Foundation drainage: 3 types + how to do it yourself

A drainage system is a set of engineering structures designed to drain rain, groundwater and melt water. Vertical drainage is one of its types used in practice. Its main purpose is to lower the soil water level.

The creation of such systems is of great practical importance. After all, as is known, excess moisture negatively affects the condition of all buildings, reducing their service life, and the development of many cultivated plant species.

Properly organized drainage improves the comfort of living conditions.

Foundation contour drainage

To drain water from an already built foundation, wall and ring drains are used.
Their operating principle is the same. The difference is that the wall system is made close to the foundation, and the ring system is made at a distance, usually 1.5-2 meters. Wall drainage is installed in non-filtering soil (clay, loam). Collects surface melt water, which seeps mainly along the wall, and not through impermeable soil.

The ring system is suitable for sandy filter soils. Lowers groundwater levels.

Types of foundation drainage based on pipe laying depth:

• Perfect
  . Drainage pipes are laid on a waterproof layer of soil. Used if this layer is shallow.
• Imperfect
  . Pipes are laid above the waterproof layer if it lies deep.

Elements of wall and ring foundation drainage:

• Drainage trenches.
• Outlet pipes.
• Filter bedding, crushed stone or gravel.
• Filter fabric (geotextile).
• Basement waterproofing.
• Inspection wells.

We'll tell you how these elements are structured and why they are needed.

Drainage trenches

The RMD states that “in soft soils with insufficient load-bearing capacity, the drainage pipe must be laid on an artificial foundation.” This base is a sand cushion. For this we use river sand of 1.5-2 mm size. The thickness of the sand bedding is 50 cm.

Drainage pipes

Typically, corrugated pipes made of low-density polyethylene (HDPE) are used. The standard pipe diameter is 110 mm. The pipes have holes through which water flows. “The dimensions of water intake holes should be selected taking into account the granulometric composition of the soil to be drained” (RMD, 10.9)

Standard polyethylene pipe

Pipes are also used in geotextile filters. They are designed for sandy and loamy soils. These soils are easily washed away by water and can wash into pipes and clog them. The filter traps dirt.

Pipes in geotextiles

Crushed stone for drainage

Crushed stone is needed to filter groundwater so that the pipe holes do not become clogged. The filtering capacity of crushed stone depends on its fraction - the size of one grain. A fraction of 20-40 mm is considered optimal. We use exactly this crushed stone.

Geotextiles

Geotextiles protect crushed stone from erosion and also keep the soil from subsidence. As stated in the RMD, “a geotextile filter must pass water and screen out soil, not be unduly deformed and not limit the access of moisture to the drainage structure, and have bio- and chemical resistance” (RMD, 10.2).

Main characteristics of geotextiles:

• Manufacturing technology
  . From one endless thread (monofilament) or from a staple (individual threads 5-10 cm).
• Material
  . Geotextiles can be needle-punched, thermally bonded or hydro-bonded.
• Density
  _ Geotextiles with a density of 200 g/m³ are used for drainage systems
• Filtration coefficient
  . Measured in meters per day.

RMD recommends the use of needle-punched monofilament geotextiles. This geofabric is also used by our company.

Basement waterproofing

To protect the base from moisture, waterproofing membranes are used. They are laid with a 10 cm overlap and connected using self-adhesive bitumen-polymer tape. Fastening is carried out using plastic dowel-nails in increments of 20-25 cm.

Manholes

Needed to monitor the operation of the system and for cleaning. The well consists of a bottom part, a vertical part and a cover. The pipes are either made at the factory or are cut in during installation. Wells are installed along the drainage route every 40-50 m. It is imperative to install wells at turns in the route, as well as when there are level differences.

Storage well

Serves to collect water and drain it into a ditch. Installed at the lowest point of the system. A float pump is placed in the well, which releases water into the ditch.

Foundation drainage device:

• Drainage trenches are dug around the perimeter of the house.
• The trenches are filled with sand. The sand is leveled.
• Geotextiles are laid at the bottom of drainage ditches.
• Granite crushed stone is poured into the geotextile in a layer of 10 cm.
• Pipes are laid on crushed stone. The minimum pipe slope is 2 mm per meter in clay soil, 3 mm per meter in sandy soil.
• Inspection wells are placed at the corners of the route, and a drainage well is installed at the lowest point of the site. Pipes are connected to wells.
• Cover the pipes on top with crushed stone.
• Wrap the edges of the geofabric so that they overlap and completely cover the pipes and crushed stone
• The trenches are filled with sand.

The drainage system cannot be combined with storm sewer. This will lead to storm and melt water washing away sand and crushed stone. It is recommended to do drainage and stormwater in parallel, in one trench.

Where should the water collected by drainage be directed?

Option for installing a drainage network
In most cottage villages there is a place for this - either a general sewer system or a system of surface drainage trays or ditches. Many villages have a deep public sewer system, and when it is laid lower than the drainage network on the site, you can dispense with the pump: the water will flow there through the pipe by gravity due to the slope.

If the above options are not suitable, then you will have to pump the water into a pond, ditch, ravine or forest located near the house by running a hose or pipeline underground. True, you need to carefully consider the location of the water discharge so that it is not in close proximity to other buildings in the village, otherwise there is a risk of flooding neighboring areas. In addition, if the system collects water in a small volume (up to 1000 l/h), then it can be discharged into the ground at some distance from the building (except in cases where the waterproof layer lies close to the surface of the earth). To do this, dig a shallow trench, which is covered with crushed stone or gravel to improve the filtration of water into the ground.

