Content
Excess moisture on the site of a country house can cause many problems. Constant dirt, crumbling foundations, flooded basements and crop disease are all the result of increased humidity. Drainage of the site done in accordance with all the rules will help get rid of excess water and protect buildings from destruction.
When to do drainage
Puddles on the site after rain and melting snow are not yet a reason to make a drainage system. It is necessary to understand when the soil itself is able to absorb water, and when it needs help. A drainage device on the site is necessary in the following cases:
- constantly flooded basement;
- soil leaching, as evidenced by the dips on the surface of the site;
- with clay soils, as a result of which the territory is swamped;
- if there is a slope nearby, from which water flows;
- the site does not have a slope;
- swelling of the soil, which leads to cracks in buildings, distortion of door and window openings.
Varieties of drainage systems
Before doing drainage on the site, you must decide on the type of drainage system. There are two main drainage systems that perform the same function, but are used in different situations:
- Superficial - designed to drain water that appears after rains or melting snow.
- Deep - is set up in areas with a high level of deep waters.
The surface drainage system is mainly arranged on clay soils and is subdivided into linear and point. Linear is a system of ditches and trays located with a slight slope towards the water collection point. To give an aesthetic appearance to the drainage system, the trays are closed with decorative grilles.
In a point drainage system, water is collected by water collectors located in places of the greatest accumulation of moisture - under a stack of drainpipes, low places of the site, near a water supply system located on the street. The water collectors are connected to each other by pipes, through which water is discharged into a drainage well.
Surface drainage construction
Do-it-yourself surface linear drainage on clay soils must be started after drawing up a plan, which indicates the location and size of trenches and other elements of the drainage system.
According to this plan, trenches with a depth of 0.7 m, a width of 0.5 m and a slope of the walls of 30 degrees are dug, which will prevent them from crumbling. All trenches are connected to one common one, which runs along the perimeter of the site and ends with a drainage well. The main advantage of the open drainage method is the simplicity of the system, which does not require large financial costs. Among the shortcomings, it is possible to note the fragility of the structure - over time, the walls that are not reinforced with anything crumble, and the drainage system ceases to function. In addition, the trenches have an unaesthetic appearance, which spoils the appearance of the site.
The problem of crumbling can be solved by backfilling with rubble. The bottom of the trench is covered with a layer of coarse stone, and on top of it with a finer one. To avoid blurring, the crushed stone backfill is covered with geotextile, on top of which a layer of sod is laid. This method degrades the throughput of surface linear drainage, but prevents wall shedding, which significantly increases the service life of the system.
There is a more modern method of linear drainage device - a closed drainage system.The difference between this method lies in the fact that the walls and bottom of the ditch are concreted and special trays are placed inside, closed with decorative gratings. The trays reliably protect the soil from slipping, and the gratings provide protection of the channel from debris. The trays are laid with a slope necessary for the smooth passage of water. In places where water is discharged, sand traps are installed to collect small debris. It is more difficult to make such a drainage system than a drainage system, but its service life is much longer.
On sale there is a wide selection of accessories for a closed drainage system, made of a variety of materials: concrete, polymer concrete, plastic. The latter is most popular due to its durability and light weight, which ensures maximum ease of installation.
Deep drainage device
The deep drainage system differs significantly from the surface one, not only by its device, but also by its purpose. You cannot do without it in areas with a high level of groundwater occurrence and located in the lowlands. For such a system to work effectively, it must be located below the aquifer. Determining the depth on your own is quite a difficult task - this will require the help of a surveyor, who will draw up a detailed diagram of the site with all the GWL marks.
The structure of the deep system is a network of drainage pipes that are in the ground and drain excess water from the soil into a drainage well. The percolation of moisture inside occurs due to the many holes located along the entire length of the pipe. The holes can be made with your own hands or you can buy products with ready-made perforations. For the device of deep drainage, the following types of pipes are used:
- asbestos-cement - outdated material, gradually becoming a thing of the past;
- ceramic - have a long service life and a high price;
- plastic - by far the most popular because of their cheapness and ease of work with them.
The sequence of laying deep drainage:
- Using a geodetic level mark the site. If there is no such, then during the rain, follow the direction of water flows and, according to observations, draw up a plan for the location of drainage channels.
- Dig a system of trenches according to the plan. To check that they are in the correct position, wait for rain and make sure that the water does not stagnate anywhere. After making sure that everything is done correctly, you can continue to work.
- Lay geotextile tape at the bottom of the trench along the entire length.
- Observing the slope, pour a layer of rubble on top of the geotextile.
- Lay the drainage pipes on top of the crushed stone cushion. The connection of individual pipes into a single system is carried out using tees, crosses and inspection chambers.
- The end of the pipe, located at the lowest point of the section, is led into a drainage well.
- Cover the drainage pipe on the sides and top with a layer of rubble. Do not use crushed limestone for backfilling. As a result of exposure to moisture, it turns into a monolithic composition through which moisture cannot seep.
- Wrap the pipe together with a layer of rubble in geotextile tape - this will prevent clay and sand from entering the structure.
- Fill from above with crushed stone or sand of a coarse fraction 20 cm below ground level.
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Fill the remaining space with soil located on the site.
To control the operation of the drainage system and clean it in case of clogging, it is necessary to install inspection wells at a distance of 35-50 m. If the system has many bends, then after one turn. Wells are constructed of reinforced concrete rings or corrugated polymer pipes of the required diameter and are closed with decorative covers.
Correctly designed and installed in accordance with all requirements, a deep drainage system can serve for more than half a century.
Drainage system maintenance
In order for the soil drainage system to function for a long time and properly, it requires regular maintenance:
- Routine maintenance involves periodical cleaning of the wells. The frequency of this procedure depends on the conditions in which the system is used.
- Mechanical drainage cleaning. Cleaning the surface drainage system is not particularly difficult and can be done independently. In the case of deep drainage, the situation is more complicated - a special pneumatic installation will be required, which has nozzles for removing deposits and crushing large elements. It is recommended to carry out such cleaning once every 3 years.
- Hydrodynamic drainage cleaning. This method consists in flushing the pipes with a mixture of air and water supplied under pressure. The mixture is fed alternately, first to one end of the pipe, which is in the drainage well, then the second, which is brought to the surface during the installation of the drainage system. Flushing is done by a pump and a high pressure air compressor. Under the action of the mixture, the deposits are crushed and washed out. The frequency of hydrodynamic cleaning is once every 10 years.
Savings on cleaning can lead to a malfunction of the system and the need to replace some elements, which ultimately will lead to additional costs for materials and work. Proper operation will help keep the system in working order and extend its service life.
