Technology and methods of laying sewer pipes


The sew­er net­work is an impor­tant com­po­nent of every­day life, which cre­ates com­fort­able liv­ing con­di­tions. Through pipelines, waste­water is trans­port­ed to exter­nal pipelines to spe­cial equip­ment that process­es and puri­fies waste­water. The domes­tic sewage sys­tem is divid­ed into inter­nal and exter­nal, which are locat­ed respec­tive­ly inside the house and in the open area.

Sew­er line to the house

Features of laying sewer pipes indoors

Sew­er­age lay­ing at a sep­a­rate facil­i­ty (apart­ment, pri­vate house) begins with the design of an inter­nal sew­er­age net­work with ref­er­ence to the premis­es. The cal­cu­la­tion and deter­mi­na­tion of the mate­r­i­al of pipes, their num­ber and type of equip­ment is car­ried out.

In the apartment

Lay­ing a net­work of sew­er pipes in an apart­ment build­ing prac­ti­cal­ly does not dif­fer from a sim­i­lar sys­tem in a pri­vate house, how­ev­er, it has its own char­ac­ter­is­tics. Before wiring and installing plumb­ing, a pre­lim­i­nary lay­out of the sewage sys­tem is made, which includes the loca­tion of plumb­ing fix­tures, the angle of incli­na­tion of the sys­tem, pipe sizes, etc.

The instal­la­tion of a sew­er pipeline inside the premis­es begins with plumb­ing fix­tures and is laid through ceil­ings or walls to the point of exit from the build­ing.

Sew­er­age in the apart­ment

When installing, there should be a min­i­mum num­ber of bends and turns so as not to pro­voke block­ages. Prop­er instal­la­tion has a small num­ber of con­nec­tions and main­tains the required angle of incli­na­tion, which ensures self-clean­ing of the line. When con­nect­ing, the pipes must be insert­ed until they are com­plete­ly abutted, the sock­ets are placed along the flow of the drains. Upon com­ple­tion of instal­la­tion, the tight­ness of the sys­tem is checked in the areas of wiring and dock­ing with ris­ers.

In a private house

Lay­ing a sew­er­age sys­tem in a pri­vate house begins with draw­ing up a plan for a pri­vate house. It is designed strict­ly indi­vid­u­al­ly, tak­ing into account the fea­tures and loca­tion of all rooms. The loca­tion of the ris­er or head­er pipe must be pre­cise­ly deter­mined, after which oth­er parts of the sys­tem can be designed. Ris­er

mount­ed direct­ly inside the house in an open or closed way. Wiring is con­nect­ed to the plumb­ing equip­ment (bath, sinks, show­ers, etc.) from the ver­ti­cal struc­ture, siphons and revi­sions are installed in the appro­pri­ate places.

Instal­la­tion of a sew­er struc­ture in a pri­vate house


The inter­nal sew­er­age device pro­vides for the place­ment of a fan pipe, which is installed on the ris­er and brought to the roof of the house. At the junc­tion, a revi­sion is mount­ed, after which they are led out to the attic at an angle. It should be locat­ed away from win­dows and doors (at least 4 m), at dif­fer­ent lev­els with a chim­ney and gen­er­al ven­ti­la­tion. Through the inter­nal sew­er­age sys­tem, waste water is dis­charged through the base­ment or the space under the floor to the out­side into the sep­tic tank.

In the country

With­in the sub­ur­ban area, as a rule, an autonomous sew­er sys­tem is orga­nized that does not have access to a cen­tral­ized high­way. Instal­la­tion of inter­nal sys­tems in the room is sim­i­lar for both an apart­ment and a coun­try house. The exter­nal sew­er net­work con­sists of a pipeline that dis­charges waste­water to a stor­age or treat­ment facil­i­ty. Sea­son­al res­i­dence does not require the instal­la­tion of com­plex and expen­sive equip­ment, so the func­tion of col­lect­ing waste­water is per­formed by a sep­tic tank or cesspool.

Instal­la­tion of wells in the ground

One of the options for waste dis­pos­al are bio­log­i­cal treat­ment plants, which are the most mod­ern and effi­cient equip­ment.

