Thanks Steve...that's another good idea! The reason behind concern is that I have seen what moisture can do to frame construction. We had a sprinkler pipe breat at work and the office had 2 inches of water on the floor when we came in the next morning. Believe it or not, when we had moisture tests done, they found that the water had wicked up the drywall 4 ft!!! So maybe a combination of a block base with the green drywall will put my mind at ease given that the garden hose and my kids might be out there together
