It is important to know!!! On any roof it is necessary to spend necessary maintenance service, for long service life. At least 2 times a year - are desirable in the late autumn, after subsidence of leaves and in the spring. Roofs should be cleared of leaves, dust and a moss. It is necessary to clean on a regular basis places of a congestion of water, water-drains and joints of a flooring with sewers and so on...