"Where tiling or mosaic is used for the upper floor in wooden construction, special preparation will be needed to obtain a thick bed of concrete or bricks under the tiles. To do this the rough floor must be let down between the timbers, and supported by strips nailed to the sides of the floor beams, as shown in Fig. 184. A bed of at least 4 inches should be provided, and the beams should be cut off to a bevel on top as shown. Even then there is a tendency for the tiles or mosaic to develop a crack over the beams, and so metal lathing is often used to prevent the concrete bed from cracking. This preparation is necessary for old floors which are to be tiled, or where the tile floor covers only a portion of a new floor, but when the whole of a new floor is to be covered with tiles, and there is nothing to prevent, it will be better to set the floor timbers enough below the finished level to obtain the same result. (Fig. 185.) Narrow boards should be used laid 1/8-inch open to allow for swelling. &8226;

To prevent the moisture in the concrete from being absorbed too quickly by the boarding, and to guard against dripping, two thicknesses of tarred paper may be spread over the whole surface before the bed is laid, and the use of corrugated metal lathing is sometimes advisable. The preparation of wooden walls for tiling is more simple. Here it is only necessary to provide a firm and continuous sheet of plaster upon which the tiles are bedded. This may be done by cutting in between the studs, horizontal pieces two inches by the width of the studding and about a foot apart, upon which metal lathing is nailed; and a rough bed of cement mortar is spread upon this, allowing room for the proper bedding of the tiles. (Fig. 185.) Hair should be used in the cement mortar on wire lathing.

Fig. 184. Old Floor Prepared for Tiling.

Fig. 184. Old Floor Prepared for Tiling.

Fig. 185. Floor and Wall Tiles.

Fig. 185. Floor and Wall Tiles.