Trench for water supply: width, optimal depth, how to dig and price

A trench for water supply is where the water supply to a private house, cottage or country cottage begins. Proper excavation in the future allows you to avoid freezing of the water supply line laid in it in winter, and ensures good pressure and quality of water. The seemingly simple process of digging a trench includes many nuances - from the correct choice of depth, width and cross-sectional shape of the trench to the distance from other nearby communications.

Methods of how and what to dig a trench with

There are two basic options for excavation digging: manual and mechanized. The first method, as a rule, can be used when installation is on a budget and it is impossible to use the equipment in a narrow area. This method is particularly time-consuming and labor-intensive.

Manual

This type of laying is mainly used in compact municipal buildings. A very labor-intensive and expensive option for developing a water supply trench, the performance of which directly comes from the properties of the soil.

The price of manual work ranges from 1000 to 2000 per m3 and depends on:

weather conditions,
width,
length of excavation and degree of soil complexity.

Digging a trench on your own will be much more economical for the project owner, but at the same time, the entire burden, both physical and monetary, will fall on him.

Mechanized

The mechanized option involves the use of repair and construction equipment. This method of digging soil for water supply is popular and practically applicable in all industries and housing and communal services. The work process is planned according to the existing vehicle fleet.

The following technique is usually used:

An excavator with a modification of a backhoe is used to produce not very large trenches up to 1 m.
The “dragline” technique is an excavator with one bucket and a special rope system that provides soil digging below the equipment’s location up to 10-12 m and an impressive grip radius of up to 10 m.
The grab has a bucket, which differs from the typical one in that it consists of 2 halves, tightly connected to each other with a rope.
Soil cutters or trenchers are devices that first loosen the soil and then move it to the surface with a specially installed auger-type conveyor.
The mini excavator with rubber tracks has great maneuverability and is suitable for trenches up to 2.5 m deep.
An earthmoving machine develops soil and loads it into a vehicle or sends it to a dump. A very popular technique with a excavation depth of 2.5 m. Its only drawback is its impassability in rocky soils and forested areas.

Width

The width of the ditch for laying a water supply pipe with a depth of more than 3 m is strictly standardized by SNiP.
However, it is unlikely that this standard will be useful on a summer cottage, because deep laying of pipelines is rarely done here. The same can be said about digging a ditch using an excavator. In this case, the width will depend on the length of the cutting edge of the bucket. Construction and calculation of storm sewerage

If you will dig a trench manually with a shovel or are going to use a walk-behind tractor or a soil cutter (trencher), then the size should be taken from SNiP. Thus, the optimal ditch width for laying a water supply pipe should be in the range of 0.5-0.8 m. This width is suitable for pipes with a diameter of 50-110 mm, since they are used for external networks of country houses.

Important: so that work on excavating soil and laying pipes can be carried out under normal conditions, the minimum width of any trench for water supply must be 0.7 m.

Choosing the optimal cross-section of a trench for water supply

Before you start digging a trench for water supply, you need to decide on the geometric parameters of the future trench.

They can be:

Rectangular section.
Trapezoidal.
Mixed type.

The choice of a specific configuration depends on a number of conditions:

The type of soil in which the water supply is installed.
Depths.
Width.

The rectangular shape is used when the width and depth of the ditch is small. SNiP standards recommend constructing rectangular ditches with a depth of no more than 1.5 m. The soil should be relatively dense to avoid crumbling of the vertical walls. This is the simplest form, requiring a minimum of time and effort.

The trapezoidal shape is used when it is necessary to dig trenches with a depth of more than 1.5 m. This sectional shape, with flat walls, prevents the possibility of soil collapse.

When constructing vertical walls near a ditch, more than 1.5-2 meters deep, there is a high risk of causing injuries and even death if they collapse. Also, a trapezoidal shape is the only possible type of section when laying ditches in soft soils - loose sandstone, sandy loam. Vertical walls in such soils will naturally slide to the bottom, taking on a flat shape.

The mixed view is a combination of trapezoidal and rectangular sections. They are used for laying pipes in areas with high groundwater levels. In this case, up to the level of subsoil water, the trench is dug in the form of a truncated cone, with flat walls. After reaching the aquifer, a pit with vertical walls is laid along the bottom of the ditch. It is used to collect and pump out water, as well as backfill the drainage mixture (coarse sandstone, gravel, crushed stone).

Pipe laying work

Technologically, the process of laying sewerage is not particularly difficult. First you need to dig a trench, the depth of which corresponds to the standard indicators characteristic of the given region.

Before laying sewer pipes, sand is poured into the bottom of the ditch. The height of the sand base is 10-15 cm, so the depth of the trench should also be increased by these values.

A sand cushion allows you to level the bottom of the ditch. Before laying pipes, the sand must be thoroughly compacted to prevent subsequent shrinkage.

The width of the trench is laid approximately 40 cm larger than the diameter of the pipe used. At the points where the pipes approach the septic tank and at the exit from the house sewer system, the trench is made a little wider so that it is convenient to carry out installation work.

To prevent the foundation and walls of the house from getting wet in the event of an emergency leak, the septic tank is installed at a distance of no closer than 5 m from the building (+)

After the trench and base are prepared, it is necessary to connect the pipes together and then lay them. It is beyond the power of one person to lay long sections of the highway evenly and correctly, so it is advisable to involve several assistants in this work.

There are special rubber seals at the ends of the pipes. Before joining them to each other, silicone plumbing grease is applied around the perimeter of the pipe, which facilitates the joining process and makes the joint more reliable.

But you cannot use force here; excessive force on the pipe can damage the rubber band or tear it out of its seat, which will lead to a violation of its tightness.

Before laying the prepared pipeline, a pipe is placed at the exit from the house drainage system, which has the required angle. The other edge of the line fits into the hole in the septic tank.

If the storage well was made recently, it is advisable not to immediately seal the hole with concrete, since the pipe may burst when the septic tank shrinks.

A pipe placed on the pipe leaving the house allows you to direct the pipeline in the desired direction

Backfilling a sewer pipe is carried out as follows: first, sand is poured so that the pipe is completely covered with it. Then it is watered with water, and after it shrinks, another batch of sand is added. After this, the highway is completely covered with earth.

