Waterproof problem seen from an apartment building in Pearl River New City

The apartment is located in Zhujiang New City. The project is under construction and the project has been basically completed. The project has three underground floors. The basement is mainly used as a garage, and civil air defense at the time of combat. The first to fifth floors are shops on the ground, and five floors are commercial buildings. The project is adjacent to the Pearl River in the south, and the groundwater is very abundant.

Recently, the building has seen some leakage phenomena one after another. At the request of the construction unit, technicians of Yuhong Company have conducted on-site surveys of the building several times.

According to the on-site construction management personnel of the construction unit, the basement floor waterproofing is provided with a drainage plate between the floor and the fine stone concrete surface. The side walls are reinforced concrete walls on the west, south and north sides, and the east side is a brick wall. Coating waterproof layer, basement earthwork has been backfilled but not waterproofed. The outer wall is a light-weight ceramic block and is not waterproofed.

Second, on-site leakage and its hidden dangers

During the exploration process, it was found that the basement, external walls and other parts of the project had different degrees of leakage, and the basement was particularly serious. Bathroom waterproof construction quality is poor, there are hidden leaks.

1. Basement leakage

In the basement, almost all the edges of the pipe that penetrates the floor have been leaked, and the roof has leaked locally. The side wall is slightly better than the south, but only partially leaked, and the other walls have serious leakage, especially the eastern brick. The wall position is almost completely seepage; the bottom three floors of the basement have serious water accumulation, and there is no evidence of water seepage in some places.

2. External wall leakage

During the on-site survey, it was found that in the case of light rain in the winter, many external wall leaks occurred.

Because the outer wall is not provided with a waterproof layer, the external wall of the building has caused different degrees of leakage in the case of light rain in winter, and leakage occurs in some weak locations such as the intersection of concrete and masonry, and it is expected that When the spring and summer rain season arrives, more and more extensive leaks will occur, and this will seriously affect the daily living of the residents.

3, bathroom waterproof construction

(1) Some bathroom wall tiles have been completed, but no waterproof treatment has been carried out. The bathroom is not waterproofed. When the decoration is completed and put into use, the water will seep through the weak position of the bottom pipe of the sinking tank and the side wall of the toilet wall to the back of the toilet or the back wall of the toilet to destroy the decoration layer and bring great benefit to the owners' living. The inconvenience.

(2) Some bathrooms have been treated with water, but the construction quality is very poor. Before the waterproof construction, the grass-roots layer is not treated, the grass-roots layer is rough, and the remaining cement mortar is not cleaned. Looking at the waterproof layer of the side wall, the thickness of the waterproof layer is obviously insufficient, and the waterproof layer cannot be used for waterproofing at all. After the construction of the waterproof layer is completed, no protection is provided, and it is obvious that the waterproof layer has been damaged, and the root of the pipeline has not been specially treated, and there is a great potential for leakage.

Third, leakage analysis

Through the analysis of actual leakage conditions at the site, combined with Yuhong's experience in the same type of water-repellent treatment for many years, the analysis has resulted in leakage or hidden leaks mainly due to the following reasons:

1, the design unit design is not properly

According to the function of the building, the level of waterproofing of the basement of this project shall be more than two grades. According to the requirements of “Technical Specifications for Waterproofing of Underground Works” GB50108-2008, two or more waterproof layers shall be installed (one of which is self-waterproofing of concrete structures. , and should be set according to the specification of a flexible outer waterproof layer). The exterior wall of the basement part of the basement is a lightweight brick block, and is a post-laying structure, and it is impossible to make a waterproof outer layer out of the basement. Therefore, a serious leakage phenomenon occurs in this part.

In addition, according to the “Technical Regulations for Building Waterproofing Projects” of Guangdong Province, the outer wall of the project shall be provided with a layer of polymer cement waterproof coating in addition to the steel wire (board) mesh to be leveled and the polymer cement mortar leveled. This project is not provided with a waterproof layer, which is the source of the leakage of external walls.

