I recently finished installing DrySpace by Timbertech under a 12 x 14 deck. The system seems logical and has already weathered two heavy rainfalls successfully.
Some people say that they leak everywhere, but that has not been my experience. Of course I had to modify some installation steps and add some metal flashing over and around the 2' set-back beam.
I suggest you go online and take a look at the installation diagrams available on line and see what you think. The material cost for (2) kits was about 640.00 total.

All the best,
Art G

Here is a link that might be useful: my album

Thanks Art!
I took a look at the installation diagrams. I know so little about any type of construction that it's difficult for me to make heads or tails of most diagrams....
By the looks of most of the systems' diagrams, the water would be getting "directed" off the bottom of the deck into one area of the yard. I'm now considering the possibility of adding a gutter and tying it into the under drain system because I'd like to avoid a concentrated swamp area. I don't know if that's a crazy idea yet or not.......
Thank you for sharing the info!!!!! I'll be sure to pass this on to the carpenter I'm working with.