[snip]
I've seen a couple of decks with a couple of different kinds of roofing underneath - getting the dry area below but without tampering with the deck above. One just had those rippled vinyl deck sheets - I guess several are linked together side by side to make the water proof cover. Tucked neatly under the deck, it hardly showed.
Another had the same kind of sheeting used on the typical backyard shed - Tin? I don't know but it was brown instead of white and had something on the front and sides to direct rain that cme through the deck into gutters and down spouts.
Another was at a "show" where they had constructed and little deck and put a little shed underneath, again I think it had extra stuff to provide for run-off. I didn't care for the look but think some construction that looked like the deck (same materials) would have looked better.
Josie