One of the best underlays for ceramic tile is brickwork.
How to put tiles on brick wall.
Start applying the adhesive in a bottom corner about 1 tile length away from the bottom and side of the wall leaving space for the edge tiles.
Spread the mortar onto the wall with the flat edge of a trowel.
Using a trowel spread an even layer of thinset over the bricks.
Use no tiles less than half wide along the outside of your tile field any tile slivers tiles that are less than half the width of the tile itself will markedly show the out of plumb wall.
The thinset will cover the bricks and mortar and provide a flat smooth surface for tile installation.
Create a smooth surface for the slate tiles to be set on by covering the brick wall with a layer of thinset mortar.
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.
Use the flat side and edge of the trowel to smooth the thinset eliminating any ridges or bumps.
Ceramic wall tiles need a firm foundation to adhere to so the tiles will not crack from movement.
Laying tile over brick will provide a polished look to the area and offer colour choices that are unavailable with brick.
The first step is to remove any existing trim or moulding from the wall as you won t want to tile over them.
Allow the thinset to cure for 24 hours before tiling.