Rainwater sometimes turns out to be a very valuable natural resource to be scattered left and right. Therefore, modern storm drainage systems are becoming more and more complex, and are often equipped with special elements designed not only to minimize the negative consequences of rainfall, but also to effectively collect water.
Classic storm drainage device
The basis storm sewer constitutes a system for directing and distributing water. In a simplified version, storm drainage includes the following elements:
- Pipe. Most often it is laid in the ground and covered with a layer of turf, concrete or a hard surface of asphalt and paving slabs;
- Drainage channels or trays. The most important element of storm drainage, from correct location water collector depends effective removal water from the surface of the walkway or area near the front door;
- Filtering and distribution elements. Their participation in the operation of storm drains is invisible, and most people are not even aware of their existence, but they are extremely important for the normal operation of the entire system.
Important! Storm drainage not only and not so much helps to effectively drain water, but above all, it protects the soil and foundation from oversaturation with water.
Basic elements of storm drainage
All elements of storm drainage are equally important for the effective removal of water from the surface of the site. Failure or abnormal operation of any of the above elements may reduce throughput sewer system to a minimum.
Device for receiving storm water flows
Stormwater inlets or, more correctly, water inlets and trays for storm drainage, gutters that serve to collect flows of water on the surface of the earth, are the most vulnerable to mechanical impact from feet, wheels, vehicles, even icicles and freezing ice. Water receivers are most often made in the form of a rectangular or cylindrical box made of plastic or fiberglass reinforcement.
They are installed directly below the drainage hole of the downspout and serve to receive the flow of rainwater collected by the gutter system. The inlet opening is always covered with a metal or fiberglass grill. There is a hole in the side wall where the drain pipeline is connected. IN individual designs water inlet is provided additional element for filtering large pieces of debris, tree branches, wood chips, small pebbles. This element does not retain sand and small particles of dirt well. Often even experts are confused and believe that this is a sand trap for storm drainage.
Storm water inlets for storm sewers must ensure shock-free intake of water flows without splashing, even if part of the receiving device is covered with leaves or pieces of ice. The condition of part of the foundation and wall of the house depends on the efficiency of this element of the storm drainage system.
In addition to water intakes, rainwater drainage trays, or gutters, collect water. Most often they are installed along paved walkways. Paved areas and paths are especially sensitive to excess water. paving slabs. Incorrect or ineffective work leads to swelling of the masonry due to frozen water in the sand cushion.
Storm drainage trays are long plastic gutters laid directly on a sand bed in the ground and covered on top with a protective cover with holes. A prerequisite for laying trays is to maintain a drain slope in the direction of the receiving pipe. In some cases, storm drainage gutters stop working effectively if people step on the installed gutters or vehicles run over them. To avoid this, a stone or tile border is laid on the sides of the tray.
The cover can be plastic or lattice, but the latter option is used less frequently due to its poor ability to trap large debris and dirt entering the sewer system.
In addition to tray systems, point-type inlets are also used in rainwater collection systems. These elements are designed to collect rainwater in a certain area where it is impossible to install gutters or trays. Most often, this is a concreted area, on the surface of which there are slopes and a grid of profiled grooves for water drainage.
A separate element in rainwater collection systems is a receiving box or tray installed directly in front of the front door to the house. Such a device is used to catch rain and storm water that enters the entrance area of the porch. The design of the pan corresponds to the structure of the rain inlet, but differs in size.
Prefabricated, distribution and filter elements
All drainage elements of rainwater collection systems direct flows through pipes to places where it is collected, settled, filtered and, if necessary, discharged into the central rain drainage. The use of polyvinyl chloride or polypropylene corrugated pipes is considered standard today. The diameter of the pipeline, depending on the load, can range from 100 to 200 mm. This version of the pipe is highly flexible, resistant to frost, clogging, and can easily withstand any subsidence or soil movement without destruction.
In addition to polymer pipes, asbestos-cement pipes are used. They are highly resistant, but their use is currently limited due to the presence of asbestos fibers in their material. Cast iron, steel, ceramic pipes are practically not used due to the high price.