Features of laying a pipeline in the ground

When arrang­ing sew­er­age in the ground, first of all, envi­ron­men­tal char­ac­ter­is­tics and the type of ter­rain are deter­mined, which affect the design of engi­neer­ing com­mu­ni­ca­tions. The main fac­tors for sys­tem devel­op­ment are:

  • Soil fea­ture. It is nec­es­sary to estab­lish the char­ac­ter­is­tics and com­po­si­tion of the soil to deter­mine the method of lay­ing sew­ers, as well as to cal­cu­late the num­ber of ris­es and slopes of the main.
  • Cli­mat­ic con­di­tions deter­mine the ways and meth­ods of orga­niz­ing ther­mal insu­la­tion.
  • Ground water lev­el. The loca­tion and amount of ground­wa­ter are of deci­sive impor­tance for the design of the sewage sys­tem and the loca­tion of under­ground util­i­ties.
  • The vol­ume of waste­water is cal­cu­lat­ed based on the num­ber of peo­ple who will oper­ate the sew­er, as well as the num­ber of orga­ni­za­tions and enter­pris­es con­nect­ed to the sys­tem.
The lay­out of the engi­neer­ing sys­tem in the ground


An impor­tant fac­tor is also the deter­mi­na­tion of the dis­tance from engi­neer­ing net­works to any build­ings, treat­ment facil­i­ties and pump­ing sta­tions.

What pipes can be used

The mate­r­i­al and pro­file is select­ed in accor­dance with the exist­ing project of the waste sys­tem.

Cast iron prod­ucts do not lose their rel­e­vance due to their low price and dura­bil­i­ty.

They are resis­tant to loads and tem­per­a­ture extremes, but are sub­ject to cor­ro­sion. Mod­ern tech­nolo­gies cre­ate anti-cor­ro­sion coat­ings that increase the life of the prod­uct. Cast iron pipes are heavy, so the trench­less lay­ing of the sew­er­age sys­tem will require spe­cial equip­ment and sup­port per­son­nel to cre­ate an engi­neer­ing struc­ture. When per­form­ing exter­nal sew­er­age, cast iron prod­ucts must be pro­vid­ed with ther­mal insu­la­tion.

In recent decades, san­i­tary prod­ucts made of PVP and PVC have appeared, which are not infe­ri­or in their prop­er­ties to met­al ones. They are much lighter, so instal­la­tion with such prod­ucts is eas­i­er. When installing an inter­nal sys­tem in a bath­room or bath­room, it is bet­ter to use PVC pipes. Poly­eth­yl­ene and polypropy­lene pipes are more suit­able for out­door sys­tems. The advan­tage of plas­tic is that they prac­ti­cal­ly do not accu­mu­late deposits.

Plas­tic sew­er sys­tems of dif­fer­ent diam­e­ters

Asbestos pipes are resis­tant to aggres­sive envi­ron­ments. In the aquat­ic envi­ron­ment, asbestos only gets stronger over time. In addi­tion, under the influ­ence of the flow of water on the inner sur­face of the pipes there is no over­growth. Instal­la­tion of the asbestos sys­tem is not dif­fi­cult, but it is sen­si­tive to mechan­i­cal stress. You need to be care­ful when trans­port­ing and installing them. Pro­tec­tion must be pro­vid­ed to pre­vent sub­si­dence and frac­tures. Asbestos prod­ucts are not rec­om­mend­ed for use in sandy soil, as they have low resis­tance to sand.

Rules for laying sewerage according to SNIP. Laying technology


Engi­neer­ing com­mu­ni­ca­tions are installed in com­pli­ance with estab­lished norms and stan­dards (SNIP 2.04.03–85), which ensures prop­er waste dis­pos­al and an increase in the ser­vice life of all ele­ments includ­ed in this sys­tem.

One of the main para­me­ters when lay­ing pipes is deter­min­ing the depth of the trench. This takes into account the lev­el of soil freez­ing in win­ter, which, in accor­dance with the stan­dards, should be 30–50 cm high­er than the depth of soil freez­ing, from the ground sur­face to the top of the pipe -

not less than 70 cm. On soils with a high load, under the road­way, the depth of the sew­er­age is increased to 0.9–1 meter.

The width of the trench should be 40 cm larg­er than the diam­e­ter of the pipe to be installed. At the exit of the pipeline from the inter­nal sys­tem and the approach to the sep­tic tank, the trench is slight­ly expand­ed for the con­ve­nience of instal­la­tion work.

In the process of lay­ing the sew­er­age sys­tem under the foun­da­tion, the opti­mal slope of the main line is observed, which is 1–2 cm per lin­ear meter. In the absence of a slope, block­ages appear in the sys­tem, since waste­water will not move.

Instal­la­tion of a sew­er­age sys­tem under the foun­da­tion

Lay­ing a sew­er sys­tem under the foun­da­tion is used when it is not pos­si­ble to bring out the sew­er pipe in the base.

You can do the work your­self. To do this, you will need the fol­low­ing tools:

  • Per­fo­ra­tor. They punch holes direct­ly. A set of noz­zles with long noz­zles should also fit with it.
  • Drill man­u­al with replace­able drills.
  • A ham­mer.
  • Weld­ing machine or sol­der­ing iron for sol­der­ing pipes.

