The cause of cracks in wood beams of new buildings is temperature cracks: for masonry structures, there is mutual constraint between floor and masonry. If the external temperature changes and the temperature between floor and masonry deforms, masonry will produce temperature stress; Cracking of latex paint: If the surface paint film cracks.
The treatment method is to clean the board joints, sew them with 1: 2 or 1: L cement mortar socks, and flatten them for maintenance. When the crack is large, a splayed groove should be chiseled along the crack. After cleaning, use 1: 2 cement mortar as the base, or repair it with epoxy mortar.