According to technical standards, rotary wells must be installed in places where the route turns, and inspection wells must be installed on straight sections of the pipeline for every 35 m. In addition, every 15 meters of the direct line an inspection or cleaning is installed.

Installing an inspection is a simple procedure, but it allows you to monitor the condition of the sewer network throughout the entire pipeline and, if necessary, clean the desired area with a cable or a stream of water

The revision can be made from the same sewer pipe, which is installed vertically in the required sections of the pipeline using a tee. It is closed with a plug on top. Using this fairly simple device, you can quickly access a clogged section of the line.

It is better to install a manhole in the most critical sections of the network.

Laying a water pipeline

Current methods

The photo shows the most common method of laying a water pipe using a trench.

Modern construction technologies suggest two main methods for underground installation of water pipes:

Laying a water pipe in a trench. With this method, before installing the pipeline, the soil is excavated to the calculated depth, the foundation is prepared, and the trench walls are strengthened. After installation is completed, backfilling is carried out, and the area above the work area is improved;
Trenchless water pipe installation. This method is more progressive and involves puncturing the soil between two technological wells and then laying a pipe into the resulting hole. Soil development, backfilling and landscaping work are not required in this case.

The use of lightweight modern technology can significantly speed up and facilitate the task.

The open (trench) installation method allows you to handle small amounts of work with your own hands using simple tools:

shovels,
scrap,
hammer drill, etc.

It is well suited for suburban farms, since the soil is not covered with asphalt, buildings are sparse, there are practically no competitive communications and infrastructure, therefore, damage and subsequent restoration will be minimal.

Open ditch mining is best suited for rural areas.

Trenchless water pipe replacement, as well as its installation, require special equipment and trained workers. The method is based on horizontal directional drilling or soil puncture using special tips and a jet of water under pressure.

Excellent for urban areas with dense buildings and developed infrastructure, where the open method is sometimes unavailable.

It is enough to dig two wells at the beginning and at the end of the straight section.

Trench development rules

Usually the pipe is led from a well or borehole.

So, for work outside the city, you can use the open method of laying pipes. So we'll need a trench.

To build it correctly, you will need the instructions, where we have collected the basic requirements and useful clarifications on a number of issues:

It is advisable to lay the ditch along the shortest direct route. If this is not possible, it is divided into straight sections with 90˚ turns; sometimes other turning angles are acceptable;
The depth of the trench is a very important characteristic. According to SNiP, the minimum laying depth, taking into account possible dynamic loads, should be at least one meter, but the climatic conditions of our country impose a different limitation: the ditch should be approximately 30 cm deeper than the freezing depth of the soil in your region (for the middle zone - approximately 2 – 3 m, for southern regions – 1.2 – 1.3 m);
The width of the trench when laying a water pipeline according to SNiP should not be less than 70 cm. However, in practice, such strict standards are applied when working with professional services, and in the garden you can be guided by the diameter of the pipe and the ease of work. Usually they dig to the width of a shovel - 45 - 50 cm;
When laying water pipes, it is necessary to maintain a slope of 0.002 - 0.005 towards the well if there is a drain valve in it to empty the system in case of repair or preservation for the winter;
Water supply and sewerage in one trench are not laid in accordance with all norms and rules. However, this requirement is often ignored when using plastic pipes in thermowells. We would not recommend doing this;
Cable and water supply can be laid in one trench subject to the following conditions: the cable (up to 35 kV) is laid in a plastic pipe above the water supply, the distance between them is at least 25 cm, above the cable is at least a meter of soil;
The bottom of the trench should be dense and compacted; it is desirable that the pipe lies on the ground with the body completely adjacent.

The width should be convenient for work with minimal labor costs.

In addition to the listed rules, you will need a number of tips. So, in the northern regions and in the middle zone it is better to cover the pipe with a layer of foam plastic or mineral wool. Sometimes extreme cold occurs, and this measure can protect you from an accident.

When filling a ditch, especially at the initial stage (the first 25 - 30 cm), throw the earth carefully into the corner of the trench. Avoid caked lumps, bricks, stones and other heavy debris, otherwise the pipe may be damaged.

It is better to insulate the pipe with foam plastic.

Video description

How a trench is made accurately and quickly using such an earth-moving machine is shown in the video:
It is also possible to cope with such work without the use of equipment, but it will take more time. We suggest considering two methods: traditional, using a shovel, and accelerated, using a drill and a special device.

Traditional way.

There is nothing complicated about how to properly dig a trench with a shovel. After removing the top turf layer, the soil is loosened with a bayonet shovel and removed with a shovel. It is most convenient to dig the ground in a trench in steps, and not all at once to the entire depth.

Trench parameters

The trench width indicator is defined in SNIPs. Moreover, if artificial foundations are used for collector systems and pipelines, and the width of the foundation exceeds the corresponding indicator of the pit, as well as when installing foundations associated with the laying of non-passable and through channels, the width of the pit is determined as the width of the base multiplied by a factor of 0.2.

If specialized equipment is used when digging a trench, then it is allowed to increase the width of the trench by such a distance that the leveling and compacting machines will work without any obstacles. If it is intended to use labor, then the distance between the reinforced vertical walls of the trench and the side of the structure should not be less than 70 cm.

If trenches are dug in clay soils or loams using trench or rotary excavators, then the depth of laying pipes without fastenings using braids is allowed to a depth of no more than 3 meters.

Standards for cable routes

Let's start with the fact that to install a cable in the ground, you need to dig a trench under it. If according to the project it is of short length, then this work is carried out manually. The terrain is also taken into account. In some conditions, you simply cannot do without shovels. Basically, trench digging is done with special equipment. The laying itself must be carried out over a bedding of sand, and the cable is covered on top with clean soil without pebbles, debris and slag. The main requirement at this stage is to reduce the risk of mechanical damage to a minimum.

Attention! If a trench is being dug for one cable or several with a width of no more than 250 mm, it is necessary to close it after installation:

or burnt brick across the trench;
or reinforced concrete slabs with a thickness of at least 50 mm;
or special protective and signal boards made of plastic.

