I live in Littleton, CO, an elevation of about 5000 ft. It is very dry here. I am trying to sell a house I bought in Dec. 1998. It failed inspection yesterday because the inspector found mold in the basement crawl space. It is a walkout basement, with structural wood flooring on top of i-beams, with a crawl space beneath. A sump operates year round, and there is a humidistat device near the sump, which I assumed turned a fan on anytime humidity was more than 30%, which I was told was a good setting for my area. The crawl space is not heated or insulated as far as I know, but the basement is. The builder left access to the sump & humidistat via a lift-up plywood panel in the corner of the basement. The inspector assumed the humidistat wasn't working, because there was mold on the panel. I saw the mold, so it is definitely damp down there, and the mold could stretch further onto other panels but I did not look. I do not know of any vents in this crawl space. The basement is approx 1500 square feet, all unfinished. All downspout drainage works fine, as does the sump pump, and grading seems to be ok. My next door neighbor, also a walkout, seems to have same problem.
I need to know how to remedy this situation--will fixing the humidistat solve my problem? How long does it take for the mold to die? Do I hire somebody or do it myself? Does it require special chemicals? Approximate costs for all of this? How will I know that problem is fixed? I mean, it has to pass the next inspector's test, so how will I know this in advance?
I don't think there is any plastic in this crawl space. I have another crawl space that I can access from the basement, it is just under my first floor living room. It has plastic and 2 vents, but no humidistat. There are no moisture problems there.