I am redoing a bathroom (gutted it to the studs). For the floor, I have subfloor, then 1/2" plywood (screwed & glued), and I was then going to put Ditra ontop of that (then tile). I have Greenboard along the walls.
Now, when I did the demo there was only one row of wall tile, with chaulk on the top and between the joining of the wall and tile floor.
When reading over the Ditra installation manual for waterproofing, it recommended using a layer of Kerdi to "join" the Greenboard and the Dirta floor in order to prevent water from getting loose where the floor & wall meet. But, only where there is a washer or icemaker, I guess because those may burst.
My question: Why not do this for bathrooms as well? Is adding Kerdi to the wall/floor seam overkill?
Thanks,
Aaron
Aaron,
I do a couple of "wet rooms" a year. Meaning that the entire floor and wall assemblies are waterproof.
In those cases I do as you described: Ditra the floor, Kerdi the seams in the Ditra, then Kerdi the walls, and Kerdi the wall/floor transition.
If part of the room will be a steam room, it's not uncommon to Kerdi the ceiling as well.
What you describe is fine. Kerdiing the floor-wall transition will prevent floor spills from going under the baseboard and into the unprotected floor/wall assembly.
I do that in laundry rooms.
Mongo
Thanks for the advice, I am wondering; would you do it in a standard bathroom (that isn't a steam room)? I mean, I can definitly see why you would want to do it there, I am just curious if it is worth the trouble? Not worried about cost, but, from what I understand, Kerdi is hard to install...or is that for more shower like installations, where you had better make sure not water gets through :).
And for this instance, while probably not going to hurt in the long run, could or could not be done, is that a fair statement? Or better yet...would you do it for your own bathroom?
PS: I have never installed kerdi before..so, after reading some of the posts here, I am a little concerned that I could do it incorrectly.
When I say "steam room" I mean a room with a steam generator. Sometimes this is a shower with a steam generator added to it, sometimes it's a steam room in and of itself.
While a regular bathroom may generate a bit of moisture, it's nowhere near the amount of moisture generated in a steam shower.
I think Kerdi is quite easy to install. It's like hanging wallpaper...which I have to admit, I've never done...but I find Herdi a treat to work with.
Every shower or tub surround that I do gets Kerdi.
Some bathroom floors get Ditra, some don't. Sometimes the Ditra is used an an uncoupling/transition membrane, sometimes It's specified so the floor will be waterproof. Sometimes it's used solely as a low-profile transition membrane. It depends.
For waterproofing, I'd Kerdi the seams in the Ditra and yes, I'd run Kerdi up the walls behind the baseboard, about 4" up the walls.
Kerdi is pretty easy to install. Trowel on unmodified thinset using a small notched trowel, then lightly pat the kerdi in the thinset with your hands. I then use a 4" drywall knife to embed the Kerdi in the thinset. As the Kerdi gets embedded, you'll see the Kerdi change color from bright orange to a muddled brownish orange.
For inside corners, pre-crease the Kerdi before setting it in the thinset.
Done!
Mongo
Whoa thanks for that link! I'm planning to DIY my own kerdi shower and that's a GREAT reference.
Here's another one:
Here is a link that might be useful: Thread for ordering John Bridge's Kerdi installation e-book
I finally got my tilesetters to use a Kerdi shower system for a mudroom, and Ditra under all the tiles. It took three calls to Shluter techs to semi-convince the tilesetters that they mustn't used modified thinset for the top coat under porcelain tiles.
They even insisted on giving me a written disclaimer that it wouldn't be their fault if the installation failed because I insisted on this newfangled plasticky stuff they never heard of.
Sheesh!
bill_vincent