Fan pipe for sewerage. Why do you need a sewer pipe for sewage Do without a fan pipe

Eco-friendly homestead: Competent arrangement of the sewer system requires special knowledge, accurate calculations and understanding of the features of the designed structure. There are no "optional" elements in such a system. Nevertheless, quite often you can hear from unfortunate specialists that the fan pipe is an extra part of the structure. Let's figure out why this element is needed and whether it is possible to do without it.

Proper arrangement of the sewer system requires special knowledge, accurate calculations and understanding of the features of the designed structure. There are no "optional" elements in such a system. Nevertheless, quite often you can hear from unfortunate specialists that the fan pipe is an extra part of the structure. Let's figure out why this element is needed and whether it is possible to do without it.

A fan pipe is a section of a sewer pipeline that extends from the riser and ends outside the house, in the open air. Most often, such an element is displayed through the roof and rises above the roof. The main role of the fan pipe is to maintain normal pressure in the sewer system, which is very important.

All plumbing fixtures are equipped with a water seal, which is located inside the siphon. This is the name of a structure that holds a certain amount of water inside. It becomes a kind of lock that prevents gases from the sewer from penetrating into the room. If the siphon works normally, there are no unpleasant odors in the room. But in some cases, the water seal can be broken. This happens when the pressure in the sewer system decreases sharply, and the water from the siphon is literally sucked out.

The most common reason for this phenomenon is the massive discharge of wastewater. The simultaneous appearance of a large amount of discharged liquid in the sewer system leads to a sharp drop in pressure and, as a result, to the breakdown of hydraulic seals of plumbing equipment. The fan pipe or pipes, if the length of the sewer is large, communicate with the atmosphere, which stably normalizes the pressure.

Thus, the installation of a fan pipe is necessary if a one-time drain of all plumbing fixtures installed in the house can block the cross section of the sewer pipe. You need to know that a 110 mm fan riser is always used for the toilet. This is due to the fact that a 70 mm pipe is usually mounted on the drain, rarely more, so when flushing one toilet bowl, the drain will not be blocked. A pipe with a diameter of 50 mm usually departs from the bath, since the through hole of the siphon used here is always smaller. One-time drains of other plumbing fixtures are much less.

To determine the total maximum value, they must be added. Practice shows that in one-story small houses with no more than one bathroom, a one-time drain is unlikely to block the cross section of the sewer pipe. Therefore, it is possible to install the system without a fan riser. SNiPs stipulate when the arrangement of a sewer without a vent pipe is prohibited. It must be present in houses with two or more residential floors, each of which is equipped with plumbing and sewerage. The fan riser is installed without fail if an autonomous sewer system is located near the house.

If the housing is equipped with risers with a diameter of 50 mm, if the building has a swimming pool or any other structure that produces a large volume of one-time drains. In addition to stabilizing the pressure in the system, the fan pipe performs another role. It ventilates the sewers, removing unpleasant odors. For this reason, it must end in a place where sewer gases can be easily removed into the atmosphere.

Most often, the pipe is brought to the roof and ends at a height of about 0.3-0.5 m from the level of the roof ridge. It is very important that the diameter of the fan riser is the same or slightly larger than the cross section of the sewer. Only then will the system work effectively.

According to SNiPs, the fan pipeline should be laid only in a warm room. If this is not possible, high-quality insulation is carried out, otherwise the pipe will freeze in cold weather, which will lead to a deterioration in the operation of the system. In addition, the upper part of the element already in the first year of operation in such conditions will be covered with an unpleasant coating. Subsequently, its quantity will only increase, which will lead to damage to the part.

Experts recommend bringing the fan pipe as close as possible to the ridge, which will protect it from snow drifts. All kinds of turns are highly undesirable. Risers should be as straight as possible to avoid unnecessary opposition to airflow. For multi-storey buildings with long internal horizontal wiring, several fan risers will need to be installed. Their exact number will be specified by the designers.

In buildings where sewage flows into an autonomous bio-treatment system, a fan pipe must be installed. This is because the aerobic microorganisms present in the system are vital oxygen. Its access is provided, among other things, by the arrangement of effective ventilation.

The fan riser can be metal or plastic. In the first case, a cast-iron sewer pipe of the required length is taken for its manufacture. This option is used for metal systems. The fan riser can also be made of a plastic pipe, this is the most common option. It can be used for both plastic and cast iron piping.

The arrangement of a fan riser is associated with certain difficulties: making an outlet through a wall or roof, increasing the length of the structure, etc. But the homeowner can be sure that the pressure in the sewer system will always be normal, and he will not be threatened with failures of the plumbing water seal.published If you have any questions on this topic, ask them to specialists and readers of our project.