In the process of digging trenches, a special warning tape must be installed along the entire site. It shows the boundaries of the area where work is being carried out using special equipment

This is especially important if the cable is laid near highways.

How to dig a trench for water supply or laying cables with your own hands

Very often in a garden plot or vegetable garden there is a need to lay a water supply or cable.

Digging a trench manually with a shovel is difficult and time-consuming; ordering an excavator is expensive and troublesome. We offer readers an original solution to this problem.

DIY trench

First, we drill holes (diameter 12-15 cm, depth depends on the specific case) at a distance of 3-5 m from each other along the line of the future trench.

When drilling, add water to the well. We lower metal containers into the wells that have longitudinal cuts approximately equal to the width of the trench. The diameter of the tanks is slightly smaller than the diameter of the wells. Then, using a narrow hoe with a strong and long handle, we rake the earth along the line of the trench and dump it into containers. We periodically lift the containers up to free them from the soil (Fig. 1).

In sandy soil, working on a trench (excluding time for drilling wells) 5 m long and 10 cm wide at a depth of 60-80 cm takes 30 minutes, drilling a well 1.3 m deep takes 20-30 minutes.

DIY trench tools

We make the tools to perform this work with our own hands.

First of all, we make a drill.

For this we will need: a steel pipe 50 cm long and 12-15 cm in diameter, a metal rod 70 cm long and 14 mm in diameter, a 1/2 inch water tee, a steel plate 20 x 20 cm and 3 mm thick (Fig. 2) .

In the steel plate and tee we drill holes with a diameter of 16 and 14.5 mm, respectively. We cut the pipe in the lower part at an angle of 50° to half the diameter, and in the upper part we make recesses for installing a tee with a rod.

Next, we hammer the steel plate into the pipe slot so that the hole in the plate coincides with the axis.

We insert the rod into the hole in the plate, put a tee on it, and place the tee itself in the recesses of the pipe. Using welding, we connect the structure into one whole.

After this, we cut off the protruding parts of the plate and the part of the pipe below it. And on the reverse side we cut out a technological window in the pipe (about three-quarters of the length and half the diameter of the pipe) and get the design of the drill.

Then we add a rod to our design, which we screw into the tee. And we screw a cross with collars onto the bar. This design allows you to add additional rods.

We make a hoe from a pipe with a diameter of 50 mm, cutting it along the axis. The length of the hoe handle should be more than 2 m.

Do it yourself - How to do it yourself

How to dig a trench for water supply or cable laying with your own hands Very often

Video description

This video shows how to deepen a narrow trench:

Fast way.

This method allows you to quickly solve the problem of how to dig a narrow trench. Along the marking line, holes with a diameter of 15 cm are drilled every 3-4 meters with a conventional or motorized drill. If the soil is loose, water is poured into the well during the drilling process.

Drilling wells Source yandex.net

A metal cup of slightly smaller diameter with a partially cut out wall is inserted into the finished hole. The cutout is turned along the channel and the soil is raked into the glass with a narrow hoe. As it is filled, it is removed and emptied.

Digging a trench by hand - how the price per linear meter is determined

Nowadays, when mechanization has reached a high level of development, when machines and mechanisms are actively used, the need for manual labor still exists.

Manual excavation work is still in demand, and there are objective reasons for this.

Dig by hand

The work of a digger is not easy. Work such as trench digging is considered unskilled and primitive, but there are often cases when manual labor is indispensable. Manual digging is recognized as the most effective for the following tasks:

laying trenches in places hard to reach for equipment,
digging wells,
laying communications in the constructed building,
installation of a subfloor in a private house.

It is also believed that wells need to be dug only by hand. This is explained by several reasons. Here are some:

precisely stop at the aquifer,
do not get into the sand so that the water does not drain away later,
stones and dense clay are dug only by hand,
It is unacceptable for engine oil to enter the well barrel.

In a word, digging a well is not easy; in addition to having specific knowledge, it requires attentiveness and accuracy. There is no automatic or mechanical way to dig a well.

What determines the cost of 1m³

Analysis of the earthworks market indicates that the ratio of the costs of manual and mechanized labor is the same. How much it costs to dig up 1m³ of land depends on several factors:

soil type,
urgency of the order,
volume of work,
seasonality,
terrain,
trench parameters.

It is also taken into account whether backfilling of the soil is necessary. Pricing takes into account all factors, plus the qualifications and experience of the team.

Pricing depending on a separate factor

It’s clear why the prices of different teams vary - the training and dexterity of workers has its price. Prices are formed differently in the capital region and in the periphery.

The cost of the work is determined after a direct study of the location of the work to be done and its features. They evaluate the location and how convenient it is to dig a hole, for example, for a cellar.

They are looking at how to lay a ditch for the sewer system. They decide how to calculate the cost of work more correctly, taking into account a linear meter or a square meter. Determine the volume of the trench, depth and width, add to this the length of the object and how hard the soil is.

In winter, prices are higher, which is understandable. Frozen ground requires more effort, the creation of additional conditions for workers, and special delivery of people.

Price per meter

Moscow and the Moscow region have the highest prices; on average, a cube costs from 1000 rubles. Wholesale prices, which come into force for large volumes of work, will reduce the price by about 100 rubles, no more. Winter doubles the cost.

The price for a trench, 100 cm deep, for a cable, for example, will be 300 rubles per meter in the Moscow region. In a small regional center, for example, Lipetsk region, the same work will cost 140 rubles.

Rocky terrain with complex terrain has its own higher prices; digging there can only be done by hand, because equipment cannot approach there. This circumstance increases the cost of manual labor.

The cost of manual labor on land work and payment for special equipment are approximately the same. Therefore, whether to hire a team of excavators to dig a foundation pit, whether to rent drilling rigs, excavators for laying water pipes or laying cables must be decided according to the situation. And cost is far from the main factor here.

Digging a trench by hand - how the price per linear meter is determined

Nowadays, when mechanization has reached a high level of development, when machines and mechanisms are actively used, the need for manual labor still exists. Manual excavation work is still in demand, and there are objective reasons for this.

To what depth should a water pipe be buried in a private house, as well as a septic tank and sewer system?

