If the foundation is not sufficiently solid, lay, as evenly as possible, a bed of concrete, composed of one part of finely riddled quick-lime, and three of gravel, and bring it to a perfectly level surface by a thin coat of cement, allowing about three-eighths of an inch more than the thickness of the tiles for the cement to be used in bedding them. In tiles of half-inch substance, the level surface of foundation should be brought to within from three-fourths to seven-eighths of an inch of the intended surface of pavement, and for tiles of inch substance, to within one and a-quarter inches of the intended surface.

In preparing concrete foundations, the introduction of lumps of unslaked lime should be carefully avoided, as they are liable to swell and displace the pavement.

A good foundation may also be prepared by laying an even layer of bricks; or if the tile pavement is to replace a pavement composed of flags or stones, they form an excellent foundation when lowered to the required depth.

Wood floors in upper stories may be readily replaced with mosaic, the foundation being prepared by nailing fillets to the joists at three inches from the upper surface, and the floor boards sawn into short lengths, and fitted in between the joists upon the fillets; concrete may then be filled in flush with the upper face of the joists, and faced with the coat of cement before mentioned. The tiles and cement will occupy about the same space as the floor-boards they replace.

Tiles should on no account be laid on boarded floors without the intervention of concrete, as they are certain to become loose within a few weeks of being laid.

Spaces intended to be occupied with a sunk door-mat should be surrounded by either a wooden or stone kerb, from two to three inches wide, and the sunk space may be paved with plain tiles, or boarded. In giving dimensions of "mat space", it should be stated whether the size is inclusive or exclusive of the surrounding kerbs.

Where spaces to be paved are interrupted by a step, a stone nosing, at least three inches wide, should be provided for the tiles to finish against; a convenient arrangement is to have the whole riser of step composed of stone (see Fig. 1) ; or a tile may be inserted in the face of the riser (se Fig. 2).

In giving dimensions of spaces to be paved, the exact width of the stone nosings of any steps should be stated.

Either Lias, Portland, or Roman Cement of good quality may be used, but Lias is preferable, and may be mixed with about one-third of its bulk of good sharp sand. No cement that is very quick in setting is suitable, as it does not afford sufficient time for the proper adjustment of the tiles. Half a bushel of cement to a square yard is sufficient for facing the foundation and bedding the tiles.

Sand employed for mixing with the cement should be sharp, and free from loam.

Some of the sand in the neighbourhood of Manchester, and other parts of Lancashire and Cheshire, contains fragments of a tarry, bituminous substance, which produces unsightly stains on the tiles, and should be carefully avoided. In this it is recommended to lay the tiles in pure cement, without sand.

After carefully marking out the position of the several parts of the design (which should be previously ascertained by laying out temporarily a part of the pavement) in chalk lines on the cement surface of the foundation, the part of the space first intended to be laid should be included by strips of wood, or guides (A A and B B Fig. 3), about four inches wide, fixed with nails on the foundation, and of exactly the thickness of the tiles and the cement used in bedding them, the cement having been spread of the right thickness within this space, and levelled with a piece of wood, thus. The tiles, after having been thoroughly soaked in water, may he placed upon it, and beaten down to the level of the guides, under a flat piece of wood, with a mason’s hammer or mallet, the joists being at the same time carefully regulated with a small trowel.

By this process the whole of the tiles will be brought to a perfectly even surface, and thoroughly consolidated with the cement, which the beating down regularly distributes under them, counteracting any slight variations in their substances, by depressing the thicker tiles, and floating upon the cement for displaced those that may be too low.

The evenness of the surface should be occasionally tested with a mason’s straight-edge, of sufficient length to bear on the guides.

The workman will have to use his discretion in determining the portion of the pavement it will be most convenient to commence upon. In regularly formed spaces, it will be best to lay a part of the general pattern across the whole width within the borders, in the centre of the pavement. This will enable the work to be symmetrically disposed; the borders may then be laid to it, after which, the general patterns may be completed within the borders. Care should be taken that the work is placed centrally with the space, so as to avoid having a wider margin on one side than the other. This can only be ensured by temporarily laying down a part of the pattern, and ascertaining the extra space the tiles occupy; the laying should then be proceeded with in every direction from the centre.

The foundation should he kept thoroughly wet whilst the pavement is being laid.

When the bedding is sufficiently hardened, mix some pure cement (without sand) with water to the consistency of cream, to run into the joints, taking care that what remains on the surface is wiped off before it dries hard. Cement or dirt should not be allowed to harden on the surface during the laying, and the pavement should be carefully covered up with a layer of saw-dust till the painting and all other work is completed. After first being laid, the pavements are liable to injury from the heavy traffic of workmen, and unless protected, may be permanently disfigured by paint stains and dirt.

When the tiles have to be cut, rule a line where the division is to be made, and rest the back of the tile on the sharp edge of a stone, immediately under the line, along which bruise the surface with a hard, sharp chisel; the parts will easily separate, after which, chip the back edge even.

It is recommended to remove the skirting boards from the walls whilst the pavement is being laid. When replaced, they should rest on the tiles; the trouble of cutting the outer tiles to fit against it will be avoided, and a much neater appearance produced than when the outer joint is visible.

An occasional washing with soft soap and cold water, applied with a scrubbing-brush, will give increased brilliancy to the colours, and will remove the saline scum which arises from the cement for the first few weeks after the tiles are laid. Stains or dirt adhering to the tiles from long neglect of cleaning may be readily removed by dilute muriatic acid applied with a piece of pumice stone. Care should be taken that the acid is all wiped off, and in every case after washing, it is desirable that the superfluous moisture should be wiped of with a clean and dry cloth. A little skim milk may be washed over the surface after it is thoroughly cleaned.