First, the definition and function of the top surface of wall foundation treatment
Refers to the use of Shuangfei powder, gypsum powder, white cement and other materials on the original wall and top surface of the blank house.
Do a good job of foundation leveling, which is convenient for later scraping putty and painting the wall.
Second, the treatment of common materials on the top surface of grass-roots wall
1, putty
Wall putty mainly includes ordinary putty and water-resistant putty.
Ordinary putty: in the past, the old-fashioned walls were plastered and plastered, with a certain thickness. Even if the wall is uneven, it can be found. I feel that the old-fashioned plastering wall does not drop ash at all, and the wall is particularly flat and there are no cracks. My old house in the 1960s was like this. Later, putty only scraped a thin layer on the concrete wall. If the wall is uneven, it will be uneven only by putty.
The earliest putty was made of 107, 80 1 glue mixed with Shuangfei powder, talcum powder and cooked rubber powder, which belongs to semi-finished putty. Although the price is low, it is troublesome to purchase a variety of raw materials, and they are all adjusted by the feelings of workers. The preparation ratio is not standardized and the quality is unstable. Old-fashioned putty is not water-resistant, easy to peel and powder, and has a short service life. Especially, the adhesive 108 used in raw materials is not environmentally friendly, which will do harm to human body.
Water-resistant putty: Water-resistant putty, commonly known as waterproof putty, was first patented by Beijing lines Coatings Co., Ltd. and was industrialized in batch production in 1995. Water-resistant putty consists of calcium carbonate, calcium lime powder, cement, organic rubber powder and water-retaining agent. It uses natural plant glue as adhesive, which has strong adhesion, high bonding strength and good crack resistance. After construction, there is no peculiar smell, environmental protection, non-toxic and tasteless, and no substances harmful to human body such as formaldehyde, benzene and xylene. Water-resistant putty wall has strong water resistance, and there will be no pulverization, cracking, peeling and falling off after being wetted. The construction is convenient, and it can be used after being mixed with water, which can improve the performance and service life of the coating, save the amount of latex paint, make the wall feel delicate and uniform in color, and can be directly scrubbed or repainted with the interior wall coating after pollution. It is the best bonding layer between wall and coating.
All components of water-resistant putty are insoluble in water. In the national standard test environment, the water-resistant putty was scraped on the cement board and soaked for 48 hours without peeling, cracking and powder dropping, and the drawing strength (that is, vertical drawing strength) still reached 0.3 MPa-negative ion water-resistant putty powder. Among them, the unique piezoelectricity and pyroelectricity of tourmaline jade lining can ionize the surrounding air and stimulate the formation of a large number of negative ions, so that the wall surface can be continuously manufactured. It can purify and reduce toxic and harmful substances in the air, such as dust, bacteria, formaldehyde and so on. Super waterproof, delicate and white, good self-cracking resistance, not easy to pulverization, completely dry, neutral PH value, excellent workability, and can effectively prevent mildew on the wall. However, at present, hollow putty products have not been widely used in the market because of their high price.
In addition, it should be noted that although water-resistant putty is commonly known as waterproof putty, it is still different from real waterproof putty. Waterproof putty is the kind of porcelain-proof paint that has long been unused. Because of its dense surface, moisture can't enter. This kind of waterproof putty will lead to airtight wall, empty drum, powder drop and many other problems on the wall, and its service life is not long.
2. Interfacial agent
Interfacial agent is a material used to seal the base. Coating the interface agent on the cement wall can improve the adhesion of putty, effectively prevent hollowing, and avoid many problems of the wall foundation caused by loose, floating soil or too dry cement wall. In the past, it was mainly 108 adhesive interface agent, which had poor environmental protection performance. Meichao wall coating is an interfacial agent at present, which is used to seal the particularity of wall foundation and increase the firmness of wall surface. The purpose of painting the wall coating is to make the wall "rough", improve the adhesion of the wall and prevent the putty from cracking.
3. Gypsum
Gypsum is used for wall leveling and is divided into bottom gypsum and top gypsum. Top gypsum and putty have the same function. The bottom gypsum has a thick surface, which is used for leveling the wall bottom and local thickness. Good leveling gypsum is a kind of pneumatic material, which has certain water resistance, higher bonding strength than water-resistant putty and faster drying and curing speed, and can be used for interior walls instead of cement mortar.
Leveling gypsum can be divided into plastering gypsum and caulking gypsum in use function. Plastering gypsum is mainly composed of gypsum and other additives, which is suitable for plastering and leveling of wall base. Compared with traditional products, leveling gypsum mortar has more stable performance and stronger adhesion, and is more suitable for rapid leveling of concrete, aerated concrete and brick-concrete mortar walls. Caulking gypsum is mainly high-strength fine gypsum powder, which belongs to sealing layer material. It is used to fill the seams and nail holes between gypsum products and gypsum boards, and is also suitable for filling holes, gaps and trunking in indoor walls, as well as repairing and leveling places with poor local flatness.
At present, there are finished products of plastering materials and caulking materials for interior walls on the market, such as "leveling mortar" in lines. Meichao's "wall lining" is a ready-made leveling material prepared by manufacturers in proportion. It not only has the advantages of early strength and quick hardening of building gypsum, thermal insulation, fire prevention and sound insulation, and automatic adjustment of indoor temperature, but also has the characteristics of high bonding strength, difficulty in hollowing and cracking, convenient construction and high speed.