When connecting communications to the cottage, it is necessary to determine at what depth to bury the water pipe in a private house, lay drain pipes and install a septic tank. The trouble-free operation of these networks and the comfort of the people living in the house depend on the correct solution of this problem. Existing standards defined for each climate zone and simple calculations will help you avoid mistakes.

Aboveground or shallow laying of pipes will certainly lead to their freezing in winter Source okeymaster.ru

Water supply network level

Everyone knows that the most dangerous phenomenon for the water supply network is freezing due to the temperature dropping to sub-zero values in winter.

At the same time, the water turns into ice, expanding in volume, and breaks pipes and pipeline fittings.

That is why the main rule for laying a water supply network is to deepen those sections of it that run along the street below the level to which the soil freezes.

But this is not the only indicator that is used when choosing the depth of pipes. Other factors are also important: the temperature of the pumped water, the type and diameter of the pipes, the operating mode of the system, the presence of additional insulation, etc.

Freezing depth

This level depends on the minimum winter air temperature, the depth of snow cover, soil composition, the height of groundwater and other factors specific to each area.

The good news for novice developers is that they will not have to perform complex calculations or involve specialists in them, since each region has ready-made pipe laying standards that take into account all these indicators.

Map of soil freezing depths Source stroy-svoy-dom.com

Having determined the maximum level of soil freezing from a map or special tables, add 50 cm to it and determine at what depth to bury the water pipe so that the water in it is guaranteed not to freeze.

However, it is not always possible to dig a trench of the required depth. This can be hampered by the complex structure of the soil, the close presence of groundwater, or, as in the Far North, the need to use special equipment and the need to go deeper by 3 meters or more, which leads to unreasonably high costs.

In such cases, the pipes are laid above the design level, but they must be insulated using insulating materials or modern heating cables that maintain a certain temperature of the liquid.

The type and thickness of insulation depend on the depth of installation and other parameters Source avatars.mds.yandex.net

Even in one area, the ground can freeze to different depths if the composition of the soil in different areas is different. For example, if we take the freezing depth of soft and loose sandy soil as the standard mark, then in the case of clay soil it can be reduced by 30 cm. And with hard and rocky soil it can be increased by the same distance.

Therefore, it is better to focus not on the average standards set out in SNiP, but on the data obtained by local geodetic organizations based on research and long-term observations.

Type of pipes used

Previously, communications were built mainly from metal pipes (cast iron, steel, copper), the strength of which was not questioned. They could withstand even very high soil pressure, so this indicator was not taken into account at what depth to bury a sewer pipe or drinking water pipe.

Now they are trying to replace old steel lines with new plastic ones Source gidroguru.com

Today, these systems are assembled from more modern polymer materials, which have many advantages over traditional ones:

low cost;
light weight;
immunity to liquids, including chemically aggressive ones;
no corrosion;
smooth surface that prevents clogging of the internal section of pipes, etc.

But the strength of such pipes is much lower: under soil pressure they can deform or collapse. Therefore, you need to look at their appearance and markings, which reflect the wall thickness or the maximum pressure they can withstand.

As a rule, HDPE (low-density polyethylene) pipes are used for underground installation of pressure water pipes. This material is plastic and has sufficient flexibility, and therefore pipes made from it can withstand high pressure and do not burst when water freezes for a short time. However, their grade must be at least PN10, and their diameter must be at least 25 mm.

Advice! If there is likely to be a high load on the ground above the place where the pipeline is laid (a highway, the foundation of a house or other building), the problem of how deep to bury the pipe can be solved not by increasing it, but by installing a durable protective case made of concrete or steel.

HDPE pipes are the best solution for installing external water supply Source images.ru.prom.st

Catalog of companies that specialize in septic tanks and autonomous sewage systems

When installing a seasonal summer water pipeline, from which water is drained for the winter, it is buried at least half a meter if a road passes over the main line.

This is done to prevent pipes from being damaged by pressure from heavy vehicles.

The same rule also applies in the southern regions, where the ground does not freeze to great depths, but the pipeline needs protection from mechanical damage, which is provided by the thickness of the soil above it.

If hot water is supplied to the house from a centralized source, reinforced or metal-plastic products are used for this line. It is advisable to insulate them regardless of the depth of installation in order to reduce heat loss along the way from the source to the room.

The video will tell you more about choosing pipes for underground water supply:

Other factors

There are also objective factors that influence the calculations. For example, the depth at which the central water supply pipe is located, to which it is planned to connect, or the bottom of the caisson above the water well.

You should not neglect such parameters as the amount of precipitation in the region and the groundwater level. When they are high, the pipes may float, which is prevented by backfilling with soil at least 100 cm thick or by anchoring the pipeline.

The conditions for using the land above the water main should also be taken into account. If there is a pedestrian path, parking lot or other object above it from which snow is cleared in winter, then the soil in this place will freeze more strongly than under the snow cover.

Sewer level

Slightly different rules apply when deciding how deep to bury a sewer pipe in a private house. This system works differently: wastewater is either drained into the septic tank by gravity due to the slope, or is pumped by a pump, so it does not linger in the pipes and there is nothing to freeze in them.

Scheme of an autonomous sewerage system Source www.alta-sib.ru

However, the depth of soil freezing cannot be ignored altogether. In regions with a warm climate, drain pipes are buried at least 70-80 cm, and the further north the area is located, the more severe the climate, the deeper the trenches are made. For example, when asked how deep to bury a sewer pipe in a private house in the Urals, experts answer: 2-2.5 meters.

However, this figure is advisory and takes into account all possible risks of system damage. You can eliminate them if you meet the following requirements:

use pipes of sufficient diameter with a minimum number of joints;
arrange a slope of at least 2-3 cm for each linear meter of the street highway;
avoid the formation of “pockets” - pipe sagging relative to a straight line;
lay the route in a straight line, without turns, from the point of exit from the house to the point of waste discharge.

Note! If the route has turns or branches, it is necessary to install inspection wells at these points with free access to them for inspection and cleaning of pipes from blockages, which cause blockages and freezing.

Such wells are also installed on very long straight sections more than 15 meters long Source postroikado.ru

At what depth to bury a sewer pipe for a septic tank also depends on its strength. The polypropylene pipes used for such systems can have different densities. They are distinguished by color:

orange - more dense and durable, they can withstand soil pressure up to 3 meters high;
gray pipes are not designed for such a load, their limit is 2 meters.

