The technology of the drainage system provides for the installation of wells that differ in purpose. They are needed to monitor the operation of the underground pipeline, regular maintenance and periodic cleaning. Previously, they were assembled from concrete rings, but now products from polymeric materials are used.
Lightweight and durable plastic drainage wells make the construction process much easier. Polymer products are resistant to mechanical, chemical and biological influences. Manufacturers of products thought out all the details, providing simplicity and high speed of installation.
We will tell you how to correctly choose polymer structures for the drainage system and how to install them. The article presented for review details step-by-step instructions. Following our advice, you can quickly arrange effectively operating drainage on a suburban area.
Classification of drainage system wells
To save the territory from rain and melt water, it is not enough to install drainage pipes and trays on the site. The same applies to moisture in the soil, drainage pipes alone will not be enough, because the liquid collected by him must be diverted somewhere. To do this, a system is created from underground pipelines, an integral part of which are plastic wells.
There are several different types of such structures, each of which has its own purpose. They have different sizes and the number of entries, can be with a sealed bottom and without it. And all this variety of devices is now made of plastic.
Well drainage facilities are needed to accumulate water and control the operation of the entire drainage system
Types of facilities by functionality
In the drainage systems, six varieties of plastic wells with different functional purposes are used:
- Collector. In the suburban areas, one collector well is arranged for receiving drains of all types of sewer systems. If there is a need to stimulate the movement of effluents, it is equipped with a pump. If it is planned to unload the system into the underlying layer, they are constructed without a bottom like filtration.
- Lookouts. Arranged for system audit and periodic cleaning. They are located at turning points, forming nodes or connecting to central highways.
- Overflow. They are installed in the joints of pipelines laid at different depths. They are also used when it is necessary to reduce the gravity flow rate or when crossing any underground structures. In drainage systems are practically not used.
According to the type of access to servicing systems, wells are divided into serviced and inspection ones. The first type provides access to the network sections passing in the well for maintenance, the second provides for repair and other operations from the ground.
Drainage is an engineering system designed to drain, lower the level of soil water, drain groundwater from the foundation, and reduce the pressure of the water treatment plant to underground structures. The system includes drains (pipes with holes) sprinkled with filter material, serviced and inspection wells
The functionality of the wells is different, but they are structurally similar. In general, it is a vertically oriented reservoir in the ground that has two or more outlet and inlet openings. Often, one well combines a number of significant functions. But in most cases, each of them is mounted for any one role.
Manhole inspection structures are designed to inspect and maintain the entire system. On the one hand, inspection wells allow you to monitor the condition and throughput of pipes, controlling the level of clogging, and on the other hand, pipelines are cleaned from them.
Image Gallery
Photo from
Drainage wells are objects of the system for the disposal of excess groundwater, which allow for the maintenance of underground utilities if necessary
Wells are installed on the turns of the underground pipeline and at points necessary to monitor its condition
Plastic products are easy to install, do not require the use of lifting equipment in the process of assembling the system
In order to easily install the drainage system together with the wells, drains, bottoms, manhole rings and hatches are produced at an extremely fast pace.
The device drainage system accompanies mainly the installation of drainage wells. Water drains through drains into a collector well, usually common for drainage and stormwater
The optimal time for a drainage device constructed to protect the foundation from groundwater is the period before installing the formwork for pouring the foundation
After the flooded foundation reaches the required strength, its walls are insulated, then the trench with drainage is filled with soil
At the top, around the neck of the drainage well, a hatch ring is installed, to which a hatch is subsequently attached
Purpose of drainage wells
Drainage service point
The advantages of plastic products
Mounting elements for drainage assembly
The main types of drainage wells
System for protecting the foundation from water
Time to backfill the drainage system
Hatch in the arrangement of the drainage well
Swivel type of manholes are used when it is necessary to turn the flow of water 90 °. Linear ones are installed on straight sections after an average of 50 meters, but the allowable distance interval between them is 40 - 150 m.
If it is supposed to flush the system manually with a descent into the well, then it should be a diameter of one meter. In other cases, a structure with a diameter of 35–50 cm is enough. Just enough to let the hose for flushing or pumping out without problems.
Accumulative or collector options are large containers in which the accumulation of effluents takes place for the subsequent movement of drainage effluents to discharge points. It can be a nearby body of water with standing or running water, storm sewers.
Pipes of the drainage system converge in the nodal well, from which water is sent: 1) to the reservoir, intended for collection and subsequent pumping, 2) to the absorption well, which serves to filter into the lower soil layer, 3) to the collector used for transportation to centralized stormwater
The well, arranged according to the filtering principle, allows you to drain water into the underlying groundwater aquifers, taking it away from the foundations of buildings.
However, it is permissible to arrange it only on sandy soils, gravel or pebble deposits with sand aggregate. Those. on soils with good filtration qualities equal to the ability to absorb water.
