1. The cracked part is not a cross joint or a straight joint before gypsum board construction. During construction, gypsum board is fixed by staggered joints and overlapping. If the cracking part is at the right-angle junction, it is the result of uneven stress; There is no joint at the right angle of the whole gypsum board, and the joint falls off at the straight ceiling. This phenomenon can't be handled well at the grassroots level. Be sure to brush the interface agent before blowing putty, and do a good job of basic treatment.
2. The position of the expansion bolt for fixing the lifting rod is selected incorrectly or the lifting point and the lifting point are stressed incorrectly. Another technique is that the expansion bolt and nut on the hanger and the screw nut fixed on the crane are screwed together, and the thread is damaged. The lower part of the expansion screw is hung with a hanger rod, and the upper opening is not fixed with a fixing nut.
3. The crack of gypsum board ceiling may also be due to the connection problem between the crane and the main keel. Due to the deformation or mismatch of the crane, the main keel is sandwiched in the middle of the crane and is not stressed at the bottom of the crane. Or the middle part is connected with the main keel and the lower part is connected with the main keel, resulting in a movable gap between the main keel and the auxiliary keel.
4. In addition, the distance between self-tapping nails for fixing gypsum board is too large or some self-tapping nails are not stressed, and the gypsum board ceiling expands with heat and contracts with cold, which is affected by wet expansion and dry contraction. The construction technology problems of caulking putty and adhesive tape will lead to cracks in gypsum board ceiling.
Next, let's take a look at how to deal with the cracking of gypsum board ceiling:
1. If it is caused by cracks, you can fill the cracks with caulking putty first, so that the caulking putty can enter the cracks, not just the "entrance" on the surface. After the surface is flat and dry, put a right-angle bandage on the crack, then batch putty, and brush latex paint after polishing.
2. When the ceiling elevation is the same as the beam bottom elevation, gypsum board must pass through the beam bottom. The advantage of this is that there is no interface, which will effectively reduce joints and prevent cracks. In addition, gypsum board should pass through the lower part and side of the beam when dealing with the ceiling elevation and the horizontal hole of the beam. Leave the seam on the edge, so that there is no bottom plate for the seam, which will reduce cracks and maintenance rate. I-shaped gypsum board is sealed at the corner of wooden keel of ceiling to prevent cracks. Leave seams on both sides of the ceiling and make them figure-eight, and then fill them with Lafarge or gypsum powder.
3. After leveling, the ceiling of keel gypsum board becomes uneven under the action of external force, resulting in stretching, deformation and cracking of the covered gypsum board. The solution to this problem is to attach importance to structural construction and take some necessary measures. This situation is more harmful and difficult to repair, so we must pay more attention to it in construction.
4. Plasterboard ceiling cracks can be filled with putty to repair the joints, and try to let them dry thoroughly before sticking the joint tape. In the process of drying, a small amount of caulking putty may shrink and crack. It is suggested to fill the putty before sticking the seam belt, and then polish it with fine sandpaper to dryness.