How often is the external wall cleaned?

Speaking of exterior wall cleaning, I believe everyone is familiar with it. Maybe everyone will immediately think of Spider-Man. Yes, high-rise buildings can be seen everywhere in Jinan, but the outer walls of some high-rise buildings facing the street have not been cleaned for a long time and are very dirty. General property companies require regular professional cleaning of the exterior walls of street-facing buildings, and also stipulate the cleaning frequency of the facades of street-facing buildings with different material types, and require key maintenance of the exterior walls, such as glass, aluminum-plastic panels, curtain walls, stone exterior walls, various ceramic tile exterior walls and painted exterior walls in the area. According to Linde Company, the facade of a building must be cleaned once every quarter, and the general maintenance area should be cleaned at least once every three years. For external walls made of different materials, we should also choose a variety of cleaning methods and arrange the cleaning cycle reasonably. For example, if we choose to clean the glass exterior wall once every three months, it will also effectively maintain the glass exterior wall. Similarly, aluminum-plastic exterior walls should be cleaned at least once every three months. Because aluminum-plastic board belongs to the special material of exterior wall. Long-term non-cleaning will form external wall scale on the surface, which can't be treated by general cleaning agents, and will accelerate the deterioration of materials over time. It will make the original clean exterior wall surface dirty. There are also landmark buildings in key maintenance areas stipulated by relevant departments to be cleaned at least 4 to 6 times a year, so how much does it cost? Jinan Linde Home Economics also learned on the website of a cleaning company that the price of external walls made of various materials such as mosaics and marbles is two to three yuan per square meter, and the price of glass windows is two to four yuan per square meter from 1,000 square meters. It's normal to have tens of thousands of pieces of cleaning area on the external wall of a building, and it's also common that the cleaning cost once reached tens of thousands of yuan. Looking back, we feel that the external walls are clean, the city looks beautiful, and the whole city has benefited. Some citizens in Rongcheng think that the cleaning expenses should be paid by the government. However, many Rongcheng citizens believe that the operating units of street-facing buildings should have the obligation to keep their appearance clean and beautiful, and frequent cleaning of the external walls is also good for the image of the building. The cleaning fee shall be paid by the management and operation unit of the building. "Like makeup, only others can see your beauty, but do you want others to pay for cosmetics?" Many friends think that the external wall is not the key, especially the businesses close to the street. We can think from a broader perspective. If only your signboard is clean, but the outer wall is dirty, is it not ideal? Similarly, what happens if your face is clean but your clothes are dirty? Therefore, the cleaning of external walls is not only a matter for building operators, but also a matter that businesses should remind and cooperate with.