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Each multi-storey building is equipped with its own sewage system. Its function is the removal of sewage and other effluents to a citywide highway or other treatment facility. To prevent the spread of unpleasant odors inside the premises, they are used.

This device, which is a continuation of the riser, is carried through the roof to the outside of the building. It removes gases from and stabilizes the pressure indicator in it.

In this article you will learn a lot of useful information about this device and you can see its photo.

General information

The mass of sewage that occurs during the flushing of wastewater into the system, entering the main, acts as a pump. Before the drain, the pressure indicator rises, and after them it decreases.

If the ventilation section of the line is not provided during use, a hydraulic seal breaks down. Air mass is sucked through the drain hole of plumbing fixtures. The effect contributes to the entry of gases into the building.

This problem happens with devices with a weak water seal. But sometimes a breakdown is possible in several areas at once. It is accompanied by characteristic gurgling sounds that appear in the drain holes.

If the line is equipped with a ventilation section, the air enters the line absolutely freely.

Due to this, the pressure indicator is stabilized. Breakdown of water seals does not occur. Accordingly, the smell of sewage does not penetrate into the room.

Design standards

The design under consideration is a continuation of the riser. Therefore, it is constructed from the same channels. Their most popular cross section is 110 mm. On top of the structure. It is needed to prevent the penetration of rain or snow into the riser. In general, the basic rules are indicated in.

To properly mount a fan channel, follow these rules:

select the indicator of the diameter of the device not less than the size of the section of the riser;
the part is mounted on the roof at a height of not less than thirty centimeters from the ridge;
it is forbidden to connect ventilated with other ventilation systems in the house;
the part is located away from windows;
part of the channel passing through the attic must be insulated;
it is categorically impossible to conclude the structure under the roof overhang, as this will lead to its breakdown in the winter.

To put a fan channel, prepare its scheme. Below you can see its general example.

Familiarize yourself with the sections of the scheme:

A - section 100 mm (toilet and bidet);
B - size 50 mm (washing machine, sink, bathtub, shower cubicle);
C - section 50 mm (dishwasher and sink).

You can prepare a fan design project on your own. To cope with the task, you need to have minimal engineering knowledge and carefully study the requirements of SNiP 2.04.01-85. Below we will talk in more detail about what needs to be considered at the stage of project preparation.

The indicator of the slope of the internal sewerage, according to SNiP 2.04.01-85, should be:

for channels with a cross section of 50 mm - three centimeters per meter;
for structures 85-100 mm - two centimeters per meter.

The slope value for branches up to one and a half meters in size is fifteen centimeters per meter. Channels must be installed in a straight line. There should be no slope of the horizontal part. You can change the direction of the channels by means of special fittings.

To combine several risers, it is allowed to use one fan. Change the direction of the channels above the area where the last plumbing fixture connected to the riser stands.

To join 2-3 channels, use. It is mounted at an angle of forty-five to one hundred and thirty-five degrees. It is necessary to change the direction of the channel only by means of a special branch placed at an angle of one hundred and thirty-five degrees.

It is advisable to place the lower part of the fan structure in a warm place, and the upper part in a cold one. This will make the level of traction optimal.

The cost of installing a ventilated duct in a multi-storey building depends on many factors. First of all, on the amount of materials needed, their quality, and the complexity of the installation. The installation of a fan structure costs on average 5-7 US dollars per linear meter. The cost of the work may include the creation of strobes, the installation of clamps and the dismantling of old structures.

Fan channels may need to be cleaned if dirt or precipitation has entered them. It's easy to prevent this. As we wrote above, part of the structure on the roof must be equipped with a special fungus.

Errors during installation and repair

During the installation of ventilation ducts, inexperienced craftsmen make mistakes. Usually they are associated with the desire to quickly complete the work.

The most common mistakes are:

The output of the fan channel is not on the roof, but in the attic. Over time, gases will accumulate in a large volume. Finding no way out into the atmosphere, they will begin to penetrate into other rooms of the building.
Installation of the device on the outside of the bearing walls. This will lead to condensation, and subsequent trouble.
The use of a decorative fungus on the upper part of the channel leads to a decrease in the traction index. As a result, the device does not perform its function. This leads to the spread of gases inside the building.

Repair of fan structures is often associated with the replacement of old ones with new ones. This procedure is preferably performed under the guidance of an experienced specialist. heavy enough. However, they are characterized by a fragile structure. Careless handling of them will lead to their breakage. You need to work with the utmost care. Otherwise, you can cause damage to any elements of the structure and your own body.