Useful tips

It is quite justified to lay out pipes simultaneously with the preparation of inspection wells. This technique will help to avoid mismatch and system inoperability. In all wells they place a container to collect sludge or simply leave space for it. Between the pipe entry point and the base of the well shaft, 0.2-0.25 m is reserved. Backfilling of crushed stone on the sides of the drains is mandatory; Closer to the foundation it is worth raising it to the height of the soil itself.

It is recommended to lift the layer of crushed stone above the drains from 30 cm. Geological textiles are placed above, preventing the mixing of materials and the accumulation of silt. Next, sand is placed, raising it to ground level. It is strictly unacceptable to compact the sand backfill; this will weaken the permeability of the soil to water. Experts and experts advise choosing drainage pipes with a high level of rigidity.

To learn how to install a drainage foundation, see the following video.

Installation of a collector well

Jheka did not immediately cut and deepen the rotary wells; he postponed it until the stage of landscaping the yard.

The collector well was assembled from two concrete rings with a diameter of 90 cm, a lid and a hatch. The rings were lowered into place using a manipulator.

Laying technology

For the system to work properly, you need to know how to properly lay the drainage pipe, depending on the type. For each drainage pipe, the installation technology will vary slightly depending on the design. But the initial stage is the same for everyone:

1. Develop a drainage scheme: location of pipes, places for wells and revisions.
2. Depending on the type of soil, the geological characteristics of the site, the location of groundwater and the required throughput, the size and type of drainage pipe are selected.
3. Based on the planned route for wiring drainage pipes on the site, site planning and markings are carried out for excavation work.

The ideal option is when the drainage scheme is developed together with the house design

1. They dig trenches. On dense soils with straight walls, on loose soils - with sloped walls, or strengthen them during work. The bottom is made 30 cm wider on both sides of the pipe.
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2. Level the bottom surface, compact the soil, form a slope towards the drainage well within 0.5-3.0% (minimum 0.5 cm and maximum 3 cm for each meter of length).
3. Pour a layer of coarse sand about 15 cm thick and compact it, observing the slope laid down during the formation of the ditch bottom.

Further technology for laying the drainage pipe depends on its design.

Laying a drainage pipe with geotextile, if it does not have a factory winding:

1. Geotextiles are laid on top of the sand. The width of the canvas should be sufficient so that the edges can then be brought together.
2. Pour a layer of crushed stone (15 cm).
3. Lay a perforated pipe and cover it with a layer of crushed stone on top.
4. The edges of the geotextile fabric are wrapped and fastened together. As a result, the pipe should be uniformly filled with crushed stone on all sides of about 15 cm, the textiles should run along the sand-crushed stone boundary, and there should be free space left to the walls of the trench.

The principle of drainage is that water seeps through geotextiles, crushed stone and perforation, then flows by gravity through the pipe to the well

1. Pour a layer of sand on the sides and top (about 15 cm).
2. The removed or imported fertile soil is put back.

If the pipe has a factory winding made of geotextile, then the drainage installation procedure is reduced by two “steps”.

Note! You can buy geotextiles separately, choose perforated pipes without wrapping and wrap them before carrying out work.

When using pipes with a filter layer of polystyrene foam granules and windings, crushed stone is not covered. And if you believe the manufacturer’s advertising video, you don’t even have to fill in the sand.

https://youtube.com/watch?v=DloSGrkFtYA

Negative effects of flooding

The foundation of the house is constantly exposed to moisture from water penetrating from outside. Routes of penetration may be different:

• accumulation of water during bad weather in the absence of storm drainage;
• drainage of rain and melt water into the lowlands of the area where the house is located;
• location of groundwater near the house.

Penetrating into the foundation and basements, moisture creates many problems for home owners:

• dampness and unpleasant odors in the basement;
• covering walls and building structures with fungal mold;
• washing the supporting parts of the base;
• cracks and destruction of the foundation as a result of freezing and subsequent thawing of water inside the soil.

The final result of exposure to groundwater and melt water will be the gradual destruction of the home and complete unsuitability for habitation.

In what cases is wall drainage necessary?

Wall drainage must be installed in the following cases:

1. If the level of hepatitis B is high.
2. The amount of precipitation in the region is high.
3. The basement and basement rooms of the house are used for household purposes. needs.
4. If the ground floor is located below the hot water level on the site.
5. Floors in the basement are no higher than 0.5 m above the level of hot water.
6. If the soil on the site is loam or clay, the level of hot water is not taken into account.
7. The house is located in a place of capillary penetration of moisture with unacceptable humidity in the premises.

But in some cases, wall drainage of the foundation is not enough. Then they make a layer on top of the system along the perimeter of the house with an angle of inclination of 20, and a width of at least 1 m. The soil with which the drainage system is filled is compacted, and a waterproofing layer of bitumen-based materials is applied to the foundation from the outside.

You should not install a drainage system near the foundation if the house is built on sandy soil, when hot water easily penetrates into the lower layers, and in winter freezing occurs at least 80 cm. In this case, it is enough to coat the foundation with protective compounds, and the moisture will not harm the structure.

What is site drainage?

To eliminate these problems in the area around the house, a drainage system consisting of pipes and wells is laid in the ground. Hollow perforated plastic lengths are laid in the ground at a depth where moisture accumulates as much as possible. In places where drainage lines turn and at the end points, revisions are installed in the form of vertical corrugated cylinders. Drainage wells serve as inspection windows through which blockages are removed.

Properly laid downhill drainage on a site absorbs excess water from the soil and removes it outside the garden area. Thanks to this, the water balance is restored in the area next to the housing construction, eliminating the oversaturation of the soil with moisture. Drainage from pipes is laid in trenches dug at a slope according to the design.

Construction of base and grooves

Option 2. Scheme of a wall drainage system.

The first stage is the construction of a sand base. Here you will need sand, a laser level, gravel, a large geotextile fabric and a shovel for digging ditches. First, we level the area around the foundation slab, after which we fill it with sand about 20 cm. The sand needs to be wetted and lightly compacted, then, if necessary, topped up and leveled again.

After this, take a laser level and use it to measure the height fluctuations along the entire length of the future drainage system. Then mark the points where the system slopes using the same level. Place pegs in the designated places.

Now you need to lay geotextiles on top of the sand. Cut out pieces of the canvas of the required size in advance and lay them on the sand, pressing it there.

Option 3. Wall drainage scheme.

Geotextiles must be overlapped. Place gravel on top of it. The height of the gravel layer should be such that small grooves can be made in it, where pipes will be deepened to remove moisture (if the drainage is linear). In the case of reservoir drainage, the gravel layer should be slightly larger.

Now, in the places where the pipeline for pumping water will be laid, make a groove. The pipe should fit easily into it, but not be completely buried.

This is an important condition for the entire drainage system. The length of the groove should be equal to the length of the system from the top to the bottom drainage point.

Preparing the trench

The trenches for the drainage system have a depth corresponding to the level of the pipes. In order to be able to organize the desired slope, the depth is made with a small margin.

The direction and configuration of the trenches is determined by the type of drainage system chosen, and the width is usually made such that pipes with a layer of filler and insulator can be freely placed.

Usually they dig to a width of 30-40 cm, so that it is more convenient and the walls do not crumble.

Installation of wall foundation drainage around the house

Before you begin installing a near-house drainage system, you need to decide on its type, which depends on several parameters:

• types of soil;
• whether the building has a ground floor or basement;
• the origin of the water that needs to be drained.

The wall-mounted underground option is used in the presence of a base, high groundwater level and loamy and clayey soils. If it is necessary to protect the foundation of the house only from precipitation, then a surface system will be sufficient.

To protect a house located on sandy or sandy loamy soils with water and without a basement, ring (trench) drainage is used.

Having decided on the type of drainage, you can begin drawing up a diagram, designing the system and planning all the work. This stage allows you to eliminate all possible shortcomings, which are then expensive to correct.

For the plan, you need to decide on the lowest point on the site for installing a drainage well, which will be connected to the general ring of the system by a pipe.

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It is better to draw the diagram on graph paper or in a special program. The drawing should show:

• house, as well as adjacent buildings;
• trees and shrubs;
• places where drains pass, depending on the type of drainage chosen;
• inspection and drainage wells.

Inspection tanks are installed at the point where the pipe turns, for example, in the corners of the house, or every 30 m for a straight section of the pipe.

The plan should also record the depth of the pipes. This indicator depends not only on the bottom slab of the foundation and the height of the floor, but also on the level of soil freezing. Pipes must go deeper than the point of zero winter ground temperatures

It is important to write down the diameter of the drains, which affects the width of the trench, and the required slope

It is better to entrust design to specialists. But you can purchase the necessary material and install the drainage system based on a competent plan yourself.

Features of the closed version

Having figured out how to properly make drainage around the house and drawn up a project, you should prepare for further work.
You should stock up on materials, as well as the necessary tools. During the work you may need:

• twine for marking and marking the position of communications;
• building level and plumb line to control the slope of the pipes;
• bayonet and shovel;
• soil compaction tool;
• a bucket and/or wheelbarrow for transporting unnecessary soil;
• tape measure for taking measurements;
• hacksaw for metal, etc.

A certain number of drainage pipes will also be required. These are special designs with perforations, usually made of plastic. Instead, you can use plastic pipes for external sewage, after making holes on their surface with a regular drill.

Additionally, you need to prepare: geotextiles, sand, crushed stone or other similar material, inspection wells according to the number of turns, etc.

In the process of installing a drainage system around the house, geotextiles are used - a non-woven filter material, as well as crushed stone of large fractions

Geotextiles are necessary to protect the filler surrounding the drainage pipe from the penetration of fine clay particles and siltation. There is no need to skimp on this material. It should be enough to completely cover the walls and bottom of the excavated trench, and also cover the backfilled pipe with a substantial overlap.

It is recommended to first mark the ground and then begin excavation work. They usually start digging from the highest point of the system, gradually deepening the trench.

When calculating the slope of a drainage pipe, you can focus on the standard of 1%. If the length of the trench is 20 m, then the height difference between its starting and ending points should be 20 cm. The necessary measurements are made using a regular tape measure.

After the trench is ready, its bottom must be thoroughly compacted. Then a 10 cm layer of sand is poured onto the bottom, which is also thoroughly compacted. After this, it is recommended to cover the entire trench with a layer of geotextile so that both the bottom and walls of the structure are covered, and the edges of the material come to the surface and lie freely on the ground.

The construction of a closed drainage system uses perforated drainage pipes, geotextiles and backfill materials: sand, gravel, crushed stone (+)

Now, at the bottom, hidden by geotextile, you need to pour a layer of gravel about 20 cm. Any filter material will be acceptable: crushed stone, expanded clay, brick fragments, etc. The main thing is that its fraction is larger than the size of the holes in the drainage pipes, otherwise blockages cannot be avoided.

After laying, the gravel must be leveled and the slope of the communications must be checked; it must correspond to the previously carried out calculations and measurements.

If everything is in order, drainage pipes are placed on the gravel and connected to inspection and drainage wells. Then the system is covered with another layer of gravel (crushed stone, expanded clay, etc.). The height of this layer should also be 20 cm. The edges of the geotextile that remain free are wrapped over the backfill layer.

In the places where the drainage pipe turns, inspection wells are installed, which are necessary to monitor the condition of the system. They are covered with lids on top

The overlap of the layers of non-woven material should be about 30 cm. Sometimes it is recommended to secure the position of the geotextile material using twine or plastic fasteners.

Now you can fill the rest of the trench with sand (a 10 cm layer is needed) and soil. The sand again needs to be compacted, especially in the space on the sides of the drainage pipe. Previously cut turf is laid on top or paths are installed.

You can come up with your own version of decorating the place where drainage pipes are laid. There must be access to the covers of the inspection wells, as well as to the point of discharge of the diverted moisture.

Inspection wells are plastic vertical containers closed with lids. They are used to periodically check the status of the system.

A drainage well is a wider container; it can be round or square in configuration. Most often, an old plastic barrel is used to arrange it.

You can also use concrete rings of a suitable diameter or make walls from monolithic concrete. In the latter case, it is imperative to reinforce the structure. The top of the drainage well should be covered with a strong lid.

The process of constructing a ring drainage

Sand is poured into the bottom of the trench

To make it easier to create drainage for the foundation, you can make markings. For this purpose, various pegs are used, which can be easily removed.

You can arrange ring drainage as follows:

1. At a distance of 5 m from the house, you need to dig a deep ditch larger than the height and width of the house foundation in order to fit a pipe with a diameter of 11 cm. There should still be 10 cm indentations from the pipe on each side.
2. Sand in a layer of up to 100 mm is placed at the bottom with a slope towards the reservoir. This way the water can drain on its own.
3. The drainage pipe is placed in the trench, on geotextiles, its ends are fixed to the walls of the ditch. The pipe is laid in a trench, covered with gravel to a depth of 50 cm, then wrapped in material twice. The seams of the structure are fastened and covered with sand or gravel.
4. The pipes are connected, but not at a right angle, so that silt does not accumulate.
5. To construct an inspection well, a hole is dug and a container with a hole for water drainage is placed. Here you also need to place geotextiles on the bottom to prevent pebbles from getting in.
6. If the soil is heavy and does not allow water to pass through well, a solid pipe can be used for drainage.
7. If there is a large accumulation of water in the reservoir, it can be pumped out and watered for garden plants.

Rules and nuances of design

The choice of drainage type for a country house or the location of channels is influenced by many factors.
For example, the terrain is of great importance. If the house is located on a hill, and the rest of the territory is located at a slight slope, then wall drainage is most likely not required, and groundwater can be drained from the site by creating a canal system. The location of groundwater is important. Difficulties with installing buried objects may arise if the level is high enough - from 1.5 m in depth

With this arrangement, installation of a drainage structure is necessary both to ensure the protection of buildings and for the safe development of the soil layer

Difficulties with installing buried objects may arise if the level is high enough - from 1.5 m in depth. With this arrangement, installation of a drainage structure is necessary both to ensure the protection of buildings and for the safe development of the soil layer

The nature of the surrounding area should also be taken into account. If the area around the site is swampy or a river flows nearby, and the plot seems dry, then for preventive purposes it is also necessary to design a drainage system.

Let us consider in more detail the nuances that should also be taken into account when laying pipelines and trenches.

#1: Line depth and dimensions

The location of the pipes of a closed drainage system is chosen based on the design development, taking into account the slope towards the drainage basin. The depth of installation of system elements depends on the groundwater level. For a wall-mounted device, trenches are dug at the level of the foundation base, since its goal is to enhance the waterproofing qualities of the underground structure and protect the basement.

Pipes arranged in a ring pattern are located at a distance of up to 3 m from the foundation. The depth of the pipes is greater than that of the wall structure, and most often below the location of the foundation (+)

Ring drainage is chosen if the construction of the house has already been completed, and accordingly, all waterproofing and protective measures have been completed.

If the soil of the garden plot constantly suffers from flooding by precipitation or seepage of groundwater, systemic drainage is required throughout the entire territory. There are many options - from arranging a system around the perimeter to an extensive network that includes all dacha objects (buildings, road surfaces, garden plots).

The direction of canals and pipelines is strict - towards drainage structures or ditches located outside the territory of the personal plot.

#2: Slope standards for drainage pipes

Water in horizontally located pipes will stagnate if installation is carried out without a slope, the parameters of which are specified in regulatory documents. For clay and sandy soil, which has different degrees of water permeability, the standards are different:

• loams and clay – from 0.003 or more;
• sand and sandy loam - from 0.002 or more.

If you convert the values ​​into millimeters, you get 3 mm/linear. meter and 2 mm/linear. meter respectively.

The minimum parameters are taken taking into account the fact that the lowest speed of water movement through channels and pipes is 1.0 m/s. This is possible if the drains are in working condition, that is, not silted or clogged with sand.

When calculating the maximum possible speed, the properties of the surrounding soil, as well as the quality of the sprinkling, are taken into account. You cannot make a slope at intervals - it must be observed throughout the entire length of the pipeline/channel

For hilly areas, options for installing drainage with differences are possible, with the installation of adapters in inspection wells.

Main types of drainage for foundations

Drainage systems can be divided into vertical, horizontal and combined. Vertical drainage is mainly used in mines or swimming pools. Such a system is equipped with pumps and special drainage wells for pumping out water. When the water drops, meter-long wells are made in the basement of the building and pumps with alarm floats are installed.

A horizontal drainage system is a horizontal pipe system. It can be open or closed. The system is divided into three parts: collecting, drainage and water receiving. Open horizontal drainage is often used to drain large areas, for example on farms. For private homes and industry, closed drainage is used. You can often find a combined type of drainage.

So, drainage for the foundations of a house involves the creation of a special drainage system of channels for underground or surface water. The construction of a drainage system largely depends on the groundwater level, the topography of the site and the magnitude of the surface slope relative to the horizontal plane.

What forces destroy the foundation?

Moisture in contact with a concrete strip causes a number of destructive processes:

• Erosion of the sand cushion, which results in subsidence and damage to the integrity of the foundation.
• Water soaks into concrete and destroys it from the inside in winter.
• When the temperature drops, the moisture in the soil layers surrounding the tape freezes, expands and begins to put pressure on the base or foundation walls (frost heaving of the soil).

Most often, these factors act simultaneously, which increases the danger to the foundation and the entire house. The waterproofing gradually fails , the insulation peels off, exacerbating the destruction process and changing the microclimate in the house for the worse.

The situation is dangerous, since all processes proceed slowly and secretly, the results become noticeable only when destruction, cracks and other signs of failure of the foundation appear.

House foundation drainage

If the groundwater level is high, the foundation must be protected not only by careful waterproofing, but also by a well-designed drainage system. Only the combination of these measures will allow the structure to be maintained in its design condition without destruction.

Which system to choose

The foundation drainage of a house can have a different structure depending on the type of soil, the amount of groundwater and the depth of the structure.

Wall foundation drainage

Such a system is necessary when laying a deep foundation with a high groundwater level. It is often installed to prevent flooding even at normal groundwater levels to protect against intense precipitation.

The wall drainage system can consist of 2 parts:

• Foundation wall protection;
• Interlayer drainage, arranged under the foundation cushion, is necessary for voluminous and saturated groundwater layers.

The device for protecting the outer wall of a load-bearing structure is carried out on all soils except sandy ones - they themselves conduct liquid well into the lower layers of soil.

The wall system includes a complex of waterproofing walls and laying drainage pipes with inspection wells. Excess liquid is collected in the pipeline and removed at the disposal site into a sewer, reservoir, site for reuse, etc.

Ring drainage

The method of installation is similar to the wall one, but differs in location: the ring system drains the entire perimeter, incl. areas adjacent to the house. It is placed at a distance of 1.5...3.0 meters from the foundation, which is convenient when laying it after the construction of the building.

Ring drainage is optimally chosen for shallow foundations without a basement.

Interlayer drainage

It is often arranged as an independent protection of the foundation from saturated aquifers that the structure reaches. Interlayer drainage additionally prevents the walls from getting wet by capillary moisture. Its arrangement is possible only at the stage of preparing the foundation for the foundation.

The system is used mainly for slab foundations. It involves compacting the soil with large sand and gravel using drainage pipes located under the foundation.

To clearly determine which type of drainage is suitable for a particular home, use the table:

Any system is necessarily accompanied by waterproofing of the external surfaces of the foundation and the arrangement of a blind area with a slope along the entire perimeter of the building - it partially drains the water coming from above.

Calculation of system and materials

Proper foundation drainage begins with calculations of the drainage system and materials.

• The depth of the pipe in the trench should be 0.3...0.5 meters greater (deeper) than the foundation cushion. This reserve is sufficient to remove excess soil fluid from the supporting structure.
• The slope of the pipeline must be at least 2 cm per 1 pm of drainage for the natural removal of water from structures to their destinations.

To organize drainage on the perimeter, you need to find the highest and lowest points.

• A water collection well is located high;
• A receiving well is installed in the low one, from which it is discharged into a collector well for further transportation.

To calculate the amount of materials, follow several rules:

1. Draw a diagram of the house indicating the sides. Draw on the plan the proposed drainage water line, taking into account the distance from the wall (up to 0.5 m for a wall outlet, 1.5...3.0 m for a ring outlet).
2. For every meter, add 2 cm to the slope. If the length of the plot is 10 meters, we get 20 cm of slope from the top to the bottom point.
3. Mark the position of the inspection wells. They should be located in the corners of the house or at every second turn, but at a distance in a straight line no more than 40 m from each other.
4. Based on the data obtained, calculate the required number of pipes and wells.
5. Provide couplings for turns, and separate special components for pipe connections.

Pipe selection

The efficiency of the entire system depends on the quality of the selected materials. Pipes made of ceramics and asbestos cement are currently practically not used due to their low efficiency; preference is given to PVC and HDPE pipes. For drainage, use products with perforations and filters:

It is optimal to use pipes with stiffeners to maintain the shape of water pipelines even under intense soil loads.

The variety of pipes and filters in stores will confuse any uninformed buyer. How not to make a mistake when choosing? – rely on the type of soil.

Preparatory work

Before you start making strip foundation drainage

, it is necessary to plan the work and draw up a project for the installation of all elements of the drainage system. Work is carried out only in the warm season. The reasons for this are quite clear. If you do construction yourself, without the involvement of equipment and specialists, it may take 2-3 months.

Preparatory work also includes:

• selection of materials, calculation of their quantity;
• strengthening the soil with retaining structures, if necessary;
• clearing the foundation from the soil and inspecting it;
• determination of the depth of groundwater and the most humid places on the protected land plot.

If the foundation of your house is not equipped with waterproofing or it has become unusable, you need to protect the foundation of the house from water. You can use coating, injection, roll or combined waterproofing. Only after this can you begin the main work.

Is wall drainage needed around the foundation of a house?

Many developers decide to build a house with a basement. The cost of building a basement is comparable to the cost of building a regular floor.

Only non-residential, auxiliary premises can be located in the basement - laundry, gym, sauna, boiler room, workshop, storage room, etc. All these rooms could be located on a regular floor or attic with better comfort and convenience.

In the recent past, it was customary to build houses on deep strip foundations. The construction of a basement in such a house was indeed beneficial - the foundation served as the outer walls of the basement premises.

The use of lightweight structures and shallow foundations in modern low-rise construction makes it unprofitable to install a basement in a house.

However, lovers of tradition and solidity often choose a house with a basement on a deep strip foundation. To comfortably use the premises in the basement, the basement must be protected from ground moisture.

Reservoir method of water drainage

Drainage under the foundation slab is necessary to ensure that the properties of the structure are maintained when in contact with water. This means removing water and preventing its effects on the foundation of the house. For more information about drainage work on the site, watch this video:

Drainage under the foundation slab can be done in various ways. One of the popular ones is the layer type. Its essence is as follows:

1. A ditch is dug 1 m deep than the size of the building.
2. A slight slope is established from the center to the sides.
3. Geotextiles are laid, then a 10 cm layer of sand and a 30 cm layer of crushed stone are alternated to level the bottom of the pit.

Creating a filtration layer

Drainage pipes are corrugated with longitudinal rows of holes to collect water. In order to prevent clogging of pipes with sand and small particles, it is necessary to surround the pipes with a layer of filtration.

The most common option is a layer of fine crushed stone surrounding the pipe by 10 cm in circumference, wrapped in a layer of geotextile . It turns out to be a double filter - the geotextile itself retains sand and organic matter, and the crushed stone layer serves as an additional filter that performs secondary purification.

Wall foundation drainage

Wall foundation drainage is designed to remove water from the foundation of the house, which will protect the foundation from destruction. The drainage system is installed around the perimeter of the house. There are two ways to drain groundwater from a house:

1. Open,
2. Closed.

The open method allows you to collect and drain rainwater. But it is of little use for draining groundwater. Especially if trays or sawn halves of large pipes are laid at the bottom of such a ditch surrounding the house. For foundation drainage, deep ditches are required, below the level to which the foundation is buried. And leaving such ditches open is not entirely safe.

Therefore, the drainage for the foundation is closed.

Foundation drainage diagram: simple and clear

The foundation drainage scheme should take into account:

• Distance of the pipe from the foundation. It should be no more than the thickness of the foundation.
• The depth of the pipe. Consequently, the depth of the trench. The drainage system should be located below the foundation level. In addition, the depth of the pipes should take into account the depth of soil freezing. The pipes are laid 50 cm below this mark.
• Presence (absence) of a drain pipeline;
• Location of inspection wells.

And since the process of digging a ditch for drainage is labor-intensive, it is advisable to install the foundation drainage simultaneously with the construction of the foundation itself, or immediately after it. The drainage pipe is laid with a slight slope (2-5 cm of slope per meter of pipe is enough) so that the water accumulated in it flows out in a given direction. The wall drainage system of the foundation should be located below the foundation itself, regardless of the type chosen: strip, slab or pile. Geotextiles are laid in the trench. This porous material acts as a filter. It is needed to prevent sand and small fractions contained in the soil from getting into the pipe. Gravel 15-20mm in size is poured on top of the textile. A smaller one will block the holes in the pipe. The pipe is laid on the crushed stone. And the top is covered with crushed stone, which is covered with the edges of geotextile.

The degree of its perforation depends on humidity. The construction market offers pipes

• with full perforation, when the holes are located along the entire perimeter of the pipe at an angle of 60 degrees and in a checkerboard pattern, along the length of the holes are located at a distance of 10-20 cm.
• With partial perforation, providing for the presence of 3 holes only on the upper half of the pipe, also at an angle of 60° and at a distance of 10-20 cm.

Important note. Under no circumstances should the drainage pipe serve as a storm drain; rain gutters from the roof of the house cannot be connected to it.

The reason lies in the perforation of the drainage pipe.

Geotextiles. This porous material acts as a filter for drainage

When the drainage system overflows, drainage water flows from the pipe into the ground, which leads to an increased moisture content in it.

But blind drainage pipes can be laid next to the perforated ones, or above them, in the second tier. This will prevent you from digging unnecessary ditches.

In the corners of the house, inspection wells should be provided into which pipes enter. Nowadays, drainage inspection wells made of plastic are purchased on the construction market along with pipes and geotextile.

Initial data for drainage system planning

To properly install drainage on a personal plot, it is necessary to study the conditions of the area around the house. These include:

1. Cadastral boundaries of the site taken from a topographic survey.
2. The nature of the terrain - the presence of slopes and their direction.
3. Depth of types of soil in different places of the site.
4. Physico-chemical characteristics of the soil (established in the laboratory).
5. The depth of groundwater is determined on the basis of geological surveys or archival topographic survey data.
6. The degree of soil heaving, the risk of landslides and flooding.

Based on the data obtained for the house project, the depth of the foundation is calculated and recommendations are given on the installation of a drainage system.

Consequences of foundation subsidence

Wall foundation drainage according to SNiP

According to building codes, when installing wall drainage, the following rules must be followed:

• pipes are laid with a slope of 2 cm per meter in the direction of the collector or well;
• inspection wells are placed in increments of no more than 40 meters in a straight line and no more than 20 when turning a corner;
• drainage pipes must be immersed deeper than the freezing of the soil;
• ditch width from 25 cm to half a meter;
• with ring drainage, the system is removed from the walls of the house at a distance of one and a half to three meters;
• the distance from the pipe to underground electrical communications must be at least 15 cm (for a pipe with a cross-section of 5 cm).