2. The construction unit does not pay enough attention to waterproofing procedures

In order to grab the construction period, the roof of the local lower room was not waterproofed and the earthwork had been backfilled for the construction of outdoor ancillary facilities. The basement floor of the basement now has leakage, and some floor slabs have also leaked. With the advent of the spring and summer rainy season, more water will accumulate on the roof and there will be more leakage. In severe cases, it will even affect the use of underground garages.

3. Problems existed in the construction quality of waterproof sub-projects of construction units

According to the person in charge of the construction site of the construction unit, the outer wall of the basement part of the project is provided with a flexible water-proof outer layer, and the self-waterproofing of the structural concrete is fully able to achieve the secondary waterproof rating, but the basement still has serious seepage. Leakage phenomenon, which is mainly due to the construction unit waterproof construction quality problems.

From the perspective of the waterproof construction of the bathroom, there are problems such as poor construction quality of the screed, insufficient thickness of the waterproof layer, and no special treatment of the waterproof detail nodes, which causes serious leakage hazards in the bathroom.

4. The supervising unit supervises the waterproofing project

It was found that the lack of design of the design unit and supervision of the construction unit's project quality was the responsibility of the supervision unit. However, during the entire process, the supervising unit neither found nor pointed out that the design unit had a lack of waterproof design, nor found any problems with the waterproof construction quality of the construction unit, which was also one of the reasons that could not solve the leakage of the basement engineering.

Fourth, the consequences of leakage

The proportion of water-proofing in the entire construction project cost is often not high, and it usually accounts for only about 3% in the country, but it is not even 3% for buildings that are really valued for waterproofing. In buildings, the most common problem is the leakage of water, and building leakage often leads to a series of adverse consequences:

1. The leakage of basement and other structures not only affects the use of its indoor function, but also leakage of water causes the destruction of alkaline environment inside the concrete, corrosion, corrosion of steel bars, etc., ultimately reducing the strength of the structure and reducing the service life of the building. .

2. Leakage of external walls, toilets, and roofs will affect the daily living of the owner. Severe words may cause the owners' dissatisfaction and affect the reputation of real estate developers.

3, repair costs caused by leakage of water leakage is often ten times or even hundred times the cost of the original waterproof layer. In addition to causing huge economic losses to the construction unit, some special parts such as the basement floor, deformation joints and other repairs are often unable to guarantee the repair effect, but also will cause the construction unit in the management of the characters and material waste.

V. Solution

It can be seen that the waterproof system of a building should not only assume the waterproof function, but also have the protective function of the protective structure, and its importance is self-evident. Therefore, we should pay attention to the waterproofing of the building from the start of building design of the building to the completion of construction of the building. As a construction unit, if you want to solve the problem of leakage of existing buildings and avoid the same leakage situation in new buildings, you should pay attention to the following aspects:

1. In terms of design, designers are required to strictly carry out special waterproof design in accordance with national and regional relevant waterproof technical specifications. If necessary, invite professional waterproof technology companies to provide professional technical advice or participate in waterproof design;

2. In the use of materials, it is necessary to use the waterproof products of the famous national waterproof brands, and strictly follow the specifications before the use of raw materials for sampling inspection;

3. In the construction, waterproof construction subcontracted by professional waterproof construction units to ensure the construction quality of the waterproof project;

4. In terms of management, the supervision unit and the construction unit should strengthen the monitoring of the waterproof quality, strictly follow the relevant national regulatory requirements for water-closed tests, and carry out sampling inspection of the waterproof finished products to ensure the waterproof effect of the waterproof layer;

5. In the treatment of areas where leakage has already occurred, an experienced professional waterproof construction unit shall formulate a practical and feasible waterproof plugging scheme according to the actual situation, and the construction unit shall select the best and take the time for waterproof plugging construction.

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