Hmmmmmm...Let me take another little look up there,,,, Fiberglass roof I am thinking this is a simi flat roof with a little fall to the outside, the sleeper part I get and I am thinking your worried about leaves and general dirt stuff falling in between the decking gaps and causing... thats the part I dont get what problems do think will happen??? in other words what is the big question mark.

Anyway with roof top decks I never go T&G material for a lot of reasons. Do not buy eon,or trex at all, ever, dont even look at them in a passing way, forget it,no, nadda,noppers, nix.

With stringers even on 16'' centers 1x6 ipe,garapa,tigerwood, TT solid 5/4, in fact any of the upper grade decking will do fine. Defintley install the strong 1/8'' gap.

If your completly cant sleep,think about it all the time kinda thing about the question marks far as stuff geting inbetween the cracks,open up the gap to 3/8'' or 3/4'' and run a garden hose thru them every now and then.

In any install T&G materials drain the same way any other kind of decking will,thru the gap,dont expect a T&G material to be any different than face fastened far as debris goes.

John Mon

Thanks John. Yes. The roof is flat with a slight pitch away from the house. The joists are 12" on center. (I am not sure that I have the lingo down correctly). We are concerned about wet leaves and debris sitting between the deck and fiberglass and perhaps causing rot or moisture buildup or buckling. In the past, we had a hard time washing crud out from under the deck. Are you saying that this wouldn't be an issue and that the crud won't hurt anything?

Do you know where we could get any of those boards in a wide plank? Which would have the least maintenance requirements and still look good? We appreciate your recommendations! We like the look of real wood, but are afraid of future maintenance issues and costs.

The fiberglass roof still has me wondering,stringers on 12'' centers should defentley do it. I cant see any major problem with cleaning out the debri with a garden hose,anyway unless the stuff builds up 2'' or so blocking the run off it wont damage a torch down modified but I am still not understanding a fiberglass roof.

Its not a good idea to use material any wider than 5 1/2'' for movement reasons.The S American lumber mentioned can be left with out finish to go silver far as cost go most of the time they cost less than a high grade composite.

J.

Thanks for all of your advice.

The fiberglass is applied over a plywood base attached to the stringers. The plan is that the fiberglass roof will waterproof the room below. The deck will lay on top of the fiberglass roof.

We are currently leaning toward TT XLM, but are concerned as it is still a fairly new product. Have you had any experience with it?

Intersting,, this fiberglass over plywood is coming up over here farily often, and the the stringers are attached to the roof.Hmmmm let me run that thru....

Plywood with fiberglass resin,web tape on the seams,stringers fastened to the plywood same fiberglass with the tape rolling over the stringers,screw the decking to the stringers. This I would like to see Man those guys are going to have to work really fast.

A lot of the upgrade composite guys are going to the solid plastic decking,in fact trex,the low life of the business,has a line coming out like that. My advice is just look at it,if you like the plastic look then that stuff is for you. J.