Li Laiquan, director of the waterproof Engineering Research Institute of Beijing Construction Engineering Research Institute, said in an interview with reporters that at present, the development of China's waterproof industry is not standardized. In order to make waterproof materials worthy of their name, the waterproof industry needs to treat "water" first.

 

The quality of coiled material is uneven

 

Li Laiquan told reporters that at present, the waterproof material market is chaotic and fake and shoddy products are rampant. Some illegal manufacturers specially produce a batch of "high-quality products" for sampling inspection and inspection. Although they hold qualified inspection reports, they produce unqualified products, "hanging sheep's head and selling dog meat"; Some make false propaganda under the guise of famous brand trademarks to promote fake and shoddy products; Some steal beams and columns in the construction process, send them to the construction site for inspection, which are qualified products, and replace them with fake and shoddy products during actual construction.

 

Data show that in recent years, the proportion of the output of various new waterproof materials in the total has increased by 7 ~ 8 percentage points, close to 40%. However, the basic situation of the waterproof material market is still in a situation where good and bad are intermingled and fake and shoddy products are banned repeatedly. Fake and shoddy products are dumped at a price more than 60% lower than regular products, which has a large market share, making it difficult for regular large and medium-sized enterprises to sustain. The new SBS modified asphalt waterproof coiled material is the most impacted. Domestic well-known waterproof companies have lost a lot of market share because they insist on product quality and even have to sacrifice the market.

 

Many system engineering vulnerabilities

 

For the causes of construction leakage, Li Laiquan pointed out that although the failure to ensure the material quality is one of the reasons for the leakage, the failure of the design to meet the relevant national standards and the failure to ensure the construction quality are also the main reasons for the leakage.

 

The waterproof design is weak. The material selection of waterproof layer should have been carried out by designers in strict accordance with the requirements of the specification. However, many designers, especially some young designers, are not familiar with the performance of waterproof materials and have a weak understanding of waterproof concept. They are easy to be misled and deceived by some false publicity and unconsciously choose fake and shoddy products. Even some designers were interfered too much by developers, and finally gave up their positions and responsibilities, leaving the most critical link of material selection to the construction unit for decision. Construction projects are subcontracted layer by layer, and each layer should pursue its own interests. Most agree to sacrifice material quality, use inferior products and buy at a low price, and designers can only let it go.

 

The construction quality is even more worrying. The proliferation of fake and shoddy waterproof materials is closely followed by the low cost of waterproof engineering, which makes it difficult for formal waterproof professional construction companies to win the bid, forcing the project to fall into the hands of some unqualified and affiliated low-quality contracting teams. Most of the construction personnel in these contracting teams have not received professional training due to the lack of relevant vocational skill certification system and skill examination.  Secondly, for their own interests, the bid winning construction team wantonly cut corners on work and materials and carried out extensive operation.

 

Standard lag needs adjustment

 

For a long time, the lag of standards is also one of the main factors hindering the healthy development of waterproof industry. "At present, the state requires all elastomer modified asphalt waterproof coiled materials to meet this requirement. In fact, the specifications formulated by the state do not involve the construction site."  Li Laiquan said. At present, the main technical index of elastomer modified asphalt waterproof coiled material is GB l8242-2008. Its low-temperature flexibility should reach - 25 ℃ to - 20 ℃ without bending and crack, and its heat resistance is no sliding and dripping at 90 ℃ to 105 ℃. However, the temperature difference in China is segmental, the temperature varies greatly in different regions, and the requirements for coiled materials should also be different. Li Laiquan analyzed from actual cases. Guangzhou is located in the transition zone between north temperate zone and tropical zone. The average temperature in the hottest month (July) is 28.5 ℃ and the average temperature in the coldest month (January) is 13.3 ℃. It is one of the largest cities with the smallest annual average temperature difference in China. If it is necessary to use modified asphalt waterproof coiled material with low temperature flexibility of - 20 ℃, it is actually a waste of resources. Because the higher the technical requirements of materials, the higher the energy consumption and the higher the cost. At the same time, Li Laiquan said that some published standards also obviously lag behind the development of the waterproof industry, but have not been revised and improved in time. National standards are an important basis for judging whether products are qualified or not and an important guarantee for promoting the development of the industry. However, at present, the lag of national standards is obvious and needs to be solved urgently.

 

Li Laiquan introduced that not long ago, China building waterproof Association issued a document to the national industrial product production license office, suggesting that some parts of the detailed rules for the implementation of production license of building waterproof coiled material products (2009 Edition) should be revised according to the actual situation and development trend of the building waterproof industry, To facilitate the implementation of the new waterproof policy of the Guiding Catalogue for the elimination of backward production process equipment and products in some industrial industries (2010 Edition). The Association believes that the detailed rules should be revised with reference to the four key indicators of the waterproof coiled material production line with an annual output of 5 million square meters and above. The association said that the implementation of the announcement and the revision of the detailed rules will better implement the national industrial policy and promote the construction waterproof industry to a new level.