Building a tiled exterior balcony and wondering which water membrane type to use? This is not over a living space but I still don’t want to be replacing this balcony due to water problems in the future.
It will get heavy rain but no frost.
My substrate is solid, 1/2 plywood over 2×6 decking on heavy joists with 1/4 per foot slope. Will put down cement type backerboard, then thinset tile on top. What membrane to use between plywood and backerboard? Not floating a mortar bed because I’m trying to keep the weight down.
Is there cement or backerboard that is made for exterior? Or is it all the same stuff?
Thanks,
Drake
Replies
bump
You're looking at Kerdi for this application. (Okay, I double checked myself, LOL; yup it's Kerdi, not Ditra.)
Lay it on the Durock with thinset, then lay the tiles on top also with thinset. If it's good for a shower pan, it oughta work for a deck....
Dinosaur
A day may come when the courage of men fails,when we forsake our friends and break all bonds of fellowship...
But it is not this day.
Would a pvc membrane work?
When in doubt, get a bigger hammer!
I don't think thinset sticks to pvc.
Dinosaur
A day may come when the courage of men fails,when we forsake our friends and break all bonds of fellowship...
But it is not this day.
I think Dino has it... if you want to put down CBU then the membrane has to be on top, otherwise you're driving a bucketload of screws thru it. There are trowel-applied membranes that you could coat the CBU with, such as Laticrete 9235.
Yeah......hmm........
I guess whenever a pvc membrane is used, they always puth lath and motar bed on top----
I've heard that the kerdi is a 10 times better than the trowel ons too
When in doubt, get a bigger hammer!
I'm currently in the same situation. My old balcony was 3/4 OSB over 2x12 joists. Flashed to the wall, then some kind of semiflexible asphaltic membrane over that, then a layer of fiberglas mesh, then thinset and 12x12 pavers over that. Water eventually leaked in through a bad flashing job and swelled the OSB at the front edge overhang, leading to tile separation and dry rot. My contractor is replacing with 3/4 marine plywood and new flashing. He is going to have a deck guy lay down a polyurethane elastomeric deck coating with embedded metal mesh. We've been told the tile guy can thinset new 12x12 pavers right over the cured membrane. FYI, the membrane is a not roll goods. it is poured or troweled on and takes a few days to cure. Hope this helps.