If you need to replace fan channels in a multi-storey building on the ground floor, choose only high-quality replacement products. It is important that the new polymer structures withstand the existing pressure in the system.

To carry out repairs, you need a variety of tools. You need a drill, a grinder and a sledgehammer. Other tools may also be needed to solve the problem. Since the replacement of cast iron products is a rather complicated and time-consuming operation. After dismantling the old channels, mount new ones. You already know how to do this.

Do I need a fan pipe in a one-story house?

All multi-storey buildings must be equipped with fan channels. Without them, it is impossible to solve the problem of the spread of gases. Sometimes the use of this element is also relevant for private houses.

If the building has several plumbing units used at the same time. If the riser has a cross section of fifty millimeters, even a small mass of drains can break the water seal. Therefore, in this situation, a fun channel is also needed. If a septic tank is located near the building on the site of a private house, it is necessary to equip it with the ventilation devices in question.

To quickly connect the washing machine to the wastewater drainage system, install a separate siphon with a channel for it. Ventilation of the riser will be required if the line is not built correctly.

check valve

To ensure the flow of fluid in one direction, there is a device called reverse. The most popular channels for sewer circuits have a cross section of 110 and 50 mm. Therefore, the part under consideration has the same dimensions.

The component is placed at the junction of the channels or a tie-in is made with a threaded joint. There are models where a “plate” is used as an element that blocks the flow of liquid. This component is located inside the instrument.

It is subjected to pressure from the right side, and it opens. If impurities start moving in the opposite direction, the component in question blocks them.

Ball models are more popular.

They work on a similar principle. But instead of a "plate" they are equipped with a spherical element. These products are more reliable.

There are parts of flange and coupling type. Each of them has its own characteristics. Parts of the first type are designed for highways installed both horizontally and vertically. Devices of the second type are placed only on vertical channels.

For the arrangement of toilet bowls, valves with a cross section of 110 mm are used. Products with a section size of 50 mm are mounted on the internal highway.

Check valves are made from:

cast iron;
plastic;
become.

You need to choose a device based on. If they are, then the device must be made of plastic.

The installation of the parts under consideration is carried out in different ways. Models with a significant throughput indicator are placed on common highways. They can be used to equip small private houses. They are not recommended for installation in an apartment of multi-storey buildings.

Installing the device at all drain points reduces the possibility of accidents. This is important for those homeowners who live on the first two floors of multi-story buildings. After all, they are at the highest risk of an accident. To learn more about the check valve device and how to install it, read this article.

A sewerage fan or ventilation pipe is a necessary attribute of any wastewater disposal system in a multi-storey building and in a private cottage. What is a fan pipe for? Installing such a pipe simultaneously solves two problems. Firstly, through ventilation, gases are removed from the pipeline network. Secondly, ventilation is needed to maintain a constant pressure in the pipe system, since at the time of the descent of a large volume of water in the sewer, air is released.

What is a fan pipe? It is customary to call a fan pipe a pipe that connects the sewer riser to the atmosphere. The presence of such a pipe prevents the occurrence of vacuum in the system, which, in turn, does not allow disrupting the operation of water locks.

In the absence of a fan pipe, at the time of the descent of a large amount of water, in all devices located above, it can disrupt the water seals. And through empty siphons, an unpleasant smell of sewerage will begin to flow into the premises.

The need to use piping

According to building codes, a sewerage system without a fan pipe can be built in a one-story house. This tolerance is based on the fact that in small houses a large amount of wastewater cannot be generated at the same time.

However, a sewer pipe for sewerage in a private house will not be superfluous in a low-rise building. Installing a pipe is a necessity if, while draining a large volume of water, the section of the riser pipe is completely blocked.

In most cases, the dimensions of the hole in the cistern are 70 mm, and the outlet from the toilet is carried out using a pipe having a diameter of 110 mm. The outlet from the bath is assembled from pipes with a cross section of up to 50 mm. Thus, when using only one piece of plumbing, a complete filling of the riser cannot occur.

Small-diameter sewer pipes are connected to the rest of the plumbing fixtures. Therefore, their use does not have a significant impact on the total amount of simultaneous discharge. Therefore, in one-story houses, the installation of a fan pipe is optional.

Advice! As a rule, the largest amount of waste is formed when water is drained from the toilet and bathtub at the same time.

Another thing is a house of two floors and above. Of course, we are talking about cases where bathrooms are located on each of the floors. In this case, several people can use the water supply at the same time.

And with the simultaneous discharge of water from two toilet bowls, the section of the riser will be completely blocked, therefore, in such houses, the installation of fan pipes is mandatory. In high-rise buildings, the normal functioning of the sewerage system without a vent pipe is impossible, since in such a house a large number of people can use the sewerage system at the same time.