Required element modern systems collecting rainwater is considered a sand trap that releases water from the smallest particles sand, dust and dirt. Essentially, this design is a large container in which rainwater settles and separates into sediment and clean water. The design provides the ability to remove sediment and contaminants. Less commonly used are vortex sand traps, in which grains of sand and tiny gravel are separated from the storm flow as they pass through an annular chamber.
In some cases, in addition to the sand trap, a filter can be installed to separate petroleum products, oils, and heavy organic substances that are insoluble in water. Typically, such elements are a mandatory attribute of storm drains at gas stations, parking lots, auto repair shops, and are used quite rarely for domestic purposes.
The most expensive and largest element of rainwater collection systems is the distribution well. This device is a barrel-shaped container to which pipelines from water collection devices in a certain area are connected. Depending on the size of the plot, 2-3 distribution wells can be installed in one household. This element is buried in the ground so that the water column in the container is at a level lower than the pipelines connected to it. In this case, the collected water will not flow from the well back into the storm drain.
From distribution wells, water is directed to a collection tank. If there is a central storm sewer, storm flows can be redirected to the central main line or, as they accumulate, pumped using a pump to the disposal site.
Distribution wells must be marked, capped and used for servicing rainwater collection systems.
All storm sewer elements are connected to each other by elastic couplings, tees and adapters, allowing the connection of pipes of different diameters. This method of connection allows the entire structure of the storm sewer to be insensitive to mechanical influences, loads, subsidence and soil movements.
Conclusion
The use of plastic and polymer materials makes it possible to build storm drains with high capacity, resistant to frost and corrosion. The service life of properly constructed storm sewer elements can reach several decades, provided that the system is properly and regularly maintained.
Heavy rains and spring thaw become a real problem for many homeowners. After all, after rain, the site turns into a kind of swamp, and regular flooding of the foundation and walls contributes to their destruction. And the cause of all these misfortunes is the absence or improper operation of storm drains. Let's consider the main points of the construction of such a device as a storm sewer - snip, GOST and other requirements that should be taken into account.
An example of a storm drain on a site
What is a storm drain? Storm sewers are usually called complex engineering schemes that serve to collect and remove moisture from the drained area that falls in the form of precipitation. When constructing these schemes, you should be guided by the requirements of SNiP 2.04.03-85; this document addresses the issues of constructing external sewerage networks. This regulatory document is mandatory for execution during the construction of new systems and during the reconstruction of old ones.
The SNP for storm drainage contains the necessary formulas for carrying out calculations when designing a system, outlines the requirements for materials, and basic operating rules.
Types of storm drainage
There are two types of storm drains:
- Point system.
- Linear system.
Let's consider these types of systems in more detail.
Point storm drainage Point type storm drainage system
Dotted patterns are a network of special elements - rainwater inlets, which are installed to collect rainwater flowing through a system of gutters from the roofs. Each of the installed rainwater inlets is connected to a common main line through which moisture is removed from the territory.
In order to assembled circuit was durable, safe and effective, technical specifications for storm drainage, installation on storm water inlets is provided protective grilles, as well as installation of special filters - sand traps.
Linear storm sewer
As a rule, such a scheme is a network of canals that are designed to collect and transport water. Unlike the scheme described above, this option is designed to collect water not only from the roof, but also from asphalt and concrete areas and paths.
According to GOST requirements, storm sewers are installed with a slight slope towards the main collector. Such a system is necessarily equipped with a combination of filters that protect the channels from debris getting into them.
Storm drainage elements
As a rule, the following elements are included in the sewerage scheme (in one combination or another):
- Storm water inlets. This is one of the important elements of the system, the main function of which is the local collection of water from the surface of the earth. These elements are installed under roof drainpipes, on areas with a water-impermeable coating (there must be a slope to the location of the rainwater inlet).
- Door pallets. This is an analogue of storm water inlets that are installed in front of entrance groups at home or at the gate.
