How to make your own foundation foundation drainage: step-by-step instruction on arrangement

Vasily Borutsky
Checked by a specialist: Vasily Borutsky
Author: Lyubamira Lysyuk
Last update: August 2019

Groundwater negatively affects underground structures. Most of all, it "gets" the foundations and basements. The former are gradually eroded and lose the necessary strength, the latter are flooded, not suitable for operation.

In order for the country estate not to suffer, it is enough to build a drainage. But first, you should familiarize yourself with the principles of its device. Right?

Home masters and zealous owners who want to make effective drainage of the foundation of the house with their own hands will find a lot of really useful information on our site. With our help, the arrangement of a groundwater drainage system will become a simple, affordable task.

The article describes in detail varieties of drainage systems designed to protect the foundation. The rules of their arrangement are given, the requirements of the standards are taken into account. Photos and videos were used as visual applications.

The need for a drainage system

Unpleasant smell and dampness in the basement, mold and fungus on the walls - such problems may be encountered by owners of houses located in places of high groundwater passage. But these are not the most serious troubles that threaten an unprotected structure.

Water, periodically penetrating the lower floors of the building, gradually undermines the supporting structure, in addition, it exerts hydrostatic pressure on the floor and walls of the house.

It is especially important to protect buildings built on clay soils, since they trap moisture, and in the winter they build up, which can lead to the complete destruction of the foundation, and ultimately the entire structure.

Properly performed drainage of the site helps to solve several important problems at once:

  • protect the basement houses from flooding, mold and deterioration of building materials;
  • secure the foundation from moisture and extend its service life;
  • drain the soil around the house and eliminate stagnation of water;
  • prevent soil oversaturation with moisture after heavy rains and stagnation of water on the surface.

However, not always and not in all areas it is necessary to arrange a water drainage system. Before planning and making the foundation drainage, it is necessary to take into account a number of factors: the location of the site, the composition and quality of the soil, the level of groundwater passage, the topography, and climatic features of the region.

Basement water level
The drainage network prevents flooding and ensures the drainage of groundwater from the basement of the house (+)

The arrangement of a drainage network is mandatory in the following cases:

  1. The basement of the house is below the groundwater level during the flood period or rises above them by less than 0.5 meters.
  2. The building was built on clay soil: sandy loam, loam, even when groundwater flows much lower than the house.
  3. The site is located in a lowland or on a slope.

It is not necessary to install a complete drainage system in areas located on sandy, gravel and gravelly soil types, on high ground or with low groundwater passage. You can limit yourself to the organization of storm sewers to divert rainwater from the building.

But this is possible only in those areas where the type of soil and the level of groundwater occurrence are precisely known. If it is planned to build a house in a new area, now engineering-geological surveys are mandatory.

Groundwater in the basement
If the basement of a building is at or slightly above the passage of groundwater, liquid will inevitably leak into it

They are necessary for the competent choice of the type of foundation foundation for the house. At the same time, studies of soils under future construction make it possible to solve the problem of the need for drainage work.

Geological engineering surveys
Engineering and geological work allows you to determine at what level groundwater is located in the area, and to establish whether there is a need for a drainage network

Types of site drainage

There are several varieties of drainage that can be done on the site.Depending on the depth of the underground water table, the drainage is divided into surface and deep.

How to make a drainage site yourself
Drainage systems for draining suburban areas are divided into open and closed varieties. It’s easier and faster to open type of drainage (+)

A feature of the surface system is that its elements are located at a shallow depth, which ultimately limits its functionality.

Outdoor site drainage
The easiest and cheapest way to install a system for draining water from a site is an open drainage device. It is a branched system of grooves, the walls of which are strengthened with crushed clay

The standard depth of open drainage is about half a meter. It is used in areas with characteristic stagnation of flood water. If it is necessary to install the system at a greater depth, concrete trays are laid at the bottom of open ditches and the width of the trenches increases significantly, which is extremely undesirable for small suburban areas.

Types of site drainage
The figures show the main types of drainage systems that can be equipped on the site for the removal of rain and underground water from the house (+)

Features of an open drainage network

This is the simplest and least expensive drainage system, which is implemented as a network of open trenches designed to collect and divert excess water from the household territory.

It is often used in the arrangement garden drainage. The open type of drainage at the same time removes rain and melt water from the building, as well as excess fluid generated during washing or irrigation.

However, this type of drainage cannot be called a complete system; it will not be able to protect the structure from the penetration of groundwater into the part of the structure buried in the ground. If the groundwater in the area is high enough, such drainage can only be used as an additional fluid drainage system.