The depth of the septic tank is a separate issue. Since it itself has an impressive size, its bottom in any case rests on a non-freezing layer of soil and is heated by it. In addition, fermentation processes with the release of heat are constantly taking place inside the container, so its contents do not freeze.

Important! Do not pour compounds that prevent water from freezing, such as antifreeze, into the septic tank. Such liquids kill living bacteria, inhibiting the natural processes of wastewater recycling.

At what depth to bury a septic tank depends on the following factors:

its location and distance from the house and the length of the sewer pipeline;
height of the pipe exit point from the building;
relief of the site;
pipe laying depths.

Installation of septic tanks in a pit Source cdelayremont.ru

It is also necessary to take into account the model of the septic tank itself: its overall height, the height of the neck, the entry points of the sewer pipes, as well as the manufacturer’s recommendations.

Sometimes, due to the low location of the final drainage point, the container needs to be deepened, which is not always advisable and not always possible due to the characteristics of the soil or the high groundwater level. In such cases, you can include a booster fecal pump in the system or build a homemade septic tank from concrete rings.

But it is better to draw up a vertical sectional design of the system in advance and try to find the best option so that surprises do not arise during the work process.

How to choose the depth of laying sewer pipes and septic tanks is described in the video:

Conclusion

If it is difficult for you to decide at what depth to lay a sewer system in a private house or install a water main, the easiest way is to walk around your neighbors and find out how they did it and what problems arose in this or that case. Other people's experience is the most reliable and inexpensive way of research. If you are building on a sparsely populated area, then it is better to seek advice from specialists.

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Author of the article
Utilities estimator
Sergey Mikhailov

Using technology

In addition, using technology can help you. Nowadays, a whole host of lightweight mini-excavators, walk-behind tractors and other similar equipment are available on the construction market. Usually, renting a device is not that expensive, and the work is done in a matter of hours, and you won’t have time to get bored.

If there is a road or other similar obstacle in the way of the trench, it is possible to use the method of puncturing the soil. To do this, wells are dug on both sides of the barrier, half a meter deep below the laying depth, and the length of the well should be one and a half to two meters. Width approximately 1 – 1.2 m.

The steel pipe is cut into 1 m sections, the ends of which are threaded. In addition, couplings will be useful. A conical tip is made from one piece using a sledgehammer, at the end of which a small hole is left.

After this, take a water pump and put the hose into the well. Then a tip is driven into the ground towards the second well, a piece of pipe is screwed onto its end using a coupling, the hose is inserted into the pipe and water is supplied.

A clamp or wrench is attached to the body of the pipe, and using a crowbar the pipe is pushed into the ground (it must be emphasized that with good water pressure it flows like clockwork).

At the time when the pipe is completely inserted, the next section is attached to it and continues without that until the section is completely punctured.

Note! It will take a couple of hours to overcome a simple two-lane highway, and you will not need to restore the asphalt and block traffic

Methods for connecting HDPE pipes

The finished project presents a plan for the backbone network: length, turns, connections. At the design stage, even before purchasing materials, they determine the method of fastening the sections together and form a final list of equipment and materials, and calculate the estimated cost of laying.

Butt welding

For a strong, reliable connection of HDPE, butt welding is used. The method is convenient and inexpensive, except for the cost of the welding machine. On average, the price of such equipment is from 180 thousand to 2 million rubles. If you do not have a goal to purchase a machine for welding HDPE pipes, it is better to entrust the joining of sections to a specialized team.

If you are planning to lay the water supply yourself, I will tell you how to do it. The welding machine consists of the following elements:

centralizer;
hydraulic unit;
welding mirror;
trimmer

Assembly consists of the following steps:

Secure HDPE pipes in the centralizer on both sides with fastening nuts.
A manual with a formula is supplied with the welding machine, through which the pressure is calculated for a specific pipe diameter. Having found out the necessary parameters, install them in the hydraulic unit.
Degrease the edges of the HDPE pipe with alcohol wipes.
Using a trimmer, smooth out the joints so that there are no burrs.
After heating the welding mirror, install it between the pipes. Apply pressure to the centralizer until the ends melt 1 centimeter. Reduce the pressure to zero and wait the time specified in the instructions.
Remove the heating element and connect the pipes.

Electrofusion

The electrofusion connection method is suitable for repairing an existing HDPE water supply system. But it can also be used to weld a new system in hard-to-reach places. You will need a welding machine for electrofusion welding and couplings. The cost of couplings depends on the diameter, starting from 200 rubles.

Before starting work, try the coupling on the pipe sections and make marks with a white marker. From the point of cut to the notch, the pipe is cleaned with a scraper to remove the protective oxidative coating and degreased.

An electric coupling is a sleeve with grooves for the contacts of a welding machine. A barcode is pasted on the coupling body, which can be read with a laser pointer included with the device. If for some reason the reading did not occur, then the data can be taken from the coupling passport. The barcode is needed for the machine to automatically select the welding mode.

Having connected the pipes in the coupling, connect the contacts. The device is given the “start” command. The current is supplied to the electrical network located on the inside of the coupling. The pipe begins to melt. The process is considered complete when beacons appear on the surface of the sleeve and the device gives a signal.

Connection with compression fittings

Less reliable methods include connecting with fittings. Leaks may form at the joints, so it is better to use this method for external water supply systems of small diameters.

To connect a water supply system from HDPE pipes with compression fittings, no additional equipment is required. By welding and electrofusion it is allowed to connect only HDPE pipes of the same diameter, grade and wall thickness, and the variety in fitting models allows you to assemble elements of different sections.

Unscrew the blue clamping nut from the fitting and put it on the pipe. A white ring is attached next. The cleaned and degreased pipe is inserted into the fitting, the ring and nut are tightened, and tightened tightly.

Socket connection

Before couplings and fittings became available in the construction markets, the socket connection method was widely used in pipeline laying. The technology consists of assembling pipes of different diameters: one pipe is inserted into another and the joint is sealed. For sealing, a rubberized coupling is used, previously placed on a wide section of the pipe.

