How to lay sewer pipes correctly: calculate, lay, insulate. We lay sewer pipes in the ground: technological features of the process Insulating pipes in trenches

Laying sewer pipes into the ground - instructions on how to properly lay pipes in the ground

Modern housing (whether country cottage or a modest dacha) cannot do without such necessary amenities as sewerage. The wastewater disposal system is designed together with the house or is completed during the reconstruction of an already used residential premises. The sewerage itself has several stages of construction:

installation of internal wiring;
installation of a septic tank (or other type autonomous system sewer);
laying external sewer pipes in the ground.

Wherein final stage requires minimal knowledge about plumbing intricacies and the principles of laying pipes in the ground in order to prevent mistakes, which in turn will lead to system failure during its operation. Laying external sewerage A fairly simple, but at the same time responsible process. It is worth remembering that all communications are subject to soil pressure, as well as changes in temperature, humidity and other environmental factors.

Types of sewer pipes

Technological process of laying external sewer system may vary slightly depending on the material your pipes are made from.

Cast iron pipes(made of gray and ductile iron). The peak of their popularity irrevocably sank into oblivion with the advent of alternative materials, replacing brittle and heavy cast iron. Cast iron pipes have been used for quite a long time. This is due to their enormous service life and ability to withstand enormous loads. However, the internal rough surface of the pipes very quickly became overgrown with plaque, and transportation and installation by hand was very difficult due to the significant mass of the products. It also mattered high price such pipes.
Sewer pipes from polyethylene corrugated(250-850 mm). They are used in the construction of private cottages (for sewerage and water supply), laid in the soil to a depth of 15 meters. Inner surface polyethylene pipes ideally smooth (made from low-density polyethylene), due to which plaque is formed extremely rarely, and the strength and rigidity of the outer corrugated walls (polyethylene is used high pressure) are very high. At the same time, such pipes are cheap and easy to transport/install/lay. The disadvantage is the inability of polyethylene to withstand heating above 40-50°C.
Sewage pipes polyethylene (PE). Similar to corrugated pipes, such pipes are easy to install and transport, quite cheap, do not require the use of special equipment, are resistant to chemicals, and durable. However, it is worth remembering the temperature range of up to 50 degrees, that smooth-walled PE pipes may be subject to deformation when laid in unprepared soil with large clods and stones, as well as the need to store such products away from sunlight.
Polypropylene pipes can withstand the operating temperature of the transported liquid up to 80 degrees, which is a significant reason for preference polypropylene pipes polyethylene. However, such pipes are not often used for external sewerage due to their low rigidity and susceptibility to deformation.
Sewer pipes from polyvinyl chloride the most popular of all of the above. PVC pipes for external sewerage can be single-walled smooth (orange or yellow color) or corrugated three-layer (110-630 mm). PVC pipes differ in connection method and type - pressure (working pressure up to 1.25 MPa) and non-pressure.
Other, slightly less popular materials from which pipes for external sewage are made: concrete, asbestos cement, fiberglass, ceramics, etc.

Prices for pipes for external sewerage

pipes for external sewerage

Technology for laying sewer pipes in the ground

When the material of the pipes for the external sewage system has been determined, installation can begin.

Furrows for laying external sewerage are dug either with a shovel or an excavator. In this case, the level of soil freezing should be established in advance, because it depends on it. According to the standards, pipes are laid in the ground at a level of half a meter less than the freezing level of the ground, but not less than 50 cm from the surface. The diameter of the pipes themselves is also taken into account.

In central Russia, the approximate level of sewerage laying is 2.5 - 3 meters, in the northern regions - up to 3.5 meters, in the south - about 2 meters.

When digging trenches, determine the places where the sockets will be located. For them, additional recesses are dug - pits. The width of the trench should allow the installer to be at the bottom and carry out pipe laying work.

It is also necessary when digging to create a slope of 1-2 cm for each linear meter sewer pipeline. For convenience, you should stretch a marking cord along the bottom of the trench.

After digging the trench, its bottom is compacted, after which a cushion of sand or fine gravel is poured (layer up to 15 cm), which is also necessarily compacted.

Important! Already at the stage of digging a trench, places for inspection wells should be noted. Even for a perfectly straight pipeline, it is recommended to install inspection wells every 25 meters.

In addition to the sewer pipes themselves, you will need: auxiliary elements(fittings and couplings, corner parts connections, etc.) and working tools (hammer, screws, screwdriver, drill, etc.).

Rules for laying sewer pipes

When connecting pipes, they are not inserted into each other all the way, but leaving a centimeter gap (you can put a mark in advance for convenience).

Insulation of sewer pipes

As the insulation necessary for the uninterrupted operation of the sewer system in the cold season, molded or roll insulation is used. The first ones are made directly to the shape of the pipes and are laid together with a layer of waterproofing, the second ones are simply wound onto the pipes by hand.

