In an asphalt shingle a layer of impregnated fibreglass is enclosed between two layers of bitumen. Consequently, the shingle is dimensionally stable, is not affected by high temperature changes and remains perfectly impermeable.

The top layer is then coated with ceramised granules, which protect the bitumen layers from UV rays and colour the shingle. The granules are coloured by means of a ceramisation process which is done at extremely high temperatures, while the use of inorganic pigments guarantees that the colour won’t wear or wash off. A layer of siliceous sand prevents the asphalt shingles from sticking together and allows them to be transported and handled more safely in building yards.

The tiles are reinforced with a layer of fibreglass: long and exceptionally resistant fibreglass threads are bound by non water-soluble resins. The fibreglass used by Tegola Indonesia is particularly heavy (10.500 kg/sqm). This confers the finished product added mechanical resistance that exceeds the standards defined by international norms. During the production process, the fibreglass is always impregnated with bitumen, so that the finished product is less absorbent and hence contains less humidity.

Tegola Indonesia shingles are made exclusively with natural "Tia-Juana" bitumen. This bitumen is exceptionally resistant to UV rays and to daily temperature changes.

The ceramised granule coating efficiently protects the internal waterproofing bitumen layers of the asphalt shingles from UV rays. These granules are made from basalt, which is a particularly resistant rock. A ceramisation process inside furnaces at extremely high temperatures vitrifies the inorganic pigments completely, thus dyeing the granules, and ensuring that the colour won't wear or wash off.