Adhesives For Tiling

Ceramic tiles should be fixed to the wall with special ceramic tile adhesive, which can be bought ready-mixed in tubs or as a powder for mixing with water. An adhesive spreader usually comes with each tub. To estimate how much adhesive you need, allow roughly one litre of the ready-mixed types for every one to one and a half square metres of tile.

Old tiled surfaces provide a flat firm surface and can be tiled over with few problems. Make sure that the old surface is completely free from grease and dirt and replace any tiles that are loose or have fallen out.

Old plaster must be firm. New plaster should be left for a month to dry out. Apply tiles to finishing plaster only, never to undercoats. (Finishing plasters have a fine texture; undercoats are generally much coarser.) Old brickwork and rendering are also good surfaces for tiling provided they are dry, sound and flat. Leave new brickwork and rendering for at least two weeks before tiling.

Gloss-painted surfaces will take tiles, provided they are sound and clean. Check the adhesion of the gloss paint to the surface beneath by putting strips of self-adhesive tape firmly on it and then ripping them off quickly. If any paint comes off, the surface is not sound. Strip off old wallcoverings and distempered surfaces before tiling.

Blockboard, chipboard, MDF, plasterboard and plywood can be tiled over as long as the surface is rigid and does not flex. The boards should be backed by a rigid framework. Natural wood expands and contracts as its moisture content changes. Ordinary tile adhesives may not be able to cope with this movement – use a flexible tile adhesive.

Most ceramic tile adhesives will work on quite hot surfaces, but around a fireplace it might be better to use a heat-resistant adhesive. Where tiles are likely to be splashed or be in contact with water – around baths, basins, sinks and showers – a waterproof adhesive should be used.

Combined adhesive/grouts are available in both standard and waterproof form. These are difficult to remove from the face of the tile if allowed to set, so should be wiped off immediately.

If the surface to be tiled is lumpy or uneven, a thick-bed adhesive can be used toiron it out but using one is not particularly easy.

Once ceramic tiles are on the wall, the gaps between them should be filled with grout a thick paste which dries hard. It is available either ready-mixed or in powder form; once again the tub or packet should give expected coverage -roughly 0.5kg of powdered grout to every two square metres of tiles. Mosaics need more. Some grouts have fungicides added to prevent mould growth. To apply grout, you need either a rubber squeegee or a sponge.

Cork tiles can be stuck in place with contact adhesive, which must be applied to both wall surface and the back of the tiles, or with a cork tile adhesive applied only to the wall.

Metallic and mirror tiles can be fixed in place either with small double-sided self-adhesive pads, which are sold with the tiles allow four or five pads per tile or with an adhesive. Contact adhesives can be used but some tile manufacturers produce special adhesives for their own tiles.

Imitation brick and stone tiles made from fired or pressed material can be stuck to the wall with ceramic tile adhesive or with mortar. Mortar or special grouting powder (available from the tile supplier) should be used to point the gaps between the tiles. Imitation tiles of this type made from plastic can be stuck in place with plastic tile adhesive -the type used for fixing expanded polystyrene ceiling tiles.