Scott's Hakatai shower projects [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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03-03-2007, 10:20 PM
My name is Scott, and I am finishing a home in which I have done a lot of floor tiling and some wall tiling. For two shower projects I will be using Hakatai Carter series glass tiles (1/8" thick, about 3/4" x 3/4" tiles on a mesh backing). The manufacturer recommends a modified thinset and a latex additive on manufacturer instructions received with the tile. Typically, I use the white Versabond thinset from HD. I will be using Kerdi for both of these showers and wonder what the pros recommend in regards to an additive to the modified thinset.

I have completed some other tilework in the house using this same tile and the white Versabond with no additive.

Thanks in advance.

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03-03-2007, 11:21 PM
I would advise you to stick to their thinset recommendations. The Custom product they recommend is MegaFlex.

03-04-2007, 10:55 AM
Thanks Dan. The instructions they included in the box did not include the specific material recommendations that are included in your link.

I appreciate the help.

03-04-2007, 11:16 AM
I just stuck thousands of those little glass buggers on the floor, walls, and ceiling of my downstairs bathroom. I did not use Kerdi (I will next time) so I can't offer any experienced advice for that. I used MegaFlex and MegaLite to set my glass mosaics. They are both really nice products, but the MegaLite was particularly easy to use. I'm pretty sure that Schluter would not approve the use of either of those thinsets on Kerdi though.

There's concern about the latex/acrylic additives of the of the modified being able to cure beneath and on top of Kerdi. John Bridge has opined that the multiple grout lines of the mosaic tile should reduce if not eliminate that problem though. I wish I had a link for that; you'll have to take my word.

Here's a link to my project thread:

03-04-2007, 12:39 PM
from what I've seen in the glass tile discussions the consensus seems to be to go with the tile vendor's instructions. But I have to say the bit about adding modifier to an already modified thinset is interesting. And I'm not sure Schluter would care much. Remember that the reason for the unmodified recommendation is you've got thinset sandwiched between two impervious materials. That makes for an awful slow cure for the modified thinset under large tiles. But we're talking 1x1 mosaics here - plenty of opportunity to breathe. I'd do what the glass tile manufacturer says - assuming you can figure out what that is. :shrug:

03-28-2007, 11:58 AM
The Kerdi drain I am using in my two showers specifies 1/4" minimum tile thickness (from Schluter, the Kerdi-Drain "accommodates a wide range of tile thicknesses 1/4" to 1 1/4"). The Hakatai glass mosaics are only 1/8" thick. I need some suggestions as to how to use these two products together. Otherwise, it seems that water will sit pooled unable to get over the drain lip.

So far, I have tiled and grouted the walls and have created the mud beds. Need to just Kerdi the bed, tile and grout it, but I have some concern about this 1/4" tile problem.

Help please.

03-28-2007, 12:53 PM

I had the same problem with a non-Kerdi drain (my project thread is linked a few posts up). I ended up having to tile over my first layer of tile. I hope you find a better solution.

By the way, your tiles look great so far. I used the same tile in your first pic on my bathroom floor, walls, and ceiling.

03-28-2007, 01:02 PM
Hi Scott,

I'm here because I found the title of your post was interesting. I thought maybe posting from Hakatai, Japan? :dunce: Now I know.

How tall is that curb in your first pic? Looks awful high - am I wrong, or is there a reason for it?

Great looking tiles :tup2:

03-28-2007, 01:24 PM
Hey scott i am going to be in the same boat in a week or two, i have'nt figured out how i'am going to do mine yet either. I am going with bizzaza mosaic, same size tiles as yours. But question for you, how did you cut your tiles?

03-28-2007, 01:37 PM
That first gray tile project is not a human shower. the curb is 13". It was going to be a human shower facing the other way to the bathroom, until I opened it up to the laundry/mud room. Now, we will hang wet snow clothes, wash dirty kids, dirty dogs, dirty boots, etc... It is only 24" x 38".

Dan, before posting I did read your posts on drain height. Of course, the Kerdi drain is different, so I need some recommendations in regard to it specifically. I would prefer not to tile the floor twice, but it is obviously a solution.

BTW Dan, your bathroom looks great. Good tile choice. I've attached a pic of one of my other bathrooms.

Ideas on Kerdi drain height in relation to this tile still welcome please.