You might be interested in information about what it is

Also, to protect sewers from freezing, a heating cable is successfully used, which, when installed, is reliably isolated from moisture from the ground. However, you can always save money and time if you purchase sewer pipes for laying in the ground with already installed insulation.

Backfilling of an installed sewer pipeline

If your pipeline has passed the leak test and has an ideal slope, you can backfill the trench.

The filling process is very simple. It is necessary to backfill a 15-centimeter layer of sand, compacting it only at the ends of the pipes. The sand cushion on top should be covered with soil, removing stones and clods from it.

Laying sewer pipes is the simplest, but very responsible job. How to do this, what should you pay attention to, what are the rules? You will find answers to these questions in our article.

Through drainage water pipes The wastewater from the house must be discharged outside its boundaries and further go to the central sewer lines or to autonomous septic tanks.

How to properly lay pipes in a trench, what rules must be followed, what materials are best to use?

These are only part of the questions exciting people who decided to carry out this type work independently, without the help of specialists, for example, when. We propose to examine these topics in more detail.

For the installation of external sewerage, smooth pipes made of polypropylene (PP) or polyvinyl chloride (PVC) are used. orange color, since they are more durable than gray ones for laying sewerage indoors. If the burial depth is large or the pipes pass under roadway, which means the load on them will be higher, we take polyethylene (PE) or polypropylene (PP) two-layer corrugated pipes.

It will be more reliable this way. The most common diameter for external sewerage is 110 mm.

Red pipes, being in the ground, are not subject to corrosion and destruction; with the correct slope, they do not become dirty inside; thanks to their smooth inner surface, they can be used at a depth of up to 3 meters.

When shaped parts are used to connect pipes (couplings, adapters, bends).

First you need to dig a trench. This can be done manually or with an excavator. But first we need to find out what depth the sewer pipes will be laid.

If you stick to sanitary standards and rules (SNiP) P-G.3-62, then this value should be half a meter more (counting from the bottom edge of the pipe) the value of soil freezing in this area.

For the northern regions of Russia it is 3-3.5 m,
middle zone– 2.5-3 m
for the south - 1.25-1.5 m.

These are approximate figures as it all depends on the terrain, soil and groundwater. The smallest depth is considered to be 0.5 m from the top edge of the pipe.

When digging a trench by hand for pipes with a diameter of 110 mm, its width must be at least 60 cm, and its depth must be 5 cm greater than the laying depth.

We level the bottom of the pit and set the required slope. For sewer pipes it ranges from 1 to 2 cm/m.

Advice! Don't think that the higher the slope the better, it's not true. The recommended speed for water flow in the sewer is 0.7-1 m/s. If the slope is greater, the ability of the pipes to self-clean is lost, and there will be more noise. A small increase is allowed when connecting devices, but in an area of no more than 1.5 m.

We tamp the bottom of the trench and begin arranging the cushion. For this we need sand or gravel. The height of the bedding should be between 10 and 15 cm.

Sand or gravel does not have to be compacted throughout the entire trench, but 2 meters before manhole or from the side of the inlet pipe, this must be done. Don't forget to make pits under the bells.

Now it's time to learn how to lay a sewer pipe.

Installation is carried out in the following sequence:

We lay sewer pipes in the trench, with the socket downwards from the slope.
We clean the inside of the bell of one pipe and the smooth edge of the other from dirt.
Be sure to lubricate with special grease (silicone or you can use liquid soap or dishwashing gel) the smooth end of the pipe and the rubber ring in the socket.
We insert the pipe into the socket until it stops (it is better to first measure the depth to which you need to insert the pipe into the socket and apply the mark).

And so on until we install the entire sewer system, that is, not yet. Work should begin from the foundation. If there is a terminal, connect the socket to it; if not, you will have to make a hole.

For this it is better to use diamond drills. If there is a need to make a turn, we use special bends (15; 30; 45). If the length of the sewer system is more than 15 meters, we install an inspection in such places.

After the pipes have been laid, it is imperative to check the slope angle and only after this can you begin backfilling the trench.

You can fill the trench with the soil that we dug, but you should first clear it of large stones and break up the blocks of earth.

Advice! When backfilling, it is not allowed to use solid soil inclusions larger than 30 cm in size, as this can lead to damage to the sewer system!

First fill the trench along its entire length to a height of 30 cm from the top edge of the pipe. Compact the soil on the sides. It’s better to fill it in small layers of 5 cm and compact it, it’s more convenient and reliable. You cannot tamp over a pipe!

Sometimes it becomes necessary to insulate the sewer system. This happens if the pipes are located above the freezing level of the ground or at the exit from the house.

