There are several types of drainage systems . To drain groundwater from the foundations of buildings, ring, wall, head networks can be used. But on aquifers of high power, in most cases, reservoir drainage is equipped.
What is a system?
Branch networks of this type are mounted only at the stage of construction of buildings or structures. A feature of reservoir drainage is primarily that it is equipped under the base of the foundation, at the level of a sand cushion.
Moreover, such networks are equipped in conjunction with pipe networks. That is, excess moisture in this case is removed from the base of the building by means of perforated highways. It enters a specially equipped receiving well, the nearest stream, pond, etc.
Benefits of Reservoir Drainage
The main advantage of networks of this type is precisely that they are able to effectively drain water from the foundations in cases where other types of systems can not cope with this task.
In addition to the groundwater itself, systems of this kind perfectly protect the foundations of buildings from capillary moisture. Particularly appropriate is the assembly of such a drainage network when building houses with basements on poorly permeable soils.
The disadvantage of this type of discharge systems, in addition to the need for installation at the stage of building construction, is the complexity of the work. The cost of reservoir drainage is also usually quite high. For this reason, the owners of suburban buildings to protect their foundations, choose such networks, only carefully weighing all the pros and cons.
Network design
When arranging the drainage system of this variety, an air gap is provided under the building, which can be manufactured using various technologies. The structural elements of this type of network, in addition to pipes and wells, are:
- waterproofing layer;
gravel layer.
In the event that a large influx of water is expected at the site selected for the construction of the house, the reservoir drainage under the foundation slab can be equipped in two layers. At the same time, its lower part is made of sand, and the upper part is made of gravel and gravel. Such networks, of course, cost the owner of the houses more expensive than usual. But their use in the construction of a building on wet soil can significantly extend the life of the foundation.
Under buildings, the thickness of such drainage is usually at least 300 mm. In the construction of large houses, the calculation of the thickness of the discharge layer of this type can be carried out separately, with the involvement of specialists.
Mounting Features
When installing drainage drainage under the building to protect the foundation from being flooded with groundwater, among other things, observe the following rules:
Under buildings, the thickness of such drainage should be at least 300 mm. When building large houses, the calculation of the thickness of the discharge layer of this type is performed separately.
The plastic drainage under the building must necessarily go beyond it by about 20-30 centimeters.
When using a reservoir system for water drainage along the perimeter of a building, in many cases a linear drainage is also arranged.
The main stages of installation
The arrangement of reservoir drainage is usually carried out according to the following scheme:
a foundation pit is excavated at the construction site of the building and deepened by 30 centimeters;
crushed stone mixed with gravel is poured at the bottom of the pit throughout its area;
perforated plastic flexible pipes with stiffeners are laid around the perimeter of the layer.
At the next stage, they begin to erect the foundation itself, using standard technology in compliance with SNiP standards.
Crushed stone for arranging the air gap under the foundation of the building is supposed to be taken not lime. Otherwise, the material will subsequently be gradually destroyed by water.
When laying on the bottom of the pit, crushed stone is necessarily carefully rammed. Otherwise, the building will subsequently settle unevenly, which can lead to the destruction of its structures. When filling the crushed stone layer, a bias is observed in the direction where, in the future, a receiving well will be equipped. When using such a system, a waterproofing insulator is laid in the pit with an inlet on the walls.
Receiving wells
Tanks for the arrangement of reservoir drainage are usually located at a distance of about 1-3 m from the foundation of the building. Digging in this case relies deep wells. The distance from the entry point of the outlet pipe to the bottom of such a receiver should not be less than 1 m.
Wells are mounted during the arrangement of reservoir drainage, usually using concrete or plastic rings. The width and depth of the pit under the receiver is chosen so that these elements are subsequently installed in it freely. When using concrete rings around the circumference of the well, a free space of 20-30 cm is left.