After the prepara­to­ry work, the scheme of work will be as fol­lows:

  • The angle of incli­na­tion of the drilling site is cal­cu­lat­ed.
  • An inclined well is being drilled.
  • A case for the pipeline is placed in the result­ing hole.
  • The last step is to mount the engi­neer­ing struc­ture as a whole.

The place­ment of man­holes is pro­vid­ed every 25–35 m of the pipeline at bends and oth­er prob­lem areas where there is a high prob­a­bil­i­ty of block­age. Such a device allows time­ly repair work and replace­ment of equip­ment.

Lay­ing a storm sew­er trench requires seri­ous soil com­paction. Thus, washout of com­mu­ni­ca­tions dur­ing rains is pre­vent­ed. The bot­tom of the trench is cov­ered and com­pact­ed tight­ly with a lay­er of sand 15 cm high. The pipes are also cov­ered with a lay­er of sand from above.

Storm sew­er on site

Sew­er­age is installed under the foun­da­tion if the foun­da­tion does not go very deep into the soil. Pipes are laid below the freez­ing lev­el of the soil, the dis­tance to the foun­da­tion must be at least 5 meters. The pipeline is brought direct­ly into the sew­er trench and con­nect­ed to the exter­nal sys­tem in the “bell” way or using fit­tings. Pipes must be met­al, since sig­nif­i­cant mechan­i­cal stress due to sub­si­dence of the foun­da­tion should be tak­en into account.

Instal­la­tion of sew­er­age under the pile-screw foun­da­tion is car­ried out in untouched soil. To avoid sub­si­dence of the soil, sand is addi­tion­al­ly poured into the trench and it is com­pact­ed tight­ly. The joints are slight­ly under­mined to main­tain the straight­ness of the pipes.

In addi­tion, it is nec­es­sary to observe the opti­mal dis­tance from the sew­er pipe to the screw pile so that the soil around the pile does not become loose. If the lay­ing is made shal­low (up to 70 cm), then in order to avoid dam­age, the pipeline should be insu­lat­ed.

The main stages of laying


Work on the cre­ation of a waste sys­tem is car­ried out accord­ing to the fol­low­ing scheme:

  • In accor­dance with the project, a trench is dug using con­struc­tion equip­ment or man­u­al­ly with a shov­el. The trench starts from the foun­da­tion of the house or the out­let of the pipeline, on which it is put on a sock­et.
  • The bot­tom of the trench is lev­eled, rammed and a sand cush­ion is made. Why a lay­er of sand of 15 cm is moist­ened with water and com­pact­ed tight­ly.
  • The pipeline is being laid, with the sock­ets point­ing down to facil­i­tate the con­nec­tion.
  • The pipeline is assem­bled by lubri­cat­ing the pipe edges with a spe­cial agent (sealant, etc.) for bet­ter slid­ing of the parts. On the prod­uct, you can make marks that will con­trol the cor­rect con­nec­tion. Before instal­la­tion, rub­ber seal­ing cuffs are insert­ed into the sock­et.
  • When lay­ing the pipeline, you should try to use less bends and turns, for which bends with angles of 15–45 degrees are used. Inspec­tion hatch­es are installed at the joints and areas of poten­tial clog­ging.
  • After the assem­bly is com­plet­ed, the cor­rect slope is checked. If the depth of lay­ing the pipe pass­es above the lev­el of soil freez­ing, then work is car­ried out to insu­late the object. For this pur­pose, min­er­al wool, cylin­dri­cal basalt insu­la­tion or a heat­ing cable is used, which is laid simul­ta­ne­ous­ly with the pipe.
Mea­sure­ment of the angle of incli­na­tion of the drain sys­tem
  • Start fill­ing up the trench. The pipes are grad­u­al­ly cov­ered with sand, care­ful­ly com­pact­ed, and then cov­ered with a lay­er of soil extract­ed ear­li­er. Each lay­er of earth 10–15 cm thick is com­pact­ed, soil can be com­pact­ed only on the sides of the pipeline. This should not be done over pipes in order to avoid dam­age or defor­ma­tion of the prod­uct.

For prop­er lay­ing of sewage with their own hands, experts rec­om­mend:

  • It is unac­cept­able to use a lubri­cant that is not intend­ed for the sew­er sys­tem. Inter­nal sur­faces should not be lubri­cat­ed.
  • When installing an inter­nal sewage sys­tem in a room with­out heat­ing, pipe insu­la­tion is used.
  • The through­put of a pipe depends on its diam­e­ter.
  • It is not rec­om­mend­ed to short­en sock­ets and fit­tings.
  • To ensure the cor­rect slope, the pipes must be fixed.
  • The life­time of the sys­tem is deter­mined by its tight­ness.

Thus, the choice of instal­la­tion method for the sew­er sys­tem depends on the place and region of res­i­dence, land­scape design fea­tures, the pres­ence of ground­wa­ter and the mate­r­i­al from which the pipes are made.


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