"If the treads and risers have to be tiled, there must be a stone, slate, or marble nosing provided for the tiling to finish against. This may be carried out in various ways.

Floor Paving And Wall Lining 350

Fig. 241.

"There are three good methods of tiling steps placed in order of merit in Fig. 242.

"If it is intended to tile the risers only, this may be satisfactorily done by either of the methods illustrated in Fig. 243.

"If the treads only have to be tiled there are two good ways of doing this, as in Fig. 244.

"No one should be allowed to walk over the floor before it is thoroughly set, which will take several days.

"If, after the floor tiles are fixed and set, any plastering, painting, or paperhanging has to be done, the tiles should be covered with plenty of sawdust, and if it is absolutely necessary to use the floor before it has had sufficient time to firmly set, which will be 3 or 4 days at least, then, in addition to the layer of sawdust, the floor must be covered with boards.

For a short time after the floor is finished a saline scum from the cement will probably appear on the surface of the tiles. This can be removed by frequently washing the tiles in the ordinary way with soft soap and cold soft water, which should be perfectly clean. This will not only remove the scum, but enhance the appearance of the pavement generally.

"If there should be any stains or dirt which the application of soap and water will not remove, then use a solution of one part muriatic acid (spirits of salts) and six parts water. This should only be allowed to remain on the tiles a few minutes and then thoroughly washed off.

Floor Paving And Wall Lining 351

Fig. 242.

"Dilute muriatic acid may also be applied by means of a pumice stone to remove stains, etc.

Floor Paving And Wall Lining 352

Fig. 243.

"Too much water must not be used in washing the floor.

"The scouring of tile floors with sand will remove the grouting from the joints and spoil the appearance of the floor.

"In every case after washing the floor should be wiped with a clean dry cloth.

Floor Paving And Wall Lining 353

Fig. 244.

"Preparation of Walls. - All walls which have to be tiled must be rendered with cement.

"In the case of new walls the brick joints should not be pointed but left rough.

"They should also be raked and brushed out to secure a good key for cement rendering.

"After thoroughly wetting the walls, the cement mortar, composed of one part best Portland cement and two parts washed sand, should be spread over them to a thickness of about 1/2 inch, or more if necessary, to make the rendering plumb.

"The face of the rendering must be well roughed or scratched to act as a key to the cement used when fixing the tiles. The rendering, which must be brought to within 5/8 inch of the proposed finished tile surface, must be allowed to harden before commencing to fix the tiles.

"When old walls have to be tiled all the plaster must be hacked off first, the mortar carefully raked out of the joints, the latter brushed clean, and the walls then rendered as above explained.

"If studded walls have to be tiled the spaces between the studding should be filled in with bricks properly built on edge, and the face of studding should be well nailed with lath or other broad-headed nails, for keying purposes, previous to rendering same. The bricks may be left out if extra studding is put in and thoroughly bridged, to prevent as far as possible any springing. The studding should then be covered with sheet or expanded metal lathing, and then prepared in the same manner as ordinary walls. In this case, however, hair may, with advantage, be mixed with the cement rendering. This will help the cement to adhere better to the lathing.

"Lime mortar must never be used on walls which have to be tiled.

"The preparation of walls and floors is usually done by plasterers, but only those who have had experience in cement screeding should be allowed to do this work.

"Tiles should never be fixed in contact with wood or plaster.

"When fixtures of any kind are to be placed against the tile work, such as lavatory and bathroom fittings, provision must be made for them by fastening wood strips or putting wood plugs into the walls before the screeding is done.

"The wood strips or face of plugs to be level with face of screeding. The tiles can then be fixed over them, and when thoroughly set holes can be drilled or bored through the tiles for fastening the fixtures without injury to tiling if it is carefully done. Of course it is of the utmost importance that the strips or plugs be fixed in exact positions."

With regard to encaustic or tessellated tiling, where geometrical patterns are used, it is essential to have the diagonals accurate and true. With this end in view the sizing of the various coloured tiles is a great consideration. Different colours have different shrinkages in the burning process. Thus a black tile, nominally 6 inches square, may be slightly smaller- than a red tile of apparently similar size, yellow and grey tiles differing from both. To remedy these defects, so fatal in a tile floor, all manufacturers pass the tile through a gauge specially made for the purpose. These are known as grades A, B, and C. It is useless to attempt true geometrical work with tiles of different gauges, for it is natural that unequally sized tiles produce unequally sized joints, however artfully a fixer may manipulate the lines.

The principal tiles used for flooring purposes are either plain or encaustic, the latter having the pattern on the same plane as the general surface of the tile, but set into it, as a species of clay inlay, before firing. The colours of plain tiles, as well as their sizes and shapes, vary to a considerable extent, and can be made up into an almost unlimited number of geometric patterns. As a general rule it will be found that the more simple the pattern for the general mass of the floor the better, diagonal and chess-board patterns being particularly objectionable, but a certain amount of richness is permissible in the borders. Rich panels of encaustic patterns may, however, be introduced, particularly in public buildings, and the chancels of churches, for which they have been used from time immemorial, usually with a red ground and yellow pattern, neither colour being too pronounced. A good example of an encaustic tile panel of this sort is given in Fig. 245, in which the red is shown in black and the yellow pattern in white, while examples of tiling, as applied both to floors and walls, are shown in Plate VII., which illustrates a series of designs by Messrs. Pilkington & Co.