The penetration effect is the main consideration for the classification of waterproof grades, how to choose the appropriate waterproof membrane.

What is the waterproof rating?
The waterproof level is the level of the waterproof protection function determined according to the nature of the building, functional requirements, importance, and useful life. The classification of the waterproof grade comprehensively considers whether it will cause major losses (personal casualties, economic loss) after penetration, and whether it will affect aesthetics after penetration.

Waterproof rating of building materials
Building materials used in home decoration must fully consider waterproof factors.
Level 1: No water leakage is allowed, and no wet stains on the surface of the building materials;
Level 2: No water leakage is allowed, and a small amount of wet stains are allowed on the surface;
Level 3: A small amount of water leakage is allowed, but no wire flow and mud leakage are allowed;
Level 4: There are water leakage points, but no wire flow and mud leakage.

Knowing the waterproof grade, then how to choose waterproof membrane?

1. Choose according to different waterproof environments
No one material is omnipotent, and different waterproof materials should be selected for different parts.
① Under the environment of alternating dry and wet, general waterproof materials can basically be solved. If the toilet is waterproof, it is very suitable to use the “wall rigid” waterproof combination.
② In long-term humid environments, such as water storage tanks and anti-corrosion tanks, due to long-term water storage, the volume of the waterproof coating will swell, the density will decrease, and the polymer cement with good air permeability will not waterproof, and the use strength is high , Polyurethane waterproof coating with large elongation, excellent water resistance and acid and alkali resistance is more suitable.
③ In some special parts, such as pipe roots, yin and yang corners, roofing, fan outlets, etc., flexible waterproof materials should be used to prevent the waterproof coating from cracking with the deformation of the base layer. Acrylic waterproof coatings can be considered.

2. Rigidity or flexibility, depending on the needs
Rigid and flexible waterproof coatings are not good or bad. The so-called “soft” and “rigid” are just different product performance effects, and cannot be used as a standard for judging the quality of materials. The materials used for rigid waterproofing are not stretchable. For example, common rigid waterproof materials include waterproof mortar and cement-based infiltration crystalline waterproof coating. Compared with the flexible waterproof roof, its main advantages are low cost, good durability, few construction procedures and easy maintenance. The main problem is that it is sensitive to the slight deformation and temperature deformation of roof members caused by uneven settlement of the foundation, and is prone to cracks and water leakage. Flexible waterproof has good comprehensive technical performance such as strong impermeability, high tensile strength, good stability and long service life. When the waterproof layer is subjected to external force, the waterproof material itself has a certain degree of expansion and contraction, which can resist the cracking of the base layer within the elastic range of the waterproof material and exhibit a certain flexibility.
There is a certain difference between the two constructions:
When the rigid coating is applied, the requirements of the base layer are not high, and it can be applied on the wet base surface. After construction, the surface of the film is hard and suitable for tiling, so it is often used for wall waterproofing. Flexible coatings have strong anti-deformation ability, but the requirements for the base layer are stricter during construction, and because the film formation is soft, elastic and smooth, and the tiles are easy to fall off, flexible coatings are often used for ground waterproofing, as well as the strengthening of tube roots and yin and yang angles.

3. Identify the truth from good quality
①: Flexibility testing
Apply waterproof coating three to four times on the flat glass, with a thickness of about 1.0-1.5 mm. After the coating is dry, stretch it by hand to see if it is elastic, and then use a straight bar to repeat the winding. See if there are cracks or even breaks.
②: Check the adhesion
If it is a two-component waterproof coating, you can find a clean cement base surface, and then paint it three to four times. After a week, use a shovel to see if it is firm.
③: Water resistance inspection
The paint is applied to the cement block in multiple times, with a film thickness of 1.0-1.5 mm, placed for 7 days, soaked in 1% alkaline water for 7 days, without delamination and emptying, it is qualified.
④: Film thickness inspection
Use needle puncture to puncture three points per 100 square meters, measure its height with a ruler, take the average value, and the film thickness should be greater than 1.5 mm. Mark the puncture for repair. Detection of waterproof coatings: one look, two smells, three comparisons: first look at the packaging, whether it meets the packaging requirements of branded products. General well-known brands will have a product authenticity query system, which is a direct and effective method of identification. In addition, the waterproof coating has no precipitation, delamination and agglomeration, and the color is bright, which is also one of the basis for judgment. Second smell: The good waterproof material liquid material will not have an unpleasant smell, and the liquid powder material will not produce an unpleasant pungent smell after mixing. Three comparisons: Compare whether there is a test report, whether the price is seriously lower than the general market price, don’t be greedy for cheap, and the good quality does not matter. Otherwise, if there is a leak in the home, rework will be more troublesome.