Modifying Kerdi niche [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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08-05-2019, 09:02 AM
Hi All
New to the forum, although have been lurking and learning for some time..great site.
Im a DIY guy that has hit a small snag in my shower stall install.
Bought a schluter niche 12x20" thinking it would fit the stud bays... nope... too many pipes and studs in the way.
So i'm thinking of moving a stud over a bit (non bearing wall) cutting down the niche to 10 1/2" wide so it will fit. Looked around the site for a while and couldn't find an exact answer. I am thinking of cutting the piece out and gluing together with some kerdi fix and then using K band over the cut on front and back.

Will that work? I know schluter won't warranty; no biggie for me and the placement will be on the wall that holds the shower valve so no direct water spray. Thx in advance for advice.


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08-05-2019, 09:07 AM
Welcome, Rudy. :)

I see no reason why that wouldn't work, but I'd still recommend returning the Schluter niche if it doesn't fit your application and simply making your own niche within the confines of your structure as needed.

My opinion; worth price charged.

08-06-2019, 08:01 AM
Thx JB I'll build one

Tiger Mountain Tile Inc
08-10-2019, 11:04 AM
It works. I like to fill it up with water when done to check it but it works.

08-12-2019, 01:30 PM
Did you have any luck adjusting your shelf that comes with the 12x20? Mine is loose fit with the product in the box but I cannot figure out how to mount it inside the niche and keep it from sliding down....

08-12-2019, 05:37 PM
Hey Rudy !

We have done a lot of Kerdi board science projects in the past few years -
And Customized many Schluter Niches as well .
I’ve worked with several Schluter Reps and they didn’t blink at all so long as
We have correctly overlapped Kerdi/band in the process .
Let me see if I can dig up some pics ;)

08-12-2019, 06:18 PM
Wow so just banding it in place is enough to hold a big bottle of shampoo for example on the upper shelf?

08-13-2019, 06:30 AM
The shelf in a niche is normally supported by the tiles on the sides and back of the niche that are below the shelf.

08-13-2019, 07:23 AM
wow Rich - it seems like such little material to support the weight - but I suppose the band and thinset does add some structure...adding tile to the bottom and side of that will help as well.

08-13-2019, 07:42 AM

The cross shelf gets thinset or Kerdi Fix as an adhesive , then it is permanently locked into place with the tile abutting it on all sides . We install slab corner shelves and small benches on The same principle of compression ( locked in by the tile ) and it’s very
Strong !

08-13-2019, 08:17 AM
Joe, the absolute minimum shear bond requirement, which would be the bond between the thinset mortar and the Kerdi or Kerdi niche material is 50psi according to ceramic tile industry standards.

So, if you had only 20 square inches of bonded tile on each side of the niche supporting the ends of your niche shelf, that would amount to at least 2,000 pounds of available support. and that doesn't even consider the tiles across the back of the niche. Doubt you'll likely have more weight than that in shampoo bottles. :)

My opinion; worth price charged.

08-13-2019, 08:19 AM
I just installed my shelf with thinset. seemed quite sturdy. and now its all tiled in.

Tiger Mountain Tile Inc
08-13-2019, 09:13 AM
Just to clarify, when I've modified mine I've used sealant to bond the two together. I've never tried it with a Kerdi niche specifically but have done it with both Noble and Laticrete foam niches.

08-13-2019, 11:27 AM
I'd probably just get a sheet of 1/2" Kerdi board and make a custom niche. You could probably make several out of one sheet.

09-09-2019, 02:39 PM
Thx guys

I have decided on building a custom niche after reading more posts. Got enough board to use.
I will have a few questions on measurements to match the grout joints later.


09-09-2019, 04:33 PM
Hi All

After deciding to build my own niche, i have come across a challenge or maybe i'm the challenged one ;-) I have searched the site and didn't find a good description of my issue. Maybe its common sense... but that is very uncommon according to Mark Twain.

I am ready to build the niche to fit the stud bay/plumbing constraints but before i mess up I need to ask a few questions.

My tile is Anatolia 3/8", 11 3/4 x 23 3/4 Will be Installed vertically with 1/8 grout joints. I want the grout joints to line up vertically; not possible to fit to horizontal joints due to stud bay & plumbing restraints I'll be using Jolly trim around the niche. Ill use the 3/8" tile for the niche sides and for top of niche and marble for middle and bottom shelf.

I need to figger out the dimensions of the niche box to fit the short side of the tile and then the best way to come up with an accurate way to measure to line up the verticals.

Help appreciated thx

09-09-2019, 10:30 PM
I'm not sure I understand everything about your last question, but hopefully this tells you what you need to know.

I always do a dry layout on the floor for something like that. If you try to go by measuring individual tiles and add 1/8" for grout joints, you'll be off a little.

Measure, then check, re-check, and re-re-check your measurements. Make sure you use the actual spacers you plan to use during the installation to get everything as accurate as possible.

Niches are a tough thing to get exactly right. Some installers chose not to install them until they have the tile installed on the wall up to that point, so they can get the spacing just right. That's another option.

09-10-2019, 08:27 AM

Thanx for the suggestion.
Ill clear an area on the floor and dry fit w spacers, Jolly trim and all. Hadn't thought of that one. It s just that 1/8 joint doesn't give much wiggle room for error. Dont want to start tiling first, just think that might get me in trouble, but i see the advantage to that as well. Nothing but respect for you pros... who do this everyday.

09-22-2019, 11:45 AM
Same project as Niche
Find my Kerdi shower pan was cut 1/2 short on the curb side. Now how did that happen: :scratch

Anyway I am thinking that I will fill that 36" x 1/2" space with deck mud. Hope I can find Mapei mud tomorrow. Hate to buy 94 lbs of cement for this little oops. Thought I would use the curb as a batter board against which I would stuff in the mud. Or maybe there is another alternative.... putting the cutoff piece of pan back and kerdi fixing it Or?

09-22-2019, 12:32 PM
Thinset the cutoff piece back in. Or if you’ve got extra 1/2” Kerdi board just cut a strip and thinset it in place.

Tiger Mountain Tile Inc
09-29-2019, 11:54 AM
For the niche, I usually add 1/8 inch onto my measurements for a safety net. Then the tile will usually hang past just a small amount. Then any gap gets filled in flat with thinset once the tile dries.

10-02-2019, 06:41 AM
Same project;: Reviewing Schluter install guide just before installing shower tray...and I see an 14 says "when installing stainless steel drain the membrane is adhered to the bonding flange with Kerdi fix"

I have a stainless drain. Is this something you all have done ? Maybe some sort of chemical reaction concern?

At least I have not mixed thin set yet

Was gonna install today and then this.....

10-02-2019, 06:50 AM
OK so I called Schluter. They explained they make a stainless flange which i was not aware of. The asterisk on pg 14 of the install manual refers to the flange not the cover.... unclear what they referred to but im good to go now

10-02-2019, 07:37 AM
Just mix your mortar on the thin side to prevent build up, Rudy.

10-02-2019, 12:12 PM
thanx Dan pan is in and drying. Seems I always mix the mortar thin anyways