The project also provides details:

• pipe section;
• filter material and type;
• soil type and characteristics;
• design capacity of the drainage system.

To install drainage near the foundation, you can use PVC, polypropylene, or low-density polyethylene pipes. There should be two perforated zones in the opposite walls of the pipe. The total perforation area is about a percent of the entire surface of the water pipeline. The solid walls of the pipe should look up and down, the perforated walls should look to the sides.

Filters are made from coconut fiber or geotextile. Their purpose is to protect perforated areas from the ingress of soil particles. Water pipes may already be equipped with filters or sold without them. If filters are not provided, the pipes are wrapped in several layers of geotextile before laying in the ditch. Fix the canvas with a nylon cord, plastic tape or other polymer material. Pipe sections are connected with polymer couplings and fittings.

Sometimes in wall drainage, polymer profiled membranes are used - this is the name of a polyethylene film, on which protrusions 8-20 mm high are made using hot molding technology. A two-layer membrane includes a geotextile layer, while a three-layer membrane also includes a smooth polyethylene film. The membrane is installed on the surface of the base after waterproofing, with the geotextile side facing the ground. This enhances waterproofing and improves drainage efficiency.

In places where pipes are laid, it is recommended to pre-lay thermal insulation material - this will make the thermal insulation of the base more effective and protect the pipes themselves from freezing and, accordingly, from ruptures. Pipes should be laid on top of a bed of sand, crushed stone, or gravel. There should also be 3-5 cm of this mixture on top: it will act as a filter layer and direct moisture from the surface to the drainage pipes.

At the last stage, a concrete blind area about half a meter wide is made. The edge of the blind area should be located further from the wall than the projection of the cornice.

In addition to SNiP, the installation of a drainage system is regulated by GOST 1839-80.

Sample Project

To understand how much it will cost to install a drainage system on a site, let’s look at an example of a project offered by specialized companies.

This includes:

Drainage project

• site drainage;
• arrangement of a trench with an average depth of 1 meter;
• laying a pipe with a diameter of 110 mm;
• wrapping the pipe with geofabric;
• laying a layer of sand about 15 cm high;
• crushed stone layer 40 cm;
• backfilling geotextile pipes with gravel;
• backfilling with soil.

Drainage calculation project

So, one meter of such a system will cost approximately 1,550 rubles.

If you need to arrange drainage for an area of, for example, 15 acres, you will need 200 linear meters of drainage. The total price will be about 295,000 rubles.

This includes drainage design according to SNiP standards, materials and work.

Site drainage

If you do the work yourself, you will only have to pay for the materials.

The calculation of the drainage system will include:

• pipe with a diameter of 110 mm – 80 rubles per coil (50 meters);
• drainage well with a diameter of 355 mm - 1609 rubles per meter;
• hatch for a well - 754 rubles;
• bottom-cover for a well – 555 rubles;
• quarry sand – 250 rubles per cubic meter;
• crushed stone with a fraction of 20-40 mm – 950 rubles per cubic meter;
• geotextiles – 35 rubles per square meter;
• plastic well with a diameter of 1100 mm - 17,240 rubles per meter.

Design of drainage systems on site

Of course, by designing drainage systems on site and installing them yourself, you can save money.

But you can do this work yourself only if you have special knowledge and skills.

First, you will need to perform all the necessary measurements and calculations to determine the required amount of materials, and accordingly, their cost.

In this case, you will not have to pay for the work.

Drainage system

Work in dry weather

Water is removed from the foundation by organizing drainage around the house. Before implementing it, you need to know some features of the work:

• installation work is carried out in summer in dry, warm weather;
• to build a foundation drainage with your own hands, it will take 2 to 3 months;
• After preparing the ditches, it is advisable to build a canopy over them to protect from rain;
• if the soil is in a loose state, then the walls of the ditch must be thoroughly strengthened;
• from the appropriate authority you need to obtain information about the condition of the soil, as well as conduct a small experiment to determine where moisture is most collected;
• Having learned comprehensive information, you can draw a drainage diagram for the building, calculate how much material will be needed and the cost of the structure.

Types of water drainage systems from the site

There are many drainage schemes, but all varieties can be combined into three large groups: open, closed and combined. In accordance with this, there are three main types of drainage structures: surface, deep and also combined. Let's look at the features of each.

Features of open drainage

Water collection by open drainage is carried out thanks to a system of ditches and trenches, that is, objects not covered with a layer of earth from above. It is arranged to collect and drain water from the soil-vegetative layer, i.e. for site drainage. The operating principle of an open system is based on the ability of underground water to rush into the space freed from soil in the same way as it flows into a well.

The branched network is positioned at a slight angle so that the water flowing into the grooves moves by gravity beyond the boundaries of the site (quarry or fire reservoir) or is accumulated for irrigation in a storage well.

If necessary, the walls of the grooves of the open system are strengthened with compacted crumpled clay, laid out with cobblestones or tiles. It is permissible to carry out strengthening with flexible branches of bushes or suitable trees woven together.

To ensure that the water intakes of the site's drainage system do not become clogged with debris and leaves, protective gratings are sometimes installed over the ditches.

The final point of water collection of the rafting drainage system is natural (rivers, lakes, ponds) and artificial reservoirs, as well as ditches, ravines, quarries located behind the fences of the summer cottage. A storage-type drainage network involves collecting transported underground water into a storage well.

