After the walls were whitewashed, they cracked after a few months. Why?

The problem of wall cracking caused by various reasons emerges in an endless stream, and here it is divided into 5 categories, so let's explain the performance and treatment methods of wall cracking caused by different reasons, let's take a look.

1.Cracking of the wall structure.

Cracks in the structural layer of the wall itself will also cause cracks on the exterior wall. There are two conditions, one is that the original wall itself has cracks, and no appropriate treatment has been taken in the later decoration process; Second, there is no cracking in the original wall during decoration, but cracks will occur in the later stage due to uneven foundation settlement and large temperature changes.

Suggestion: This kind of cracking cannot be repaired by ordinary decoration methods, and it is necessary to find professional building structure personnel to take corresponding measures according to the actual situation.

2.Cracks in the seams.

Cracks in the bottom layer of wall joints can cause cracks in the wall layer. The cracking of the joints mainly occurs at the joints between the reinforced concrete shear wall and the ceramsite bricks, the joints between the reinforced concrete beams and the ceramsite bricks, the doorways of the rear blocking, and the joints between the gypsum board partition wall and the original wall. Cracks at joints are mainly due to the influence of the surrounding environment or external forces, gypsum boards, prefabricated partition panels and prefabricated floor slabs will show shortening and azimuth changes, resulting in cracks at joints, usually vertical or horizontal.

Suggestion: It is recommended that the whole building should be repaired after the deformation trend is stabilized, and the repair within a short period of time is prone to recurrence.

3.The putty layer cracks.

Wall scraping putty can make the wall more lubricated and delicate, and the flatness is much higher than that of the cement wall, so that the wall paint effect is better, and at the same time, it also saves paint. If the putty layer cracks, it will simply cause the surface layer to crack. Therefore, it is necessary to pay attention to prevent cracks in the putty layer during construction.

Suggestion: If the crack has penetrated deep into the putty layer, you can first use a sharp tool to expand the crack to a cone size, then fill in the caulking plaster and polish and level, paste the mesh cloth or kraft paper and then use putty for leveling, and finally paint or paste wallpaper according to the normal process.

4.The plastering layer cracks.

The cracks of the wall plastering layer are divided into two types: normal cracking and abnormal cracking, and normal cracking mainly refers to the cracks in the plastering layer caused by the shortening of cement mortar; Abnormal cracking is mainly caused by cracks caused by improper construction technology. Normal cracking is difficult to prevent, but abnormal cracking can be avoided.

Suggestion: If there is a large area of hollowing in the plastering layer, the original plastering layer should be knocked out, the plastering layer of cement mortar should be redone, and then painted according to the normal process after leveling. However, the cost of this treatment will be relatively higher.

If there is only a small area of cracking, there is no sand, hollowing, or falling off, you can paste the mesh cloth all over the wall, and then paint it according to the normal process.

5.Cracking of the paint layer.

The cracks on the wall surface caused by the cracking of the wall paint layer are mainly caused by the poor quality of the wall paint products and the improper operation of the wall paint construction process.

Suggestion: If it is only a crack in the surface paint film, use fine sandpaper to polish the crack, choose the same color wall paint, and repaint it.

There are two possibilities for cracks. The first is that there is no primer, only a topcoat. The topcoat is brushed directly on the wall and adheres unevenly, so cracks appear.

The second is to paint the primer, but there is an infill wall at home, that is, a non-load-bearing wall, because the non-load-bearing wall and the load-bearing wall were built at different times, and there is no steel bar in it, the density is not the same. Before decoration, a V-shaped opening should be shoveled at the interface between the non-load-bearing wall and the load-bearing wall, and then painted with latex paint until it is level with the wall as a whole, and then brushed with primer and topcoat, so that there will be no cracks. If Wang Xian has cracks now, he can only shovel it and start over.

Suggested workaround:

1. If there is peeling or cracking in the front, it is generally a problem with the latex paint, and you only need to remove the peeled part, then re-apply the primer, and then brush the latex paint to solve it.

2. If the wall is eroded by moisture, there will also be cracking, generally the waterproofing of the wall is not done, you should buy waterproofing agent or waterproof material to recoat the wall, you can solve the problem of water seepage on the wall.

3. If the wall is slightly cracked, it may be because there is a problem with the application of this layer of putty. It is necessary to re-polish the putty layer, and after the putty is repaired, it can be solved by doing it again according to the previous process.

After the painting of the wall cracks, can be repaired according to the size of the cracks, for small cracks can be smeared with toothpaste, the cracks are filled with a small blade, and sandpaper is used to polish them after completion; For larger cracks, use putty paste to fill the gaps, modify the edge of the gaps to a smooth degree, and then polish them with sandpaper to paint the latex paint of the same color as the original wall. The reasons for the cracking of the original wall: 1. It may be that the workers operate improperly, or the workers cut corners during the decoration and cause the original wall to crack.

2. It is also possible that after the putty layer is not completely dried, the latex paint will be painted, and the wall paint will crack, and in serious cases, it will cause a large area of peeling. 3. After the new house is delivered, it is necessary to open the window for ventilation for up to three months before decoration, so as to ensure the dryness of the indoor wall. 4. When the house is decorated, the walls should be waterproofed, especially near the bathroom, once the water pipe is broken, the wall will be flooded.

5. It is very easy to cause excessive moisture in the house, and the excessive moisture invasion will not be discharged in the wall, which will cause the wall to appear alkali cracks.

Generally speaking, there are several reasons for wall cracks: First, the concrete is not dry after the delivery of the new house, and the owner is in a hurry to decorate, because the undried concrete contains water, and the putty powder also contains water, and after the putty is dry, there will naturally be cracks. Second, there is a hollow drum phenomenon on the mold wall, which is caused by the construction of the wall powder wall, the loss of cement is low, you can dig it out at the cracks, knock it, and pick it by hand to see if it can be moved, the wall of the hollow drum is easy to crack, and it is easy to fall off. Generally, this situation should be noted when approving putty, in the Dankong vertical specification, a very small amount of hollow drums are allowed, if there are many hollow drums, it is regarded as unqualified projects, and you can find the merchant to settle accounts.

Third, the wall is uneven, putty powder is thick, this is the painter's problem, because the wall is uneven, the painter does not ensure that the wall is flat, putty powder will be thick, but also cracks, in fact, this reason can be avoided, experienced painters will add a layer of grid cloth in the batch.