What are the factors that affect waterproof engineering?

At present, there are many varieties and specifications of waterproof materials in China, and the product quality is different. At present, the domestic waterproof material market is chaotic, and many inferior waterproof materials are flooding the market.

Factors affecting the quality of waterproof engineering and countermeasures

The poor quality of building waterproof engineering is the direct cause of the leakage of waterproof engineering. According to the investigation of authoritative organizations, 24 million m2 of linoleum and 27, tons of asphalt are used to repair the waterproof layer of the roof every year in China, and the annual maintenance cost for building waterproof engineering is more than 1.2 billion yuan. There are many reasons for the leakage of waterproof engineering. Material quality, construction technology, design level, management and maintenance are important factors affecting the quality of building waterproof engineering. To improve the quality of waterproof engineering, we should take materials as the basis, design as the premise, construction as the key, and strengthen management and maintenance to comprehensively manage waterproof engineering.

The factors that affect the quality of waterproof engineering are analyzed as follows:

1. Material factors

The quality of waterproof materials is the basis for doing a good job in waterproof engineering. At present, there are many varieties and specifications of waterproof materials in China, and the quality of products is different. At present, the domestic waterproof material market is chaotic, and many inferior waterproof materials are flooding the market. If unqualified waterproof materials are used in waterproof projects, the quality of waterproof projects will be seriously reduced.

By analyzing the quality of paper-based felt and waterproof coating, it can be seen that:

1. The quality of base paper in paper-based felt of petroleum asphalt decreased. In 195s, the base paper contained a lot of waste cloth pulp and a certain amount of coarse wool, but now waste paper and straw pulp are mostly used, which reduces the tensile strength, elongation, moisture content and quality of linoleum.

2. The density of base paper increases and the oil absorption rate decreases. The oil soaking rate dropped from 14% ~ 16% to over 115%. Because the asphalt can't penetrate the base paper, it is easy to cause the asphalt felt to delaminate and rot.

3. The quality of petroleum asphalt is not good. After the 196s, domestic petroleum asphalt with high wax content and sulfur content was used to produce linoleum, which resulted in poor aging performance of linoleum, easy flowing and brittle cracking, and the paraffin in asphalt was mobile, which easily made the waterproof layer of linoleum lose its cohesive force gradually, resulting in the waterproof layer becoming warped and falling off.

4. The quality of waterproof coating is low. In particular, some township enterprises producing waterproof coatings have weak technical force, backward production equipment, primitive operation technology, uncontrolled raw materials and poor quality of most products. According to the relevant departments' random inspection of three manufacturers producing plastic ointment, only one manufacturer's plastic ointment is qualified, and the qualified rate is only 14.3%. If these unqualified waterproof materials are applied to waterproof projects, the quality of waterproof projects will be seriously reduced.

second, design factors

the waterproof design of building waterproof project is very important, which is the premise of ensuring the quality of the project. However, there are the following problems in the design of waterproof engineering in China:

1. China has not formulated the design specifications of waterproof engineering for a long time, and designers have no specifications to follow. There are no clear regulations on how to design waterproof for buildings with different types and different functions, what waterproof materials to use, and what specific technical requirements.

2. Designers have little knowledge of modern waterproofing, and they don't know much about the performance, scope of application and conditions of use of new building waterproofing materials. They can't choose waterproof materials correctly according to the specific conditions of buildings, either following the old rules or causing leakage or waste due to improper selection of materials.

3. Since 1958, most roofing waterproof projects have been simple waterproof methods of 35 # linoleum, two felts and three oils, thus reducing the quality of roofing waterproof projects. From previous investigations, it can be found that the roof leakage phenomenon has increased obviously.

4. Most of the roof joint structures are outdated, and they still follow the practices of 195s and 196s. For example, the method of laying wood bricks and nailing wood strips is used for the treatment of linoleum, which often causes warping, deformation and decay due to wind, sun and rain, resulting in the destruction of cold water nodes and roof leakage.

5. Some buildings have insufficient overall roof stiffness during design and construction, and cracks sometimes occur due to large deformation; Some roof slopes are too small, the number of drainage pipes is insufficient or the diameter is too small, and the drainage route is too long, which makes the roof accumulate water and cause leakage.

III. Construction factors

Through the investigation and analysis of house leakage accidents, it is shown that the construction factors are the main causes of house leakage. If there are qualified waterproof materials and excellent waterproof design, but the construction is not serious and the construction quality is poor, the house will still leak. Therefore, ensuring the construction quality is the key to improve the waterproof quality of buildings. The main factors causing poor construction quality are:

1. Lack of waterproof professional construction team, even using workers who do not know waterproof technology at all to carry out waterproof construction of houses, which will inevitably lead to the failure of waterproof projects.

2. The quality control and management of waterproof construction process are ignored, the leveling layer and waterproof layer are operated carelessly, and the construction and acceptance are not carried out in accordance with the design drawings and construction technical specifications, especially the joint parts are not handled seriously, leaving a hidden danger of leakage.

