BURNED CLAY AS ROOFING MATERIAL.* Under the head of burned clay as a roofing material, the word tile expresses the material it is made of, how it is made, and its uses. "The Century Dictionary" defines the word tile as a thin slab of baked clay used for covering the roofs of build ings, etc. A thin slab of tin, iron, or metal of any kind is not tile. Tile is burned clay as a roofing material, and nothing else, and that is what I want to occupy your attention with for a few minutes.
Edward L. Morse published a series of articles in the Ameri can Architect, in 1892, on the older form of roofing tiles, that are exhaustive in tracing their history. He traces their use back to China, several thousand years before Christ, and says they were made even before the sloping roof was first used. Palm leaves, straw, and the bark of trees formed the first cover ings for sloping roofs, and then came terre-cotta tile, made in the form of bark, with the larger pieces curving upward, and smaller pieces to cover the joints. Relics of these ancient tiles are found in the art galleries in Berlin, Dresden and London. The articles are illustrated with cuts of tiles made in different countries, and it is a remarkable fact that tile are made and used in this country to-day of the same general form that was used four thousand years ago.
In his classification, Mr. Morse shows that the Normal (Asiatic) tile were used in the Orient, Ancient Greece and Italy, China, India, Greece and Italy, the Pan (Belgic), in England, Scandinavia, Belgium, Holland, Japan, Java and various modern countries ; the Flat (Germanic), in Germany, Austria, Hungary, Poland, Switzerland, France and England.
In the shape and form of these tiles you will see the same shapes and forms most generally used to-day, both in Europe and America. It is shown that these old forms of tile are bedded in mud and clay—it is necessary in laying most of the tiles made at this day to bed them in cement. The most ar tistic tiles are found in China, Korea and Japan, where they are highly glazed, in different colors, with very elaborate finishings, making a very showy and ornamental roof.
The old form of tile were made of material the most endur ing of man's fabrications, and the terra-cotta roof tile, when properly made, is, all things considered, one of the cheapest and most durable. Acting as a non-conductor, the upper portion of the house, under a tile roof, is warmer in winter and cooler in summer. Slate absorbs and transmits a great deal of heat. Shingles are short lived, and a menace in times of conflagration. With the best tile clays in the world, and an abundance of the unskilled labor usually employed in making tile, there is no reason why roofing tile should not come into common use in this country, as they have in all other parts of the world. These are the conclusions of Mr. Morse, and after an exhaustive inves tigation of tile roofing I must say that I fully agree with him.
In " the Encyclopedia of Architecture and Construction," A.
Rospide has an article on roofing tile in France, which gives a good description of the latest improvements. He divides his article on Roofing Material into four parts : first, Clay; sec ond, Stone ; third, Metallic ; and fourth, Wood—giving the preference in the order named. In speaking of the manufac ture of tile, he says it is still carried on just as it was before the development of machinery. The clay must be selected with great care, reduced to a paste, run into a plaster mould, then dried and burned. This necessarily makes the tile thick, and requires a great deal of trimming and handling. The simple and flat tile was long ago almost universally superseded by the lapping and interlocking tile. He says the following are requi sites of every good roofing material : 1st. It must exclude moisture, which rots wooden frame work.
2d. It must be capable of withstanding the forces of the wind, and must admit of provision for all expansion and con traction consequent upon variations in temperature.