Unevenness of the wall to be tiled

[blackarrow1990]

Hello,
I am a noob trying to tile our shower. Since the old tiles were taken off, some of that wall material has been taken off as well, so everything had to be smoothed. After smoothing with some cement compound and waterproofing "mud" layer I measured the evenness of the walls.

On 1 m of straight edge there is about 2-3 mm of difference on bigger surfaces. However, when approaching the corners and bottom of the shower with the straight edge the difference is about 5-8 mm (siehe sketch).



The mortar will be applied to the wall (10 mm trowel) and to the tiles itself (4 mm trowel).
The tiles will be 60x60 cm (8 mm thick) with a seam of 2 mm.
In my opinion I should be able to correct the unevenness of the wall using the mortar, since it is 14 mm thick and could be "compressed" when putting the tiles on the wall. What worries me a little bit is that the tiles have to be vertical so at the bottom they will barely have any mortar and at the top there will be a lot of place to be filled with mortar.

Or should I try to put the first row a little bit inclined until I reach the surface which is far more even?

Thanks.

 

[Tile Marble Granite]

Prep work is the key to success. Is it brick wall or studs? Send us some pictures. That would help.

 

[blackarrow1990]

Brick wall, plastered. I did make it smooth and got to 2-3 mm difference in a meter. However, after putting the mud waterproofing (using strips) I got few mm more at the corners/edges. That is why I have more difference now.

 

[Tile Marble Granite]

Heck of a gap you got over there mate. I would try my best to straighten up the walls prior to waterproofing/tiling, that saves me adhesive and installation time. Easier when installing the tile as well.
Is it a shower? If yes, you got to do some waterproofing over there.

 

[blackarrow1990]

That was when the first coat of waterproofing has been applied. With the second coat I managed to even thing out, and now I am about 4 mm of difference on a 1 m straight edge.

 

[blackarrow1990]

That was when the first coat of waterproofing has been applied. With the second coat I managed to even thing out, and now I am about 4 mm of difference on a 1 m straight edge.

View attachment 135982

 

[Tile Marble Granite]

What brand waterproofing are you using?

 

[blackarrow1990]

It is the german product called Schomburg 1k Aquafin. Has to be applied in at least two coats which get thinner as they dry. This corner does not to be completely waterproof because it is partially outside shower. The shower itself has to be waterproofed (as well as floor of the whole bathroom) with special sleeves and strips at the edges and pipes. At least 2 mm of dry coat is required according to the code we have to follow.

 

[Tile Marble Granite]

That is cool. What kind of drainage, large flange?

 

[blackarrow1990]

No, the drainage is in the middle, I just applied new sleeve and waterproofed everything as required from the waterproofing manufacturer. It would be nicer to have some lineal drainage, but that would required complete remodelling of the shower which is not that easy (everything put in concrete here in Germany, see Photo).



I am not facing a problem that my wall in the corner is not that vertical anymore. I had to put more waterproofing material in the lower part (see Photo). Should I be able to correct this with mortar? I guess my tiles on the left have to be still vertical, should I just make them completely vertical and then fill the gap in the upper part (so the tiles are flush with the wall in the corner).



It will be hard to put the edge profile correctly if the corner is not vertical. Or am I thinking too much about this detail? Thanks.

 

[Tile Marble Granite]

Inside the shower speaking, is there a pitch down towards the drain from the four corners? That would be the main concern inside a wet room and of course the waterproofing itself. Other than that, you are good to go for large format tile.

 

[blackarrow1990]

Yes, there is. I removed the old tiles and put new waterproofing so I already had all slopes already done.

I also checked because the corner is not completely vertical I will for sure have some deviations up the wall. Not sure how to fix it though.

 

[Tile Marble Granite]

Send more pictures with the area of concern

 

[blackarrow1990]

Basically, the corner that I "fixed" is not bowed anymore but it is not vertical either.
The problem is that once I start tiling the tile edge of the tiles at the corner will be vertical (it has to be) so going up the wall the gap behind the tiles will be bigger and bigger. As you can see in the photos I guess there is at least 5 mm of gap on 2 m of wall. And I not sure what to do about it.
Taking off waterproofing is not easy, it is solid as a rock, but if there is no other solution, I will have to take if off and apply new coat, since this is where the problem actually started (too thick waterproofing right at the bottom of the corner).

 

[Tile Marble Granite]

You can grind off the (excess waterproofing) using a diamond cup wheel