Hi, I'm working with some contractors on an addition to my house in the Washington DC area, and my addition includes a 2 car garage with a patio/deck over one bay and the rest of the addition over the other. We are thinking of eventually screening the porch in (within 10 years). Patio is about 13' x 21'.

The question has come up on what a good material for the roof deck, and I'm having trouble deciding on what would be the best product for us. I would like to retain as much ceiling height in the garage as possible. Here's what we have discussed so far:

1) Traditional wood deck on top of rubber membrane underneath - It gives a traditional look while keeping things waterproof underneath. This would require the ceiling to be lower in garage to allow room for deck framing. Also afraid of needing to hose out stuff that falls through the deck.

2) Gratedex (my favorite) - Gives a great look, I would put stone tile down, etc., and would require membrane or sloped draining solution. Still run into problem of having to hose stuff out underneath. Most expensive option. http://www.outdoorfloor.com/pg_rooftop-pad.htm

3) DecTec or similar membrane with a finished look - would give a membrane that looks "finished" and would not require additional framing that would take up ceiling space from garage. My fear here is how the product looks in person (i haven't received a sample yet, and don't want it to look like a cheap hotel patio. I would be ok if it just looked like concrete. http://www.dec-tec.com/products_membranes.cfm

OK so am I missing any products that might fit our project? Anything I'm leaving out to consider from the choices above?

Here's a current picture of the proposed deck: