Groundwater negatively affects underground structures. Most of it “gets” to 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 winter they build up, which can lead to the complete destruction of the foundation, and ultimately the entire structure.
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The construction of a groundwater discharge system from the foundation is required in areas with characteristic flooding during the flood period and stagnation of water after rain
Drainage will protect the foundation from the aggressive effects of groundwater, from the gradual leaching of the binder from the concrete and the final destruction of the structure
The drainage system will prevent the penetration of melt, atmospheric and groundwater into the underground part of the structure, into the premises equipped in the basement and basement
The depth of the drainage circuit depends on the engineering and geological situation on the site and on the tasks
The drainage circuit will protect the base of the house from damage during the frosty period due to heaving of the surrounding soil layers
Drainage and stormwater drainage are two different systems that perform different jobs. The first lowers the level of groundwater and diverts it from the site, the second - collects and discharges rainwater. They are laid separately, but they can have a common viewing well and go into one collector
Despite the fact that drainage transports only groundwater, it is a serious sewer system that needs viewing and control points
The water collected by the drainage is discharged by the system either outside the area where it is discharged into the general sewer or sewage pond, or disposed of through an absorption well located on the territory
Prerequisites for drainage
Protection against weakening and destruction of the foundation
Basement Flooding Prevention
Small depth of the contour
Elimination of winter damage
Drainage and stormwater drainage
Point of control of the drainage system
Well for disposal of collected ground water
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 doing 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.
The drainage network prevents flooding and ensures the drainage of groundwater from the basement of the house (+)
The installation of a drainage network is mandatory in the following cases:
- The basement of the house is below the groundwater level during the flood period or rises above them by less than 0.5 meters.
- The building is built on clay soil: sandy loam, loam, even when groundwater flows much lower than the house.
- 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 restrict 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.
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 foundations 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.
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 types 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.
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.
The easiest and cheapest way to create a system for removing water from the 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.
The figures show the main types of drainage systems that can be equipped on the site to drain rain and groundwater from the house (+)
Features of an open drainage network
This is the simplest and least expensive drainage system, which is performed in the form of a network of open trenches designed to collect and drain excess water from the household territory.
It is often used in arranging drainage of a garden plot. 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 full-fledged system; it cannot protect the building 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 with a decorative grill.
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 divert fluid from the house and from the surface of the soil 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.
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. It is precisely there that it prevents flood and atmospheric precipitation from penetrating into the underlying layers. In areas with high groundwater level, usually located in lowlands, even a foundation buried in sandy soil needs a protective drainage system.
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 a collector or a filtration 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 dug out 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 surface water and clay rocks, wall drainage of the foundation is arranged. 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.
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.
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, it is necessary to provide a certain slope of the pipeline in the direction from the house.
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, a pump is installed for pumping water.
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Closed drainage trench
Waterproofing device
The use of geotextiles in the drainage device
Conclusion of a drainage pipe in a collector well
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.
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 liquid
Important elements of the drainage network are wells. Usually, several types of wells are installed in a system. On all turning sections of the highway, as well as at the junction points, audit tanks are mounted.
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.
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 terrain features or for technical reasons, it is not possible to carry out water diversion 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.
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.
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Around the house we dig a trench about 20 cm deeper than the depth of the foundation. To speed up the development, we rent a mini tractor, we retreat about 1.2 m from the wall of the house so that the equipment does not damage the house
In the direction in which the sewer pipe will be laid to drain the collected water into the collector, we try to make a bias. The lowest point of the trench around the house should be the angle at which the sewer will be connected to the drain pipe
During development, we try not to damage the existing communications. If the route is crossed by a water supply or sewage system, the entire trench will have to be deepened by the diameter of the opened pipe. As a result, the drain must be laid under the communications, while the slope of the trench must be observed
Before laying the drainage pipe, we wrap it with geotextile, which filters the groundwater and protects the drain from sand
We fill the bottom of the trench with sand and level it before laying so that there is a slope of at least 3-5 cm by 1 meter. We put drain on top and sprinkle with gravel
Where it is more reasonable to lay a drainage pipe near the sewer at the same height, we put them in one trench and fill it with gravel and sand
We lay a drainage pipe around the house throughout the trench, sprinkle it with gravel so that you can dig up and change position if necessary
We continue to develop the trench to the pit, which was previously dug by a mini-tractor. We comply with the required slope throughout the route
Step 1: Design a trench for a drainage device
Step 2: Slope to Unload
Step 3: Digging In Existing Communications
Step 4: Winding the drainage pipe with geotextile
Step 5: Laying the Drain Pipe in a Trench
Step 6: Laying the drain near the sewer
Step 7: Partially Filling the Drain Ditch
Step 8: Development of a trench to the installation site of the well
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:
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Step 9: Transporting Concrete Rings to an Object
Step 10: Assembling the Well from Concrete Rings
Step 11: Preparing the bottom of the well for the filter device
Step 12: Laying Geotextiles On The Bottom Of The Well
Step 13: Backfilling Sand and Fine Gravel on Top of Geotextiles
Step 14: Fill Coarse Gravel and Pipe Inlet
Step 15: Installing the Overlap on the Absorption Well
Step 16: Pumping Water From The Trench Before Laying Pipes
Now we can safely admit that the system is actually arranged, it remains only to carry out work on the finishing filling and arrangement of the site:
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Step 17: Backfilling a Trench with a Sewer Pipe
Step 18: Finishing the Trench with Sand
Step 19: Arranging the neck of the absorbing well
Step 20: Leveling the site and removing loam
System device work
When arranging a wall drainage network, before making the foundation drainage directly, 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.
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 whole 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 retreat 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 creates 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 with a height of 10 cm is poured, and drainage pipes are laid on it, which are also covered with crushed stone filling from above.
Wrapped on all sides, the drainage pipe 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 of turning the pipeline, 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, and does not enter 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 finished backfilled with soil excavated from it. On top of the wall drainage, after tamping it, make a building blind area.
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.
Have something 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 arranging the drainage system. The contact form is located in the lower block.