Foundation with drainage in a trench. Drainage system around the foundation. Backfill drainage - a system of backfilled trenches

Groundwater adversely affects underground structures. Most of all, it “gets” foundations and basements. The former are gradually eroded and lose the necessary strength, the latter are flooded, unusable.

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

Home craftsmen 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 website. With our help, the installation of a groundwater drainage system will become a simple, affordable task.

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

Unpleasant smell and dampness in the basement, mold and fungus on the walls - owners of houses located in places with high groundwater flow can face such problems. But these are not the most serious troubles that threaten an unprotected structure.

Water, periodically penetrating into the lower floors of the building, gradually washes away 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 retain moisture, and in winter they swell, which can lead to the complete destruction of the foundation, and eventually the entire structure.

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

• wall drainage carried out in close proximity to the building;
• ring method- the trench is dug at a distance of at least 1.5 m and not more than 3 m from the foundation of the house.

In areas with a high level of groundwater occurrence and on clayey rocks, they are equipped. It is also recommended to do it when the building has a basement.

The ring is most often equipped on soils with good permeability (sandy, pebble, gravel, gravel) and in cases where the house does not have a lower floor.

In view of the fact that wall drainage of the foundation is laid near the house, it is desirable 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 drainage pipes were not laid during the construction of the building, ring drainage of the house can be done even when the house has already been built.

As for the wall option, it is not advisable to perform it next to the finished building, since interference with the foundation structure can adversely affect its strength and durability.

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

The main rule here is that the pipeline should run half a meter deeper than the base of the foundation. For a good outflow of water, it is necessary to provide a certain direction from the house.

In areas with a natural slope, the pipeline is laid in accordance with the channel that the water has made. 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 set.

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

Through rotary wells it is easy to clean and flush the system in case of blockage. To do this, you just need to send a jet of water under high pressure into the pipe

In areas where, due to the peculiarities of the terrain or for technical reasons, it is impossible to drain water into natural reservoirs, water intake wells are installed.

They are designed to collect liquid, which can later be used to water the site or other household needs. To prevent incoming water from overflowing back into the pipes, a check valve is installed.

All pipes through which groundwater flows are diverted to one collector, which is often used to collect liquid from the surface drainage network.

In soils with a high absorption capacity, filtration wells are installed. In these structures, instead of the bottom, a special drainage backfill is provided, through which the liquid, after undergoing 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 liquid does not exceed 1.5 m 2 per day.

A 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. Up to the level of the foundation of the building, the geological section is represented by loam and a soil-vegetative layer from above, 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 the freezing and thawing of the soil, it sags unevenly.

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

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Around the house we dig a trench about 20 cm deep more than the depth of the foundation. To speed up the development, we rent a mini-tractor, we retreat approximately 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 slope. The lowest point of the trench around the house should be the corner at which the sewer pipe will be connected to the drainage pipe.

During development, we try not to damage 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 exposed pipe. As a result, the drain must be laid under the utilities, while the slope of the trench must be observed.

Before laying the drainage pipe, we wrap it with geotextile, which will filter the ground water and protect the drain from sand

We fill the bottom of the trench with sand and level it before laying it so that there is a slope of at least 3-5 cm per meter. We put a drain on top and sprinkle it with gravel

Where it is more reasonable to lay the drainage pipe next to the sewer at the same height, we lay them in one trench and fill it with gravel and sand

We lay a drainage pipe around the house along the entire length of the trench, sprinkle it with gravel so that you can dig it out and change position if necessary

Sometimes, even the best foundation waterproofing cannot withstand moisture penetrating into the basement. The reason for this may be the high level of groundwater. The consequence of this will be not only dampness in the basement, but also the inevitable appearance of fungus and mold. In addition, over time, the base is washed away and the underground elements are destroyed.

Why is Foundation Drainage Necessary?

Wet soil, when frozen during the low temperature season, expands and increases in volume. The pressure from such an expansion is very high and can cause the destruction of the foundation, and therefore violate the integrity of the structure itself. Therefore, at high water levels and poorly permeable soils, it is necessary to drain the foundation.

Indeed, in order to reduce the groundwater level of the walls of the foundation of a house or basement and thereby prevent wetting of the underground parts of the structure, it is possible to arrange drainage for the foundation for the house - a system of pipes laid according to certain rules around the foundation.