- Trays or gutters. Elements installed in ditches for water drainage. So that water can move through them by gravity, a slight slope of the storm sewer is provided, directed towards the collector.
- Pipes. This element performs the same function as the trays, but is laid not in surface trenches, but underground.
- Sand catchers. These are filter elements that prevent debris and soil particles from entering the drainage system.
- Inspection wells. Parts necessary to control the operation of the system.
Storm sewer calculation
Storm drain diagram for calculations To make the correct calculation of storm drainage, you need to know:
- The average amount of precipitation that falls in a given area.
- Frequency of precipitation.
- Drainage area, that is, the area of roofs, platforms and paths with a waterproof coating.
- Soil properties at the site.
- Locations of already constructed underground communications on the site.
You can calculate what the diameter of a storm drain should be using the formula:
Q = q20 x F x Ψ
Designations in the formula:
Q is the volume of water that the system will have to drain.
q20 – precipitation intensity.
Advice! This value depends on the climatic conditions of the area; you can find its value in the tables according to SNiP 2.04.03 - 85.
F is the area of surfaces from which water is planned to be drained.
Ψ is a correction factor that depends on the covering material of the site from which water is collected.
Advice! The correction factor for roofing is 1.0, for areas and paths covered with asphalt - 0.95, for concrete coverings– 0.85, for crushed stone coverings – 0.4 (and if the crushed stone is treated with bitumen, the coefficient will be 0.6).
After the calculation is carried out using the tables given in the regulatory documents, the required pipe size is determined.
At what depth should pipes be placed when constructing storm drains?
The question of what the depth of storm drains should be is widely discussed on construction forums. Meanwhile, a completely understandable answer is given in SNiP 2.04.03-85 - the minimum depth of storm sewer installation is determined by the experience of operating systems in a given area.
Advice! As a rule, subject to operation in middle lane and the use of pipes with diameters up to 500 mm, the minimum depth is taken to be 30 cm. In the event that larger diameter pipes are used for the construction of a system such as a storm sewer, their laying depth should not be less than 70 cm.
In practice, the depth of the pipes is determined based on the need to reduce the volume earthworks, but at the same time, eliminate the possibility of pipe damage due to external influences, and also minimize the risk of freezing.
Slope of stormwater pipes
In order to find out minimum slope storm sewer, you need to consider:
- Type of drainage;
- Pipe diameter;
- Surface coating.
Advice! When using pipes with a diameter of 200 mm, the slope should be from 0.005 to 0.007. If pipes with a cross-section of 150 mm were used, then the slope should be 0.007-0.008.
Construction of storm drainage
In general, installation work on the installation of storm drains is carried out in the same way as when laying external pipelines of a conventional sewer system.
Installation of the roofing part
This part of the work goes like this:
- Openings are made in the ceilings for installing rainwater inlets, and all junctions are carefully sealed.
- Drainage pipes are strengthened when constructing a point system or trays when installing a linear storm drain.
- Install sewage risers or pipes.
- A unit is assembled for discharging water into a collector or discharging into tray systems.
- All devices are attached to walls and ceilings using clamps. Places for installing clamps are planned in advance, not forgetting to follow the recommended slope values.
Laying the underground part
- Installation begins with the installation of trenches. When constructing systems such as storm sewers, the depth of installation is most often determined not by the depth of freezing, but by the experience of operating the systems at the construction site.
- Trenches are dug with a slope, and their bottom is well compacted.
- If solid inclusions (stones, hard lumps of soil) are found at the bottom, they should be removed, the resulting holes should be filled with soil and compacted again.
- At the bottom of the trenches there is a sand cushion, the layer height is 20 cm.
- A pit is being prepared for installing the collector. Today it is much more convenient to use ready-made plastic wells than to build a collector yourself.
- Pipes should be laid in the prepared ditches, the pipes should be connected to each other and connected to the collector using conventional fittings.
