The problem is that the wall is uneven.
Tiling with unlevel walls.
If you put a 48 straight edge up against the most sunken areas there s a gap of almost a 1 2.
It simply involves applying mortar as normal to the substrate but then also applying mortar to the back of the tiles.
Plastering backer boards and self levelling compound are all great options.
I explain why this method works soooo easy.
Here is an easy way to set your 1st row and the rest going up your wall then lastly the first row is set.
Believe it or not there are more uneven walls and floors than there are even ones.
Back buttering is a common solution to tiling uneven walls and floors or using tiles of varying thicknesses.
The area of the wall to be tiled minus the area of the window is 37 square feet.
There are numerous ways to make a bumpy uneven or unlevel surface ready for tiling.
Things you will need measuring tape tile wet saw leveling spacers and wedges trowel thinset mortar rubber mallet grout grout float grout sponge.
Back buttering is a trick used for tiles of uneven thickness like ungauged slate or handmade tiles extremely large tiles or for tiles being installed on an uneven surface.