03-28-2007, 01:39 PM
Ray, I use a pair of hand cutters that Hakatai sells via their web site for cuts that will not be obvious. For cuts that will be real obvious along a long line, I hold a mosaic sheet and run the line of tiles through my wet saw at a slow pace. I may use a push board to push the tiles through in a straight line.

03-28-2007, 02:14 PM
Sorry I don't have any useful advice, but I had to say - great job on the showers and tub surround! They're beautiful!

03-28-2007, 09:46 PM
I still need ideas on how to match 1/8" thick tiles to the Kerdi drain, which specifies adjustability for 1/4" to 1 1/4" tiles. I could tile the floor twice (don't want to), I could trowel a layer of thinset and let it dry and then tile on that to build up to desired height, but I would be concerned with my ability to float thinset without creating birdpaths or other drainage irregularities.


03-29-2007, 04:58 AM

I thought of the same thing, but would also be concerned about getting the thickness consistent. The other thought I entertained for your issue was laying down 1/4" Hardi. I'm sure there's a good reason not to do this, but I can't think of it right now.

Perhaps the best solution is to recess the drain 1/8" somehow. I don't know enough about the Kerdi drain to say how though.

Finally, you can't be the first person to encounter this issue on this board. Surely someone can come forth with their solution to the problem.

03-29-2007, 07:19 AM
Scott & Dan,

I have a thought about getting a skim coat into a consistent layer. It may not work,but it is a thought.

first, determine how thick your skim layer needs to be

second, find a square notched trowel that matches this thickness, or modify a larger notch to your desired depth.

third, lay a nice clean layer of notched thinset on the floor and let cure

fourth, using the dried notches as a screed, fill your voids to flush

Any thoughts from the pros?

03-29-2007, 08:03 AM
That sounds good to me, Todd.

03-29-2007, 08:55 AM
Scott. You can lower the entire drain grate assembly another 1/8" by using shorter screws. For now, temporarily remove (or back off) those two drain grate screws, set the grate and lateral adjustment collar onto the drain and you will see what I mean.


03-29-2007, 10:00 AM
You don't need shorter screws. Rotate the retaining collar to position the two elongated trapezoid holes over the screws. Viola!!! Seems Mr. Schluter has thought of everything. Seriously, I've done it that way on thin tiles, This will leave you the thickness of the grate which with the thinset and glass should solve your problem.

03-29-2007, 11:13 AM
You are absolutely right Jim about aligning the screws up to those elongated slots on the lateral adjustment ring using shorter screws, you can even lower more, an additional 1/8".

The screws, at least on the drains I have, are actually long enough to go through those elongated slots and hit the drain, preventing it from being lowered all the way.

03-29-2007, 12:04 PM
We both are correct in what we say. I have never seen them with the long screws as you described. I just got off the phone with my rep and He informs me that there are some with longer screws. This is normally not the case, but for some reason it does happen.
Thanks for the info, it is a good thing to store in the old memory bank.

03-29-2007, 12:22 PM
Thanks Mike and Jim. I have the shorter screws, and it is a good tip to align them with those elongated slots - I might not have payed attention otherwise. It appears that I might still end up with a slight lip even tough I have tightened everything down. The metal itself above the lateral adjustment collar is almost 1/4". With these 3/4"x3/4" 1/8" thick glass tiles the thinset does not raise their height much at all (due to the trowel size to prevent thinset from squeezing up in the grout joints). The Kerdi membrane will raise the tile a bit.

I have attached a pic showing my drain and the 1/4" height over the lateral adjustment collar.

03-29-2007, 12:31 PM
Well, then I still like Todd's skim coat suggestion.

03-29-2007, 12:35 PM

03-29-2007, 01:41 PM
Thanks for the follow-up on different screw lengths. All the Left Coast versions of these drains I've ever seen have the long ones.

Wasn't even aware shorties existed. Learning something new everyday, eh? :)


Scott, once the drain grate assembly is nested into the recessed area on top of the drain and one layer of Kerdi is applied, only half of the metal grate should rise above the surface plane of the floor [see yellow marks]. Does that sync with what you can see happening with your drain? Or do we unknowingly have yet other differences with these drains?

Do you think your tiles with bond coat will be even thinner than that?


