After cracks appear, first of all, we should analyze how the cracks are caused, find out the defective pipe fittings, and then make a rest plan, and don't blindly construct. Otherwise, you may fall into a vicious circle of tinkering.
Second, the paint surface crack repair
If only linear, polygonal or uncertain cracks are produced on the ceiling paint film, then the problem is not very serious. The reason may be that the primer is too thick or not dry repainted, the substrate is too loose or rough, and the primer and topcoat are not matched.
Repair measures: remove the affected paint film; Ensure that the paint film of a construction is not too thick; Ensure that the previous paint film is dry before repainting; If necessary, seal the substrate with a suitable primer; For substrates with large roughness, it is recommended to use products with good flexibility; When the base temperature is lower than 5℃, latex paint cannot be constructed; Primer and topcoat should match.
Third, the ceiling cracks caused by temperature changes.
If cracks are caused by temperature changes, they usually appear on the surface and will not affect the safety of the ceiling, so the surface can be treated.
Small gap: If the surface gap is not large, it is recommended to stick a layer of kraft paper on the gap and then brush the top coat.
Wide gap: If the surface gap is wide, it is best to cut out a gypsum board, polish it into a suitable shape, fill it in the gap, and then paint it.
Fourth, the ceiling cracks caused by improper construction.
If the cracks in the ceiling are caused by improper installation and construction of the ceiling frame and gypsum board facing, then in the maintenance, we should start with the inspection of the keel, deal with the quality problems at the grassroots level, and then do the facing article. But the next step is not simply to repair the joint with putty, but to open several lath joints on the plate near the original joint and repair them at the same time to eliminate the deformation under the action of internal stress.
If the problem is serious, the original ceiling board has been deformed, bulged and damaged, the demolition area should be appropriately expanded, the keel should be leveled, replaced with a new board, paved in blocks according to the size of the area, and the subsequent repair work of the operation surface should be completed according to the normal construction steps.