The main materials of the slope roofing are various: wood, bark, bamboo, thatch, straw, even stone, etc. But these materials have poor water resistance and short life, until the artificial firing of clay tiles after the emergence of real roofing materials. The so-called "qin brick and han tile" refers to the clay tile that appeared in China more than 2,000 years ago. Clay tile is mainly made of clay with less impurities and good plasticity. After water mixing, embryo making, drying and sintering, the clay tile can be divided into flat tile and ridge tile according to its use. According to its color, it can be divided into green tile and red tile. According to the national standard clay tile (gb1170-89), there are three types of flat tiles: I, II and III. The sizes of each type are 400mm x 240mm, 380mm x 225mm and 360mm x 220mm. The minimum folding load of a single tile shall not be less than 680N. The tiles covered with 1M2 roof shall not exceed 55kg after water absorption. After 15 times of freezing cycle, no delamination, cracking, peeling and other phenomena are required, and no water drop is required for impermeability. The ridge tile is divided into grade 1 and grade 2, the length and width of which are greater than or equal to 300 and 180 respectively. Clay is mainly used for slope roofing of civil and rural buildings.