03-29-2007, 02:48 PM

Thanks for the info. As I planed out the tile to the grate, I could see that it will be very close. It would be easy if they were bigger tiles that would bear on the flange of the drain where the Kerdi membrane will be.

The only trick with these 3/4" x 3/4" mosaics will be floating them in the span between the support area (outer flange where the Kerdi membrane will be) and the drain grate. I can apply thinset over the lateral adjustment collar and then place them without squishing them down to keep them on plane. A picture may help. You can see the difference between the tile height and the drain grate height if I just place it on the lateral adjustment collar.

04-01-2007, 10:32 PM
After careful analysis after applying the Kerdi membrane to the floor and drain flange, it still appears that the tiles will plane in under the lip of the drain.

I've given thought to the idea of building up with thinset using a square notched trowel and filling in. Due to the way the drain gets locked in with thinset on both height and lateral adjustment, I think it is best to go by the book and simply install the drain at tiling time with no prvious buildup of thinset on the Kerdi membrane.

I studied the Kerdi installation video on tile installation and see that the main advantage of the lateral adjustment collar is to minimize cuts. It is 1/8" thick. The thinset will actually lock it in place and the thinset will end up locking the height adjustment of the drain. Therefore, it seems that since my problem would be that the drain lip will be at least 1/16" too high for my tiles, instead of using the supplied lateral adjustment collar, I could make one out of metal lath. The metal lath is not nearly 1/8" deep in profile. I could fit it tight for the vertical adjustment. The vertical adjustment piece would then come in contact with the inside of the drain assembly, so I would have to cut it down at least 1/8" inch to compensate for the elimination of the plastic lateral adjustment collar.


04-02-2007, 08:10 PM

Thoughts on the above idea?

04-03-2007, 04:19 AM
Hey Scott,

I used the same tile with the Kerdi drain. I am just a DYIer and it was my second tile job. I cut the screws down and lined up the holes as some others suggested. I did have to build up around the drain a layer of thinset. Wasn't that hard.

I tiled all around the drain leaving space to fill with a skin coat, but close enough to see where the drain would line up with the tiles so I knew where I wanted the drain. I then locked the drain in place with a skim coat (thicker than skim right around the drain to lock in the flange). I kinda feathered it from the drain to the existing tile so there was no bump or ridge. Let it setup and then put the tile in and adjusted the drain height. Did the job about three years ago and works fine. Even used the wrong thinset and still no tiles moving or cracked grout.

I did learn from this job I will never use little tile again. Such a pain to work with. As the pros say you better have your substrate level and flat. Not much adjusting you can do with a 3/4 in tile. I also didn't like the way the carter series picks up grout. I used a white sanded grout it gets in every little nook and crevice in the tiles. Even after many, many, many, many, many, many washes with different solutions and pads there is a slight white washed effect to the tile. It really changes it's look. My advice set yourself a little test board with some scrap tile and test your grout there to make sure you are happy with the final look after the grout sets up. It may change your mind about color.

Good luck,

04-03-2007, 08:54 AM
Scott, when you actually set the tiles they will not drop down low next to the grate like your picture suggests. Before setting those tiles the entire recessed area "A" will be filled with thin set mortar and left to firm up. At that time those thin tiles should be very close to being level with the top of the grate.

How about this? Place a piece of Kerdi temporarily onto the drain flange. Then using a straight edge, lay it flat across the flange "B" with one end at the drain grate. That is the approximate height of where the bottom of the tile will be, which is what I tried to show in post #24 above.


P.S. The actual tile height will be even somewhat more, raised by the thickness of the thin set under both Kerdi and tile.


04-03-2007, 09:38 AM
Mike and Frank,

Thanks for your replies.

I will do as you suggest, tile toward the drain so that I know where the tile will line up, and then I will skim some thinset into area A and let it set up. I will then complete the tile in area A.

I will post a picture when it is done. I am doing this today. Kerdi'd the floor yesterday.

Frank, I agree these 3/4" mosaics are a bit of a pain to work with. I figured out with the grout that you have to start your clean-up within about 5 minutes for better results, but even then, with all of the pits and crevices and recesses in the tile, the tile will end up being altered by the grout. Fortunately, I like the look, though I realize if you wanted the "clean" look from these tiles you would inevitably be disappointed.