Mortar bed over Kerdi

[scousi]

Hi,

I installed kerdi over a pre-sloped mortar bed but I am not using the Kerdi drain (Didn't know it existed before I started)

I have a drain like this generic image. It's the same drain type but not my setup.



The problem I am facing is the following:

The drain sticks out too much so I won't be able to get a flush drain. The top drain flange is on top of the Kerdi. I basically need to raise my mortar bed for the weep holes to work properly. I've already tiled my walls over Kerdi.

I have a question:

Can I lay another layer of the mortar bed on top of Kerdi and re-apply Kerdi on top of it? I have enough leftover. I'm no longer sure about re-doing the joints with the walls since I have already applied the tiles on the walls. So the 2 inch overlap is a problem.

I was also thinking of laying my 2x2 travertine mosaic tiles over 1/2 inch of thin set for the shower floor. Is that a feasible solution? This would give me a flush drain but I'm not sure the weep holes will work properly in this case.

Thanks in advance.

[muskymike]

Hi there, welcome. Gotta first name we can use?
If you used the Kerdi, you need to use the drain too to make the system work.

I was also thinking of laying my 2x2 travertine mosaic tiles over 1/2 inch of thin set for the shower floor. Is that a feasible solution?

No. You need to set tile on a mud base or on the Kerdi not on 1/2" of thinset.
Looks to me as if you have a pan liner in the pic.

[scousi]

Ok thanks for the quick response. You can call me Sly.

The pic just shows my drain type. It's not actually my shower. I will post my PIC tomorrow.

Is there no way to use Kerdi using weeping hole drains? My drain is now glued and stuck in my mortar bed. Changing it would be quite a lot of work!

What I meant by 1/2 inch of thinset was actually using 1/2 notch trowel. That would bring me to the correct height. i was wondering if 1/2 notch was too much for 2x2 mosaic. I guess I would have to cut the sencond flange on the drain for the weeping holes to function.

I also though about lying a layer of Ditra on top of my Kerdi. That would give me some extra wiggle room. I realized that the drain I used requires a second cast of mortar for the bed.

[muskymike]

Hi Sly, you need to either raise your drain up to put another layer of mud in minimum of 1 1/4". Dunno if Kerdi would work with that drain. I doubt it. And yes 1/2" trowel is WAY too big for 2x2's.

[scousi]

Ok thanks,

If I raise my floor another 1 1/4" with mud, can I do it on top of Kerdi or should I remove the Kerdi first?

I guess I will have to remove 6" inches of already laid Travertine on the wall to rejoint the Kerdi (from new cast of mud) with the walls. Is there any way to save this tile or will it be wasted?

I noticed that the "interior" of my drain pipe is 2 3/4" so I may well still be able to fit a Kerdi drain into it.

Can the Kerdi drain be inserted and glued to the interior of my drain? It's black ABS.

[Brian in San Diego]

Sly,

Go to the User CP tab in the dark blue toolbar above and under "settings and options" click on edit signature. Put your name in there and it'll appear at the bottom of every post. Are you sure of that pipe size? Or are you measuring inside of the drain? The kerdi drain is designed to connect on the outside of 2" ABS or PVC pipe. (When ordering the drain you must specify the material.) I believe you are going to have to remove the clamping drain. You can get an inside pipe cutter for plastic and cut the pipe. You can demo the bed around the drain and may find a way to install the kerdi drain and then you could kerdi into the new drain w/o building another mudbed. Let's see some pictures and tell us what kind of substrate you are on.

Brian

[scousi]

Thanks Brian,

Here are some pics:



The mortar bed is sloped with Quickrete (Yellow Bag). The first part of the drain is imbedded in the cement mortar bed. There is actually 2 1/2" inches of water in those pictures to make sure the drain doesn't leak.

My solution is the following:

I was inspired by this post:

http://www.johnbridge.com/vbulletin/...ht=clamp+drain

The problem is caused by the second flange with the weeping holes. If I screw on the drain cap in it, it is higher than my thinset + tile thickness at the lowest setting.

It turns out that I simply don't have to use it. If my Kirdi is set right up to the lip of the drain, I can't see how water could go anywhere else but down the drain! It could occasionally flow up under the tiles if my S-trap gets clogged.

I will still have the screws so that my drain cap can rest on them and adjust the height. The plastic part of the cap is beveled so that the water flowing in the gap between the tile and the metal drain cap will still end up in the drain.

I will still patch another 20"x20" Kerdi on top of the drain and cement it to the internal wall of the ABS drain pipe.

Unless that over time, the bond that exists between the drain and the mortar bed, deteriorates I can"t see a problem here.

So basically, I won't use the second platic flange as it is made for a second casting.

Does all this make sense?

Sly.

[Brian in San Diego]

Sly,

If it was as simple as your solution, there would be no need for a kerdi drain. The kerdi drain provides a wide bonding flange for the kerdi to adhere to. You don't have that with a clamping type drain. If I were going to attempt your method (which I wouldn't), I think I'd use kerdi-fix to make that seal of the kerdi to the drain. I do not believe that the 20x20 "patch" is approved by Schluter. You may want to order one of the "dimple hats" that JB refers to.

Brian

[scousi]

Thanks again Brian.

Who's the "They" that JB is refering to for the dimple hats?

If I set another layer of Mortar bed, do you recommend removing the older Kerdi?

How long should I let the second coat dry? I let the first one dry 7 days but I don't think my wife has much patience left for another 7 days!

If I do that, I stil have to remove the bottom tiles of my walls, can I recuperate those tile or must I break them off?

[Brian in San Diego]

Sly,

The "they" is Schluter Systems. Perhaps a call to their customer service department may be in order. You can call them in Canada at 800.667.8746 or you can go to their website (click on Schluter Systems in right margin) and you can click on contact and fill in the dialog box and they'll call you. You may be able to salvage your floor w/o another mudbed. If you have to remove the bottom row of tile, I'm afraid you'll not only lose them, but may damage the kerdi as well. A mudbed only has to cure 24 hours prior to working on it.

Brian

[scousi]

So it would be something equivalent to this:

http://www.noblecompany.com/Portals/...Decription.pdf

However, this would not solve my height issue due to the second clamp flange but the solution is maturing!

I called and they will try to contact the regional rep for me. Seems that Schluter is located in my own backyard!

[scousi]

Other than acting a screw hole for the beveled drain cover, I still can't figure out the use of the scond flange (clamp) if I don't have a second mud bed.

The part number for the "dimple hat" is Kerdi DF32 for those interested.

[Brian in San Diego]

Sly,

That's exactly what I was talking about. I haven't read enough about the installation to guide you on it...perhaps someone else will chime in here to help.

Brian