Third, the construction technology of wall top surface base treatment
(a) the construction process:
Clean up the wall → repair the wall → scrape putty → brush latex paint for the first time → brush latex paint for the second time → brush latex paint for the third time.
(2) Construction operation:
1. Cleaning the wall surface: clean the peeling and looseness of the wall surface, fill it with cement mortar, shovel the residual ash, and then sweep the wall surface.
2. Wall repair: use gypsum to level the uneven and potholes on the wall, dry them, grind off the protruding parts with sandpaper, and sweep away the floating dust.
3. Blow putty: The frequency of blowing putty can be determined according to the flatness of the wall, generally three times. The waterproof putty for kitchen, toilet and bathroom is polyvinyl acetate emulsion: cement: water = 1: 5: 1. For the first time, scrape horizontally with rubber scraper, one scraper is followed by another scraper, leaving no joint, and the end of each scraper is clean. After drying, brush the paper, polish the floating putty and spots, and then clean the wall.
4. Scrape vertically with a rubber scraper for the second time, using the same materials and methods as the first time. After drying, smooth it with sandpaper and clean it.
5. For the third time, fill the putty with rubber scraper or scrape the putty with steel scraper, scrape and smooth the wall, dry it and smooth it with fine sandpaper, so as not to scrape or wear through the putty.
Four, the top surface of the wall at the grass-roots level processing acceptance method
Wall surface treatment is to make the wall surface smooth, clean, dry without cracks, holes, and solid without floating dust.
1. The concrete or plastered base wall of new building shall be coated with alkali-resistant sealing primer before putty.
2. Before pasting, the loose old decorative layer should be removed from the old wall, and the interface agent should be painted.
3. The moisture content of concrete or plaster base shall not be greater than 8%.
4. The putty at the grass-roots level should be smooth, solid and firm, without pulverization and peeling, and the bonding strength of cracked putty should comply with the regulations.
5. The flatness of the base surface, the verticality of the facade and the founder of the angle of Yin and Yang should meet the requirements of advanced plastering.
6. The surface color at the grass-roots level should be consistent.
Five, the grass-roots wall top treatment matters needing attention
1. The putty shall be suitable for the coating performance, solid and firm, and shall not be pulverized, peeled or cracked. Kitchen and bathroom gutters must be filled with cement to prevent wall tiles from cracking in the future, and other rooms should be filled with gypsum or quick-adhesive powder to prevent wall paint from cracking. Due to the limited performance, the thickness of ordinary putty powder cannot exceed 3 mm. If it is scraped too thick, it will fall off and crack easily in the future. The total thickness of putty scraping shall be 2-3 mm, preferably no more than 3 mm2. The coating solution should be fully stirred, and water should be added if the viscosity is too high. The amount of water added shall be subject to the construction consistency, and it shall be stirred evenly, and it can only be used after being placed for 10 minutes.
Six, different wall base top surface treatment
1. For old houses or walls with serious pulverization and falling off, remove the putty from the original wall until the cement wall is exposed, and then make putty again.
2. After the completion of hydropower transformation, other different walls should be treated as foundation walls.
3. Yin-Yang angle (the Yin angle of the wall refers to the concave angle, such as the angle between the top surface and the surrounding wall; The external angle of the wall refers to the protruding angle, such as the angle between the window and the wall), leveling, first fixing the wall surface, and then sticking the anti-crack cloth. The position of plastering cloth is generally non-bearing wall, the junction of bearing wall and non-bearing wall, and the position of construction hole to prevent cracks. Especially around the heating, many people have cracks in the wall for half a year because there is no cloth during construction.
4. The load-bearing wall should be pasted at the cracked place, the light wall should be pasted with cloth, and the cracked place should be pasted. If you stick kraft paper first, the effect will be better. The putty should be scraped after the cloth is pasted, and the putty should be scraped before the wall painting. Generally, it needs 1-3 times, during which the normal drying time is 1-2 days. However, when scraping putty in rainy days, wipe off the water vapor on the wall with a dry cloth and try to keep the wall dry. At the same time, according to the actual situation of the weather, it is advisable to extend the drying time of putty as much as possible, generally 2-3 days. After the putty on the wall is leveled and polished, the wall should be painted with varnish or basement membrane before painting.
5. Special walls are mainly treated according to different bases to prevent cracks. Of course, the harmony with the overall home environment can not be ignored.
6. Combination of wallpaper and paint: The combination of wallpaper and latex paint solves the problem that the corner is easy to crack, and it also has a certain impact on spatial vision. Paint first, then press wallpaper on it. When you can't paste wallpaper, you should pay attention to finding a professional construction team, otherwise it will be easy to get pimples and blisters.
7. Wood-based panel decorative hollow wall: generally used in porch or large space that needs to be divided. If you want to hang things on the wall, you can't use gypsum board as the base material, but use wood-based panels. Blow putty on artificial board, but the putty is thin and has no wall effect. When it is thick, it is easy to peel, and the base should be properly treated. It's best to put on anti-crack bandage before scraping putty.
8. Painting construction with thermal insulation wall: Because the thermal insulation wall is hollow and easy to crack, it should be lined with a layer of crack-resistant kraft paper before painting. Don't apply too much glue when making the substrate to prevent cracking, which is not good for your health.