The storm sewage system is designed to drain water from the local area, which naturally flows there with natural precipitation (rain and snow). At the heart of any drainage system are special containers, through which water flows. Trays for storm sewers vary in size and material, they are used to install one complete drainage structure on a country site.
Device and types of storm sewer
The system of sediment removal includes a large number of components, each of which is designed to fulfill specific goals:
- water inlets for collecting water – pallets, funnels, linear trays;
- elements that move water to storm wells or other destinations – pipes, gutters, plastic or concrete trays for storm sewers;
- inspection wells for monitoring the entire system;
- special filters that keep various debris from entering the system with water and protect it from contamination.
All these elements are simply combined into a single system, the type of which depends on the characteristics of the territory or personal preferences. Storm sewers can be laid at a shallow depth in the ground, or mounted on the surface.
According to the method of collecting water, storm sewers can be point or linear. In the first case, the storm water intake is mounted underground with access to the drain. The hole through which water enters the system must be protected by a special grate to prevent various debris from entering it. Linear sewage is mounted on the surface and is a trench of shallow depth created for the installation of drainage trays. In the second case, the grids for drainage trays are laid along the entire length of the system and perform the same protective function as in the point drain.
The point system is good in the case when rain or melt water needs to be removed only from the roof surface. If you need an effective drainage system from a large area, then the device of a linear system makes sense, since it can cover a large area, and its installation is relatively simple.
Note! When arranging storm sewers of any type, it should be borne in mind that the trays must be laid with a slope in the direction in which the planned drainage.
The construction of storm sewers from trays with their own hands is relatively simple, but for its implementation it will be necessary to make a number of calculations. These calculations will not only more accurately design the system, but also save money by acquiring exactly the number of elements that are required for the most efficient drainage system.
To calculate the storm sewer will require the following data:
- the frequency of precipitation in your region, as well as the thickness of snow cover. The last parameter is necessary to calculate the discharge of melt water;
- average rainfall in the region. This indicator is expressed in millimeters and corresponds to the thickness of the layer of precipitated water;
- runoff area. In the case of a linear sewage system, this will be the total area of the territory from which water is planned to be drained, and with a point sewer – the area of the roof;
- location of already existing underground communications;
- full characterization of soils on the territory.
You can choose and buy a drainage tray of the required type only if all these parameters are taken into account when designing the system, otherwise the storm sewage system will not be as efficient as possible.
The volume of water that the system must divert is calculated by producing three factors: a numerical expression of precipitation intensity, surface area (from which water is required to be drained), and a correction factor. Data on precipitation can be obtained at the local meteorological station. The latter value is constant and depends on the type of coverage of the territory:
- 0.4 – area covered with rubble;
- 0.85 – concrete or reinforced concrete pavement;
- 0.95 – asphalt tracks and sites;
- 1 – roofs.
The depth of installation of drainage trays depends on the size of the product and the planned type of system. At the same time, it is necessary to take into account the presence of a drainage system in the territory: storm sewers should always be laid above it. The average depth of drain installation is usually 0.3 m for trays whose diameter does not exceed 50 cm, and 0.7 m for larger trays.
The main element of any type of storm sewage system are special trays, along which water is drained from the territory. They are made of various materials and differ in a number of characteristics, the most important of which is the maximum permissible load. In accordance with this parameter trays are divided into the following classes:
- A15 – used for the installation of storm sewage systems in home gardens, sports grounds, parks and pedestrian areas. The maximum load is 1.5 tons;
- B125 – trays of this type withstand a load of 12.5 tons and can be used for diverting water from car parks, in garage cooperatives, as well as on roads for passenger cars;
- S250 – used at gas stations, car washes and in other areas of automotive service. Maintain a load of 25 tons;
- D400 – storm sewers of this type are widely used in small industrial enterprises, in transport terminals, industrial areas and on highways with high traffic. The maximum load is 40 tons;
- E600 – mounted in warehouses, large enterprises, marinas, logistics centers. Load – 60 tons;
- F900 is the most resistant to physical loads type capable of withstanding up to 90 tons. It is used to drain water from airfields, military bases and places where various super-heavy equipment is used.
The second significant parameter by which the trays differ is their throughput. It depends on the hydraulic section of the structure, which is determined by its height and width.
As for materials, for the production of trays, the following options are used:
- Concrete or reinforced concrete.
- Various metals and alloys, such as cast iron.
- Composite materials.
The use of concrete or RC drainage trays makes sense when it is planned to drain water from the territory, which is constantly subjected to heavy loads. It can be a busy freeway, parking and many other places. The price of concrete drainage trays is slightly higher than plastic, but lower than composite, and their performance characteristics are high.
