Thanks guys, that's what I was hoping to hear. The patio seems sounds and true for draining. The house is only about 3 years old and the backyard has a pretty good slope with tile taking all the water out from the foundation. It does have a basement as well with a sump. I will look into deck-blocks. I'm heading out for some 'discovery' and see what I can find for anchoring pylons or footers to the concrete. Thanks!