- If the sewer network consists of a single branch more than 10 meters long, then it is worth planning to install a manhole in the middle of it. Such wells should be installed at network branch points.
- From those sides of the house where there is no drainage systems(for example, on gable roof drainage is provided only on two sides, and two more remain free) it is planned to install water inlet gutters. They are installed in shallow trenches (30-50 cm).
- Sand traps are installed at the junction of the water inlet gutters and the stormwater pipe system.
- The system should be tested before digging trenches. To do this, a bucket of water is smoothly poured into each of the rain inlets and into the gutters. Now you need to make sure that the moisture leaves easily and does not stagnate. Also, you should pay attention to the tightness of the pipe connections, especially those that are located close to the foundation.
- Now all that remains is to backfill the trenches and cover the trays or gutters on top with gratings.
The need to create security zones
Construction and sanitary rules provide for the creation of special security zones in the area where pipelines are located. Thus, the storm sewer security zone provides for a distance of 5 meters from the pipe walls in each direction.
Ready-made storm drainage system on site IN security zone prohibited:
- Build permanent or temporary structures.
- Set up garbage dumps.
- Arrange parking.
- Plant trees or bushes at a distance of less than three meters from the pipe.
- Block free access to manholes.
So, installing a rainwater drainage system is a necessary measure when landscaping a site. When constructing such systems, it is necessary to strictly comply with the requirements and rules that are formulated in regulatory documents - construction and sanitary rules.
- The principle of operation of storm drainage and its purpose
- Requirements for laying system elements
- How to properly design a storm drain for an open and closed type
- Preparing for installation and laying out the system yourself
- Instructions for installation of closed storm drainage system
- Recommendations for installation and maintenance of storm sewers
Storm sewerage is a complex that includes channels and devices that allow the collection and removal of excess rain and melt water outside the drained area. The wastewater is first filtered, and then it must be collected in a collector well. From it, wastewater flows to the loading points. Further collection of atmospheric moisture is carried out on filtration fields, in special reservoirs, and reservoirs.
Accumulations of debris from the sewer must be periodically removed, which requires cleaning the linear network, which is the storm sewer. These steps are not difficult to do yourself. Cleaning can be done using the services of a specialized company. At the same time, it is important to know how the storm drainage system works, what elements are included in its composition, and what technical requirements are imposed on the equipment in the storm drainage complex.
The principle of operation of storm drainage and its purpose
A storm sewer system includes a set of device channels that serve to remove excess moisture that creates discomfort and destroys structures. It consists of the following standard elements:
- Storm water inlets in the form of funnels.
- Pallets.
- Linear trays for collecting water.
- Gutters.
- Pipes.
Technical conditions require equipping raincoats with sand traps or filtration devices, as well as gratings. This prevents suspended soil particles or debris from entering the storm drain system.
All elements of storm drainage are combined into common system according to technology, which can be of two types: point and linear. The choice of one scheme or another depends on the method of collecting wastewater. If storm drainage channels are laid in the ground, then pipes are used. Plastic, concrete or asbestos trays and gutters are used to equip surface ditches, arranging internal and external drains that form a point system.
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Requirements for laying system elements
There are certain requirements for the methods of laying elements, for example, trays, sewer pipes or gutters. It is necessary to maintain an inclination when laying the listed elements towards the catchment structures, as well as loading points. Stormwater inlets for storm drainage are installed under the drain, and a funnel receiving water must be equipped using a filtration mesh. However, you will need an internal basket for collection. Another method of installing storm water inlets involves following the following installation diagram of elements:
- On the right is a chute and a sand catcher.
- In the center there is a funnel for receiving water from the drain.
- On the left is the door tray.
A linear storm drain is a network of channels that are laid underground or in shallow trenches. Trays designed to collect and move water are laid open method. At the same time, they are equipped not only with gratings for storm drainage, but also with sand traps. The gratings are installed along the entire line. For the purpose of drainage, more elements are involved in a linear sewer system than in a point scheme. Therefore, water is collected both from roof gutters, and from platforms, paths, which can be paved with sidewalk bricks or covered with concrete.
