Do-it-yourself wall drainage of the foundation: stages, technology and features

Do-it-yourself wall drainage of the foundation: stages, technology and features
Do-it-yourself wall drainage of the foundation: stages, technology and features

In order to prevent flooding of the house on the site, wall drainage should be equipped. Such a system will limit the rise in groundwater levels to a critical level, when there is a possibility of flooding the first floor and basement, which can cause the destruction of the foundation.

The described system is a whole complex of elements that are below the basement floor level and protect the structure from storm water and the penetration of underground moisture. You can carry out these works on your own, they will not be too costly financially, but you will have to work hard. After all, you have to dig a pit along the perimeter of the house, and then fill it with the components of the system.


wall drainage

Drainage system for the base of the house is necessary if the building has a basement or basement. It is necessary to think about the need for such work even at the initial stage of construction, when the foundation pit is being laid. If athe building is already ready, and drainage was not provided for in the design process, then you will have to spend not only effort, but also time and, of course, money.

To provide the existing building with reliable protection from 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 manholes should be placed in the corners. Elements will connect at these points.

The pumping well should be located at the lowest point of the site, excess moisture will flow into it and be removed to the storm sewer 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 water penetration.

Varieties of drainage elements

wall drainage device

Wall drainage is equipped using elements of several types, among them:

  • linear drainage;
  • reservoir drainage.

The first variety involves the use of PVC sections, which are equipped with gutters. The whole system is closed with bars and arranged around 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 with the sand cushion. Moisture in this case enters the receiving well throughperforated drains, which are sprinkled with rubble and river sand. This layer acts as a protective filter.

Calculation of the drainage system

wall drainage calculation

Calculation of wall drainage must be carried out without fail, and 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 pad by 0.5 m. The minimum value is 30 cm.

When calculating, it is important to determine the slope. Wall drainage should have a uniform decrease towards the collector. The angle is calculated using a factor of 0.02. This indicates that for each meter the slope should be 2 cm, which will ensure the drainage of liquid and prevent water stagnation in the pipes.

The lower and upper points of the system must be determined in advance. The depth to which the upper section 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 point is the well that receives drains.

Calculation features

house wall drainage

An example of wall drainage calculation will be discussed below. In this case, 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 tap will be 15 m, this value is the sum of the width and length of the house. The total length of the well will be25 m, to obtain this value, you must add the distance from the well to the house to the length of each section. The allowable slope of the system will be 50 cm.

Out of 25m total length, 2cm will go to each meter. If the discharge point turned out to be high, you need to install a special drainage pump that will pump the liquid out of the receiver. When drawing up a foundation wall drainage scheme, it is important to consider 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 the groundwater freezes. The presence of a blind area made of concrete is important to provide. It should move away from the base of the house by 1 m or more.

Stages of work

wall drainage scheme

If you decide to build a wall drainage around the house, then it is important to act according to a special technology. To begin with, sand is laid, while it is necessary to determine the height difference using a laser level. You can make marks to add coarse sand to create a uniform slope. This will eliminate the need for a pump. A layer of geotextile is laid on top of the sand. Washed gravel is poured on it, in which recesses for drainage pipes should be made.

The same slope must be observed along the entire length of the ditch. Perforated PVC pipes are laid on the gravel. The pipes must have holes, the size of which should not exceed the minimum particle size of the gravel, otherwiseclogging occurs.

The wall drainage project must necessarily provide for 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 location of the elements using a stretched cord. It is important to provide for a vertical pipe, which will have a closable lid. This node is provided when turning. Such elements will facilitate the flushing of the system.

Specialist recommendations

wall drainage project

The laid pipes are wrapped with geotextile, there should be no gaps between the turns, this will eliminate the possibility of gravel getting into the holes. Fixation can be done with a nylon rope. The wall drainage scheme provides for backfilling the pipes with clean gravel by 20 cm. The gravel cushion is covered with overlapping geotextiles to prevent soil from getting into 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 outlet of the sewer pipe, which will depart from the house, should be insulated. It is covered with a layer of foam 25 cm.

General requirements and norms

wall drainage calculation example

Wall drainage at home should be equipped in accordance with the 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 andfeatures of the placement of manholes. If the base of the house is located at an impressive depth, then drainage can be laid above the sole of the foundation, however, these recommendations are correct only if measures are taken to prevent the drainage system from sinking.

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 geotextile on one side. The 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. The geotextile filter will allow water to pass through, but retain soil particles.

Choice of drainage pipes

The wall drainage device provides for the need to select pipes. The material must be selected taking into account the depth of installation and the aggressiveness of groundwater. The most popular plastic pipes are from:

  • polyvinyl chloride;
  • HDPE;
  • LDPE;
  • polypropylene.

Plastic drains are widely used, because they are light, easy to deliver to the site 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 drains

The pipes can be connected to each other by couplings, which are made of material identical to the pipes. Important during installationmake sure that the water intake holes are on the sides. The bottom and top sides of the pipes must be solid, without cuts.

In order to prevent clogging of holes, pipes must be wrapped with geotextile. In addition, this measure will protect the material from silting. It is not necessary to increase the longitudinal slope of the pipes more than 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 water flow rate. This setting is 1 m per second.

Installation of manholes

It is important to provide a gap between the manholes, which is 40 m in straight sections. Neighboring drainage wells should be 50 m apart from each other. It is important to ensure a distance of 20 m from the turn of the drain. Additional wells are installed after one turn if the system has several turns in a difficult area between two wells.

If you are arranging drainage yourself, then you must definitely remember the depth of the drainage and water intake elements. If it is not possible to organize the release of water by gravity from the drainage, then it is important to provide for the presence of a pumping station.


One of the most effective ways to protect the foundation of a building from the effects of water is wall drainage. Its device is the key to long-term operation of the building. It is possible to solve the problem of water ingress into basements in a complex way, using several protection methods at once.

If youdecided to equip a hydraulic seal, then the clay is laid with a mandatory rammer. Several layers should be supplemented with crushed stone. This method will reduce the inflow of water from the lower horizons. After that, you can start laying the drainage system around the perimeter of the building. Pipes should be looped, providing drainage wells at the corners.

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