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Kerdi Situation

Posted by wilkinte (My Page) on
Sat, Dec 14, 13 at 23:49

Hi Folks:

Thanks in advance, this site has been great especially for Kerdi advice. Well, should have read more before jumping in. As you can see in the pic, I have a tricky situation. I had the thinset too stiff and as you can see it's kind of glommed up on that box corner. It's also a little bumpy underneath. Also, it dried darker than the nice light gray you see elswhere in the pic. My thoughts:

Skim coat proper consistency thinset over the kerdi to make a nice surface for the tile. Is this ok?

I'd hate to try and tear the kerdi out, it is stuck very well on the wall.

As I continue I will sponge the extra thinset off the kerdi, but is is OK to have dried thinset over the kerdi as you can see?

Do I have to tear this all out???? Hope not!

Thanks again for your counsel


Follow-Up Postings:

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RE: Kerdi Situation

What are we looking at?


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RE: Kerdi Situation

thanks for looking, here's another picture. My main concern is this corner, where my lack of thinset applying skills has left that area bumpy and not plum. My worry is that when I apply the tile it wont sit nice and level. My question is does it make sense to skim coat thinset over that area to smooth it out before I apply tile. Any other kerdi advice is appreciated too,


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RE: Kerdi Situation

But, what is it a picture of? Is is of the ceiling, a seat, a corner on the floor? What size tiles will you be using? With large format tiles the surface needs to be smooth and without a wavey slope. If you added more thinset to the area you would end up with a ramp of thinset and the tile may not install correctly with the adjoining tiles and create some lippage.

I'd probably see what I could do to take it off. But I've never used Kerdie and I am a DIY'er with modest tile experience.


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RE: Kerdi Situation

Got ya, this is the ceiling area, the box is the hvac I sheetrocked over. If you look at the first pic you can see the shower spout in the top right.


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RE: Kerdi Situation

Take a drywall knife, along the lines of a 4" wide knife. Hold it at a very shallow angle. Run it back and forth over the thinset globs.

The goal is to knock any nubs down, to sort of chip them off. Understand that the thinset is bonded to the Kerdi fleece, so you don't want to try to get the fleece completely clean. All you'll do if you try to get it clean is you'll probably separate the fleece off of the Kerdi's poly sheet core, ruining the Kerdi.

The goal is to simply chip thinset off of thinset, little by little, but leave a thinset "stain" on the Kerdi fleece.

Once the nubs and bumps are gone, then if need be you can skim coat or feather the surface to smooth it all out.

After the skim coat has cured, then you can tile.

For future work, when you smooth out the Kerdi on inside corners like that use two drywall knives, or a trowel and a drywall knife. Use two tools.

Press one blade right into the inside 90-degree corner and hold it there. Put the second blade right next to the first, then draw the second blade out over the Kerdi. The second blade will clean up your surfaces while the first blade prevents the Kerdi from being pulled out of the inside corner.

If you haven't seen this thread, you might want to give it a quick look-through. It's not the only way to do Kerdi, it just shows a few techniques.

Good luck!


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RE: Kerdi Situation

Mongo I was hoping you'd catch my thread, thanks a ton!


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RE: Kerdi Situation

wilkinte:

Why only install Kerdi on half the ceiling and only on the long rear wall? What is the point? Are you not tiling the rest?


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RE: Kerdi Situation

just haven't moved on to it yet. Wanted to sort out my seeming problem that the mongo showed me wasn't a big deal. I'll post pics as I progress, but yes the thing will be tiled. thanks,


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RE: Kerdi Situation

Hi guys, getting ready to set the kerdi tray and I need a little advice to maybe save some time. Haven't seen this specific topic addressed anywhere. My concrete floor is pretty level, with some dips I used some floor patch on. But it seems my tray is a little off. Maybe from how it was stored. In one corner it is about 1/4 inch high ( I can press it down to get it level), and there are some other low spots in the floor that I've notice by placing the tray in position (again, 1/8 - 1/4 inch off, not much). Heres an assumption: If the tray is dead level around the outer edge of the tray (all the way around) then life is good and the pitch in the tray will go to the drain. If that's true, what about putting thinset on the floor, embedding the tray and ensuring full coverage, and then stack some tiles the "high spots" to hold the tray in while the thinset cures. Again, ensuring that the top edge of the tray is dead level. Also, is there a recommended dry pack for the edges? Due to drain/wall issues my tray will be sitting off one of the walls about 1/2 inch. Since HD doesn't sell "drypack" is there something else suitable? What about versabond mixed stiff? thanks in advance


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RE: Kerdi Situation

If the floor is indeed flat and level and the tray is simply warped a bit, yes, you can install it then weigh it down while the thinset cures.

If the floor is out of whack, level it. You don't want any voids under the tray.

For drypack, you can make your own.

Depending on how much you need, buy a bag of portland cement and a bag (or two) of sand, both are sold at the box stores. Mix at about a 5:1 sand:cement ratio. The 5:1 is probably the median ratio. Some go richer, some leaner.