Before installing the well at the bottom of the pit, a layer of crushed stone is poured with a thickness of 30 cm. In this case, the drainage material is also carefully compacted. At the final stage of arranging the receiver, the drain pipes themselves are introduced into the rings. Next, the space between the walls of the well and the pit is filled with crushed stone. When using a receiver of this design, water coming from under the house is diverted to the soil layers.
Useful advice
The design of reservoir drainage is relatively simple. However, each of its elements will continue to fulfill a very important function. This concerns, of course, including the receiver.
Do-it-yourself concrete or plastic well thoroughly should not be completely filled up. In order to prevent rain and melt water from entering the tank, you just need to cover it with a reliable lid. If the well is covered with earth, it will be difficult to get close to it if it is necessary to clean pipes or revisions.
Perforated pipes when installing reservoir drainage should be laid with an inclination towards the collector of about 2-3 mm per square meter (for highways with a diameter of 5-10 cm). It is necessary to adhere to such indicators. Otherwise, in the future, the system will work inefficiently or will become clogged. Pipes with a diameter of more than 10 cm are laid with a smaller slope.
What mistakes can private developers make
Arrangement of reservoir drainage is a laborious task, but technically it is not particularly difficult. Nevertheless, when installing such a network, private developers often make mistakes that reduce the effectiveness of its work in the future.
In order for the drainage system to divert all the water from the foundation of the building, when installing it, it is worth, among other things, to adhere to such recommendations:
Do not use geotextiles as a filter for pipes when arranging such a system. After a few years, this type of layer is simply clogged, which will lead to a significant decrease in network efficiency. It is especially important to comply with this rule if the house is located on a site with sandy or loamy soil.
When arranging reservoir drainage, the installation of pipes, as already mentioned, is made with a slight bias. To arrange these network elements as accurately as possible, it is worth using a level. When applying the usual building level in this case, it will be very easy to make a mistake.
Water drainage from the foundation of the reservoir drainage is actually very effective. In the event that such a system will be equipped under the building, its service life will significantly increase. But such networks are intended, of course, for the removal of groundwater. At the same time, the foundation itself can be destroyed, including melt or rain.
Hoping only for reservoir drainage in terms of maintaining the integrity of the base of the building is therefore not worth it. When constructing a house, it is absolutely necessary to additionally mount a gutter system with rainfall. When assembling such a network, it must be borne in mind that it is impossible to combine stormwater and drainage to the same pipe. Otherwise, the soil in the immediate vicinity of the foundation will be waterlogged. And this, in turn, can cause the destruction of the base of the building as a result of spring heaving.
How to choose the right materials
Pipes for reservoir drainage, in fact, you can take any. But perforated lines made of composite or polymer material are best suited for such a system.
For a well, it is most advisable to use concrete or plastic rings. But if desired, the walls of the receiver can be laid out, for example, with a brick. Only ceramic material should be used in this case. Silicate brick is not suitable for this purpose.
You can also lay a well with a piece of rubber rolled into a pipe or use any other moisture-proof materials.
Off-well withdrawal
If a stream flows near the house, for example, it is not necessary to equip the receiver on the site. In this case, the pipe can be brought into such a reservoir. The highway to the stream should also be laid with a slope of several millimeters per linear meter.
Drainage lines located under the house are connected to the outlet pipe in this case using a tee. The outer line itself should be pulled below the freezing ground. Use for a branch line, of course, should also be perforated pipe. In this case, it would be better to wrap it with geotextiles. Replace this material if necessary in the future will not be difficult. The highway laid in the ground when using geotextiles will be clogged less. Today, on sale you can also find pipes wrapped with this material initially.
How to extend the service life
So that the drainage system does not stop fulfilling its functions ahead of time, it must, of course, be operated correctly. For example, no equipment should pass between the foundation of the house and the receiving well above the drainage pipe. Of course, you can not install in this place and any heavy structures. It is best to break a flower bed or lawn in this place.
The drainage pipes themselves under the house should be washed at least once every 2-3 years under high pressure. If these rules are neglected, the system subsequently quickly clogs. To clear the blockage formed in such a network, of course, will be quite difficult.