Tiles, as compared with slates, are a more expensive roof-covering material, not only from their composition and manufacture, but also on account of the extra trouble and battens they require for their smaller size. They also require that the roofs be of a steeper pitch, and no less than 45 degrees rise from the horizon, for the reason that any less pitch is subject to the liability of making the tiles absorb the rain instead of throwing it off. Again, the roofs for tile-coverings must be constructed of greater dimensions and strength, on account of the greater weight of the tiles, as compared with slates.
Against these disadvantages of tiles must be set their greater ornamental appearance, and their action as non-conductors of heat, and also their colour; these are all great considerations in their favour, even although they are sometimes, when absorbent, apt to hold the wet.
Tiles are made of a strong clay which has been specially mellowed, and beaten when half dry to prevent warping, and they are ail of one size, 10 1/2 inches long, 6 1/4 inches wide, with 2 nibs or projections at the shoulder or top edge, on the underside or bed, as Fig. 511, to hold them up over the battens, and they should be curved slightly, to make them fit over each other the better.
There are several kinds of tiles for roofing besides the plain tiles, but they are all made out of the same material. A good tile should be hard, well burnt, well shaped, non-absorbent, of good colour, and with a glazed or vitrified face to prevent vegetation. The best tiles are made at Ruabon, in Wales, though they are also largely made at Broseley and Madeley Wood, in Staffordshire. They can be of innumerable colours, from red to blue and yellow.
Ridges, hips, and valley tiles are also made of clay, to the required pitches; and the former to almost any design.
Tiling is subject to the same rules and regulations as slating, in regard to lap, gauge, bond, battening, double eaves, etc, so hat it is needless to repeat those details.
Fig.. 512 is a plan and section of a few courses of plain tiling laid to a 2 1/2-inch lap or 4-inch gauge. The tiles are generally secured merely by the lugs over the battens; but in very exposed positions they are sometimes nailed, though this is very expensive, besides which the tiles must be made with holes for that purpose, in the process of manufacture. Special tiles are made for double eaves and ridges, to save cutting; and "tile and halfs " for gable ends, where, for purposes of bond, half-tiles would otherwise have to be used; and these being only 3 1/2 inches wide, they would make very imperfect work, which is obviated by the use of "tile and half."
Pantiles are peculiar-shaped tiles, used in some parts of the country for roofs, but now only for common work. Fig.. 513 is an illustration of one tile.
Corrugated tiles are similar to the last, but with more hollows or corrugations, as Fig.514.
Wade and Cherry's are a patent tile of ornamental appearance, similar to Fig.. 515, rebated at the head, on the top side, and on the underside at the tail.
Taylor's patent tiling, as Figs. 516, 517, and 518, consists of channel and capping tiles of special patterns, which fit over one another in alternate rows, from eaves to ridge, as shown. It should be noted that the same tile can be used as channel or capping tile by being reversed. They have a very novel and pleasing ornamental appearance.
Italian tiles are illustrated by Figs. 519 and 520, which explain themselves, and give an idea of their effective appearance in work; though it will be seen that they are anything but well adapted to our snowy climate.
The plain tiles are often banded with ornamental tiles, as Fig. 521, which break the monotony of a plain-tiled roof considerably; and these bands are sometimes laid in blue-coloured tiles, while the plain are red, and vice versa; but this is unadvisable, on account of the different nature and properties of the different varieties of tiles to withstand wet, frost, etc.