Both for safety and aesthetic reasons, it is important to lay tiles flat, on an even surface so that no tile stands out from the rest. Most of the uneven tiling problems arise from an uneven substrate (the underlying layer on which tiles rest). So how does one ensure that tiles are laid flat on an uneven wall? Follow these tips.
Self-Levelling floor compound: If you are installing floor tiles on an uneven substrate, use a self-levelling floor compound. This is a liquid that can simply be poured over the entire floor, and it naturally seeks out low areas and fills it up. They require no additional work once pouring is done, but they need a day or two to dry completely. Once dry, you can install tiles on top of it. The only drawback is that it increases the thickness of the floor and might require you to build a threshold at the doorway.
Beating tiles in: For surfaces that are only slightly uneven, user could beat the tiles into the mortar bed and gain an even tiled surface. To do this, lay an extra thick mortar bed with the help of a grooved trowel. Then lay the tiles. After this you need to hold a flat board against the tile and beat on the areas that are jutting out with a rubber mallet. This firms up the tile by driving it deeper into the mortar, giving you an even finish.
Patch repair mortar. For occasional deep holes in an otherwise even surfaced wall, you could use a patch repair mortar. Fill the holes in with the mortar, and smooth out the entire surface. After this you are good to start tiling on the wall. This is particularly useful for small areas such as the kitchen backsplash.
Back buttering What if your substrate is even, but the tiles are not? Sometimes, handmade tiles do not have uniform thickness. You can use a back buttering technique. First spread a normal layer of mortar on the substrate with a grooved trowel. Now pick the uneven tiles and apply a layer of mortar at the back of each of them, in the areas that have low points.
A quick fix If you really do not want to mess with the substrate, or do not know the plastering technique, use small tiles. The more uneven the surface, the smaller size tile is recommended. That is why mosaic art works brilliantly on uneven tiles. One, the design camouflages uneven sections, and two, because the tile is small, it sits snugly on the surface and does not slop on uneven surfaces as big tiles do. A mosaic tile wall would also be a brilliant and creative DIY project for you.
It always pays to ensure that your tiles are laid evenly. Unevenly laid tiles stick out like sore thumbs, and look as bad. New tiling products are available quite easily these days, and with a little effort, you are sure to get a beautifully finished tiling job done. Good luck!