How to repair the cracks on the wall?

First, we must find the cause of the crack. If it is an expansion joint between a structural wall and a brick wall, it is generally necessary to completely remove the base during maintenance, clean the gap, and then inject epoxy resin into the gap until the gap is filled, and then do subsequent treatment. If the cement paint layer cracks, it is usually because the proportion of cement and yellow sand is wrong when plastering the wall. For this kind of crack, it is only necessary to remove the crack of the putty layer exposed from the cement paint layer, and then paste it directly with carbon fiber anti-crack cloth.