Just slide the spacer right left a little so it can be removed when tiles are just setting up.
Tiling wall not straight.
Repeat the process for the rest of the installation and.
You may need to move the trowel over the adhesive a few times to ensure that it s thin and level.
Scoop out a golf ball sized amount of adhesive onto a notched trowel and spread enough adhesive in a thin layer over the wall to hang 2 3 tiles at a time.
I explain why this method works soooo easy.
If your plumb or level is off by no more than a half inch over the course of eight feet it will show in your tile installation.
Much faster than individual spacers.
Pre mixed adhesive tends to be less expensive and work well for wall tiling.
The wedge will pull the tiles together and create a smooth straight installation evening out any bumps or jogs caused by the uneven wall.
Holding a bubble level to a straight six or eight foot board make sure that both walls and the floor are plumb vertical and level.
Alternatively if the long wall is not tiled it could be feathered off with plaster to make the tiles look straight but it is not possible to guarantee success without seeing it first.
But this can be remedied by taking the following step.