How much does it cost to manually dig a trench for the water supply

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

Preparatory work

Before starting to dig a trench, it is necessary to calculate its depth, width, prepare all the necessary tools and materials, and mark the boundaries.

Depending on the type of soil where the trench is being laid, the cross-section can be as follows:

• Trapezoidal - has side walls beveled at an angle of 45-60 degrees. Well suited for trenching on all types of soil, but best suited for ditch digging 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 a trench on cohesive sandy loam, loam, clay. It is characterized by sheer walls and small width. When digging on sandy loam, the walls of the ditch are reinforced with boards and transverse struts to avoid soil shattering.
• Combined (mixed) - has beveled side walls and a small section of the bottom with a rectangular cross-section, starting from the upper level of the upper water or groundwater. A trench with this cross-sectional shape is suitable for light soils, underlain from a certain depth by heavy clay, loam; for places with a high groundwater table (GWL).

Trench width depends, first of all, on the way of digging it:

• When digging by hand, the trench is made of such a width that it is convenient to work with a shovel, pickaxe and other tool in it, 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 with the help of various equipment, the width of the ditch is determined by a similar indicator of the working body of an excavator, a trencher.

According to SNiP 2.04.02-84, the depth of digging a water supply trench should be 50 cm below the level of soil freezing, indicating how much the soil freezes over the average winter for a particular region.

Estimated depth of soil freezing for different regions of Russia.

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

Hpr = √∑t × K

where, Hpr - depth of soil freezing,

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

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

• Clay and loamy soils - 0.23;
• Fine-grained sands and sandy loams - 0.28;
• Coarse sands - 0.3;
• Stony ground - 0.34.

Thus, for the Middle Lane, the depth of digging a water supply trench is from 180 to 220 cm, for Siberia - 230-300 cm, for the southern regions - 110-140 cm.

Distance from other communications

When digging a ditch for laying a water pipe, the following indentation should be made from the nearby communications:

• gas pipeline - 1 m;
• telephone cable - 0.5 m;
• power electric cable -0.5 m;
• sewer pipe - 0.2 m.

Information about the passage of sewerage, telephone, power cables, gas pipelines in the places of digging a trench should be found out in advance in the organizations that are the owners of these communications.

Markup

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

• A minimum path is laid from the source of water supply to the place where the water pipe enters the house using a measuring tape or cord.
• In the place where they will dig a trench, they remove all shrubs, flower beds, stone paths, free the entrances for a wheelbarrow or small-sized construction equipment: a mini-tractor, an excavator, a trencher. Also at this stage, places are provided for where the soil removed when digging a trench will lie.
• The centerline of the future trenches is indicated by stakes driven into the ground and a nylon cord stretched between them.

Materials and tools

To dig a water supply trench, you need the following tools:

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

To strengthen the walls of the ditch, an unedged board and spacers made of bars are used. To protect the eyes and respiratory organs when working with dusty soils, protective glasses and respirators are used.

Methods for digging a trench for a water supply

Manual digging provides for digging a ditch for a water supply using a trench tool - a shovel, pickaxe, crowbar. This method is used with a small length of the trench and a limited space, inconvenient for the entrance and operation of equipment.

The advantages of this method:

• cheapness - digging a trench on your own will cost several times cheaper than hiring special equipment;
• a small set of tools - with this method, simple entrenching tools available to any owner are used;

Disadvantages:

• duration - in comparison with a mechanized digging, which sometimes takes 1-2 light days, this process will last 3-4 times longer;
• labor intensity - manual excavation requires significant physical effort, especially when digging trenches on heavy and dense clay and loamy soils.

For mechanized digging trenches for the water supply, an excavator mounted on a walk-behind tractor is used, or a mini-tractor trencher - a special cutter that allows you to make narrow and deep ditches.

A mechanized digging is used when digging long trenches (more than 20-30 m) in places with normal entrances and sufficient space for equipment to work.

Benefits:

• minimum amount of soil excavation - with this method, the minimum amount of soil is extracted, due to which the narrowest ditch is obtained, into which the water pipe fits well;
• short term of work - the use of special equipment allows you to dig a trench very quickly, without thereby delaying further work on laying a water supply system and connecting it to a water supply source.

Disadvantages:

• high cost - compared to manual digging, the use of equipment will cost several times more;
• the inability to use in places with limited space, for example, in a small cottage with a small personal plot.

Self-excavation of trenches

When building a private house, cottage or summer cottage, with a small amount of work, it is more profitable to quickly dig a trench for the water supply with your own hands, without resorting to the services of expensive equipment and specialists. This process consists of the following stages:

• marking the contour of the trench with stakes and a nylon cord;
• removing the fertile soil layer and storing it at a distance of at least 1 meter from the edge of the ditch;
• excavation of the underlying soil layers and laying them separately from the fertile layer;
• covering the soil removed from the trench with plastic wrap to prevent it from being washed out and wet in the rain;
• strengthening the walls of the ditch with boards and struts to avoid crumbling.

When laying water pipes under an asphalt or dirt road, a "puncture" is made. To do this, on both sides, it is necessary to dig two trenches 1.5-2 meters wider than the width of the roadway. After that, a steel pipe with a sharpened end is inserted into the sheer wall of the ditch, bordering the road. With this pipe, blows on the opposite end with a sledgehammer pierce ("pierce") the soil thickness under the road without labor-intensive and costly earthworks. In a similar way, the foundation of a house that has already been built is pierced.

Price per running meter

The average price per meter of digging a trench for a water supply by contractors involved for this depends on the method used:

• When manually digging a ditch for a water supply, a running meter at a depth of 130-150 will cost 1000 -1200 rubles. This cost includes the wages of the trench digging workers and the contractor's stated profits.
• The price for which mechanized trenching with an excavator or trencher will be carried out varies from 8,000 to 10,000 rubles. for an 8-hour day of work of technology. This rate includes the cost of the fuel consumed by the equipment, its depreciation, the operator's salary, and also the profit.

It is more profitable and more convenient to dig a trench for a large-sized water supply using special equipment. With this method, in less than 2 days the ditch will be dug and ready to lay pipes, while manual digging will take several times longer.