The construction process of polyurethane waterproof coating: 1. Clean the base layer, 2. Apply the primer, 3. Add a layer of detail, 4. Apply the first layer of film, 5. Apply the second layer of film, 6. Apply the third layer of film and adhesive slag.

1. Cleaning the base layer: Use a shovel to remove the dust adhered to the leveling layer, and use a broom to clean the dust, especially the pipe roots, floor drains, and drainage outlets. If there is oil stain, it should be brushed off with a steel wire brush and sandpaper, or a layer of intermediate paint and cement should be applied to the surface of the oil stain. The surface must be flat, and the recesses should be leveled with 1:3 cement mortar.

2. Brush primer: Mix the two components of polyurethane A and B with xylene in a ratio of 1:1.5:2 by weight, and use them evenly. Use a rolling brush or paint brush dipped in the primer to evenly apply it to the surface of the base layer, without being too thin or too thick. The appropriate amount of application should be around 0.2kg/m. After painting, it should be dried for at least 4 hours before proceeding to the next process.

3. Additional layer for details: Mix and stir the polyurethane coating waterproof material in a ratio of A component to B component=1:1.5, and use a paint brush to dip the coating on weak areas prone to water leakage, such as floor drains, pipe roots, internal and external corners, and water outlets. Do not miss the coating (at the junction of the ground and wall, the waterproof wall of the coating should be 100mm high).

4. First layer of coating: Mix the two components of polyurethane A and B with xylene in a ratio of 1:1.5:0.2 by weight, pour them into a mixing bucket, use an electric mixer to stir evenly (about 5 minutes), and use a rubber scraper or paint brush to scrape a layer of paint with a uniform thickness. The appropriate scraping amount is 0.8-1.0kg/m, and operate from the inside out.

5. Second layer of coating: After the first layer of coating is applied, when the coating solidifies to the point where it does not stick to the hands, proceed with the second layer of coating according to the material ratio method of the first layer. In order to ensure uniform coating thickness, the scraping direction must be perpendicular to the first layer of coating, and the scraping amount must be the same as the first layer.

6. Third layer of coating: After the second layer of coating solidifies, the coating material is still stirred according to the material ratio of the first two layers, and the third layer of scraping is carried out, with a suitable scraping amount of 0.4-0.5kg/m. When the coating is not cured after application, it can be thinly spread clean on the surface of the coating film φ 2～ φ A 3mm particle size stone slag is used to increase the bonding strength with the cement mortar cover layer.

During the operation, ingredients should be mixed according to the amount of operation on that day, and excessive mixing is not allowed. If the viscosity of the coating is too high for scraping, a small amount of xylene can be added for dilution, and the amount added should not exceed 10% of material B. If the curing rate of material A and material B is too fast after mixing, which affects the construction, a small amount of phosphoric acid or benzenesulfophenol chloride retarder can be added, and the amount added should not exceed 0.5% of material A; If the curing of the film is too slow, a little dibutyltin di lauric acid can be added as a coagulant; However, the addition amount shall not exceed 0.3% of material A.

After completing the waterproof coating and passing the inspection and acceptance, the water storage test can be carried out. If there is no leakage within 24 hours, the surface layer construction can be carried out.