1, check the crack size, and clean around the crack. When maintaining, try to operate in sunny days. 2, the crack is not very big, you can use the method of surface repair, with a special adhesive through the compressor to fill up the crack. Some cracks can also be filled with epoxy resin or glass glue. 3. If the crack is wide and the surface repair is useless, it needs to be filled with resin mortar. Before filling, all sundries, dust and stones in the gap must be cleaned before operation. In addition to resin mortar, ordinary cement mortar can also be used for filling. Paint cracking reason: 1. The cause of roof paint cracking may be related to the paint itself. The roof is exposed to high temperature and rain for a long time, and the internal relaxation of its building materials causes the paint to widen on the original basis, resulting in unevenness and cracks. 2. The bottom gypsum is scraped too thick and uneven, or the amount of bottom gypsum and putty is too small and the adhesion is not enough, which may also lead to cracking during use. 3, wall problems, construction problems, and roof structure settlement, cracks in its structure and building materials will extend to the wall, which seems to be cracks formed by latex paint. Once such problems are found, they must be dealt with in time.