For these purposes we use special insulation stenoflex (energoflex). It is also used if installation has been carried out water pipes in the zone of soil freezing.

We completely wrap the pipe in a circle with insulation throughout the entire sewer system. After carrying out this work, we again check the slope of the pipeline, and then proceed to backfilling.

If we talk about autonomous sewerage, which requires electricity, then an electric cable can be laid in the same trench.

After the pipe is pre-filled, you can lay the wire, just first put a protective corrugation on it. Now we finally bury the trench. Definitely with a slide. This is due to the fact that over time the soil sags.

After reading the article, you already realized that there is nothing complicated in installing an external sewer system. There’s just a lot of responsibility, and physical strength will have to be applied.

If you are replacing sewer pipes rather than installing them from scratch, it is still best to completely remove the old pipes first. Then you can start laying the required pipeline. This will be faster than changing it piece by piece.

Until recently, most people used the so-called “backyard amenities.” Wooden or stone. These times have passed, and now they have all the amenities right in their houses or apartments.

All this is great, but the sewage needs to be disposed of somewhere. But as? And at one time a system was invented according to which all sewage was discharged into. First, pipes are laid inside the house, which are connected to pipes laid in the ground. Laying sewer pipes in the ground is, in principle, not a difficult job, but very responsible. After all, it depends on whether their installation is carried out correctly. reliable operation home sewer systems.

Metal

Until recently, sewer pipes could only be made of metal - steel or cast iron. These materials are characterized by high strength and durability. Which is very important! After all, the pipes will have to be buried in the ground. And there is not the slightest desire to carry out repairs every year. Metal pipes can be transported without problems high temperatures. They are very easy to install. And their cost was low. And if steel pipes could rust during operation, then cast iron pipes are not afraid of corrosion!

The durability of cast iron pipes is amazing: those pipes that were laid in the ground 100 years ago, in most cases, cope with their difficult responsibilities remarkably well.

However, metal pipes, along with a huge number of undoubted advantages, there are many disadvantages. For example:

weight. Cast iron pipes weigh a lot. Steel ones weigh less, but still a lot. Therefore, laying a sewer line in the ground from metal pipes is very difficult! Yes, and delivery of pipes to the site requires special equipment;
sealing. Socket joints of cast iron pipes are quite difficult to seal. This is a long and complex process;
processing of the internal surface. Since the inner surface cast iron pipe It is almost impossible to make it perfectly smooth; what is moved is delayed on it, and over time, congestion can form.

Asbestos cement

At one time, asbestos-cement pipes replaced cast iron pipes. Yes, their inner surface is smooth, and blockages practically do not form in them. And connecting main pipes to each other is much easier - special couplings have been invented for this. And they weigh asbestos pipes less than metal ones. But they also have a drawback: they are extremely fragile. Therefore, when performing work, they should be handled very carefully.

Reinforced concrete

Sewer pipes made of reinforced concrete are used where it is to be done highway large diameter . Since pipes of this diameter cannot be made using other materials.

Reinforced concrete pipes are characterized by exceptional strength during expansion or compression, frost resistance and absolute water resistance. However, it is possible to install a main line from such pipes only using specialized equipment.

Ceramics

Ceramic sewer pipes are very similar in their characteristics to asbestos-cement pipes. And they are also very fragile. Therefore, they are used extremely rarely.

Polymer

For private construction, polymer sewer pipes - perfect option. They are very light, but at the same time quite durable. One person can install them. Connecting them together is very simple, and the seal is almost perfect.

There are several options for such pipes.

PVC

If the soil is loose and soft, then the bottom of the trench must be compacted. But it should be remembered that in any case, no matter the soil, a pipe cushion is poured onto the bottom of the trench. This pillow does not compact. The surface is simply leveled, and pits are made in those places where the bells will be located.

Laying pipes

The technology for laying sewer pipes in a trench is no different:

First, the internal sockets are cleaned and the O-rings are checked. Laying pipes begins from the foundation of the building. If a sewer pipe outlet is laid in the foundation of the house, then the part to be laid is put on it with a socket. The smooth end of the pipe is coated with silicone. Then the pipe connection takes place without problems. If there is no outlet in the foundation, then either a hole is cut in the foundation, or pipes are laid under it;
The pipe is laid with a slope. SNiP specifies the standard slope: per 1 meter - 2 cm. Then the liquid through the pipes will flow smoothly and silently;
The pipe from the building to the collector does not always run perfectly straight. There are often twists and turns. For this purpose, bends are used at an angle from 15 to 90 degrees. If length sewer main is 15 meters, then a revision is installed above the knee;
The pipes are connected to each other until they stop. They are joined manually. You should ensure that the bell is perfectly clean. And to make docking easier, you should use silicone grease;
if it is not possible to make a trench of greater depth, and the pipes fall within the freezing level, then the pipes should be insulated with stenoflex.

