the ideal environment for mold, dust mites and insects, including termites. Further exacerbating this issue is the open vents homes tend to have to crawlspaces. Instead of drying out the crawlspace the transfer of air allows mold an opportunity to enter directly from the outside as well as raising the relative humidity to well above the acceptable range to prevent mold growth. As long as those vents are open if it’s 75% relative humidity outside it will be 75% relative humidity in your crawlspace. Mold and dust mites thrive anywhere that’s above 50% relative humidity
Main Line Waterproofing can inspect your crawlspace and recommend ways to dehumidify the area and fix other issues.