1. Application scope of polyurethane waterproof coating construction technology. Polyurethane waterproof coating aging resistance, corrosion resistance, heat resistance, cold-resistant, stretch strength, good elasticity, acid-proof alkaline, strong adhesion, high cohesive force, of commodity concrete, wood, metal, ceramic surface has strong adhesion force and cohesive force, etc. The waterproof layer and the base can form a whole, not empty drum, when there is accidental leakage, use this coating to scratch again, save time and effort. The construction process of this polyurethane waterproof coating is suitable for all kinds of roofing waterproofing works with protective layer, toilet, underground building waterproof project, etc.
2. Preparation of polyurethane waterproof coating. 2.1 main materials: group a (prepolymer) group b (solidified body) 2.2 construction tools: Electric mixer: mixed a and b material. Paint brush: brush bottom glue to use. Mixing bucket: mixed a and b material. Scroll brush: brush bottom glue to use. Small paint bucket: for mixing. Small float: repair the base use. Plastic scraping plate: used for scraping mixture. Oil scraper: clean up the base. Small sheet metal scraping board: apply the mixture to the complex part. Mop: clean up the grass roots. Rubber scraping plate: used for scraping mixture. 50KG scale: weighing and weighing.
3. Construction process of polyurethane waterproof coating. Basic surface treatment - polyurethane coating - local enhancement - coating of polyurethane coating 1, 2, 3 times - surface protection or modification.
4. Basic requirements and treatment. 4.1. The waterproof base shall be made of 1:3 cement mortar with 1/50 water gradient according to the design requirements, and the surface shall be smoothed and pressed, and there shall not be any defects such as uneven surface, loose and loose sand, etc. Drain or floor drain should be lower than the entire waterproof layer to remove stagnant water. The pipe should be more than 20MM above the base surface. The Angle of yin-yang Angle should be made into a small round Angle of 10MM to facilitate the construction of paint. 4.2 all fittings, sanitary equipment, floor drain or drainage outlet must be firmly installed, with tight joints and smooth head, no looseness is allowed.
4.3, construction, in construction of traditional polyurethane waterproof coating, waterproof base should be basic in dry state, it is advisable to moisture content is less than 9%, the simple determination method is the area of 1 ㎡, thickness of 1.5 ~ 2.0 MM rubber cover on the base, place 2 ~ 3 hours, such as the coverage of the surface of the base without the watermark, close to the primary side rubber sheet and no condensation watermark, according to the experience shows that the moisture content is less than 9%, conform to the requirements of the construction. Chengmei paint company produces polyurethane waterproof coating without this requirement, as long as the basic level of no clear water can be constructed.
4.4 before construction, remove the protrusion from the surface of the base surface with a shovel and broomstick, and clean up the dirt and debris thoroughly. Roots, floor drain and the drain Angle of Yin and Yang, the pipe mouth should be more serious in areas such as cleaning, such as have found oil, rust, etc., to use steel wire brush, sand paper and organic solvent to clean it outright.
5. Construction requirements for polyurethane waterproof coating. 5.1. Coating adhesive: this process is equivalent to the traditional asphalt waterproof construction coating cold base oil. The purpose of this process is to cut off the moisture of the base and prevent the water-proof coating from falling off. Strengthen the base layer, improve the adhesive strength of the film and the base, and prevent the defects such as needle hole in the coating. Our company suggests using polyurethane adhesive as the base treatment. The preparation of polyurethane base adhesive: the polyurethane material and the b material shall be proportionally 1:2 ~ 3 (weight ratio) (other coating shall be proportionally proportionally with the product specification). When the material is thicker, it can be diluted with special diluent, and it should not be diluted with acid or oil diluent, so as not to affect the quality of the original product. In preparation, should mix b material dilution for 2-3 minutes, if you don't need to dilute, can be directly with a distribution of b and 5-10 minutes, stir up the agitator, visible to the uniform liquid slowly slide from the container to be beautiful, at the same time, should pay attention to open the material should be immediately cover tightly, in order to avoid solidification of scrapped, mixture should be based on actual usage, which match the box.
5.2 local enhancement: for expansion joints, control joints, Yin and Yang Angle, pipe joints, etc., it can be reinforced by a layer of reinforcement, and then the whole waterproof construction will be carried out after curing.
Coating construction: 5.3, for the first time in the bottom basic dry cured rubber, plastic or rubber scraper uniform coating a layer of paint, coating uniform requirement when, not too thick or too thin, it is advisable to surface thickness of 0.8 MM or so commonly. In the beginning of the painting, the construction area should be considered according to the size, shape and material of the construction area. 5.4. Coating construction for the second time: after the first coating is basically cured, the coating shall be coated on the surface of the coating for the second time, and the coating shall be coated with the first time. In order to ensure the quality of the waterproof project, the direction of the coating must be perpendicular to the direction of the first layer. The interval of repainting time is determined by the temperature of the construction and the degree of curing of the film (by hand touch).
