"Schluter Systems Kerdi Installations Part II," in the Ceramic and Stone Q&A forum, begins: "I was going to ask this in the other thread but it got closed before I could, so here we ..."
I was going to ask this in the other thread but it got closed before I could, so here we go.
Next Monday I'm starting a new phase in a high end condo project that I've been working on, off and on for the last couple of months. So far all I've done there is floor tile in landings, lobby, elevator areas, and the elevator. Apparently the General Contractor was not happy with the quality of work done in the actual suites and fired all the tile setters that did the other work on this project and I guess the rest is up to me. I did some real nice custom stuff in his own house about 3 years back so he knows my work and we are comfortable with each other.
Topic sponsored by:
Here's where my question comes in. Every unit has two showers that require Kerdi to the ceiling. About the only thing I've ever used Kerdi for is cracks in slabs. Do I just use a wall trowel and some good polymod mud to stick this stuff to the wall or is that a job failiure waiting to happen? Also, they have a black shower pan membrane that runs up the walls 3 or 4 inches and it's very uneven. I would like to cut it down to an inch or two above the shower pan nice and level so there's no overlap between the membrane and the Kerdi. I want to get this surface as flat as I can before I start laying tile. Good Idea or not? I sure don't need a moisture problem down the road so if it's best to overlap the Kerdi on to the membrane I will.
One last thing. It's a two wall shower so I have one inside corner to deal with. Do I try to do the Kerdi in one piece or do I cut a seperate piece for each wall and seal the corner with something? As you can probably tell by now, Kerdi ain't my thing.
Thanks in advance for any info you can give me here.
KERDI can be done in pieces. In fact with things as crooked as they always are that's the only to do it in some cases. The junctures are then lapped a minimum of two inches using KERDI Band. There are also really nifty preformed inside corners also made of KERDI. It's a pretty slick deal.
The KERDI must lap over the pan liner material so as to create a gravity watershed type effect. Sorta like roof shingles.
KERDI on walls in big flat sections is a bitch. If the wallboard is Hardi or CBU I would suggest you wet the walls before you spread the thinset. If you don't the thinset will wick into the substrate before you can get the KERDI in place and smoothed out.
Let me back up a little. The pan liner should run up the wall not less than three inches above the highest point of the curb/dam.
How about you just use liquid waterproofing on the walls and save the heart attack.
I can definately see the advange of a 2 inch overlap of the Kerdi in the corners. The odds of me getting this Kerdi band or the corners to do it are probably slim to none. Half assed as usual. They go for the Kerdi but not all the extra stuff that goes with it to make it work right. I'll bug the boss BIG TIME to get this stuff, with the stipulation that if he don't, if the jobs fail (many showers) it will be on him.
I figured the pan thing would be better with the shingle effect but I had to ask.
I'm not even sure what is on the walls (I'm guessing green board, hence the Kerdi ) but the wetting it down first is a good tip. 3/16 V-notch be ok for setting this Kerdi into or should I go a bit deeper?
In regards to the pan liner Bud. I'm not even sure if it runs that high up the wall in some places.
P.S. You wouldn't happen to have a spare 45 gallon drum of liquid waterproofing you could send me do ya???
Stullis. I have no idea on the pan liners because I didn't do them. I'm just the guy that's supposed to tile them. I will look a lot closer when I get there tomorrow and ask some questions about how they were done. I was just to busy today to get into a lot of detail. As a matter of fact I was hoping I never had to see this place after this Friday but work is work I guess. If I won the lotto tonight all my questions are moot. I'll be retired. I better go check them numbers now.
Gotta agree with Bud on this one. Sounds like a lot of liability. The old BS line of you tiled it you approved it. If there are leaks they could also say you damaged the pan during your installation.
You don't need Kerdi band either. Just cut your own strips from the regular kerdi.
Kerdi band is way overpriced IMO. Rarely use it myself.
The preformed corners are nice but doesn't sound like you need them if all you are doing is running down to their pan.
KERDI Band is thinner than KERDI Mat and thereby easier to fold and bend for lapping corners and turning up walls. Less bulk, less probable distortion when it comes time to place tile over the seams and lams of the KERDI. I use it all the time, makes my life easier.
Thanks for the tips guys. One last question here. I'll try to get the boss to get me some Kerdi band for next week but if I end up cutting my own out of Kerdi would they go in the corner before I put the large sheet of Kerdi up or would it go on after, or does it really matter either way?
You can do it either way. I prefer to put hang the full sheets first and do the corners last except when using kerdi for the pan then I like to do the perimeter walls first
I do the inside and outside corners, then Kerdi band up the inside walls and across the pan area, then sheets last, then skim and feather it all out nice.
The reason this looks like it does, is, it was a repair of a leaky pan and wall.
The Kerdi membrane is part of a system, it is not intended to be used with other types of liners. I know for a fact that Schluter would never warranty an installation done in this manner.
Your best bet with Kerdi is to use the whole system, including the Kerdi Drain, or use some other waterproofing method.
Having said that, I like to run the Kerdi about three inches out of each corner and start my next sheet overlapping almost into that corner. This way you don't need Kerdi band for the vertical corners. The Kerdi drain comes with four inside, and two outside, preformed corners. Kerdi band at the floor wall connection is definitely a benefit. It helps cut down on build up.
Okay, I had the format of the forum screwed up, I was responding to the post at the bottom of the page, sorry about that. Carry on.
The Kerdi membrane is part of a system, it is not intended to be used with other types of liners. I know for a fact that Schluter would never warranty an installation done in this manner.
Your best bet with Kerdi is to use the whole system, including the Kerdi Drain, or use some other waterproofing method.
Having said that, I like to run the Kerdi about three inches out of each corner and start my next sheet overlapping almost into that corner. This way you don't need Kerdi band for the vertical corners. The Kerdi drain comes with four inside, and two outside, preformed corners. Kerdi band at the floor wall connection is definitely a benefit. It helps cut down on build up.
Okay, I had the format of the forum screwed up, I was responding to the post at the bottom of the page, sorry about that. Carry on.
That's ok HS, yer allowed one screw up here. They make exceptions fer me
I did some real nice custom stuff in his own house about 3 years back so he knows my work and we are comfortable with each other.
Do I just use a wall trowel and some good polymod mud to stick this stuff to the wall or is that a job failiure waiting to happen? Also, they have a black shower pan membrane that runs up the walls 3 or 4 inches and it's very uneven. I would like to cut it down to an inch or two above the shower pan nice and level so there's no overlap between the membrane and the Kerdi. I want to get this surface as flat as I can before I start laying tile. Good Idea or not? I sure don't need a moisture problem down the road so if it's best to overlap the Kerdi on to the membrane I will.
Half assed as usual. They go for the Kerdi but not all the extra stuff that goes with it to make it work right. I'll bug the boss BIG TIME to get this stuff, with the stipulation that if he don't, if the jobs fail (many showers) it will be on him.