According to the rules, a geodetic engineer, having taken samples of the land on the site, even before the start of construction, gives an opinion on the maximum level of groundwater. Based on this data, each developer plans for himself which system foundation drainage needed or can be done without it. But many refuse to do geotechnical surveys relying on chance or trying to save money. As a result, the walls of the foundation begin to dampen, mold and fungus appear inside the basement, and constant ventilation of the basement no longer helps. This problem can be solved with the help of drainage. But often the owners of such a house simply sell it, and the next owner, in the spring, runs to the store, buys a pump and pumps water out of the basement.

When is foundation drainage necessary?

If the groundwater level is below the floor of the basement, then consider yourself lucky and there will be no problems with constant dampness. In addition, it is possible not to drain the foundation of a country house when it stands on well-permeable soils, which include sandy or gravel.

If the water rises high, and the house is built on soil such as clay or loam, then it is better not to save on this and make high-quality foundation drainage. The peculiarity of such soils is that they retain moisture, which cannot pass further down. During rain, a similar situation occurs.

If your house is on a slope, then the basement will be constantly moistened from the side of the rise. atmospheric precipitation will inevitably flow down the slope towards the building. Therefore, for such conditions, it is also necessary to arrange foundation drainage.

Drainage system at home

Simply put, the drainage of the house is a system of pipes with holes laid in a certain way to drain the site. Nowadays, special drainage perforated pipes are more often used. They are laid around the perimeter of the building and manholes are made at regular intervals. Further, the water naturally flows into one large receiving well, from which it is subsequently discharged.

There is a budget option for a drainage device from asbestos and ceramic pipes. Holes or cuts are made in them, they are necessarily wrapped with geotextiles or other material that allows moisture to pass through, but not soil particles, and they are also laid in the ground. The more holes the better, but do not forget that the pipes are buried in the ground and experience constant pressure, so do not overdo it.

With the development of industry, plastic has been increasingly used for the manufacture of drainage channels and wells. Asbestos and ceramic pipes are a thing of the past, but still remain relevant. Modern drainage pipes are already produced with special slots, have a length of 50 to 250 m, which is very convenient for laying, are produced in different diameters depending on the type of soil and the volume of water. The undoubted advantage of plastic is its lightness and ease of processing, so such pipes require much less transportation costs and can be cut even with a conventional knife.

Now many produce drainage pipes wrapped with geotextiles in order to prevent silting of drainage channels. In addition, the service life of the system is increased and the work of builders is simplified. In addition to geotextiles, special non-woven fabrics made of coconut fiber can be used, but the cost with such a filter material is an order of magnitude more expensive.

Pipes wrapped with geotextiles are best used on sandy, sandy and silty soils. In this case, it is necessary to make a backfill around the pipe in the form of crushed stone or pebbles.

On clay and loamy soils, it is advisable to use pipes with coconut fiber protection. On clay soils, it is also possible to do without protection, due to the fact that clay has the property of plasticity, but at the same time it is necessary to make a backfill with a thickness of at least 20 cm from crushed stone.

Do-it-yourself foundation drainage

There are many manufacturers on the market that can complete foundation drainage system all elements. Many of them give detailed instructions for installing the system, which depend on the soil and the depth of the installation.

Drainage pipes should not lie below the level of the base of the foundation, otherwise soil particles will be washed out from under the base along with water, which can lead to subsidence of the entire structure.

The arrangement of all drainage systems for the foundation is similar and begins with the digging of inspection and water intake wells, and trenches along the perimeter of the building. Trenches must necessarily have a slope for the natural flow of drainage water. The slope is 2-10 mm per linear meter. Of course, the steeper the slope, the easier and faster the water will flow down the gutters. After the trenches are prepared, a layer of gravel or crushed stone of about 5 cm is poured into them and rammed. Once the preparatory stage of work is completed, you can proceed with the installation of the drainage system at home.

Drainage pipes should be located at the level of the base of the foundation, while they should not freeze on the site itself. Indeed, the depth of soil freezing directly near the house is small, and the farther from it this value increases. Therefore, in the spring, when the groundwater level is maximum, the drainage system is fully functional, the pipes are laid either to the freezing depth or a special cable is laid, which, when connected to the electrical network, heats up and melts the ice in the foundation drainage system, if any.