Which way is better

For underground water supply it is better to use the butt welding method. This connection guarantees long-term operation of the system without leaks. The pipe welding process is quick and one person can handle the job.

Backfilling trenches

Before filling the soil, the pit is cleared of snow and debris that has fallen into it. The lower part of the ditch to a height of 40-50 cm is filled with thawed earth, regardless of the time of year. Tamping is carried out immediately. When laying a route outside of highways, it is allowed to use no more than 15% of frozen soil.

https://youtube.com/watch?v=lAfNG7EotlE

Loading of soil is carried out in such a way as to prevent stones and other solid objects from getting on the pipes. When loading soil into deep objects, the pipeline is covered with boards, which are then removed. The soil is distributed evenly on both sides of the pipe to prevent it from bending. Final compaction can be done with heavy equipment using a blade, bucket, tracks and wheels.

Material of pipeline products

Traditionally, for underground communications they were used, which combine strength and sufficient resistance to external negative influences.

Currently, steel pipes

are preferable when laying volumetric lines.

Private pipelines

, increasingly, are equipped with the use of reliable and modern, reinforced polypropylene products that can withstand significant temperature fluctuations within the range of -5 o C to +140 o C.

Polyethylene pipes

can be laid both when installing an individual water supply system with water supplied by a pumping station (why it takes a long time to build up pressure - it is written), and in the pressure drainage system of a centralized, municipal water pipeline.

Distance from water supply to foundation and sewerage - requirements and standards

The functionality of a residential building and the convenience of living in it are ensured by the connection of water supply and sewerage networks to the building. Depending on the ownership of the sources of water supply and wastewater disposal, utility networks can be classified as centralized or autonomous systems. But their specificity in no way affects the permissible distance of the pipes being laid from the foundation of the building, which the regulatory documentation requires to maintain. In particular, SP 42.13330.2011, which is an updated version of SNiP 2.07.01-89*, provides the minimum setbacks for external water supply and sewerage systems from the side walls of the foundation of both the house and various fences, as well as power poles. Of course, these rules have nothing to do with releases.

Requirements for laying pipes in the ground

There are certain requirements, compliance with which will allow installation to be carried out correctly without causing problems during operation. It is preferable to choose reinforced pipes, as they are more reliable and can withstand increased loads

It is also important to carefully insulate the system to avoid leakage and freezing.

Compliance with all requirements allows you to minimize heat loss and extend the service life of the structure. The pipeline does not need to be rigidly fixed, since the pipes will expand when transporting hot water.

In some cases, it is necessary to use additional elements for insulation and insulation. The latter is especially true for areas with harsh winters. The following options can be used as insulation:

using a case;
use of foam concrete;
use of mats for insulation;
installation of heating cable;
increase in pressure in the pipeline.

Other requirements may be imposed on the arrangement of the system, depending on climatic conditions and soil characteristics. For more correct installation, it is recommended to consult a specialist.

How is the external branch of the water pipeline laid?

We have already discussed how to dig a trench for a water supply system, so further in the text we will look at the technology for installing an external pipeline connecting the source and your house. This process can be divided into three stages - preparation, laying pipes and backfilling the trench.

Preparation involves the following actions:

A 20-centimeter sand cushion is added to the bottom of the trench, which is generously moistened and trampled down. Usually, with the help of such a “cushion”, the supporting capacity of the soil is increased, but in this case we are simply leveling out the unevenness at the bottom of the trench, so the selected soil can be used for backfilling.
Having finished with the “pillow”, you can work on the foundation of the building - you will have to cut a through hole in it through which the water pipe will pass. To do this, use a hammer drill and a drill with a carbide tip. At the pass point, draw a square into which the outer diameter of the pipe can be entered. Next, you need to drill a whole chain of holes along the perimeter of the square, breaking out pieces of concrete or bricks with a hammer and chisel.
After “breaking through” the foundation, you need to move on to the shaft of the well or well. A hole is drilled in its wall with a special crown, the diameter of which must be larger than the external dimensions of the adapter, which ensures the joining of the external section of the water supply system and the pump intake pipe.

When connecting the water supply to the main line, the last point becomes irrelevant.

Pipeline installation is carried out as follows:

The measured section of pipe is cut off from the coil and laid on a sandy “cushion”. Moreover, the length of the segment is selected based on the expected dimensions of the pipe section located in the basement (behind the foundation) of the house. However, at this stage there is a high probability of error in choosing the length. Therefore, it is better for you to bring the entire bay into the house and push the free end through the hole in the floor and foundation, stretching it all the way to the well.
Next, you lower the pump or pipe with the ejector into the well and mount the adapter. The free end of the pipe is soldered to the external fitting of the adapter or mounted on a collet coupling (if there is a thread at the outlet of the adapter).

Finally, you cut the pipe and take the coil out of the house. Moreover, it is better to leave a 30-centimeter outlet above the floor level, which can be shortened before installing the central shut-off valve.

The third stage - filling the trench - requires only physical effort. You simply transfer the soil from the storage area to the trench, laying it in 25-centimeter layers, which are carefully trampled down. And do not rush to dispose of the remaining soil - in the spring the backfill will “fail” and you will lay the remains on top of the sagging soil.

Well, that's all - now you know how to dig trenches and lay the external branch of the water pipeline. All that remains is to apply the acquired knowledge in practice.

Basic methods of digging trenches

The question often arises: “How to dig a trench for a water supply using the most rational method?” There are two main options:

The first option is usually used when the homeowner does not have the funds to hire an excavator. Another reason is the inability to operate heavy earthmoving equipment due to limited surrounding space. This option, despite the absence of financial costs (if the homeowner does the work himself), is the most time-consuming and labor-intensive.

The use of mechanized equipment allows you to dig a trench as quickly as possible and with a minimum of physical effort.

Preparatory work

Before you start digging a trench, you need to calculate its depth and width, prepare all the necessary tools and materials, and mark the boundaries.