Portland is usually sold in 94lb bags. Not sure if it comes in smaller sacks. If you only need a small amount and that 94lb bag of portland will result in too much waste or leftover material, then...

You'll also see "Topping Mix" sold at the box stores, also in Quikrete sacks. Probably 60-lb sacks. Topping mix is a mix of sand and portland cement mixed at about a 3:1 ratio. If you also buy a bag of regular sand and mix the two together at roughly 2 parts topping mix to 1 part sand, the sand will lean the topping mix out to a decent deck mud ratio.

While you may already know this, I'll toss it out anyway. Don't forget that a deck mud or dry pack mix is not anything like a typical mortar or concrete mix. You add just enough water to the dry ingredients so it's just moist. Just enough so when you take a fistful and squeeze it together, it'll clump and hold the ball shape.

That's why it's call dry pack. It's sort of "dry" and you have to "pack" it into place. Or something like that.



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RE: Kerdi Situation

Thanks again Mongo, I just set the tray.

With the suction of the thinset ridges it pulled everything perfect. The drain is of concern, I really want it tight to the floor and supported, please see pic and comment if you can. One thing, when I dry fit my drain to the pipe the kerdi drain goes all the way to the bottom of the tray insert. I get about 1/4-5/16 of an inch "mating area" with the 2 " drain pipe sticking up. Make sense? I'm a little concerned that when I fill the tray insert with thinset and apply abs glue to the assembly my drain wont have very much glue overlap. I thought about maybe coupling in there but I'm only talking about raising the 2 inch pipe up like 1/2 inch.

Another thought, when installed, the drain should sit in that drain insert in the tray, right? Do you then fill that tray up with thinset for the application of kerdi? If so, I imagine you have to be gentle when taking your sheetrock knife and spreading out the orange. If you press on that mud filled tray around the drain it will just squirt out! right? In all of this i'm assuming the drain assembly needs to be flush with the entire floor in prep for tiling. Thanks again and I appreciate your help. Will toss a couple more photos in next posts


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RE: Kerdi Situation

tray set with some tiles for weight. Interesting how the assembly squishes when you step all over the set it in.


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RE: Kerdi Situation

closer shot of the tray, level from top to top.


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RE: Kerdi Situation

I'd want more than 1/4" overlap at the ABS coupling. So yeah, as much of a pain as it would be, I'd do what you need to do to add a coupler in there.

Setting the drain: Dry fit it one last time. Then yes, you thinset the depression in the tray. Then back butter the drain flange with thinset. Glue the fittings, then set it in place. Be deliberate, press it down in place, get it level, and get it set in one single motion.

Clean up any thinset squeeze out.

Another thought, when installed, the drain should sit in that drain insert in the tray, right? Do you then fill that tray up with thinset for the application of kerdi? If so, I imagine you have to be gentle when taking your sheetrock knife and spreading out the orange. If you press on that mud filled tray around the drain it will just squirt out!

After doing the walls, the floor uses the same methods. There's really no trick to doing it. If everything was set correctly you should have a fairly smooth transition from the surface of the tray to the surface of the drain flange.

At the drain cutout, you do want some squeeze out there to endure that you have a good bond between the kerdi and the drain flange. But the squeeze out should not be significant.

If you're getting a lot of squeeze out you might be using too large of a trowel, ie, applying too much thinset.

Lemme see if I can find a video...

Here's a schluter video that might help.

Does that video help clarify things?


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RE: Kerdi Situation

Thanks a bunch, and I've watched those videos a lot. It's just when the rubber hits the road a bunch of miscellaneous thoughts run through your mind. I just had a hard time with filling that entire flange tray up with mud, given how much time I've taken getting the excess mud out of the way with my knife.
For my dry fit, where would you recommend the drain flange to end up? Flush with the top of the tray? a little below. That's what I'm struggling with, how much to raise my drain with a coupler and two tiny pieces of 2 in abs


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RE: Kerdi Situation

One more thing sir, do you think this would work as a dry pack if I mix it stiff:

http://www.ctscement.com/Specs2005/PDFdocs/Data_Sheets/MortarMix_data.pdf
And thanks again for the counsel!


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RE: Kerdi Situation

Heres an update: I made my dry pack this morning based on Mongo's recc. and a page I found on John Bridge. Now I have more leftover materials to deal with, but confident I used the right thing for filling my 1/2 inch void. I also see now that the drain flange needs to come up 1/2 inch so the plumber hat is going on. I'll keep posting as I go, and I want to encourage other DIY's to look at Kerdi. Apart from learning how to work with all the different materials it's easy. I know if I were to do a second shower it would go much smoother. Soon I get to learn how to do tile! Thanks folks,


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RE: Kerdi Situation

I have no real input but I am following this thread. Glad to hear you are progressing.


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RE: Kerdi Situation

thanks man, wait till you see the pics of "simply raising the drain 1/2 inch"!!! of course the coupling to do that has dimension, as does the kerdi drain. Needless to say if I just cemented the coupling on and tried to get a half inch "sticking out of that" with the ABS my drain would be 2 inches too high. Out comes the dremel with it's attachments to cut the drain pipe in the floor down. Pics will follow and you can have a chuckle!