After the pipes are laid, they are covered with 30 cm of crushed stone, pebbles, expanded clay or gravel and covered with geotextile to prevent silting. Next, you need to proceed with the installation of manholes. They are necessary for cleaning in case of unforeseen clogging. Installed at a distance of 50 m from each other, but not less often.

Modern drainage wells are also made of plastic. They are much lighter and cheaper than traditional reinforced concrete rings, which are difficult to install without a crane. Therefore, plastic rings are becoming more popular. They have the necessary strength, are light in weight, and can be installed without special equipment, as they say in manual mode. All these advantages lead to significant savings, which has a positive effect on their growing popularity.

The traditional diameter of plastic wells is 200-250 mm. This is sufficient for free access to drainage joints and for periodic flushing. Flushing is carried out on average every 7 years, but this depends on the conditions in which the system is operated. For washing, a regular watering hose is used, from which water is supplied under pressure. The purpose of this process is to get rid of the silt and sand in the system.

It is possible to install a special sand trap in the wells, into which sand, silt, and various small particles settle during the drainage process. Once a year, as a rule, in the autumn before frosts, they take it out, shake out the settled sand, and put it in place after cleaning.

To ensure safety and to prevent the ingress of foreign debris, wells are covered with hatches. If you do not want to spoil the view of the site with hatches, they can be covered with a film, and covered with soil from above and sown with grass. Just don't forget where they are. Many decorate hatches with various flower vases, flower beds, sculptures, etc.

After the installation of drainage channels and manholes, they dig the largest water intake well. It is located at the lowest point of the site. Over time, the well will fill up to a certain level and will need to be drained somehow. Many use water from a well for irrigation, someone drains into the central sewerage system, if any. But there is another way to drain. True, it is not suitable for all types of soil. For example, if the building stands on clay soils that do not allow water to pass through, and after them there is a permeable layer, such as sand, then it is necessary to dig a clay layer and the water will begin to go deeper.

For such conditions, a special absorption well is dug, to which a drainage channel is connected. The bottom of such a well is not concreted, but covered with layers of rubble and sand, through which the water naturally leaves the underlying layers.

Additional protection against moisture can be created by changing the relief. To do this, it is necessary to provide a slope from the house to the sides. When creating a properly executed blind area, tightly adjacent to the building, a positive effect is also observed. The blind area helps water to flow away from the foundation, thereby reducing soil moisture near it.

Foundation drainage inside the house

Sometimes there are situations when the drainage of the foundation of a country house was not installed, and the walls become damp in the basement or a puddle appears on the floor. The reason for this may be a superficial attitude to the geotechnical conditions of the site or dense buildings around the house. To get out of this situation, drainage is done right inside the basement.

The foundation drainage device inside the house is the same as outside. The only limitation here may be the height of the basement, because. about 30 cm will go to the device of the drainage system.

If you need to drain the foundation inside the house, then first remove the layer of earth inside the building to the level of the lower plane of the foundation. After that, pipes, drainage manholes are mounted. They fill everything with rubble or gravel, lay waterproofing and make new floors. Drain in this case also needs to be brought out.

Video on the topic "Drainage of the foundation"

After watching this video, you will learn what to do if water seeps into the basement not through the walls, but from below. Hear recommendations about the device of the drainage system of the house outside and inside.

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When building a private house, the problem of draining groundwater from the foundation often arises. This is very important when their level is high, and at the base of the soil there is clay or loam. It also has great importance if the house has a basement or basement. If the foundation of the building is not drained, then the basement will always be damp, the walls will be covered with mold, and it is also possible to flood the floor with groundwater.

Water adversely affects the durability and strength of the concrete structures of the foundation of the house, regardless of the quality and composition of the waterproofing. The foundation drainage scheme is developed at the design stage and carried out together with the foundation device, which saves on earthworks.

The main types of drainage system

According to the functional purpose and method of installation, there are several main types of drainage around the foundation of the house:

• surface drainage - acts as a storm sewer around the house, is closely connected with the roof drainage system;
• wall drainage of the foundation;
• circular foundation drainage;
• reservoir drainage.

