ROOF/FLOOR Ceiling

[Patrick Baize]

I have a leaking 2nd Floor porch. It is also the roof/ceiling for a down stairs room

Whats the best way to redo this. I would like floor tiles as the floor / roof

I know I have my floor joists first, then plywood decking. What are the next layer(s)

Thanks in advance. I've searched all over the internet with no luck

Thanks, Pat

[Colbyt]

I have never done it. I have seen it done 5 ways.

Joists, plywood, EPDM, hardi-backer (or wonder board) and tile. Joists, plywood, copper , hardi-backer (or wonder board) and tile. Joists, plywood, hardi-backer (or wonder board) and tile. The first two above using a mortar based pour over the substrate in lieu of the backer board.

If it were mine I would use the first method because the only entry point for moisture is the nail/screw holes. The copper welds can separate. The pour is a bitch to manage. Hardiebacker or wonder board needs a moisture block.

Colbyt

[m Ransley]

A Rubber torch down sounds best, with floating floor above.

[bill a]

I've been researching this myself, and haven't found a good solution yet. One common concept I'm hearing, though, is that trapped moisture will cause fairly short lifespan in any underlying sealing material. For that reason I think that the exterior (walkable) surface should not trap water under it where it will not be able to dry out. I've found a few possibilities, but I'm not sure if they are tough enough to withstand furniture, along with not causing dirt to be tracked in to the adjacent living quarters. If you can start with clean plywood, this might work

bill