The use of those plates of baked clay which we call tiles, is nearly as ancient as that of bricks, but, on account of the state of ruin of the ancient buildings belonging to civilisations before the Roman period, it is difficult to ascertain what kind of roofing covered them. On the other hand, all the necessary materials exist for observing the manner in which the Romans used their tiles, fragments of them being found wherever Roman dominion extended.
They used two kinds of tile. Some rectangular and flat, and furnished with flanges, were 12 to 15 inches long and 8 to 10 inches broad: these were called tegulce; the others, called imbrices, were semi-cylindrical in shape. The tegulae were fixed on the roof by means of notches in the flanges which were placed in the direction of the slope of the roof; the imbrices covered these flanges and were held at their lower extremity by a larger tile (antefix) which was fixed to the cornice and had one end generally decorated.
The Latin buildings were covered with tiles of Roman shape, but generally defective, except in Italy, where they were well made.
Up to the 11th century the Roman roofing with its flat rectangular tiles and curved covers was still preserved in the south of France, but after that period the trapezoid shape was substituted for the rectangular.
In the north, Roman tiles had been given up as offering too much hold to rain and wind, and had been replaced by-flat tiles furnished at the top with a flange which attached them to the laths. Roman buildings which were roofed with tiles generally had their ridge-pieces decorated with terra-cotta ornaments.
The 13th century saw the introduction of two kinds of tile called "Champagne"; the ordinary ones were .35 x.215 metres, were slightly convex in order to give less hold to the wind, and were furnished with a hook, instead of a flange, to fasten them to the laths, and with a hole by which they could be nailed to the rafters, these latter being placed at distances apart equal to the width of the tile. The second kind, called Comte Henri, were of smaller dimensions than the others, but were still better finished and usually enamelled on the uncovered part. We may mention, among important roofings executed with these tiles, the cathedral at Troyes, the chapel of the Abbey of Saint-Denis, the chateau of Beaute-sur-Marne, etc.
In Nivernais and Poitou, tiles in the shape of shells were manufactured at that period, .50 x 165 in dimensions, and having three flutings to carry away the water.
The Ƨ-shaped tiles, called Flemish tiles, still used at the present day, date from the 15th century, and were generally used at that time.
In the south, the flat Roman tile had been abandoned, and the roofing was done entirely with curved tiles, the channel tiles being simply cover-tiles turned upside down; it was the Flemish tile, but in two parts. This system of roofing still remains in the whole of the south of France as far as the Vendee.
The ridges were covered with ornamented tiles usually varnished; at the ends were placed spikes which were sometimes real monuments, especially in the 14th century.
From the 15th to the beginning of the 19th century, the tile industry in France made no improvement; on the contrary, the tiles during this period were roughly fashioned and poorly baked. In 1851 the invention was made which revolutionised tile-making, and raised it to that pitch of perfection at which it stands to-day. We refer to the invention of machine-made fitting tiles; this was a French invention due to the brothers Gilardoni of Altkirch in Alsace.
Up to that time tiles had only been made by hand, and the introduction of machinery for their manufacture brought with it rapid improvements which considerably extended the use of these products for the roofing of buildings. If many flat, hollow, or Flemish tiles are still made, it is almost entirely for maintaining existing roofs.
The preparation and choice of the clay for the manufacture of tiles should be performed with even more care than for that of bricks. The clay should have been weathered, should be sufficiently rich to prevent the tile from being too porous, and should be well separated.
Fig. 368. - "Planchette".
Fig. 369. Mould for Flat Tile.
Fig. 370. Mandrel for making Curved Tiles.
"planchettes" (Fig. 368). For the demoulding is done on the table itself by raising the mould when the excess of clay has been removed with the "plane." The boy takes away the "planchette," and on his way forms the hook by raising with his thumb the small portion of clay moulded by the notch, then he deposits the tiles side by side on a well-levelled and sometimes paved space. When the clay has attained a sufficient degree of consistency, it is taken to the drying-rooms, and after it has become firm enough it is stamped and curved; this is done with a wooden beater, the workman being seated on a bench in front of the tiles. The seams having been cut off and the edges dressed, the tiles are placed in the drying-sheds to complete their desiccation, which takes from a week to a fortnight according to atmospheric conditions. Curved tiles are made by bending the flat slab over a mandrel of suitable shape.
A large number of special tiles, such as ornamented ridge-tiles, end-pieces, finial-pieces, etc., which are used with machine-made tiles, are also made by hand in plaster moulds of the desired shape.