Line the inside of damp walls with aluminium foil, using a proprietary adhesive, before wallpapering. First, remove any old paint and wash the surface down with a solution of one part of ammonia to eight parts of water. Leave it to dry and then apply the foil, smoothing it down carefully to avoid creasing.
Begin tiling from the left-hand corner created by the two battens. Working horizontally and building upwards. Apply the adhesive directly to the wall with a serrated spreader, working in areas about 300 mm 12 in square and finishing off by spreading the adhesive in horizontal lines. Press the tiles into position and, unless they are fitted with spacer lugs, place matchsticks between each tile to get an even spacing for grouting. Every two or three rows check that the horizontal and vertical are still accurate, because tiles tend to creep out of alignment. Once this half of the wall has been tiled, remove the battens and tile the rest of the wall by eye. Leave the job to dry for twenty-four hours – longer, if necessary.
When the adhesive has dried. Grout the tiles. Remove the matchsticks and, working with the palm of the hand and fingers or a small piece of sponge, rub grouting compound into all the joints. The compound should be mixed to the consistency of a fairly thick cream.
As the compound dries, rub off the surplus with a dry cloth and then finish the joints by running a rounded stick down them to get an even, slightly concave, finish to the grouting.