Each species has its own characteristics and purpose. Often several types of drainage are performed simultaneously, while surface drainage drains rainwater from the roof of the building, and wall drainage drains groundwater from the base of the foundation.

Photo from the site when laying the drainage.

Ring drainage is often used in the construction of private houses in areas with a high level of groundwater. It consists of drainage perforated pipes laid along the perimeter of the foundation of the house, and manholes.

Such a drainage system can be around any foundation - slab, tape, columnar. This system ends with a common drainage well, into which all discharged water is discharged. Water is drained from it by a sewer pipe towards the street or ravine.

The difference between wall and ring drainage is the distance of its device from the foundation surface. For ring drainage, this is an average of three meters, and wall drainage is arranged at a distance of about one meter.

Reservoir drainage is carried out under the entire building area and can be used with slab and strip foundations. It is often used in the construction of baths.

There is a system of so-called. foundation drainage light, used to protect basements from groundwater in clay soils. It is usually used for unused basements.

Materials and tools

For the foundation drainage, the following materials will be required, which must be purchased in advance, taking into account the drafted project:

• perforated plastic pipe;
• geotextile;
• manholes;
• sand;
• rubble.

If necessary, you can use the available improvised materials for the construction of manholes.

Film for waterproofing.

In addition to materials for high-quality installation, you will need the necessary tools:

• shovels and bayonet shovels;
• jackhammer;
• wheelbarrow for transportation of soil and gravel;
• laser or conventional level;
• roulette and pegs;
• cord;
• grinder for cutting pipes;
• knife for cutting geotextiles.

All work on the installation of an annular drainage system around the house does not present much difficulty in their implementation and can be done by hand, without the involvement of specialists. However, project documentation, which stipulates the need for a drainage system, must be ordered from specialized design organizations that can assess the composition of the soil in the selected area.

Drainage device

A common type of drainage system for the foundation of a house is ring drainage. It is better to perform it in parallel with the construction of the foundation of the house. Consider step by step the entire process of installing such a system. Waterproofing must be done before draining. All work can be divided into the following stages:

• preparation of a trench around the house to the depth of the base of the foundation, its width can be any, but not less than 50 cm, while the bottom is made with a slope of about 2 cm per meter;
• backfilling of the underlying cushion of sand with a thickness of 150 - 200 mm;
• installation of revision and drainage wells at the corners of the building, holes must first be made in their walls;
• laying geotextiles up to two meters wide at the bottom of the trench;
• arrangement of a layer of crushed stone of the middle fraction at the bottom of the trench over geotextile, this layer should be up to 20 cm thick;
• laying perforated pipes with a slope;
• backfilling pipes with crushed stone with a layer of approximately 30 - 40 cm;
• wrapping pipes covered with crushed stone, overlapped geotextiles;
• backfilling the trench with soil to the level of the blind area.

Foundation drainage can be done by hand without the involvement of specialists. The considered option refers to the device of deep drainage to combat groundwater. Using the same technology, surface drainage can be performed, which acts as a storm sewer, collecting and discharging rainwater from the roof and from the local area.

Let us consider in more detail the device for deep drainage for the foundation of a building. This type is suitable for strip foundation Houses. Ring, as well as wall drainage around the foundation, can be performed both after the construction of the house, and in parallel with the foundation, which is much more preferable.

The depth of the drainage is different, but basically it depends on the depth of the foundation. It is optimal when the drainage pipes are at the level of the lower plane of the strip foundation.

For proper slope design, it is best to use a laser or optical level, setting a slope of 2 cm per linear meter. The trench mark is easy to determine, knowing the depth of laying the pipe for drainage - it is approximately equal to the depth of the foundation. At the same time, the trench is deepened 300 mm lower - for the installation of a sand cushion and crushed stone bedding.

After laying the pipes and connecting them to the revision wells, the slope is finally checked, if necessary, filling or deepening is done - this is the most important stage of the whole work. The slope is checked throughout the drainage system: between manholes, between the annular drainage and the last well, as well as the exit from it to a street well or ravine. Everywhere there should be a slope of at least 2 cm per meter.

Wall drainage.

