Requirements before construction of exterior wall coating:
1. Base material requirements: the base plastering has been completed and maintained for about 20 days, and the pH value of the base is below 9. At the same time, the base has been dry (at least 15 days), and the humidity is lower than 8%. The surface of the base is flat, the internal and external corners and corner lines are dense, and the outline is clear; the wall surface is free of structural problems such as water seepage, cracks, hollowing, blistering holes, etc. No powdered loose matter, no oil, grease and other adherents.
2. The coating used shall have factory certificate and meet the requirements of relevant national specifications and standards through inspection.
3. The coating used shall be approved by the owner, and the sample wall shall be approved by the owner, the supervisor and the designer.
4. As the exterior wall coating is water-based, it requires high construction and maintenance conditions. The temperature required for construction and maintenance is higher than 5 ℃ and the ambient humidity is lower than 85% to ensure good film formation. Low temperature will cause paint film pulverization, cracking and other problems. Environmental humidity makes the paint film not dry for a long time, and eventually leads to poor film formation. Weather factors must be considered in the construction of exterior wall. Before painting, it does not rain for 12 hours to ensure the base is dry. After painting, it cannot rain for 24 hours to prevent the paint film from being damaged by rain.
Construction process of exterior wall coating:
Repair exterior wall - Cleaning - filling putty, partial puttying - grinding - pasting fiberglass cloth - puttying and re grinding - primer construction - first finishing coat construction - second finishing coat construction
1. Repair: 1:3 cement mortar (or polymer cement mortar) shall be used to repair the defects such as missing edges and corners, holes, etc. of the substrate before application.
2. Cleaning: dust and powder can be washed with broom, brush and high-pressure water; grease - cleaned with neutral detergent; mortar - removed with shovel and scraper; mold - washed with high-pressure water outdoors, rinsed with clear water and dried.
3. Putty filling and partial putty scraping: if the wall is flat and smooth, putty can not be used; in addition to being easy to be approved and polished, putty shall also have good strength and durability. When filling and partial putty scraping are required, it is better to apply the putty thinly rather than thickly. It is required that putty should have better adhesion, adhesion durability and water resistance.
4. Grinding: grinding must be carried out after the base course or putty is dry, and wet grinding is not allowed to avoid the influence of adhering sandpaper on operation. The thickness of sandpaper should be determined according to the hardness of the ground surface. If the sandpaper is coarse, it will produce sand marks, which will affect the final decoration effect of the coating. When grinding, first use a coarse abrasive cloth or a grinder, and then use a fine abrasive cloth to polish. Pay attention to the flatness of the surface. After grinding, remove the dust on the surface immediately to facilitate the construction of the next process.
5. Paste glass fiber cloth: use mesh with uniform density, do not use too dense glass fiber cloth for paving.
6. Puttying and regrinding: polymer puttying is used for leveling, which is mainly aimed at leveling the irregularities caused by sticking glass fiber cloth and preventing the capillary cracks on the surface.
7. Coating application: the surface moisture content of the base course is required to be no more than 8% for coating application. In case of strong wind, rain, fog and other weather, the surface coating shall not be applied; during construction, the sample wall shall be made according to the design requirements until the completion acceptance.
Construction acceptance standard of exterior wall coating:
The exterior wall coating construction shall be free from leakage, bottom penetration, powder dropping, peeling, anti alkali, color biting, consistent color requirements, uniform density, sagging, pimple, brush lines and pollution of doors and windows.
Painting paint for exterior wall decoration is a common decoration method and relatively low decoration cost, so many people will choose paint to decorate the exterior wall.
In this paper, the construction technology and acceptance standard of exterior wall coating are sorted out and published by Follette paint (http://www.zsfulite.com/). If there is any reprint, please indicate the source.