[dkjos]

Bill,
If the problem is due to "wicking" why isn't it a problem every day of the year?

Given the the low water vapor permeability of concrete, especially when it has a vapor barrier on one side, I can't see the possibility of much moisture travelling through. The vapor pressure in the area between the vapor barrier and the concrete would have to be quite high to cause significant amounts of water vapor to migrate through 4" or more of concrete.

I think we need to devise an experiment on this.

BTW, it was good to meet you at DVSF III and finally connect a real person to your on-line persona.