3. The quality of mastic boiled on site for petroleum asphalt linoleum roofing is unqualified; Did not do the mixture ratio test in advance or did not measure accurately according to the mixture ratio; Excessive boiling temperature, excessive volatilization of oil, and easy aging of asphalt; High wax asphalt is used without dewaxing treatment.

4. due to the time limit for a project and the progress, the waterproof layer was laid before the leveling layer was dry, and effective measures such as exhausting the roof were not taken, resulting in bulging, delamination, rot and leakage of the waterproof layer.

5. When coating waterproof construction, waterproof failure is often caused by uneven coating thickness or thin coating. Another example is that in order to get the project, some construction units try to lower the cost, and use some waterproof coatings with low solid content.

6. The rigid roof is not compacted by vibration, is poorly maintained and has insufficient thickness, and the proportion of various sand and gravel materials in concrete is not handled properly; The isolation layer under the waterproof layer is not well done, which has no isolation effect; Improper setting position of frame joints, serious and imprecise filling of sealing materials, etc., will cause leakage of rigid waterproof layer.

iv. management and maintenance factors

after the project is completed and put into use, the management and maintenance of the housing project must be done well. If the management and maintenance are not good, not only the materials, design and construction are of high quality, but also the roof leakage will be caused by poor management and maintenance. The causes of leakage caused by poor management and maintenance are as follows:

1. The housing management department has no special person to inspect the roof project regularly, and some local defects have not been treated in time, which will lead to the expansion of defects, the development of cracks, the destruction of nodes and the roof leakage over time.

2. The roof is not cleaned regularly, and the gutter, eaves gutter and drain are dredged. Downspouts is blocked, and the roof accumulates water for a long time, which makes the waterproof layer delaminate and rot. Some roofs are not cleaned for a long time, plants breed, and the roots of plants plunge into the waterproof layer, which damages the waterproof layer.

3. In recent years, after many projects were put into use, TV antennas, light boxes, solar water heaters, advertising placards and other facilities were added to the roof, and construction operations were carried out on the roof waterproof layer, so that the waterproof layer was partially damaged and completed in time.

4. Some households raise poultry and play on non-human coiled waterproof roofs or coated waterproof roofs; Or pile up sundries and garbage on the roof to build a small house, which has been left unattended for a long time and accelerated the decay and damage of the waterproof layer.

V. Countermeasures to improve the quality of waterproof engineering

Since there are many factors affecting the quality of waterproof engineering of houses, the control measures should also be comprehensive

(1) In terms of waterproof materials

In each chapter of Technical Specification for Roofing Engineering, the section on requirements for waterproof materials is to set requirements for the technical performance of various types of waterproof materials from the perspective of engineering needs, and it is stipulated that only the requirements can be met. It is also stipulated that the waterproof materials used must pass the sampling inspection and certification of testing units designated by the construction departments of provinces, autonomous regions and municipalities directly under the Central Government before products are allowed to enter the "market". At the same time, in order to control the quality of waterproof materials entering the "site", it is stipulated that the construction unit should sample and retest according to the new specifications. Only in this way can unqualified waterproof materials be effectively prevented from flowing into the "market" and "site". Once unqualified waterproof materials are found to have entered the site, they are never allowed to be used in building waterproof projects.

(2) Waterproof design

In order to make designers follow in the design of roof waterproofing, the new code has two sections: "design points" and "detailed structure" in each chapter for different roof projects. At the same time, in the new regulations, it is also stipulated that designers should "design waterproof structure according to the engineering characteristics, regional natural conditions and the fortification requirements of roof waterproof grade, with detailed drawings for important parts". Roof drainage system and thermal insulation system should also be determined by calculation, instead of relying on experience or writing the words "two felts and three oils" as in the past.

(III) Construction quality

In each chapter, the new specification stipulates the technical requirements and quality standards of each kind of roof waterproof construction. It is stipulated for the construction unit that before the construction of waterproof project, the blue prints.the design should be passed to master the detailed structure and relevant technical requirements in the construction drawing, and the construction scheme or technical measures of waterproof project should be prepared. Moreover, the qualifications of waterproof construction teams and operators have also been stipulated, requiring that "roof waterproof projects must be constructed by professional waterproof teams or waterproof workers." It is strictly forbidden for non-waterproof professional teams or non-waterproof workers to carry out the construction of roof waterproof projects. " It is emphasized that in the construction of waterproof engineering, inspection should be carried out according to the construction process and level, and the next process and level can be carried out only after passing the inspection. At the same time, the new code also stipulates the acceptance standard and inspection method of waterproof engineering quality to control the construction quality of roof waterproof engineering.

Only when all links of design, materials, construction, management and maintenance are completed, can the service life of building waterproof engineering be guaranteed and extended.

How do you need other supplementary information? I suggest you go to China Waterproof Enterprise Network. There are many related information for reference.