5.5. After the film is cured in the second time, apply the coating on the third time.
5.6, the shop is stuck layer or facing material: in the third time is not completely cured film are completed, can dilute sprinkle a small amount of clean sand on the surface (no more than 2 mm in diameter), to increase the coating layer and will cover the bonding ability between the cement mortar. When the film curing is complete and checked and accepted, it can be applied to cement mortar protection layer or paste face brick, Mosaic and other veneer. 5.7, three two cloth construction process: this process using the market at present is not many, the process of the operation method is: according to the above description for the processing of grassroots etc is the same, after besmear after the first pass, the shop is stuck on glass fiber grid cloth evenly, rely on polyurethane glue relay to be glued down, after the first pass dry by the same method for the second time, after being all dry, finally according to the requirements of the above besmear again polyurethane waterproof coating. The construction method of toilet, kitchen and roof is consistent. It is important to note that the glass fiber grid is required to be flat on the paving, because the space of the toilet is relatively small, and it should be dealt with in the early stage when the grid cloth is applied. Other requirements are consistent with the traditional construction process of polyurethane.
6. Precautions for construction of polyurethane waterproof coating. 6.1 when the coating viscosity is too large, and it is inconvenient to do the scraping construction, a small amount of special diluent can be added for dilution to reduce the viscosity, and the amount of addition shall not be greater than 10% of the material. (note: if the user needs to dilute polyurethane waterproof coating, it must be used with the diluent of chengmei coating company. The company is not responsible for the quality problems caused by the purchase of other diluents such as xylene and gasoline.
6.2. Air pores and bubbles: the mixing method and stirring time of materials do not mix well. In construction, the power and speed of the agitator should be used. Another reason is basic level processing unclean, do clean up carefully before coating at the grass-roots level, can not have float sand and dust, more should not have hole in the grass-roots, coating layers appear porosity should be dealt with according to the technological requirements, prevent the leakage of coating damage.
6.3. Drum: the base has the skin, sand, crack, and not dry, making the film adhesive bad; The basic construction should be carefully operated and maintained. After the grass roots are dried, the primer coating should be applied first, and then the waterproof layer shall be applied layer by layer.
6.4. Membrane warping: the edge of the waterproof layer and the joint of the sub-item brush appear in the same base. The main reason is that the grass roots are impure or not dry, the receiving operation is not careful, the sealing is not good, the bottom coating adhesion is not strong, etc. Therefore, the grass root should be clean, dry and meticulous operation.
6.5. Damage: in the process of laminating construction of the coating waterproof layer or all the coating construction, the operation activities of the person or the materials of the tools shall be placed before the film is cured, and the coating will be damaged. Scratch. The integrity of the coating should be protected during construction. 6.6 during construction, fire prevention should be paid attention to. The construction personnel should take protective measures, and the construction site should be well ventilated to prevent the solvent poisoning.
6.7. If there is precipitation in the work, it should be mixed before use, so as not to affect the quality.
6.8. Both materials are packed in iron drums, flammable and poisonous. They should be sealed when stored, and placed in a cool, dry place with no strong sunlight.
6.9, construction temperature should be above 5 ℃.
7. Quality record
7.1. The factory certificate (quality guarantee) of the various materials used and the re-examination record of entry;
7.2. Concealed engineering inspection data and quality assessment materials for each process;
7.3 handover information of the process;
7.4 record of roof water storage test;
7.5. Special construction plan and technical disclosure;
7.6 construction log.
8. Analysis of the cause of waterproof failure of polyurethane waterproof coating. , inferior material: 8.1 because waterproof material price competition on the market, many domestic manufacturers to cut corners on the waterproof material, polyurethane material that will bring down the waterproof material itself physical properties, leading to failure of waterproof.
, bottom water: 8.2 because of polyurethane waterproof coating waterproof material for oily, so must be confirmed before applied to whether dry, otherwise the waterproof done, moisture wrapped inside, through the sunlight into power of steam, will cause polyurethane waterproof layer of the peel.
8.3, the bottom is not clean: because before waterproof construction, the bare floor must be clean, and try not to have dust and loose material, can appear otherwise the waterproof layer and basic cohere unstable phenomenon, leakage hidden trouble.
8.4, polyurethane waterproof coating waterproof layer too thin: the thickness of the polyurethane waterproof layer must meet to have waterproof effect, because the pu material itself still has low water absorption properties, if the waterproof layer thickness, after days of heavy rain, the rain through the polyurethane waterproof layer to the bottom, through the sunshine, good weather will still be in the bottom of the water vapor, caused the waterproof layer. It is better to strengthen the fiberglass mesh fabric at all corners to prevent the leakage of polyurethane waterproof layer.
8.5. Construction experience is not enough: waterproof construction should be carried out by the waterproof professional construction team, and can not go to the hardware building materials line to buy some waterproof materials. It is necessary to carefully judge the reason of the leakage before applying it.