A linear type storm sewer scheme allows you to cover a large area. Drainage can be carried out both from sidewalks and landscaped areas. If the specifics of the pitched structure do not provide for the presence of drains, then the drains are discharged from certain sides of the house.
The type of system chosen will depend on the extent of area coverage. But these selection criteria are not fundamental. You can install a storm drain with your own hands at your dacha if you have some experience related to the organization and operation of complexes of this type. In this case, it is important to determine not only the type of channel laying, but also their depth.
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How to properly design open and closed storm drains
The open type of storm drain is called linear because the water must flow over the roofs to a specific place.
You can install an open sewer system if you use gutters made of concrete, metal or plastic. To protect the sewer system from contamination, gratings should be placed on the gutters to perform an aesthetic function. To prevent soil shrinkage, it is necessary to provide a slope by making channels under the gutters. Channels can be installed using waterproof sealants.
Calculation of closed storm sewer:
- Determine the characteristics of the territory and landscape features.
- Provide for the presence of architectural structures around the house on the summer cottage.
- Calculate the average degree of precipitation.
- Understand the placement of technical structures.
After this, preliminary drawings should be prepared, which will indicate the layout of pipes and locations for installing equipment, and calculate the depth of the storm sewer. Designing a closed storm sewer will require the preparation of the following documents:
- Information about the project.
- Sewerage diagram.
- Preliminary drawings.
- Work report.
It must be remembered that the operation of any sewerage system will be of high quality if all equipment and sealants are of appropriate quality. Preventative cleaning of storm drains should be carried out at least once a year, which will prevent blockages of water inlets and trays.
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Preparing for installation and laying out the system yourself
Materials used during the work must be waterproof and anti-corrosion. Corrugated pipes They are not suitable for such sewage systems, so there is no point in using them due to rapid clogging. Should not be used complex circuits, determining the location of the pipes. When laying pipes, you should not make additional routings or turns. Connections structural elements must be sealed. Having prepared the installation diagram, it is necessary to calculate the footage of pipes and other required elements. Protection of the system and high-quality cleaning of storm drains requires the installation of two additional wells. Pipe cleaning is done with a metal cable.
The technology for installing gutters on the roof of a house is as follows:
- Prepare special holes for installing rainwater inlets.
- Install the elements and then seal all joints.
- Install pipes to allow water to flow through them.
- Strengthen all devices and elements with clamps to the roof and walls of the building.
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Instructions for installation of closed storm drainage system
For the purpose of arrangement closed system storm drainage systems adhere to the following actions:
- Having approved the installation plan, they mark the territory using the designations of the preliminary places for installing the sewerage system;
- dig holes, compacting their bottom and covering it with 15-20 cm of sand;
- insulate trenches with geotextiles, if necessary;
- prepare a pit for the collector by digging a hole and filling it with concrete using metal rings or a plastic container.
To create a pit, you can use a factory well placed in a prepared pit. To make work easier, use plastic pipes and fittings. Pipes are laid in trenches dug in advance. They are then connected to the trays and manifold. An inspection well should be located every 5 m of sewerage. In places where there is no water intake, a gutter is installed, covered with a grate. The sand cleaner should be located between the chute and the tray. This ensures that purified water flows into the system.
When the entire system is already assembled, you can start testing it. This will reveal the functionality of the design. 10 liters of water are poured into all water intake wells that are installed. Next, you need to determine at what speed water leaves the system and in what quantity. At a fast enough speed, the volume of water flowing out will be equal to the volume of water flowing in. This means that the system was assembled with high quality and all work was done correctly. In the future it will function correctly.
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Recommendations for installation and maintenance of storm sewers
When constructing a sewer system, you should use PVC pipes with a diameter of 110 mm, which are connected by a double coupling. If pipes with maximum strength are used, then their laying depth should be greater. If the site has drainage system, then the storm drain is installed above it. To insulate pipes with less strength, laid at shallow depths, geotextiles and crushed stone are used as insulation.