Stormwater as an effective supplement

To collect and withdraw from the site of water stagnant as a result of precipitation, a storm system is arranged. It is constructed if there is a need for unloading drainage that does not fully cope with the drainage of the territory. The storm line is equipped with point or linear water inlets.

Point or in another local water collector, designed to drain fluid from certain areas. It is mounted in places where water periodically flows: under drains, in front of doors, under taps, etc.

A pit is dug under it, where a storm water inlet is installed, which in turn is connected to the pipes of the sewer system of the site. The top is closed by a decorative grill.

Spot drainage
When laying pipes from the storm water inlet, a slope of at least 5 mm per meter of pipe must be provided

The linear water intake is designed to drain fluid from the house and from the soil surface throughout the entire site. It connects to a network of channels located in accordance with the developed installation scheme.

Typically, the network is mounted around the perimeter of the building, at the bottom point a sand detector is installed to collect garbage. The system joins an underground storm sewer, through which water is discharged into drainage wells.

Linear drainage
Trays designed for linear drainage devices have different widths, depths, and throughputs. They are selected in accordance with the characteristics of a particular drainage system.

To arrange linear drainage, a trench is digged around the foundation, then a concrete base is laid on its bottom, where special plastic or concrete trays for receiving water are installed.

The network can be left open, but the closed withdrawal system, on top of which a decorative protective grille is mounted, is more popular.

Closed System Device Rules

If the foundation of the house is installed on clay soil, it is possible to solve the problem of fluid drainage only by arranging a full-fledged deep drainage system.

The low filtration properties of sandy loamy loamy sandy loam prevent the free flow of water into the underlying layers, which is why watering is felt even at the level of soil development - 0.2-0.4 m from the day surface.

The situation is similar in areas with high standing groundwater mirrors. There, it is it that prevents floods and atmospheric precipitation from penetrating into the underlying layers. In areas with high groundwater levels, usually located in lowlands, even a foundation buried in sandy soil needs a protective drainage system.

House drainage scheme
Very often, a combined system is installed at the sites, including drainage and storm sewers, while the fluid coming from both networks is discharged into one collector well (+)

Closed, i.e. underground drainage to protect the base of the building can be performed in two versions: wall or ring. In both cases, the drainage system is a closed network of perforated pipes laid underground, through which liquid is discharged into the collector or filter well.

The difference lies in the location of the pipeline in relation to the house:

  • wall drainage performed in close proximity to the building;
  • ring way - the trench is excavated at a distance of not less than 1.5 m and not more than 3 m from the foundation of the house.

In areas with a high level of subsurface water and clay rocks foundation wall drainage. It is also recommended to do it when the building has a basement.

The ring is most often equipped on soils with good permeability (sand, pebble, gravel, gravel) and in cases where the ground floor is not provided.

Wall drainage
In view of the fact that the wall drainage of the foundation is laid near the house, it is advisable to carry it out at the construction stage

Work is recommended to be carried out at the initial stage of construction, this option is more preferable and convenient. However, if during the construction of the building drainage pipes were not laid, the ring drainage of the house can be done even when the house is already built.

As for the near-wall option, it is not advisable to carry it out next to the finished structure, since interference with the construction of the foundation can adversely affect its strength and durability.

Ring drainage around the foundation of the house
Both wall and ring drainage are a single closed network of pipes laid along the perimeter of the building. In both cases, it is necessary to observe the recommended parameters for the drainage depth (+)

The effectiveness of the drainage network depends on two key parameters: the laying depth and the slope of the pipeline. The depth of the drainage depends on the deepening of the foundation of the house.

Here the main rule is that the pipeline should go half a meter deeper than the bottom of the foundation. For a good outflow of water, a certain pipeline slope in the direction from home.

In areas with a natural slope, the pipeline is laid in accordance with the channel that the water did. For flat areas, the slope will have to be done independently, giving the bottom of the trench a certain relief. Water will drain well if the slope of the pipeline is 1-3 cm per linear meter.

If it is not possible to create the desired slope, it is established pump for pumping water.

Underground Drainage Equipment

For laying the drainage system, special pipes are used - drains made of PVC or polyethylene. They differ from other types of pipes by the presence of small holes located on the surface at the same distance from each other. The holes serve for the penetration of groundwater into the pipeline.

Drainage pipes
Drains are produced with a diameter of 50 to 200 mm, which allows you to choose pipes for the desired size of the outlet openings and ensure the removal of the required volume of fluid

Important elements of the drainage network are wells. Usually, several types of wells are installed in a system. At all turning sections of the highway, as well as at junctions mounted audit tanks.

Swivel wells are needed for periodic inspection of the system and, if necessary, for cleaning operations. Wells are containers made of plastic with a diameter of 315 or 400 mm. They can be made independently using plastic pipes of the required diameter.

