The past few weeks have pointed out that too many homeowners just become complacent about checking around their homes and completing seasonal maintenance.  Opening and closing the crawl space vents seems to be one of those chores that is just too easy to forget.  If you forget or ignore, you run the risk of frozen pipes (vents left open) or moisture and mold (vents left closed). During the just mentioned two-week period I wrote two contracts for one client and both failed because of mold in the crawl spaces of the respective homes.  These homes were in the $400,000 range so it was not a case of lack of resourses to do maintenance.  It may just have been lack of knowledge.  I do not quite get the latter.  As long as I can remember, inspectors have always reminded buyers of this maintenance activity.  Perhaps these two owners passed on an inspection, did not have a good inspector, or just did not pay attention. Even in our relatively dry climate, moisture control is important.  Check your enclosed spaces frequently!