The wall surface should be clean and dry. It is possible to tile over painted plaster or plasterboard (gypsum board), but old wall coverings should be removed and brick walls must be rendered. Note that modern tile adhesives allow tiling over existing tiles, so there is no need to remove these if they are securely bonded to the wall surface. There is also no need to fill minor cracks or holes; the tile adhesive will bridge these as it is applied to the wall surface.
When estimating quantities, first select the tile size, then set out the area to be riled on the wall using a device called a tiling gauge and use a batten(furring strip) to mark out the tile widths. Use the marks to count how many tiles will he needed in each horizontal row and each vertical column. Count cut tiles as whole tiles, and then multiply the two figures together to reach the total required. Always add a further 5 per cent to the total to allow for possible breakages and miscalculations.
MAKING AND USING TILING GAUGE
1. Use a pencil and one of the chosen tiles to mark up a straight piece of timber about 1.2 m/4 ft long, for use as a tiling gauge.
2. Hold the tiling gauge 110670m against the wall to see how many tiles each row will rake, and also to centre the tiling on a wall or window opening.
3. Similarly, hold the gauge vertically to assess how many tiles will till each column.
MARKING OUT A SPLASHBACK
1. When tiling a small area with rows of whole tiles, use a cling gauge to mark the extent of the tiled area on the wall. Here each row will have five tiles.
2. Next, use a spirit level to mark a true horizontal base line axle which the first row of whole tiles will be fixed. Cut tiles will fit below it.
3. Then use the spirit level again to complete a grid of horizontal and vertical guidelines on the wall surface, ready for the support to be fixed.
FITTING TILE SUPPORTS
1. Use masonry tacks to fix support battens(furring strips) to the wall aligned with the guide line. Drive the pins in only part of the way so that they can be removed later.
POSITIONING CUT TILES FOR PANELS
If the height of a tiled splash back is determined by a feature such as a mirror or window, position a row of cut tiles along the top of the panel.
If the width of the tilling is defined, as with a bath panel, always position cut tiles of equal size at either side.