In addition to the ability to withstand heavy loads, concrete products are characterized by increased resistance to various adverse effects and weather conditions. They do not rust, they withstand persistent exposure to chemicals, such as fuel. In addition, the simplicity of the design causes a long service life. As a rule, concrete trays are made with the expectation of draining large amounts of water, so systems based on them have a high throughput.
The disadvantages of concrete and reinforced concrete structures can be attributed to their great weight, which significantly complicates the installation of storm sewage on their own, this requires the use of specialized equipment.
Note! All versions of drainage trays of concrete products have special grooves that are combined during installation, which eliminates the possibility of leakage. This means that concrete trays can be simply connected to each other without the need for additional sealing of joints.
According to GOST, concrete drainage trays can be produced with different parameters. Thus, the width of the hydraulic section can vary from 100 to 500 mm, the height from 90 to 760 mm, and the length of a single groove is usually 1000 mm.
The use of plastic trays for storm sewers is often found in private construction, as well as in arranging park and garden areas, footpaths and other areas that are not subjected to heavy loads. This type is made of extruded polyethylene or propylene and has the following advantages:
- low weight of individual elements compared with concrete or polymer concrete drainage trays;
- simplicity and ease of transportation;
- the ability to easily install plastic drainage trays on their own without the use of specialized construction equipment;
- resistance to moisture, as well as temperature changes;
- long service life.
In order to increase the strength and durability of plastic structures, they are supplied with special figured ribs. Products may vary in color and shape. The grille supplied with a plastic drain pan is usually made of the same polymer or of lightweight steel. The second option is stronger and more reliable.
Before you buy a plastic drainage tray with a grate and proceed to the installation of storm sewage based on it, you should consider one thing. Due to the smooth surface of the material, plastic products have a higher permeability than other materials. This means that a water removal system based on them can be made with a smaller slope than from concrete or composite trays.
Sizes of plastic drainage trays can be different. The hydraulic section is usually from 70 to 300 mm, the standard length of one segment is 1000 mm. Weight can be from 1.5 to 20 kg, the maximum parameter is calculated complete with a metal grill.
Composite gutters for storm sewers are manufactured in two versions:
- Polymer concrete – consist of a mixture of plastic and concrete.
- Polimerpeschanye – a mixture of concrete, plastic and sand with the addition of special additives.
According to their performance characteristics, composite trays are located approximately halfway between concrete and plastic. They can boast a lighter weight than the reinforced concrete trays for storm sewer, but not as light as plastic troughs. They are also characterized by increased strength and wear resistance, but are not able to withstand as much load as concrete. Like plastic products, they have a smooth surface that improves the permeability of the system.
In this case, to protect the system from debris, various types of grids for drainage trays are used: cast iron or plastic.
When installing drainage trays made of composite materials, the same special grooves are used as in the installation of concrete gutters, so additional treatment of the joints is not needed. The average price of the polymer-sand drainage tray is 430 rubles, the polymer-concrete one is 970 rubles. (in both cases, for the meter product without a grid).
The hydraulic section of the gutters from polymer concrete is from 100 to 200 mm, from polymer sand – 70-150 mm. The length of one tray, as in other cases, is standardized and is 1000 mm.
Metal drainage gutters are far from the most popular option, and there are a number of reasons for this. Metal is more susceptible to corrosion from regular contact with water. In order for such a product to last as long as possible, the metal layer must be sufficiently thick, which directly affects the weight of the structure. Usually cast iron is used as a material for the manufacture of metal gutters, which is very heavy. Accordingly, the installation of the system of metal gutters becomes impossible without the use of specialized equipment.
The price of trays for storm sewers made of metal is also significantly higher than concrete and even plastic. Therefore, use this option only when it is really necessary.
Helpful advice! A good compromise in this case is the use of gutters with steel bars. The price of a concrete drainage tray with a cast-iron grill is lower than that of an all-metal product, and the metal grille is characterized by an attractive appearance and long service life.
The price per unit of product depends largely on the material from which the chute is made. So, the prices of concrete trays for storm sewer vary from 1300 to 2500 rubles per unit and higher. The price of a plastic tray for storm sewer starts from 500, and reinforced concrete – from 1,800 rubles.
For example, the drainage tray Gidrolica costs from 530 rubles per piece. It should also be borne in mind that the cost of a unit of a product depends largely on the components that come with the chute and its dimensions. For example, the cost of a concrete drainage tray with a grill will be higher than without it.
Of the advantages of self-production can be noted not only exactly the size you need concrete drainage trays, the price will also be much lower than when buying a finished product. However, if you decide to buy plastic drainage trays for storm sewers, this will definitely save your time. So the decision about whether to buy or make gutters personally, depends only on your personal preferences.