Depending on the type of soil at the site where the trench is laid, the cross-section may have the following shape:

Trapezoidal - has side walls beveled at an angle of 45-60 degrees. Well suited for trenches on all types of soil, but most justified when digging a ditch on light sandy soils. A trench with such a cross-section is more labor-intensive, takes up a significant area and takes a lot of time.
Rectangular - used when digging trenches on cohesive sandy loams, loams, and clays. It is characterized by steep walls and a small width. When digging in sandy loam, the walls of the ditch are reinforced with boards and cross braces to prevent soil from falling away.
Combined (mixed) - has beveled side walls and a small section of the bottom with a rectangular cross-section, starting from the upper level of perched water or groundwater. A trench with this cross-sectional shape is suitable for light soils, underlying heavy clay or loam from a certain depth; for places with high groundwater levels (GWL).

The width of the trench depends, first of all, on the method of digging it:

When digging by hand, the trench is made of such a width that it is convenient to work in it with a shovel, pickaxe and other tools, while the hand holding the tool does not scratch the walls of the ditch. The optimal width of the ditch with this method is at least 70-80 cm.
When digging using various techniques, the width of the ditch is determined by a similar indicator of the working body of an excavator, a trencher.

Estimated soil freezing depth for various regions of Russia.

Region/city	Soil freezing depth according to SNiP, cm
Loamy and clayey soils	Fine-grained (silty) sand, sandy loam	Coarse and gravelly sand
Middle lane
Vologda	143	174	186
Ekaterinburg	157	191	204
Kazan	143	175	187
Moscow	110	134	144
Nizhny Novgorod	145	176	189
Saint Petersburg	98	120	128
Saratov	119	144	155
Eagle	110	134	144
Ryazan	136	165	177
Samara	154	188	201
Yaroslavl	143	174	186
Average value	133	161	173
Siberia
Novosibirsk	183	223	239
Surgut	222	270	290
Tyumen	173	210	225
Chelyabinsk	173	211	226
Average value	188	229	245
Southern regions
Rostov-on-Don	66	80	86

You can more accurately calculate the depth of soil freezing using the following formula:

Soil freezing depth map

Hpr=√∑т×K

where, Hpr – depth of soil freezing,

∑т – sum of average monthly temperatures for winter without taking into account the minus sign,

K is a correction factor that takes the following values depending on the granulometric composition of the soil:

Clayey and loamy soils – 0.23;
Fine-grained sands and sandy loams – 0.28;
Coarse sand – 0.3;
Rocky soil – 0.34.

Distance from other communications

When digging a ditch to lay a water pipe, you should make the following indentation from nearby communications:

gas pipeline – 1 m;
telephone cable – 0.5 m;
power electrical cable -0.5 m;
sewer pipe – 0.2 m.

Marking

The contours of the trench on the ground are determined as follows:

From the source of water supply to the point where the water pipe enters the house, a minimum path is laid using a measuring tape or cord.
In the place where the trench will be dug, all bushes, flower beds, stone paths are removed, and entrances are cleared for wheelbarrows or small-sized construction equipment: a mini-tractor, an excavator, a trencher. Also at this stage, places are provided where the soil removed when digging the trench will go.
The center line of the future trenches is marked using stakes driven into the ground and a nylon cord stretched between them.

Materials and tools

Bayonet drainage shovel

To dig a water trench you need the following tools:

bayonet shovel,
scrap,
pick,
wheelbarrow,
hammer,
stakes,
nylon cord,
measuring bar with ruler.

The main factors that influence the determination of the depth of the water pipe

Maintaining the temperature in a given area during the cold and hot seasons.
At low temperatures, the water in the pipes freezes; at high temperatures, its integrity is compromised; both temperature factors affect the functionality of the plumbing system;
Properties and characteristics of the soil (the depth indicator varies depending on the type of soil: clayey, viscous - 1.3 m, soft, loose - 1.6 m, hard - 1.9 m);
The presence of vegetation on the surface of the earth (shrubs with growing massive roots damage the integrity of the water supply system);
The temperature of the water passing through the water supply (frequent temperature changes negatively affect the structure of the pipe system);
Percentage of direct sunlight (exposure to the sun will affect the outer shell of the pipe and will shorten the duration of its use);
Availability and distance of groundwater (if the water is too close, then only shallow trenches can be used).

To perform the job efficiently and for a long service life, take into account all the factors presented.

Bookmark standards according to SNiP

The required depth for laying water pipes is 0.5 m (this is the minimum value to maintain the integrity and life of the communication system) below the freezing level of the soil, but it also depends on the geographic area and the nature of the soil.

Average indicators according to SNiP. Residents of the northern regions should adhere to 2-3.5 m depth, for the intermediate zone 1.2-2 m, for the southern regions 0.5-1.2 m.

What materials should the pipe be made of:

Steel. Structural steel pipes were used in older buildings. Now it is not the most relevant choice, since there are better and more durable materials;
Cink Steel. An improved version of the previous material. The use of zinc on the surface prevents the negative effects of external factors and increases service life. There is an opinion that this material spoils the quality of water, so it is not used for drinking systems;
Metal-plastic. The combination of plastic and metal guarantees a long service life. High resistance to adverse external factors;
HDPE. This material has a number of advantages: low cost, resistant to environmental influences, high flexibility, easy to use.

Possible methods of thermal insulation

Let's look at exactly how we can prevent freezing and damage to sewer pipes from exposure to low temperatures.

The following methods are distinguished:

Lay the pipe to a depth that will retain the necessary heat and prevent it from freezing;
Use of special heat-insulating materials;
Using a heating electric cable.

Depth below freezing level

The first method is not suitable for those who took up the work on their own. The advantage is that if you laid the pipe below the soil freezing level, then you will not need additional insulation methods. But this is quite labor-intensive work that requires special equipment, practical knowledge and additional financial resources.

If you choose this method, then you cannot do without specialists and large investments.

Materials for thermal insulation

Polyurethane foam.
This option has high efficiency, low cost, and moisture resistance. It consists of cylinders that are placed like a “shell” on the insulated system. Excellent for sewerage.
Penoizol.
Liquid, highly effective thermal insulation material that creates a monolithic, impermeable shell. Requires specialist skills and special equipment to use. Therefore, it is not suitable for independent construction.
Foamed polyethylene. A highly effective material that is easy to use and guarantees quality. It is a pipe with a cut of various diameters, which is put on the insulated area and secured at the cut site.