The next stage is backfilling the pipes with a layer of rubble and wrapping this “pie” with geotextiles so that the canvas overlaps. It remains to backfill - it can be done with sand or soil previously removed from the trench.

Errors in the installation of drainage at home and its maintenance

The device of the drainage drainage system from the foundation of buildings is carried out in such a way that it is not connected with the deep drainage system. Many people make the mistake of draining rainwater from the roof into foundation drainage. This is a mistake, since this system is designed exclusively for the removal of groundwater. And the ingress of water at different times of the year into the deep drainage system can quickly disable it.

And also a very important point at which they make a mistake is the insufficient slope of the drainage pipes and, as a result, stagnation of water in them. This problem is very difficult to fix after all work is completed. Therefore, the issue of correct and sufficient slope must be paid attention from the very beginning of the drainage device. The wall drainage of the foundation is connected to the drainage well, into which water is drained and from the storm sewer, at the same time it has an outlet towards the street well or, if there is none, beyond the territory of the site into the ravine.

Like any other engineering network, the foundation drainage system requires periodic inspection and maintenance. This is due to contamination of the drainage pipes during operation. For this, revision wells are provided at the corners of the building. You can lower the hose in them and wash all the sediment with a jet of water under pressure, but you need to start from the top point.

Foundation drainage video

Conclusion

The drainage device near the foundation begins to be decided at the design stage. And it is necessary to entrust this to specialized design organizations that can correctly assess the geological features of a particular site and determine the depth of groundwater. To mount drainage around the foundation with your own hands according to the finished scheme and with knowledge of the technology, any person can do it.

There are several places in a private house that need to be protected from getting wet from the outside. This is the foundation and recessed buildings. Rainwater, all kinds of runoff and rising groundwater gradually destroy the monolithic foundations and walls of the basements. A properly equipped drainage system around the house can prevent the occurrence of this process. It is able to remove excess moisture from structures. Even a very good blind area cannot be compared in terms of the degree of protection of a house with a laid drainage system. It is highly recommended to equip such a system near each house, regardless of the presence of a basement or basement.

A high-quality drainage system around the house with your own hands can be made in several ways:

Features of different foundation drainage systems

The choice of a particular type of drainage depends on the presence of buried rooms, the depth of groundwater, the composition of the soil on the site and the topography of the site itself. Consider what features the drainage device around the house has.

In total, there are 3 types of drainage, which differ in their location and design:

Important: Please note that formation drainage does not replace other types of drainage, but only complements it. Therefore, in addition to it, the main drainage system should be carried out.

Please note that if you decide to do ring drainage around the house with your own hands, the system should be located 0.5 m below the foundation level. Such an arrangement will ensure high-quality removal of groundwater from the building at any time of the year.

And if you are thinking about that, then our separate material on this topic may be useful to you.

Drainage installation

Consider how to make a drainage system around the house in two ways.

Production of wall drainage

Before performing work, it is necessary to prepare the foundation, since the system will directly adjoin it.

For this, the following work is carried out:

1. The foundation from the outside is primed with a special bituminous primer.
2. Bituminous mastic is applied to the dried surface.
3. A reinforcing mesh with 2 x 2 mm cells is glued onto the mastic.
4. The next day, after the mastic has hardened, the second layer of mastic is again applied to the mesh.

• a collector well is mounted, to which drainage pipes will be connected. It is located at the lowest point on the site;
• using a laser or building level, the slope of the trench passing near the foundation is ensured towards the water collector;
• the bottom of the trenches is covered with a layer of sand of at least 5 cm;
• geotextiles are laid on the sand, the sides of which will subsequently be overlapped;
• a gravel backfill is created having a thickness of the order of 10 cm;
• prepared perforated pipes are laid on the gravel layer. They are provided with a slope of 2 degrees;
• pipes are joined by adapters and corner connectors;
• at the corners of the building, all pipelines enter the installed manholes;
• pipes are laid from the manholes, diverting water into a collection well or drain pit. These pipes are also located in trenches and have a slope;
• the pipes are backfilled with gravel (about 10 cm) and the entire contents are wrapped with geotextiles. By means of synthetic ropes, the geotextile is firmly fixed;
• further backfilling of the trenches to the level of the soil is carried out with sand or soddy soil.

