Laying sewer pipes in the ground: we equip and insulate the external sewer

Laying the sewerage of a private house does not require any complex skills, special tools or deep specialized knowledge. However, small errors during installation work can subsequently lead to serious damage to the system. A layer of soil exerts quite serious pressure on communications, they are exposed to cold, moisture, etc. Therefore, it is necessary to make sure that the laying of sewer pipes in the ground is carried out correctly.

Types of sewer pipes and their features

The process of laying an external sewage system looks quite simple. Pipes are laid in a dug trench, joined with a system located inside the house, as well as with a collector, and then covered with earth. Before you design an external sewage system, you need to determine the type of pipe. The dimensions, trench, slope, etc., depend on the diameter, cross-section, and material of these elements.

The pipes that are used to create the external sewage system are distinguished by many parameters, such as the diameter and configuration of the section, as well as the material. Today, sewer systems are made from:

• cast iron;
• ceramics;
• concrete;
• asbestos cement;
• plastic;
• fiberglass.

Pig-iron pipes weigh quite a lot, their inner surface is not too smooth, and installation is very difficult, so this type of sewage is rarely used in household plots. Ceramic elements are easier to install, but if handled carelessly, they are easily damaged. Concrete constructions of heavy weight are also difficult to install, so they are rarely used for external sewage of a private house. Inexpensive and lightweight asbestos-cement structures were popular in the past, but they are somewhat fragile, and the smoothness of their inner surface leaves much to be desired.

Plastic pipes for outdoor sewers are usually orange in order to distinguish them from elements for the internal system. These are lightweight, durable and easy-to-install pipes.

The undisputed leader in the market of sewer systems is plastic. Pipes made of PVC, PP, PVP have all the characteristics necessary for external sewage:

• light weight;
• considerable strength;
• resistance to chemicals;
• simplicity in installation;
• smooth inner surface;
• ability to tolerate very low temperatures, etc.

Very good for sewage and fiberglass, which is a composition of polyester resins reinforced with special fiberglass. However, such designs weigh significantly more and cost much more.

To create a sewer in a household plot, plastic pipes of circular cross section, the diameter of which is usually 110 mm, are most often used. When laying pipes by puncture, for example, under the roadway, as well as in other places with a high load, it is recommended to use two-layer pipes with a corrugated outer surface.

Note! Pipes made of polyvinyl chloride (PVP) can withstand heating only up to 40 degrees, and polypropylene (PP) designs can withstand temperatures up to 80 degrees. High-strength polyethylene (PVP), which is used in the production of sewer pipes, takes average positions in terms of heat resistance.

The procedure for creating an outdoor sewer

The laying of sewage pipes begins with the project. It is recommended to make a trench with a minimum number of bends, the optimal solution is a completely straight pipe without any turns. If you can’t do without them, and the system is more than 12 meters long, observation wells are installed in such places, since it is here that blockages and breakdowns most often occur.

Note! Even perfectly direct sewers must be provided with inspection wells every 25 meters.

It is important to correctly determine the depth of the sewer pipe. When determining it, take into account the depth of freezing of the soil and the level of entry of the sewer pipe into the septic tank or pipe of the centralized sewer system. In addition, it is necessary to ensure the necessary slope of the sewage system, which is 2 cm for each running meter of the structure.

When determining the depth of the laying of pipes of external sewage, it is necessary to take into account the level of freezing of the soil, the necessary slope, as well as the depth at which the pipes will be connected to the treatment plant

Often the creation of a sufficiently deep trench is too time-consuming, and sometimes impossible. In this case, it is necessary to carry out thermal insulation work to protect the drains from freezing in the winter. According to the rules for laying sewer pipes, the minimum width of the trench is defined as the diameter of the pipe plus 20 mm on each side for the pipes. If the pipe is wider than 200 mm, the free space should be increased, otherwise it will be difficult to carry out the correct installation of the structure.

After the plan is drawn up and all the factors are taken into account, they begin to perform the work. To install an external sewage system:

1. Dig a trench of a suitable size.
2. Lay a sand pad about 50 mm thick at the bottom.
3. Tamp the bottom of the trench carefully.
4. Lay and connect the sewer pipes.
5. Connect them to the internal sewage system and to the septic tank.
6. Check the system and make sure that it is tight.
7. Sand up the space on the sides of the pipes, ramming it in layers.
8. Fill the sewer from above.

Note! A layer of sand or soil laid over sewer pipes does not need to be tamped.

Practical experience of outdoor sewage is presented in the following video:

When figuring out how to properly lay sewer pipes, one should take into account the recommendations of specialists:

• the number of joints and turns should be minimal;
• all bells must be directed towards the movement of drains;
• it is impossible to shorten bells and shaped elements;
• pipes should be secured to ensure proper sewage slope.

To observe the slope, use a marking cord that is pulled along the bottom of the trench.

At the bottom of the trench for the sewer pipe, lay and carefully tamp the sand cushion. Sand is also rammed, which is filled up on the sides, but sand and soil above the pipe should not be rammed

A few words about warming

Warming of sewer pipes is used quite often. For this, special roll or shaped insulation is used. The former must be wound on the pipe during the installation of the sewer system, the latter are made under the pipe of a specific diameter and simply put on it. Since heat-insulating materials in contact with water can lose a significant part of their useful properties, it is important to cover them with a reliable layer of waterproofing.

As an alternative or additional method of thermal insulation, a special heating cable is used, which is mounted along the entire length of the pipe. You can save time and effort if you buy pipes with an already installed insulation layer. Elements are produced, equipped not only with ordinary insulation, but also with a heating cable.When using such structures, it is necessary to carefully seal the joints so that moisture does not get on the insulation.