There are other highly advanced heat-saving materials, but they are rarely used in practice due to their high cost.

Heating electric cable

This method is divided into two options: budget and more expensive.

In the first case, an ordinary cable is used, which warms up the communication throughout its entire length. The downside is the irrational consumption of electrical energy.

In the second case, a stand-alone cable is used. It also heats the pipe, but selectively in those areas where the temperature decreases. The high price will justify the service life and save costs.

To be more economical, combine two options at once. The basic cable will be an ordinary cable, and in less heated areas a stand-alone cable.

Step-by-step guide to laying a pipeline in the ground

First, dig a place for the water pipe to pass through.
Choose the width of the trench yourself. The main condition is the distance of the communication system from other engineering objects of 0.5-1 m;
Using a welding machine, connect the pipes used for installation;
To avoid soil displacement, it is necessary to pour sand 15 centimeters high at the bottom of the trench;
Before installation, the pipes are thermally insulated. In order to create optimal pressure in the pipe when entering the house, you need to lay it at a slight angle, tilting it towards the house in a vertical plane;
Provide high thermal insulation at the points of entry and exit of communications from the ground to prevent freezing of the water supply;
On the first day after installing the structure, check its functionality. Pay attention to whether there are leaks in the pipes, whether there is sufficient pressure when supplying water;
If the inspection reveals no violations, dig a trench. At the very beginning, pour a layer of sand 15 centimeters high, followed by soil.

Testing the performance of water supply pipes is mandatory. Before you start digging a trench, don't forget about this.

As you can see, in order to determine the depth of the water pipeline, many factors should be taken into account that will directly affect the quality and service life of the constructed communication system.

At what depth should a water pipe be laid for a private home Link to main publication

Planning and calculation of a trench for a water supply system

The easiest and fastest way to lay a pipeline from a water source to a home is to seek help from employees of specialized companies with the appropriate experience and equipment. But this option is not always suitable.

In some cases, the internal space of the site and the location of outbuildings do not allow the use of heavy earth-moving equipment. In other situations, hiring a professional team can be financially expensive. Then the only acceptable solution would be a trench for the water supply, laid on your own.

Preparation

Calculation of the volume of excavation work
Before starting digging, it is necessary to prepare for the work. The main preparatory activities are drawing up a plan for the passage of the future pipeline and making the necessary calculations. When choosing a route for laying a water pipeline, you should take into account the possible presence of other communications along its route that were laid earlier: electrical and telephone cables, gas and sewer pipes. Search for underground communications.

If you do not have design and technical documentation indicating the location of communications, carry out excavation work as carefully as possible to avoid accidental damage. The pits should be laid in a straight line, from the source of water supply to the entrance to the house. If this is not possible, then it is recommended to make pipeline turns at right angles. This way, in the future, it will be easier to join the pipes.

Nuances of digging and laying

When you know the location of other communication networks on your site, you should comply with SNiP standards for laying a pipeline near them.

The indentation values when digging a trench for the water supply network from other communications look like this:

The distance to gas pipes is at least 1 m.
To sewer systems - 20 cm.
To heating pipelines - 1.5 m.
To power supply cables – 0.5 m.

At the same time, laying sewer and water pipes in the same trench is prohibited by SanPiN (sanitary standards). In exceptional cases, it is possible to lay water and heating pipes together, as well as electrical cables, but only if the rules for their mutual insulation are observed.

The next step is collecting the necessary permits. If the trench for the water supply is laid from an autonomous water source - a well or a well - then no permission will be required for this.

An exception is if excavation work will be carried out outside your land plot. So, when passing a trench for a water supply through a neighbor’s property, of course, you will need to ask the neighbors’ permission for this. If the underground utilities you are laying will pass through public lands, it is recommended that you notify local authorities.

Even if your ditch does not bother anyone, municipal officials have the right to initiate an administrative case against you and impose a fine for such arbitrariness. To insert into the central water supply network, you will need to obtain permission from the local resource supply organization.

Unauthorized entry into the highway is fraught with the creation of an emergency situation, and may lead to prosecution, including criminal punishment. How to escape punishment.

Calculation and planning

To install an autonomous water supply, you do not need to obtain any permits.
But you should still make sure that there are no networks passing through your area. This information can be obtained from the relevant authorities. If there are any communications, you need to clarify their depth and location. If there are other utility networks on the territory of your site and parallel laying of water supply pipelines, you must be guided by the standards from SNiP 3.05.04-85 (external sewer and water supply networks). According to these standards, the horizontal distance from the installed water supply networks to other communications should be as follows:

from the sewer (diameter 110 mm) you need to retreat 0.2 m (from the outer walls);
there must be at least 0.5 m between the power cable and the water supply;
1 m away from the gas pipeline;
heating networks cannot be closer to the water supply than 1.5 m;
there must be at least 1.5 m from other water supply networks to the pipe being laid.

According to SNiP, if water pipes need to be laid under a road or other paved area, then the networks must cross this area perpendicularly in order to minimize the length of the pipe, which will be subject to significant loads.

SP and SNiP requirements

The principles and requirements for calculations are set out in construction regulations (SP - codes of rules and SNIP - building codes and regulations, TTK - standard technological maps).

Construction rules and standards for excavation work when constructing trenches are approved in:

SP 45.13330.2012 on earthen structures, which sets out the basic requirements for the arrangement of trench widths, wall heights, and permissible deviations;
SP 104-34-96 on excavation work;
SNiP 2.05.06-85 on underground laying of pipelines;
SNiP III-42-80 on earthworks.

Requirements may differ for gas pipelines, water mains and other process facilities.

Sizing goals

Creating a trench for pipes is a labor process that can be measured in various units.
Calculation of the volume of excavation work is necessary in order to determine:

Volume of excavated soil.
Costs of labor time for manual labor and machine hours (costs can be calculated taking into account the fact that after laying the pipeline, the trench will need to be buried).
The carrying capacity of the transport required to remove excess soil.

The final task is to calculate the total cost, taking into account workers’ salaries and rental costs for machinery.

The calculations take into account additional work, such as:

unloading soil into transport and removing it,
installation of fastening of vertical walls,
backfill,
bringing the area back to its original condition.