If your feet are cold, put a hat on — an improbable but true old folk saying. Here's a new one: If your windows are wet, waterproof your basement. We've known for a long time that much of the moisture that condenses on windows in winter, or promotes mold growth in summer, comes from the basement or crawlspace. In fact, a 1986 survey of 500 homes conducted by the University of Illinois Small Homes Council, found a strong correlation between attic moisture problems and wet basements or crawlspaces. The new discovery is that even "dry" basements and crawlspaces may be significant sources of moisture in homes. I constantly hear of moisture problems in tightly built new homes where there seems to be