We looked at how to make drainage around a wall-type foundation. Next, we will pay attention to the manufacture of trench drainage, which is even more popular.

Production of an annular drainage

For this type of work, you will also need perforated pipes, crushed stone, sand and geotextiles. When an annular drainage system is made around the house, the technology involves digging trenches at a distance of 5-8 m from the foundation of the building in order to exclude the possibility of subsidence of the soil around it. The trenches are located around the building and represent a closed system. The depth of the trenches should be such that the drainage passes below the level of the foundation by 50 cm.

A trench (or several trenches) is immediately carried out towards the main catchment well. The slope of the trenches is provided at least 2-3 cm per linear meter. The slope can be adjusted by adding sand in the right places.

• the bottom of the trenches is lined with a layer of sand, and then with geotextiles, the edges of which are wrapped around their walls;
• crushed stone is poured onto the geotextile with a layer of 10 cm;
• pipes with holes drilled in them are laid out on crushed stone. It is desirable to use a pipe diameter of at least 10 cm. It is advisable to pre-wrap all pipes with a layer of geotextile, which will prevent their clogging;

Tip: Ordinary PVC pipes used for sewerage are quite suitable. In them, you can drill holes of small diameter with a drill, placing them in a certain order.

• the slope of the pipes is checked, which must be at least 2 degrees;
• manholes are mounted at pipe bends, closed with removable covers. The same wells should be installed on long straight sections, with a step of 12 m;
• crushed stone or gravel is poured over the laid pipes with a layer of 20-30 cm;
• the entire “pie” inside the trenches is wrapped with overlapping geotextiles;
• the place remaining in the trenches is covered with river sand and covered with turf.

Features of drainage wells

Any drainage around a site or structure should be constructed using multiple manholes located at pipe bends. It is in these places that clogging of drainage pipes most often occurs. Through the manhole, you can control the cleanliness of the drains and clean them if necessary. Wells can be purchased or made from any material. They should be of such a width that it is convenient to clean them by lowering your hand there.

In addition to several manholes, at the lowest point of the site is collector well designed to collect all the water flowing through the channels. This is a wider and more voluminous structure, which can be concrete, plastic or metal. Its depth is chosen in such a way that the pipes entering it are at a considerable distance from the bottom. This makes it possible to periodically clean the well from sediments accumulated at its bottom and allows the well to be filled with sewage. From the collector tank, water can be pumped out by a pump or go by gravity to designated places.

By creating a drainage system around the house in accordance with all the rules, you will get rid of the detrimental effect of excessive dampness affecting the foundation and recessed rooms of the house.

With a high level of groundwater, the foundation must be protected not only by thorough waterproofing, but also by a well-arranged drainage system. Only a combination of these measures will make it possible to keep the structure in the design state without destruction.

Which system to choose

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

Foundation wall drainage

Such a system is necessary when laying a deep foundation with a high level of groundwater. Often it is arranged to prevent flooding, even with normal GWL, 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 bulky and saturated groundwater layers.

The protection device for the outer wall of the supporting structure is performed on all soils, except for sandy ones - they themselves conduct liquid well into the lower soil layers.

The wall system includes a complex for waterproofing walls and laying drainage pipes with manholes. Excess liquid is collected in the line and removed at the disposal site to the sewer, reservoir, to the site for reuse, etc.

ring drainage

According to the method of the device, it 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 arranged 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 bases without a basement.

Interstratal 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 with capillary moisture. Its arrangement is possible only at the stage of preparing the foundation for the foundation.

The system is mainly used for slab foundations. It is a compaction of the soil with large sandy rocks and gravel using drainage pipes located under the foundation.

Let's summarize

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

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

Calculation of system and materials

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

• The depth of laying the pipe in the trenches should be more (deeper) than the value of laying the foundation cushion by 0.3 ... 0.5 meters. This reserve is sufficient to remove excess ground 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 the structures to the destination.

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

• In the high place there is a well for collecting water;
• A receiving well is installed in the low one, from which it is diverted to the collector well for further transportation.

