The first essential for successful tiling is to make sure that the walls are scrupulously clean, firm and dry, and that all traces of cleansing detergent are washed off. If the adhesive you use — the one recommended by the tile manufacturer — is applied to a powdery surface it will stick to the loose parts and eventually come away with them. Grease may upset the formulation of the adhesive, and so will detergent mixed with grease.
Although you should fill cracks and depressions with cellulose filler to achieve a level surface, it is possible to tile over a slightly uneven surface, such as that presented by an unplastered brick wall, by using Nic-O-Bond Thikbed which, as its name implies, spreads on in an extra thick coating.
As angles and levels of houses are seldom true, never rely upon floor, skirting board or top of bath for your horizontals, nor wall corners for your verticals. Use spirit level and plumb-bob.
Determine the lowest part of the wall by running the spirit level quickly round the floor perimeter or top of skirting board. Place the bottom edge of a tile on this spot and mark its upper edge with pencil. Remove the tile and place a long, perfectly straight batten with its top edge coinciding with this mark. Stand a spirit level on it to check that it is horizontal and rough-nail it to the wall.
Where tiling is to continue all round the room, nail similar battens to line up with the first one, checking each with a spirit level. The last batten should now meet the first one dead on. It is worthwhile taking care over this preliminary work. If you do not have sufficient battens, a pencil line around the room will do; but laying the first row of tiles will not be quite so easy. If there is an awkward corner to negotiate use a lath and, with a tile as the unit of measurement, mark it off throughout its length. You can then push the lath this way and that to decide which arrangement gives the best effect.
Now find the dead centre of one wall and place a tile over it. Rub chalk on the string of a plumb-bob and drop it so that it lines up with either the right or the left side of the tile. Then, holding the bob with one hand, twang the string to leave a mark on the wall — as you would do when hanging wallpaper.
Using a serrated spreader, spread adhesive to a thickness of 1.5 or 2 mm, for about 450 mm (18 in) on either side of the mark and about 1 m (3 ft) up. Press the first tile firmly on to the wall against the perpendicular mark, with base resting on the batten. Do not slide it into position or you will disturb the adhesive.
Continue tiling in this way, working upwards and outwards, and checking for evenness with a straight edge from time to time. Leave the corners (which will show an equidistant gap) and also the bottom row (below the batten) until last.
Remove the batten the following day and finish corners and bottom row, this time spreading the adhesive on the back of the tiles rather than on the wall which, owing to the narrow space now exposed, will be difficult to reach. Some of the bottom tiles may have to be cut to fit.
To cut a tile, score the surface with a cold steel blade or tile scriber, place it over a matchstick, press down evenly and firmly and it will snap. Use pliers or a tile cutter to cut corners out of tiles intended for awkward places or to fit round pipes. Score at the unwanted part first and then snip off a little at a time. Tiles cut for internal corners are best mitred to an angle of 45 degrees by rubbing their edges on emery cloth.
If your tiles have no spacer lugs use a piece of thin card to give the necessary tolerance.
Support the tiling, stuck on to a soffit above a window or door, with a piece of plywood jammed into position over wooden uprights until the adhesive has set.
It remains to grout the joins; and for this you will have to buy a packet of grouting powder. Mix according to the maker’s instructions and rub it on with a sponge. Now ‘point’ with a thin stick with a rounded end, and polish off surplus with a dry cloth. You can get coloured grouts. White becomes dirty-looking, but it can be kept clean for longer if it is brushed over with a silicone damp-proofing solution when dry. Brush tiles as well and then wipe their glossy surface clean.
Calculate how many tiles are required and generally plan the work in advance.