The entire system of pipelines and wells is built in such a way that the last structure in the chain is at the lowest point of the drained territory. It is in the drive, filtering or collector well that all water from the site must drain.
In this case, it is desirable that the movement of water was by gravity. In the event that a gravity-flow system device is not possible according to technical specifications, the collector well is equipped with a pump to stimulate the movement of water.
The task of the differential type of well structures is to quench the speed of the water flow
Overflow wells according to the internal arrangement differ in:
- chambers with one water damper inside;
- collectors with a water stripper system;
- high shafts with a lead-in from above and a downpipe from below;
- constructions from a pair of independent sections connected by an overflow channel at an angle.
In some cases, the flow energy is extinguished by the bottom, while in others this is due to special chippers. The choice of a specific option depends on the level of the difference between the sewage pipes, as well as the relief of the site and the characteristics of the soil layers on it.
Polymers used in the manufacture
In the manufacture of plastic wells for drainage, polymers of various structures and different technologies are used. The cheapest products are obtained on rotary forming machines. They are most often found in domestic stores.
The technology of rotational formation allows to obtain strong well bodies with walls equal in all places in thickness
Wells are produced using the following polymers:
- PVC (PVC) - polyvinyl chloride.
- PP (PP) - polypropylene.
- PE (PE) - ordinary and high density polyethylene.
Most often one of them is used with some kind of placeholder, but various combinations are not uncommon. Various components can be added to the resulting plastic: from dyes to sand.
Polyvinyl chloride products are the most resistant to the effects of aggressive chemicals that enter inside with effluents.
They are even used in the construction of sewer systems at industrial enterprises. Polypropylene casings are characterized by high wear resistance and ductility, but they become quite fragile with a strong decrease in temperature.
Polyethylene drainage wells are resistant to frost. They can freeze, but after thawing this element of engineering communications quickly regains its shape without losing tightness. This is the best option for moving soils.
The advantages of plastic products
Among the advantages of plastic wells for drainage are:
- Light weight, which allows without a crane during loading / unloading and installation.
- Resistant to aggressive environments, mechanical damage and low temperatures, the body material.
- Service life of 50–70 years without major repairs.
- The presence in the case of all the necessary inputs and outputs of the factory version.
- The minimum amount of excavation due to thin walls and a reduced diameter of the well structure.
- Extremely simple installation - a plastic product is easily cut to the desired size.
- The strength of the structure, which is able to withstand tens of tons of load from above and the accumulation of soil in winter from the sides.
The lightness of the plastic elements of the well body allows all installation work to be performed by a couple of people. But in this lightness lies the main drawback of plastic wells - during floods and swellings, they can be banally squeezed out of the ground.
To prevent the light well structure from being pushed out of the ground by water, it must be tied to a heavy “anchor” in the form of a concrete slab
Another relative drawback is the high price of a plastic drainage well. However, it is worth considering not only the cost of the product itself, but also the cost of its installation. In the case of a plastic construction, you don’t have to order lifting equipment, a couple of installers and ropes will be enough to lower the assembled elements into the pit.
Given the long life of several decades without major repairs, the price no longer seems so overpriced. The initial cost of a plastic well pays off.
In addition, it is much easier to connect pipes to it than to a concrete or brick counterpart. Specialized skills for its installation will not be required, it will not be necessary to invite highly qualified specialists.
Plastic well device
Structurally well construction made of plastic includes:
- conical neck;
- a circular working chamber (shaft);
- sand tray and bottom.
Instead of a sealed bottom, a drainage cushion made of gravel can be arranged, because leakage of drainage water during the repair of the system is not dangerous for underlying soils and the environment.
From above, the entire structure is closed by a hatch or a conventional cover. They are made of plastic, cast iron or polymer sand. In this case, the neck of the well tank may be absent, then the hatch is laid directly on the shaft.
The prefabricated plastic well consists of a neck, a shaft of various heights, a tray and sealing cuffs for tight connection of pipes
The mine is made corrugated, so its strength characteristics increase. When compressed by the soil, it will not collapse, remaining intact and tight.
The bottom and the tray with pipes make up the kinetic part of the well, where pipe wiring is arranged. Also, all trash and sludge falling inside it with drains settles in it. Often complete with them is a special form for pouring a concrete support base (“anchors”).
When installing a sealed well structure for a drainage system, it is permissible not to use a tray. Instead, you can install a simple flat bottom. So the design is cheaper, but this option is more prone to clogging with large debris. You will often have to look into the well shaft for the purpose of inspection, and at the slightest clutter - immediately clean it.
Inside the well, a hinged staircase can be built in or steps can be made in the form of inserts into the body. Piping is connected to special holes cut at the factory. Also, a similar insert can be made at almost any point in the body.
Details on the classification of plastic wells, their design features and scope are described in this article.
Which is better: precast vs monolithic?
A prefabricated well for drainage is assembled from various plastic parts, like a constructor. The monolithic product is already ready for installation, it only needs to be lowered into a hole dug for this.