System Features:

• coverage of all water storage points;
• calculation of the slope of drainage trenches;
• ensuring system protection from clogging;
• measures to prevent the emergence of new wetlands;
• location of the reservoir at the lowest point of the relief.

The norms for the slope angle of canals depend on the type of soil: for clay from 0.002, for sand – from 0.003.

There is an opinion that open drainage is not aesthetically pleasing. This is not true, because many ways have been developed to beautifully design external drainage systems.

One way is to create a small waterfall or stream using a pump. In the dry season, the rocky or pebble bottom turns into a “dry stream”, which also looks very attractive among the greenery

A significant disadvantage of open drainage lies in a noticeable reduction in the usable area of ​​the site. There are restrictions on the depth of ditches and grooves, because It is not customary to arrange them below 0.5 - 0.7 m from the day surface.

If it is necessary to build a drainage system at greater depths, it is necessary to increase the width of the trenches, install transition bridges, and carefully consider the drainage scheme so as not to impede the movement of people and personal equipment around the site.

Types of closed drainage

To arrange a closed drainage, an engineering project will be required, since all the elements are underground, and the functionality of the system depends on their correct location. There are local and general types of deep drainage.

If you need to protect the foundation of only one building or drain water from the road, this is the local variety; if you decide to drain the entire area, this is the general version.

Local types of systems, in turn, are divided into:

• wall (in clay soils, on the surface, along the perimeter of buildings - houses, bathhouses, garages);
• reservoir (in the ground under the building);
• ring (in sandy soils, around buildings, below the foundation).

All of the listed types of closed drainage serve to prevent flooding of the foundation, as well as to protect against the seepage of groundwater into basement and basement rooms.

Depending on the location of the drainage pipes, systems are divided into different types: horizontal (most popular in dachas), vertical and combined.

All of the listed types (wall, ring and reservoir drainage) belong to the horizontal variety. The pipes are placed with a slight slope under or around the foundation

Pumping equipment is used to construct a vertical system. This is a complex design, therefore it is used extremely rarely for improvement of the private sector. Accordingly, the combined type of deep drainage is not common.

Image gallery

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Shallow drainage system

Drainage device for drying the soil

Deep version of the drainage system

Laying depth of wall drainage

Organization of waterproofing for different types of foundation

Arrangements for protecting a constructed building from moisture vary depending on the type of foundation. The most common types are slab, pile, column, strip and monolithic foundations.

Plates

Here it is best to wrap the foundation with rolled roofing felt. When any irregularities are detected.

They must be removed using a leveling screed.

Then a water-repellent material and insulation are placed on the concrete slabs and the surface is leveled again.

Pile and column types

It is not easy to waterproof concrete piles and pillars. It is provided by adding water-repellent additives to concrete. Wooden structures are treated with special liquids that prevent rotting and moisture absorption.

Strip and monolithic foundations

Most often, monolithic structures are insulated with hot bitumen mastic

To properly waterproof these types of foundations, the following several methods are used. They are varied and quite effective.

1. Treat the foundation with a special mastic, only the surface must be dry and smooth. This method is not entirely reliable, so to strengthen the composition it is necessary to cover it with insulation or build a brick wall.
2. Just as in the first case, you need to carry out all the manipulations using hot bitumen mastic, and stick roofing material on top in 2 layers with an overlap of about 15 cm.
3. Using a special sprayer, a water-repellent composition is applied to the dry foundation. It is advisable to use geotextiles on top, then the waterproofing will last a long time.
4. Another reliable and high-quality method is penetrating waterproofing. It contains quartz sand, cement and special additives. This mass has penetrating properties.

Why do we need drainage and its design?

Drainage is an engineering structure designed to drain water from areas, various buildings and structures, such as:

• Foundation slab;
• Foundation in the form of a tape;
• Other foundation construction;
• Basement or basement walls;
• Football fields and other sports facilities;
• Roads;
• Wetlands and areas.

Good drainage, performed in accordance with standards and technology, is needed in order to:

• The completed waterproofing of the walls and foundation (if any) lasted 5 times longer, since it will not be under constant water pressure.
• Reduce the fluid pressure on the foundation of the house, which, if there is a basement or plinth, will help reduce the volume of leaks and their intensity.
• Prevent destruction of concrete and foundation. In the absence of drainage and high-quality waterproofing, under the constant influence of moisture, foundations made of concrete, brick and other materials gradually collapse. Concrete and brick are porous substances that absorb water like a sponge and are destroyed both by the influence of minerals and salts present in groundwater, and by temperature changes - at sub-zero temperatures, the moisture that has been absorbed into the concrete freezes, and at positive temperatures it thaws. thereby forming cracks, capillaries and voids in the concrete. Drainage helps remove excess moisture from a foundation made of concrete or other material, thereby greatly improving the situation and helping the foundation last longer.
• Prevent constant erosion of the foundation, which can ultimately lead to cracks and displacements.
• To rid a site or a certain area of ​​constant waterlogging and the inability to exploit it at certain times of the year.

Why do you need to prepare a project before implementing the system:

• Understand in advance at what depth and where the drainage structure will be located, so that the builders do not make a mistake and carry out work where this is absolutely not necessary;
• Have a complete understanding of what materials, according to the standards, an engineering structure must be made of;
• Have detailed guidelines and recommendations for installing drainage around a house, structure, building or site;
• Obtain an exact specification of all materials used;
• Get accurate prices for system installation, taking into account all the necessary work and materials.