The design of a house's storm drainage system should include its connection to the site's irrigation or water supply system.
If there is a pond near the summer cottage, then the collector should not be installed. The system is arranged so that water can enter the reservoir.
Sewer maintenance involves the use of appropriate cleaning methods:
- Mechanical.
- Vodyanoy.
- Thermal.
- Chemical
The mechanical method involves removing dirt, plugs or sand. Water based on the use of a jet of water that breaks through plugs. Thermal is associated with the use of water, which has high temperature. Chemical involves cleaning sewers using reagents. An external system located on the roof is connected to the use mechanical method. For this purpose, gutters and water intakes for garbage collection are inspected. Storm water inlets are cleaned using the water method, when a stream of water is directed onto the grates under maximum pressure.
Opportunity correct operation sewer system is determined primarily by the depth of the sewer system and the system as a whole included in the project. Also, the depth of laying sewer pipes directly affects the cost of laying and constructing sewer networks.
Therefore, the best and most expedient way would be to lay sewer pipes at depths that satisfy the minimum technical requirements for a given area.
In general, a certain amount is needed only in order to avoid freezing in winter and various mechanical damage from outside.
Your attention!
The depth of the sewer system must be calculated based on the experience of the systems in this particular area. It is necessary to reduce the laying depth only if the sewer pipes can be insulated.
If there is no experience in operating sewerage systems in a given specific area, then the depth of installation should be calculated using the following method:
- Take pipes with a diameter of up to 5 cm
- Lay them to a depth of 0.3 m
- For pipes with large diameters- to a depth that is 0.5 m lower than the freezing depth of the soil in this particular area.
- It should be taken into account that the distance between the top of the pipe and the planning mark was not less than 0.7 m.
- In order to avoid damage to sewer pipes by mechanical vehicles, it is necessary that the depth of the sewer pipes be calculated in such a way that there is at least 1.5 m of soil to the top of the pipe.
- The minimum depth to which collectors must be laid must be determined by static and thermal calculations.
In order to most accurately and reliably determine at what depth to lay the sewer system, you need to find out what is the depth of soil freezing in your area of residence.
You can find out about the depth of soil freezing in your area using many regulatory documents, among which there is, for example, SNiP 2.01.01-82 “Building climatology and geophysics”. There is a detailed map with soil freezing zones in individual areas.
For example, you can cite several cities. For Moscow, the depth of soil freezing is 1.4 meters, for St. Petersburg this depth is 1.2 meters, but for Sochi it is generally less than 0.8 m.
Let's check with an experimental example at what depth sewerage should be laid in Moscow.
For this:
- Let's take a pipe with a diameter of 200 mm
- Subtract 0.3 meters from the freezing depth
- Having carried out simple mathematical calculations, we find that the depth of laying the sewer pipe for Moscow will be 1.1 meters.
This is exactly what all serious organizations do.
In reality, everything is not so rosy. Pipes are laid in accordance with all the given norms and rules only if the building or structure is a serious, government-owned, capital and expensive structure.
They will not spare any money for this: they will conduct both state and non-state examinations, hire serious designers, builders and installers.
It’s a different matter when it comes to what the actual depth of the sewer system is in most private houses. Most homeowners have small wastewater treatment plants in their country houses or dachas of the type and likeness of Topas, Biofluid and others.
The instructions for such systems state clearly and clearly: the depth of the sewer pipe should be within 0.5 meters. Otherwise, the pipe simply will not fall into the drain hole of the treatment facility.
For such cases, SNiP has a separate clause. It states that pipelines and sewer pipes laid to a depth of less than 0.7 m must be protected from damage by ground traffic and freezing.
In practice, none of the above is usually done. Installers assure gullible people that nothing will freeze in winter, citing their “vast experience in maintaining installation work in the conditions of the Far North."
This determines the theme of numerous construction and installation forums in winter, dedicated to the question “what to do if the sewer pipe is frozen and the drain does not work?”