Before purchasing a monoblock well, it is necessary to carefully calculate everything, replace its part or build up the shaft after installation will not work
Monolithic options are cheaper and stronger than their prefabricated counterparts. However, they are available in a fairly narrow range of standard sizes. Their installation is carried out only to the depth specified in the instructions.
Separate elements of a prefabricated structure are easier to transport and load in a car than a single-piece product of large sizes. But in terms of compressive strength, even in the assembled state, they are inferior to the initially solid well. A solid casing, by definition, can withstand large hydrodynamic and mechanical loads.
To lengthen the hull, the prefab well can be equipped with several shaft rings in the middle part and an additional telescopic extension under the hatch (+)
The assembly of plastic parts for a drainage well involves the need to seal their joints. And each such junction is a potential gap and leak.
Plus, to tighten the elements, you need bolts with nuts. They should be included. If they are not, then buy only galvanized fasteners, less susceptible to corrosion.
Plastic drainage well installation technology
If a prefabricated structure is selected, then it must first be assembled. You can do this in the pit, but then it will have to be dug up larger.
Image Gallery
Photo from
Installation of the collected part of the drainage in the trench
Corrugated pipe trimming for a well shaft
Corrugated Manifold Shaft Device
Fixing the conical neck to the corrugated part
The depth of the pit under the plastic drainage well breaks out so that the pipes enter it below the freezing point of the soil and above the upper aquifer in it. At the same time, it is worth remembering that under the construction it will still be necessary to pour a crushed stone pillow of 10-15 cm and lay a concrete anchor plate of a similar thickness.
If a plastic well will be used to drain moisture into the soil, then the layer of rubble at the bottom should be at least 30–40 cm. In this case, a large hole will have to be digged.
The width of the pit is 30-50 cm larger than the outer diameter of the mounted tank. This is quite enough to lower the plastic product inside, and you won’t have to dig extra land.
The well structure is selected in height so that it cannot rise more than 20 cm above the ground. The only exception is the catchment option with a grill on top instead of a cover.
Hatches of all other types of drainage system wells should be located 10–20 cm above the level of turf. Otherwise, during the rain, water flows will begin to flow into them, carrying with it foliage and other garbage.
Image Gallery
Photo from
Preparing for the installation of a drainage well
Leveling the bottom of the constructed drainage well
Connecting drainage pipes to the bottom of the well
Corrugated pipe trimming to design height
Installing a seal on a well shaft
Silicone bottom treatment
Installation of a well shaft at the bottom
Filling the trench around the well with soil
If groundwater regularly rises to the surface in spring, then a concrete base under a plastic well must be made without fail. Between them they are connected by a nylon cable, which certainly does not rot in the ground. A concrete anchor is not needed only in areas with dense rocky soils.
To cut additional holes, you will need a milling cutter of the appropriate size. After making a hole, a rubber sealant is inserted into it, into which a transition sleeve is placed. The latter should go into the rubber gasket tightly without gaps.
To do this, they must have the same size. In order to seal the joints, they are lubricated with silicone grease, which facilitates the indentation of the coupling and at the same time forms a tight joint.
The installation of small plastic wells can be done alone, and to install medium or large, it is enough to attract one or two helpers
Then, perforated drainage pipes and sealed sewer pipes, necessary to drain the water collected by the drainage, are connected to the well installed in the pit.
To ensure free movement of the water collected by the drainage, they are laid with a slope. So under the influence of its own weight, the water will spontaneously flow towards the reservoir, collector or filter well.
And then it remains only to backfill the pit with soil or a sand-cement mixture. This is done evenly and in layers, so as not to sharply squeeze the plastic housing and not destroy it. The hatch is laid on top, installation is completed.
Sawing a well shaft to the desired height is done with a conventional hacksaw in the center of the protruding corrugation segment
Well insulation
Drinking and sewer wells should be covered with insulating material. They are used year-round, while the water in them should not freeze.
But with the construction of the drainage system of the site, the situation is somewhat different. They are not used in winter. Frosts in spring and autumn for plastic wells are not terrible. By all means, they are not required to be insulated.
However, if there is a desire to perform thermal insulation, then the ideal option here is polystyrene sheets. This material is not afraid of moisture and cold.
Video # 1. Insertion technology into a plastic pipe body using a sleeve:
Video # 2. Overview of drainage wells from different manufacturers:
Video # 3.Step-by-step installation of a well structure made of plastic:
A well made of plastic, intended for use in a drainage system, is a practical, durable and easy-to-install product. For its installation you will not have to involve construction equipment.
A variety of prefabricated and standard sizes of monoblock structures makes it possible to arrange drainage systems of any complexity. It is only necessary to choose their model in accordance with the functional purpose.
Please write comments in the block below. Here you can ask a question or tell about your own experience in installing plastic wells. Share interesting facts and photos on the topic of the article.