3. Preparing a surface for tiling

The surface for tiling should be clean and dry. It is possible to tile over painted plaster or plasterboard (gypsum board), but old wallcoverings should be removed and brick walls must be rendered. 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 need to fill minor cracks or holes; the tile adhesive will bridge these as it is applied to the wall surface. Printed wallpaper can easily be removed because it will absorb water splashed on it immediately; other types will not. With paper-backed fabric wallcoverings, it is often possible to peel the fabric away from its paper backing.
If you apply it to the walls, you must wash the surface down with sugar soap (all purpose cleaner) or detergent, working from the bottom-up, the rinse them with clean water, working from the top down. Wash ceilings with a floor mop after disconnecting and removing the light fittings. Again, rinse off with clean water. Then removing wallpaper as the nex step. To strip printed wallpaper, wet the surface with a sponge or a garden spray gun. Wait for the water to penetrate and repeat if necessary. Start to scraping the old paper from the wall at a seam using a stiff wallpaper scrapper not a filling knife (putty knife). Wet it again while working if necessary. Turn off the power before stripping around switches and other fittings, then loosen the faceplate screws to strip the wallpaper behind them. After removing the bulk of the old wallpaper, go back over the wall surface and remove any remaining nibs of paper with sponge and scraper. To strip a washable wallpaper, start by scoring the plastic coating with serrated scraper or toothed roller, then soak and scrape as before. For quicker result, use a steam stripper to remove washable papers. Press the steaming plate to teh next area while stripping the area just steamed.