Separately, it should also be said about storm drainage.
Why do we need rainwater drainage? At certain times, especially in spring, there is so much rain and melt water after the snow melts that it can seriously flood courtyard areas, summer cottages and even large areas of various bases, plants, factories, etc.
Therefore, a rainwater drainage system exists to discharge unnecessary melt water into low-lying areas of the area or into nearby bodies of water.
Features of the design of a rainwater sewer system include such elements as:
- Tracing
- Hydraulic calculation
- Constructing and linking network elements
Tracing provides:
- Collection of melt and rainwater from the designated area
- Their removal to the nearest treatment or release sites
So, the depth of storm sewers, as well as household sewers, is calculated based on the minimum required depth for laying pipes in this area according to the experience of previous laying or experience in using sewer networks.
The location and distance of inspection wells in collectors is set similarly to household sewer network. Initially, the depth of the collectors under the roadway should be at least one and a half meters.
This is necessary in order to avoid crushing the collectors by heavy equipment. Well, taking into account the fact that in the future it is possible to build an intra-block network, the depth of the storm drainage system should be at least 2 meters.
It is necessary to take into account that for each area it is necessary to carry out a comprehensive survey taking into account various parameters, such as the depth of soil freezing, soil properties, etc.
Having chosen closed drainage systems for draining rain and melt water from the site and the roof of the house, you are often faced with the question of where to start and how to calculate the amount of work associated with laying pipes. First you need to sketch out a tapping diagram Wastewater in a vertical plane.
Ideally, the depth of the storm drain should not be higher than the depth of soil freezing by the diameter of the pipe itself. Moreover, when digging a trench, you also need to take into account the thickness of the compacted sand cushion, which serves as the foundation of the entire highway and compensates for seasonal soil movements. However, in practice, this amount of work is quite difficult to accomplish.
In some places on the site, it is simply impossible to dig a ditch one and a half meters deep. In addition, if a closed type storm drain is used, then the area has an uneven topography. But all the sloped pipes ultimately converge into one common drainage system, directed to the collector. It turns out that some of them should lie 1.5 meters below ground level, others 2, etc.
What happens if you lay pipes right at the surface? Storm sewers, although made from the same materials as the outer part of the centralized sewer, are radically different in the temperature of wastewater in the autumn-spring period and the frequency of their discharge. Sewage from the house when drained always has room temperature and thanks to regular descent at a distance of up to 5 meters from the building, they partially warm the soil around the pipe.
It’s frosty outside and the soil temperature in the area is a dozen or two below zero. The sun warmed up and streams ran from the roof, but where? Right in the freezer! So it turns out that it is easier to insulate all closed drainage systems than to drive them a couple of meters underground.
Insulation for sewer pipes differs in structure and cost, but most importantly, in durability, because they need to be buried in the ground. The most unsuitable for insulation will be mineral wool, even if you design a special box for it, which itself will not last long in constant dampness.
Polyurethane - more suitable option, parts made from it are easy to put on pipes. Thanks to its thickness, it practically insulates them from external temperature changes.
The shell is made of polystyrene foam or polystyrene foam, specially made for different diameters, consists of two halves and has locks, which is very convenient. Insulation with such elements can be done very quickly and efficiently.
Penoizol - even more original version, insulation in finished form has no seams, since it is poured with a liquid reagent into a pre-prepared ditch with a pipe inside. True, not every site can be accessed by a filling machine, which is also worth taking into account.
Foamed polyethylene is a widely used material that has long won general recognition among the people. However, it is better not to use it to insulate storm drains; it is too short-lived in the harsh conditions of climate change.
Summarizing all that has been said, it is better to calculate the optimal depth for laying storm drains not from the thickness of soil freezing, but from the general slopes, their length and the terrain in a particular place. In any case, the distance from the surface of the earth to the pipes should not be less than 30 cm, so as not to accidentally touch the insulation with a shovel. And it is strictly necessary to insulate the entire route, inspection wells and vertical sections from storm water inlets.
