How to Repair Exterior Wall Putty

1) The putty coating is too thick and cracked. Generally, the thickness of putty is 1-2mm, generally not more than 3 mm .. The flatness of some internal and external walls is poor, with an error of 3-5cm. If leveled with putty powder, it will definitely crack. Mortar shall be used for leveling. The greater the error, the thicker the mortar is required. Only when the base is leveled with masonry mortar and flexible mortar can the putty be completely qualified. 2) When the amount of inorganic binder (calcium lime powder and cement) is too large, cracks will also occur if the strength is too large. Generally, cracks will appear in waterproof putty for internal and external walls. When the addition of calcium lime powder and cement exceeds 50%, the strength of putty is too large, and the veneer is hard and brittle, which is easy to cause turtle cracks. In the past, glue was used in most parts of China (not 107 glue, which was stopped because of environmental problems), and old powder or exterior wall glue and white cement were added in whole batches, which was easy to cause peeling and cracking. 3) The paint layer of the internal and external walls is loose and dusty. If it is not solved, a whole batch of putty is covered with a layer of powder, which is easy to bulge and delaminate. If the sound of knocking by hand is different, with the change of external cold and hot temperature, cracks will appear slowly, and the cracks will crack in the direction of empty drum. When you open the crack, you will see that the putty and the bottom of the wall are two layers, with a layer of dust in the middle. To solve this kind of wall bottom, we must first look at the wall foundation. If the powder removal is serious, it must be removed, and the putty can be washed with water before scraping. If it is not too serious, the surface layer can only be filled with putty after brushing glue. 4) The formula is unreasonable. Generally, when designing the formula, it depends on the requirements of the project, whether it is internal wall or external wall, rigid or flexible. Whether it is putty or thermal insulation mortar, there is a law: strength and flexibility are inversely proportional. The greater the strength, the worse the flexibility, and the easier it is to crack. Different strength and flexibility require different rubber powder. There are many kinds of rubber powder with different uses. For example, the rubber powders SP 1026 and SP126 provided by our company to customers have high strength and cost per kilogram 17 yuan, which are suitable for interior wall toughening, exterior wall waterproofing, bonding mortar and tile bonding mortar. If flexible SP 1 126 is selected, the properties of cement and quicklime powder will be changed, the flexibility will be increased and the anti-cracking effect will be enhanced. 5) Correct selection of filler materials is also a very important aspect to solve the cracking of putty powder. The flexible filler includes sepiolite powder, talcum powder, mica powder and wollastonite powder. These fillers can increase flexibility and reduce cracking, which is the most effective way to reduce the production cost of putty and mortar. The more latex powder, the stronger the crack resistance. We have a customer in Ma 'anshan who used Wacker's rubber powder to raise it to 40kg per ton, and the cost of polishing rubber powder was per ton 1.300 yuan, and the cost of cellulose, additives, cement, sand and Shuangfei powder was 2,000 yuan, but it still failed to reach the flexible putty. 5, improper equipment selection, uneven mixing, leading to cracking, such as the use of vertical equipment, mixing time is too long, where there is more cement or quicklime, it will crack. Because the manufacturers of putty powder do not agree with the choice of equipment, they think that as long as it is a blender, materials with different specific gravity and addition amount are very important to the accuracy of the blender. For example, adding 3kg cellulose per 1000kg mortar requires 3‰ accuracy, that is to say, to achieve more than 99% accuracy, the general vertical feeder can only reach 90%. The special mixer for putty produced by our company can achieve this effect and obtain a patent. 6. Exterior walls facing the sun and the wind, that is, walls that are wet by rain, are generally prone to cracks. In particular, some walls often have rain flowing through them, which will definitely produce cracks, such as ①, ② and ③, which are often washed away by water; Due to the low-temperature rain flowing on the wall surface of a batch of walls under the high temperature in summer, the wall surface that expands with heat and contracts with cold repeatedly is bound to crack.