To count the amount of materials, follow a few rules:

1. Draw a diagram of the house with the designation of the sides. On the plan, apply the proposed drainage water supply line, taking into account the distance from the wall (up to 0.5 m for a wall outlet, 1.5 ... 3.0 m for an annular outlet).
2. For each meter, add 2 cm per slope. If the length of the section is 10 meters, we get 20 cm of slope from the top to the bottom.
3. Mark the position of the manholes. 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. According to the data obtained, calculate the required number of pipes and wells.
5. For turns, provide couplings, for pipe joints - separate special components.

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; PVC and HDPE pipes are preferred. For drainage, take products with perforation and filters:

• Geotextile;
• coconut fibre.

It is optimal to use pipes with stiffeners to maintain the shape of conduits even under heavy loads from the ground.

The variety of pipes and filters in stores will mislead any ignorant buyer. How not to make a mistake when choosing? - Depend on the type of soil.

Wells are made of the same material as pipes.

• Manholes with a draining bottom direct water into deep layers of the earth. Crushed stone and coarse sand fall asleep under their base. These are placed at the intersection of the sides of the highway in wall systems and with interlayer protection.
• Blind receiving wells transfer water to a pipeline that discharges liquid to a place of further disposal. These are placed in places where deep drainage is impossible.

Do-it-yourself foundation drainage

After the calculations, we proceed to the construction of the drainage system. Let's consider each separately.

Reservoir drainage

As already mentioned, it is installed as an accompanying system for protecting the foundation from getting wet by groundwater and capillary water and as an independent tool for draining the soil under the slab.

After digging a trench or foundation pit for the structure, the earth is compacted and covered with sand, gravel or a mixture of ASGs. Depending on the quality of the base, there may be 1 or 2 layers, but not less than 30 cm in total. The area of ​​the drainage formation should be larger than the area of ​​the foundation, the perimeter protrudes beyond the structure by 20-30 cm. With a combined drainage system, the formation layer is equipped with pipes that are laid along the perimeter of the pit and the ends lead to the locations of the wells. Next, the foundation is erected in the usual way.

Wells are installed after construction work. To do this, they dig recesses 1 m below the occurrence of pipes and mount equipment, introduce lines. The pit is covered in layers with rubble and sand, compacting each of them.

wall drainage

Ideally, it is equipped during the construction of foundation walls. If it happens that the house is already functioning, then the walls will have to be bare to the very pillow in order to carry out maintenance work.

1. At the base of the pillow, it is necessary to create a design slope. To do this, the soil is cut or topped up and compacted in the right places. It is important to achieve a height difference of 2 cm per 1 pm of drainage pipes.
2. Geotextiles are covered along the entire perimeter of the trench to its top, the bottom is fixed with a layer of clean gravel with a layer of 20 cm, in which a recess is formed for the pipe.
3. Pipes are laid and connected with couplings, the ends at the locations of the wells are left free.
4. The highway is covered with a 20 cm layer of gravel, which is covered with textiles on top to filter small soil particles.
5. Install wells. Pipes are inserted into the holes, fixed, covered with geotextile and covered with crushed stone, then sand, compacting each layer.
6. Fall asleep trench.

It is advisable to carry out the work after the completion of the construction of the foundation.

ring system

It is possible to make a drainage of a shallowly ruined foundation according to the same algorithm as a wall one, but several nuances must be taken into account:

• The depth of the pipes should be located strictly below the level of soil freezing, below the level of the sole by 0.3 ... 0.5 m;
• The receiving well must be equipped with a solid bottom; crushed stone should not be poured under its base.

Work order:

1. Dig a trench at a given distance from the perimeter of the house.
2. Compact the base, align the slope and fill it with rubble.
3. Lay and install pipes.
4. Protect them with geotextile.
5. Fill with gravel at least 20 cm.
6. Install wells, connect them to pipes.
7. Fill in the wells.
8. You can fill the remaining volume of the trench.

Summarize

Prevention of foundation flooding should be provided for during construction on any soil, since the danger can come from the outside from intense precipitation and when snow melts. Do not spare time and effort for these simple events. Of course, lower energy costs will be obtained with the timely arrangement of drainage during the construction of foundation walls. Additionally, do not forget to waterproof the outer walls with effective roll and coating materials, the pillow will help protect the roofing felt lined in several layers.