Swivel well
Through swivel wells, it is easy to clean and flush the system in the event of clogging. To do this, just send a stream of water under high pressure into the pipe

In areas where, due to the nature of the terrain or for technical reasons, it is not possible to drain water into natural water bodies, water intake wells are installed.

They are designed to collect liquid, which in the future can be used to irrigate the site or other household needs. So that the incoming water does not overflow into the pipes, a check valve is installed.

Water well
All pipes through which groundwater flows are diverted to a single collector, which is often used to collect fluid from the surface drainage network

In soils characterized by high absorption capacity, filtration wells are installed. In these designs, instead of the bottom, a special drainage filling is provided, through which the liquid, after preliminary cleaning, goes into the ground.

The diameter of such a well is from one and a half to two meters. The design can serve drainage systems in which the volume of incoming fluid does not exceed 1.5 m2 per day.

Short photo course on the construction of drainage

Consider the process of installing a drainage system designed to drain groundwater from the foundation of a newly built house. To the level of laying the foundation of the building, the geological section is represented by loam and a soil and plant layer on top, the thickness of which did not exceed 20 cm

Loam is characterized by low filtration properties, poorly and extremely slowly passes water. During the flood period, the site is flooded, and during freezing and thawing of soils it sags unevenly.

In order to get rid of groundwater, it was decided to build a drainage system with its output into the collector well with an absorbing bottom.

Now let's start the construction of a well with an absorbing bottom, thanks to which the water collected by the drains will be disposed of in the underlying layers with good filtration qualities:

Now we can safely admit that the system is actually arranged, it remains only to carry out work on the final filling and arrangement of the site:

System device work

When arranging a wall drainage network, before making the foundation drainage itself, it is necessary to properly waterproof it. To do this, you must first coat the walls of the house with two layers of bitumen mastic. In this case, the first layer is reinforced with a paint net.

This work helps to strengthen the foundation and prevent its destruction.

Wall and ring drainage
The same materials are used to equip the wall and trench drainage. But in the first case, it is necessary to additionally carry out waterproofing and insulation of the foundation (+)

A trench is excavated around the perimeter of the entire house half a meter deeper than the foundation foundation. On turning areas, it is necessary to provide places for the installation of drainage wells. When installing a wall system, the trench digs either near the house itself, or at a distance of no more than half a meter from the house.

If the ring option is selected, 1.5-3 m away from the structure. The bottom is carefully tamped, then sand is laid at the very bottom with a layer of 5 cm and also well compacted. Using sand at the bottom of the trench create the necessary slope. Geotextiles will first fly onto a sand cushion - its edges should protrude about 50 cm from each side.

Geofabric will serve as a filter that protects the system from siltation. Then crushed stone 10 cm high is poured, and already on it drainage pipes are laid, which are also covered on top with rubble backfill.

Drain pipe
A drainage pipe wrapped on all sides is the center of a kind of cake made of waterproofing materials. With this backfill, it will well tolerate subzero temperatures and other adverse weather events.

The resulting structure is covered with both edges of the geotextile overlap so that the pipe is completely wrapped in fabric. In places where the pipeline is turning, inspection wells are installed.

Taps for inserting pipes are made at a distance of at least 20 cm from the bottom. This indentation is necessary so that debris that enters the drains along with water settles at the bottom of the well, rather than entering the collector. When the system will be audited, debris can be removed with a jet of water.

After the pipes are connected to the pivot wells, the trench is backfilled with soil excavated from it. On top of the wall drainage, after tamping it, blind area of ​​the building.

Conclusions and useful video on the topic

This video details how to properly drain the area:

The video tells how to drain the foundation of the finished house:

So that dampness and mold do not settle in the house, and does not turn the life of its inhabitants into a continuous nightmare, it is necessary to timely drain the foundation. This work is recommended to be performed at the construction stage. For calculations it is better to attract a specialist, and the drainage itself can be equipped independently.

Is there anything to supplement, or have questions about organizing the drainage of the foundation of the house? You can leave comments on the publication, participate in discussions and share your own experience in installing a drainage system. The contact form is located in the lower block.

Was the article helpful?
Thanks for your feedback!
No (12)
Thanks for your feedback!
Yes (82)
Visitors Comments
  1. Leonid

    For our site, open drainage did not fit at all, yes - it was easy to execute, but I had to constantly clean it, and the view of the site deteriorates, plus you constantly stumble and fall. It was quite difficult to withstand a tilt angle of 1/100, so in practice it is still better to use 2 cm per 1 pm, and I did not want to install the pump, additional noise was excluded.