Filling up the trench

After the pipes are laid and the tightness of the system is checked, the trench should be backfilled. It is advisable that the trench be filled with crushed soil. Without large cobblestones and lumps of earth. After 5 cm of layer on the sides of the pipes, the soil is compacted.

The earth is not compacted above the pipe. Since you can damage the pipe or break the tightness of the joints.

Ideally, the pipes should be covered with sand, onto which the soil that was previously dug out from the trench should be poured.

Common mistakes

Unfortunately, despite the relative simplicity of the process, some craftsmen make mistakes when laying pipes in trenches. Such errors can be called typical:

trenches are made of shallow depth. As a result, the efficiency is low, and winter period the system may even freeze;
use of pipes of the wrong diameter or type for the main line. Not only will the system work poorly when maximum load, it will also clog regularly;
a small angle of inclination or its complete absence. As mentioned earlier, there is a standard angle: 2 cm per linear meter of pipe. If this is not done, the system will not work.

Are you about to buy a water meter? Find out what criteria you should use to do this by reading.

Insulation of pipes in trenches

If the depth of soil freezing is small (in southern latitudes) and the trench has a decent depth, then no additional measures to insulate the pipes are required. But if the soil freezes to a decent depth, and it is not possible to make a trench deeper, then you cannot do without insulation. If this is not done, then there is a very high probability that the frozen masses will not only tightly clog the pipe. They will simply tear it apart.

To prevent this from happening, sewer pipes are insulated. For this use:

glass wool;
basalt fiber;
polyurethane foam;
stenoflex;
expanded polystyrene.

If sewer pipes made of polypropylene were used, then polystyrene foam is usually used for insulation. But not the usual one in the form of plates (it is impossible to bend it - it will burst), but a foam plastic “shell”. Put on such insulation with a slight overlap and fix it with tape.

Quite often, pipes are insulated using special cylinders, inside of which there is basalt fiber. This insulation is distinguished by its high strength. It is also not exposed to moisture. Does not deform. And not as fragile as a foam shell. On top of such a cylinder there is an additional protective layer from glassine, foil-isol or roofing felt. And installing such cylinders is very simple. Even an amateur can do this.

If in the area winter time the temperature often drops below -20 degrees, then conventional measures to insulate sewer pipes may not be enough. And then they use heating cable

Hello! We drilled a well, and the question arose of what to fill it with, since there were gaps of 4-5 cm on each side between the casing pipe and the soil (the diameter of the trunk was 200 mm, and the diameter of the pipe was 125 mm).

Answer

First of all, you need to figure out what you are planning to fill - the well (the aquiferous section of the shaft) or the so-called annulus (the rest of the pit). In the first case, backfill with fine crushed stone (approximately 5X20 fraction or even less) is used. It will create a frame for smaller sand inclusions and will not allow clay to float onto the filter. In dusty sands, it is better to add coarse stone to the crushed stone. river sand in a ratio of 3:1. This will increase throughput near-filter zone. The filling is kept low - otherwise, overflow from the upper aquifer is possible. As a rule, in order to create a high-quality natural filter, 12-14 buckets of the mixture will be enough.

As for the annulus, it is best to fill it with clay - it will create a reliable waterproof castle. At a distance of 1.5-2 m from the surface, the clay can be replaced with sand. A similar trick is needed to obtain a drainage channel through which water from the pit will flow into the upper layers of the soil. Finally, I would like to remind you that when backfilling casing pipe it is necessary to strictly monitor its vertical position. Otherwise, there is a possibility of the walls being rubbed by the holding cable or the filter being damaged by the pump housing.

When starting to develop their newly acquired plot, many happy owners are faced with the problem of difficult access to it. The reason for this is the sewage or sewage that runs along the road or even along the entire perimeter of the village. The most affordable thing that you can easily do with your own hands and that is the first thing that comes to mind for inexperienced summer residents is to drive a bulldozer or arm yourself with shovels, fill the ditch well, level it, compact it and pave it with asphalt.

Construction of the entrance to the site through a ditch

Many people do this. Great, no problems until there is a period of heavy rain or snow melting. The fact is that the sewage ditch is left for a reason, but with the purpose of directing ground or wastewater bypassing the site. Otherwise, flooding threatens the buildings, cellar, and basement of the house.

Making a correct entry into a site is more difficult than simply burying a ditch, but it is more reliable.

This work does not pose any great difficulties, the main thing is to take into account some nuances.

The dissimilar location of the sites, the terrain, and the type of soil determine various device entrance to the territory through a ditch, but still some general features must be taken into account when doing this work with your own hands. What do you need to decide before you start?

Diagram with dimensions for installing an entrance to the site through a ditch