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RE: Kerdi Situation

as promised, here's my kerdi update. I had to raise my drain pipe in the floor for my drain installation. While it seems simple enough from watching the videos out there, when the rubber hits the road it's tricky. Also, this is the most important part of your schluter shower. It has to be done right. Working against you are challenges in accurately dry fitting ABS, and challenges in making accurate measurements, especially given the drain assy needs to be flush with top of the tray with enough overlap between the drain pipe and the drain for a good glue connection. You basically have 1/2 an inch to work with if your drain is in the floor like mine. Not much room for error for a novice.
So for my installation, I had to raise the pipe up about a half. To do that I had to cut a hunk out of my drain and use an ABS coupling. Glad I had bought the expensive dremel with all the wondrous attachments. Actually worked great to cut the drain and burnish the edges.

One thing I got from one of the schluter videos is using a 4 inch (maybe 5?) sleeve around the drain pipe, they call it a coupler. This keeps the concrete away from your drain and is great if you have to stick a dremel in your drain to reduce it.

A good video, like all of them out there, but the measuring issues are covered very quickly. My one day effort is between 1:57 and 2:01.
http://www.youtube.com/watch?v=Swj264jRu1E


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RE: Kerdi Situation

Here is the finished drain with the kerdi over it. For me the whole kerdi effort has been a fight between getting good thinset coverage without bulking up underneath. Hence I spent a lot of energy chasing the thinset out with my drywall knife.

This has significant meaning when putting the kerdi over the tray and drain assembly. Schluter recommends installing the drain in the tray and the plumbing at the same time. This provides best support for the drain.

So you comb your thinset over the tray, fill the drain depression up with thinset, put glue on your drain flange and drain, and quango, set it in and make it flush with the tray and give it a good glue connection. You literally have 10 seconds before the glue has welded. As Mongo points out in his excellent thread, you get one shot at this.

Back to chasing thinset, so now you have a full depression in the tray full of thinset. I elected to chase a fair amount of it out while ensuring my kerdi had a nice bond to the fleece top of the drain. If you look at the pic carefully you can see a slope down into the drain. I may have overdone it, but I just didn't want any bumps or humps around the drain.


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RE: Kerdi Situation

Now I'm leveling for the curb, the product in the picture is something I used on the floor under the tray, from HD. Expensive, like 20 bucks a gallon. But, it goes on out of the tub, is workable, and drys rock hard in about a day. You can also scrape it down with a sheetrock knife, or a trowel. I found the teeth in my trowel cut into it nice when I overdid it.


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RE: Kerdi Situation

Hi Guys:

Hoping for some great counsel again. As you can see, I've had to remove some tiles due to chippage. Now I've found I've breached my kerdi on the floor. My plan is to apply another layer of kerdi overtop of what you see with my thinset. My question is what about kerdi fix?

Would that be useful in the two cuts in the kerdi prior to thinsetting another layer on?

Next pic will be a closeup of the breeches


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RE: Kerdi Situation

close up of kerdi cuts


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RE: Kerdi Situation

Just make a patch with Kerdi or Kerdi Band. Embed it with thinset and make sure you have at least a 2" overlap. If you want to smear some Kerdifix around the borders after it's dried, for "insurance," no problem.


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RE: Kerdi Situation

Agree with StoneTech.

The thing to remember is to get a good seal with K-F you need K-F to be embedded in the Kerdi fleece itself. If you smear K-F on thinset, theoretically moisture can still wick through the thinset. I'm being a bit cautious there.

So if there's thinset everywhere, then you could do a smear of K-F in the slice itself, then cover it with a Kerdi patch going for a 2" overlap. Or like Stonetech wrote.

I hate to even mention this, but...after you do the repair, dry fit a couple of tiles over the repair to check their elevation against the already set tiles. There's a small chance that the cured thinset and the Kerdi patch could "bump" the tiles up a bit.

If you think the new tile might stand proud, you could grind the bottom of the tile down a bit with a grinder and a diamond blade. ie, if they are waffle-back tiles, just remove the waffle.

The good news? You'll have all the kinks worked out for your next Kerdi shower!


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RE: Kerdi Situation

Thanks so much guys, especially the re-tiling counsel. And yes this has been a learning experience!!


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RE: Kerdi Situation

Just to add to Mongo's suggestion, if the patch does create a "bump," you can certainly mix up a bit of thinset on the "loose" side and feather out the area a bit. Use the flat side of a 12" trowel for this...

Also, I don't have a problem with just taking some KF and squeeze it slightly under the torn area, push it down flat and smooth some more of it on the face of the cut and feather it out. As long as you have a smooth, continuous covering, I would trust it. Note that this is NOT the Schluter recommended way for a repair.


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RE: Kerdi Situation

Just a quick note to you all, there's a day left on my auction for a BT 17 better bench on ebay. current bid is .99!
good deal over there. Shower is coming along, and I'll throw up some pics. Thanks to Mongo et al for the counsel through it all.


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