Maybe there's something wrong with your mortar. Mortar: A binding substance used in the laying of bricks on buildings, consisting of a certain proportion of sand and cementing material (cement, stone plaster, clay, etc.) and water, also called mortar, also known as sand mortar.
Mortar is made of cementing material (cement, lime, clay, etc.) and fine aggregate (sand) mixed with water. Commonly used are cement mortar, mixed mortar (or cement lime mortar), lime mortar and clay mortar.
The inorganic cementing material is mixed with fine aggregate and water in proportion, also known as mortar. Used for masonry and plastering works, can be divided into masonry mortar and plastering mortar, the former is used for bricks, stones, blocks and other masonry and component installation; The latter is used for plastering the surfaces of walls, floors, roofs and beam and column structures to meet the requirements of protection and decoration.
Ordinary mortar materials are also prepared with gypsum, stone plaster or clay mixed with fiber reinforcement materials and water into paste, called ash, paste, mud or mastic. Commonly used are hemp ash (stone ash mixed with hemp), paper ash (stone ash mixed with paper), gypsum ash (stone ash mixed with plaster of Paris and paper or glass fiber, etc.) and mixed plaster (clay mixed with a small amount of lime and wheat straw or straw). I hope I can help you shed some light.
The quality of raw materials is the main factor affecting the construction quality. The cement quality does not meet the quality inspection requirements, and the cement label is insufficient. The sand particle size is not good, the mud content is too large will cause the mortar strength is insufficient
Water cement ratio, cement sand ratio is too large. In the construction, the ratio of the bottom plaster is strictly according to the ratio of 1∶3 cement mortar, and the ratio of the surface layer is strictly according to 1∶2.5. In order to save cement, some construction teams arbitrarily expand the proportion, or in order to facilitate construction, increase the workability of mortar, and add white ash paste. There are also the use of expired cement, and even caking cement, which will make the strength of cement mortar too low, forming sand phenomenon.
In the construction, it should also be noted that cement mortar should be mixed with the use, can not be stacked too much,3h ~ 4h can not be used up, has been the initial setting or close to the final setting of cement mortar, must not casually add water to continue to use, these practices will cause the strength of cement mortar is too low, the formation of wall plaster layer sand base treatment is not pass. Before the construction of anti-cracking mortar, the base is treated carelessly or even does not do any treatment, resulting in damage and weathering.
The cement sand wall is washed off after it rains because the construction material of the cement sand wall is a mixture, which contains water, and when the rain is wet, the water will penetrate into the mixture, causing the mixture to become loose and easy to fall off.
Because of the phenomenon of soaking water, after the cement and sand walls are built, due to the relatively small proportion of cement and tofu slag engineering, it is washed away when it rains, and the sand will have the consequence of falling quickly
Improper construction: During the construction process, if the scraping coating of the wall is not scraped or not sufficiently smooth, this may cause the cement wall to sand off. If the bottom wall is not handled properly, it will cause the paint to detach from the bottom wall when drying.
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Cement quality: The quality of cement is also a key factor that causes wall sand to fall off. Using low-quality cement can cause walls to fall off and sand to fall off. Using expired cement can lead to the same problem.
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External environment: The external environment will also cause the cement wall to sand off