NATURAL TILE

Tile is one of the oldest roof materials in the world used by people more than 4000 years. The beauty of the shape and colour has served a model of architectural image of a roof for thousands years. Even ancient Greeks and later Romans used marble and potter's tile. The recipe of tile was created by nature itself. Mixing limestone, sand and water, people got a particularly stable material.

Modern technology is also based on the usage of raw materials. Quartz sand and water are mixed with cement, which has substituted limestone and clay. The received mass is pressed under pressure and dries without the usage of firing and becomes firm due to the hydration of cement, which is present in the mixture. It's much cheaper than ceramic tile. To get a desirable shade of colour pigments, are used, which are received from oxides of the metal, the oldest due known to the mankind since the old times.

We must notice that clay (ceramic) and cement-and-sand rolled tile may be called "natural" as clay (to be more exact clay-carbonate marls) serves as a raw basis of cement.

Englishmen began to produce analogical roof covering in 1820. But cement-and-sand tile became widely spread in Europe in the middle of the XXth century when its appearance was polished so much that it was impossible to differ of from clay one.

Cement-and-sand tile has been in great demand during the last decades. Though natural ceramic (clay) tile has been preserved on the market, new types of false tile made of other materials: metal (metal tile) and on the basis of bitumen (soft tile) have appeared.

Today in the west in a new building and repairing natural tile occupies 86%, metal tile - 3%, other roof materials - 11%. Tile may be used for stone, brick and wooden buildings as in new construction and while being reconstructed. Modern tile (both ceramic and cement-and-sand) affords to fulfill pitched roofs of any difficulty from simple two-pitched roofs to the most complicatedly shaped roofs: hipped roofs with attics and attic windows - round-shaped towers with conic forms and many other roofs. It is possible to build angles or arched forms, eaves, gutters on the roof.

There is an opinion that the main limitation in the usage of tile is its big weight what requires the construction of high-capacity rafters. However, it is not really so. The share of the own weight of tile concerning the calculated load on the construction of the roof is not so great in comparison with the load of snow for instance. A simple comparison shows that the calculated load for roofing made of cement-and-sand tile is 25-30% higher than for simple metal coverings. When using tile it is not necessary to increase a section of rafters, it will be enough to install the same rafters with a lesser step. For example, for metal roofing you need rafters 150 x 50 mm with a step 90 cm; for tile roofing - 150 x 50 mm with a step 70 cm.

As for "excessive", according to some mistaken viewpoint, weight of tile it may be considered as its advantage, realized necessity. Technologically the weight of tile can be lighter but it is not done for the sake of wind-steadiness. Thanks to its weight it protects the roof and the whole building from wind and outer forces. When the other kinds of roofing are carried away from roofs by the wind, a tile roof is always untouched by different strong winds. When engineers of the German concern "Braas" proudly demonstrated the models of rather thin and light cement-and-sand tile to German federal building committee, it turned out that they violated the norm of wind-steadiness. They had to write off the expenses and readjust the equipment for the production of articles with normal thickness, weighing about 45 kg per 1m2, as it is required by the norm.

TECHNICAL CHARACTERISTICS

Both ceramic and cement-and-sand tile are one of the most durable roofing, the exploitation period of which is more than 100 years. Tile is not sensitive to any influence: heat and frost, hail and hurricanes, oxygen of the air, acid rains, the activity of bacteria and the plants of the lowest development, ultra-violet radiation and infra-red radiation of the sun etc. In comparison with metal roofing, there is less possibility of a lightning getting into the roof, as the roofing does not collect static electricity, which is dangerous for a man and possible to cause fire.

Tile roofing easily adapts to inevitable deformations at a seasonal subsidence of buildings and fluctuation in temperature - the role of temperature joints is performed by tile joints. By the way, the joints of such type provide effective airing of under roof space from excess of vapor of every-day moisture, which is very active during a cold season and at a day overfall of temperatures. As we know, the condensate is a main enemy of wooden and metal constructions of a roof. It is rather cool under such roofing in summer and warm in winter because of low thermal conductivity. Low thermal conductivity combined with massive material provides the minimal formation of a condensate on the internal surface of a tile covering.