Diverting water from a second floor deck

I would like to construct an open second floor deck over a first floor porch. Both are new construction. How do I do this so the first floor porch stays dry? Is there a way to divert the water that would fall through the deck into a gutter or would using tongue and groove boards suffice?
Replies
MYoung,
Investigate TimberTech's Dry space Deck Drainage System (http://www.timbertech.com)
MYoung, what you propose is commonly done with tapered joists, EPDM rubber membrane, and decking installed on tapered sleepers on top of the rubber membrane. The system is good enough to be used over covered living space.
M Young,
Try http://www.grailcoat.com
Graicoat is a great product, but is a proprietary product. Finding a certified applicator in any area of the country is hit or miss. Thus far I have not had much luck in getting acceptance for a DIY project. I am still working on it though.
Dave
WHERE DO YOU LIVE? THERE ARE SEVERAL HUNDRED SOLID SURFACE FIBERGLASS DECKS IN NEW JERSEY/ DEL/ MD ALONG THE COAST. A GREAT PRODUCT THAT WILL LAST FOREVER. ANY COLOR/ NOT TO HARD TO DO IF YOU FOLLOW THE INSTRUCTIONS....