In order to exclude flooding of the house on the territory of the site, wall drainage should be equipped. Such a system will limit the rise in groundwater level to a critical level, when there is a possibility of flooding the first floor and flooding the basement, which can cause the destruction of the foundation.
The described system is a whole complex of elements that are below the level of the basement floor and protect the structure from storm water and the penetration of underground moisture. You can do this work yourself, they will not be too expensive financially, but you will have to work hard. After all, you have to dig a pit around the perimeter of the house, and then fill it with the components of the system.
Features
The drainage system of the base of the house is necessary if the building has a basement or basement. You need to think about the need for such work at the initial stage of construction, when the foundation pit is laid . If the construction is ready, and drainage was not provided during the design process, then you will have to spend not only strength, but also time and, of course, money.
To provide the existing building with reliable protection against groundwater, it is necessary to dig a pit, which will be located around the building. Wall drainage requires the use of pipes called drains. They are located around the perimeter of the house, and in the corners should be located viewing wells. At these points the elements will connect.
The pumping-out well should be located at the lowest point of the site, excess moisture will enter into it and be removed to storm sewers or a nearby body of water. At a maximum distance of 1 m from the foundation, it is necessary to lay a clay castle, which will provide additional protection against the penetration of water.
Varieties of drainage elements
Wall drainage is equipped using several types of elements, among them:
- linear drainage;
- reservoir drainage.
The first variety involves the use of polyvinyl chloride sections, which are equipped with gutters. The whole system is closed by gratings and arranged along the perimeter of the blind area. In this case, excess moisture enters the receiving well through pipes.
The second type of drainage elements is reservoir drainage. It is located under the foundation slab and is on the same level as the sand cushion. Moisture in this case enters the receiving well through perforated drains, which are sprinkled with rubble and river sand. This layer acts as a protective filter.
Calculation of the drainage system
The calculation of wall drainage must be carried out necessarily, while it is necessary to determine the depth at which the foundation will be laid. It does not matter what material you plan to use to drain the liquid, the entire drainage system should be located below the base cushion by 0.5 m. The minimum value is 30 cm.
When calculating, it is important to determine the bias. Wall drainage should have a uniform decrease towards the collector. The angle is calculated taking into account the coefficient of 0.02. This indicates that for each meter the slope should be 2 cm, which will ensure the drainage of liquid and prevent stagnation of water in the pipes.
The lower and upper points of the system must be determined in advance. The depth at which the upper part of the system will be laid depends on the place of collection and removal of excess moisture. The top point is usually the corner of the house, while the bottom is the well that receives drains.
Features of the calculation
An example of calculating wall drainage will be discussed below. The width and length will be 6 and 9 m, respectively. A well will be located 10 meters from the house, while its upper level should rise 30 cm above the ground.
The length of each section to the branch will be 15 m, this value is the sum of the width and length of the house. The total length of the well will be 25 m, to obtain this value, you need to add the distance from the well to the house to the length of each section. The allowable slope of the system is 50 cm.
Of 25 m of total length, 2 cm will go for each meter. If the discharge point is high, you need to install a special drainage pump, which will pump liquid from the receiver. When a wall drainage scheme of a foundation is drawn up, it is important to take into account the conditions of a particular case, but they do not affect the distance from the house to the drainage of the foundation slab. This value should be 3 m or more. Gravel and sand are poured to a depth where they will not swell if groundwater freezes. The presence of blind areas made of concrete is important to provide. It should move 1 m or more from the base of the house.
Stages of work
If you decide to build a wall drainage around the house, it is important to act on a special technology. To begin with, sand is laid, while you need to determine the height difference using a laser level. Marks can be made to add coarse sand to create an even slope. This will eliminate the use of the pump. A layer of geotextile is laid on top of the sand. Washed gravel is poured onto it, in which recesses for drainage pipes should be made .
The same slope must be maintained along the entire length of the ditch. Perforated polyvinyl chloride pipes are laid on gravel. Pipes should have openings, the size of which should not exceed the minimum size of gravel particles, otherwise clogging will occur.
The design of wall drainage must necessarily include the need to connect pipes to each other. The whole system is equipped with a general slope, which is 2 cm per 1 m of pipe length. You can check the correct arrangement of the elements using a stretched cord. It is important to provide a vertical pipe, which will have a lockable lid. This assembly is provided when turning. Such elements will facilitate the flushing of the system.
Specialist recommendations
The laid pipes are wrapped with geotextile, there should be no gaps between the turns, this will eliminate the likelihood of gravel getting into the holes. Fixation can be done using a nylon rope. The scheme of wall drainage provides for filling the pipes with clean gravel of 20 cm. The gravel cushion is covered with geotextile overlapping to prevent soil from entering the cracks.
Large river sand is poured over the drainage, which will act as an additional filter. Particular attention should be paid to the tight fastening of the textile winding at the ends of the branches. The release of the sewer pipe, which will move away from the house, should be insulated. It is wrapped with a 25 cm foam layer.
General requirements and standards
Wall drainage at home should be equipped with rules and regulations. The system should be located outside, along the contour of the building. The step between the wall and the drainage pipe is determined by the design width of the foundation and the features of the placement of inspection wells. If the base of the house is located at an impressive depth, then you can lay the drainage above the sole of the foundation, however, these recommendations are only true if measures are taken to exclude subsidence of the drainage system.
If you want to save on sand and reduce the cost of construction, you should use geocomposite materials, which consist of profiled plastic membranes glued with geotextiles on one side. Membranes will be able to protect the base of the house from moisture and will cope with the drainage of water to perforated pipes, because they have a unique surface. A geotextile filter will allow water to pass through but retain soil particles.
Drain pipe selection
The device of wall drainage requires the choice of pipes. The material should be selected taking into account the installation depth and groundwater aggressiveness. The most popular are plastic pipes from:
- polyvinyl chloride;
- high density polyethylene;
- low pressure polyethylene;
- polypropylene.
Plastic drains are widespread, because they are lightweight, they are easy to deliver to the object and easy to lay. Drains can be selected with full or partial perforation. They are intended for a specific laying depth, but usually this value does not exceed 6 m.
Features of laying drain
The connection of pipes to each other can be carried out by couplings, which are made of material identical to the pipes. During installation, it is important to ensure that the water inlets are on the sides. The lower and upper sides of the pipes should be solid, not have cuts.
In order to avoid clogging of the holes, the pipes must be wrapped with geotextile. In addition, this measure will protect the material from siltation. It is not necessary to increase the longitudinal slope of the pipes above the minimum standards, as this will increase the volume of construction work. The maximum slope was mentioned above, and it is determined taking into account the permissible value of the speed of water flow. This parameter is 1 m per second.
Installation of manholes
Between the inspection wells, it is important to ensure a gap of 40 m in straight sections. Neighboring drainage wells should be 50 m apart. It is important to provide a distance of 20 m from the drain turn. Additional wells are installed in one turn if the system has several turns in a difficult area between two wells.
If you arrange drainage on your own, then you definitely need to remember the depth of the laying of the discharge and water intake elements. If it is not possible to organize the release of water by gravity from the drainage, it is important to provide for a pumping station.
Conclusion
Wall drainage acts as one of the effective ways to protect the foundation of the building from the effects of water. Its device is the key to long-term operation of the building. It is possible to solve the problem of water entering the basement in a complex, using several protection methods at once.
If you decide to equip the hydraulic seal, then the clay is laid with compulsory tamping. Several layers should be supplemented with crushed stone. This method will reduce the flow of water from the lower horizons. Then you can start laying the drainage system around the perimeter of the building. Pipes should be looped, ensuring the presence of drainage wells in the corners.