Consequently, the probability that the entire section of the riser will be occupied by drains increases many times over. Thus, it is mandatory to include fan pipes in the system if:

For the construction of the riser, a pipe with a cross section of less than 110 mm was used.
The house has several bathrooms and it is possible that they will be used at the same time.
If the house has a device that can provide the simultaneous appearance of a significant amount of drains. Such devices include, for example, a swimming pool.
The house is equipped with local sewerage and the treatment plant is located a short distance from the house. In this case, ventilation from sewer pipes helps to prevent the penetration of the smell of gases formed during the decomposition of organic matter in the septic tank into the premises of the house.

Installation and repair of fan pipes

The sewer pipe for sewerage can be made of both plastic and cast iron:

Metal pipes. This is a traditional solution, since 50 years ago domestic sewage systems were assembled exclusively from cast iron. The material is durable, but it is very inconvenient to use, because it has a significant weight.

Plastic. This is the most popular sewer assembly material. Many owners change their old cast-iron sewerage to plastic, and when building new houses, this material is the most in demand. Plastic pipes are lighter, more cost effective and more aesthetically pleasing. Therefore, today cast-iron pipes are used much less frequently.

Advice! When installing or replacing a fan pipe, if necessary, parts made of cast iron and plastic can be joined. The main thing is that the diameters of these elements match. Narrowing of the diameter in the fan pipe must not be allowed, otherwise it will not fully function.

In addition, there are conditions that must be observed regardless of what material the pipes are made of:

The diameter of the drain pipe must be equal to (or greater than) the diameter of the sewer riser. The use of a pipe of a smaller cross section is prohibited by building codes.
The fan pipe, as a rule, is displayed on the roof. It should not be installed near windows and balconies. The minimum distance from the surface of the roof ridge is 30 cm.

Fan pipe installation rules

When installing a fan pipe, you must strictly adhere to the recommendations enshrined in SNiP.

When purchasing material, you need to make sure that the diameter of the fan pipe is not less than the diameter of the riser.

Advice! In private construction, most often, for the construction of risers and, accordingly, fan pipes, a plastic pipe with a cross section of 110 mm is used.

The starting point of the sewer system must necessarily be in a heated room. But its end point, on the contrary, should be located in a cold place. This will provide the necessary temperature and pressure difference and allow ventilation to effectively remove gases.

The sewer ventilation pipe is actually a continuation of the riser, so it is made from the same material as the riser itself.

Advice! Sometimes the constant presence of an unpleasant sewer smell in the premises is due to the fact that siphons of insufficient volume are installed under the plumbing fixtures. If you do not use the appliances for several days, then the water plug will simply dry out and unpleasantly smelling gases will penetrate into the rooms. Installing a vent pipe will help solve this problem. The air in the house will remain fresh, even if the plumbing is idle without use.

Roof ventilation outlet

Fan pipe installation rules:

The outlet of the ventilation pipe to the roof must be organized at a height of at least 30 cm, and preferably 50 cm from the ridge. However, if the roof is an exploited object (for example, a summer terrace is arranged on it), then the output height can reach three meters.

If several risers are installed in the house, then they can be equipped with one fan pipe.
The horizontal distance from the windows and balconies of the building to the outlet of the vent pipe must be more than 4 meters.

When constructing sewer ventilation, it is strictly prohibited:

Bring the fan pipe to the attic, and not to the roof.
Organize the outlet of the fan pipe together with the outlet of the chimney and the ventilation duct.
Lead the fan pipe under the roof overhang, because in winter, when snow and ice come off the roof, the pipe can be damaged.

Some homeowners, in an effort to improve sewer ventilation, are trying to install additional exhaust devices on the pipe. Such as deflectors, wind vanes, etc.

In fact, such devices not only do not give the desired effect, but can also contribute to the fact that condensate will accumulate in the system. And in the cold season, moisture can freeze and block the movement of air and gases.

Check valve installation

A non-return valve must be installed on the exhaust pipe. They put the valve on the sewer pipe immediately after installing the toilet. Valve working principle:

When the water is drained from the drain tank, the valve cover opens, passing drains.
In the absence of fluid from the house, the valve cover is tightly closed. At the same time, it has such a design that it is impossible to open it from the back.

That is, installing a valve helps to avoid such an unpleasant situation when drains from an external pipeline (for example, as a result of a blockage) enter the house, flooding the premises with dirty water.

So, a fan pipe is an element of the sewer system, which is used to ventilate the pipeline and maintain normal pressure in the system. The installation of the exhaust pipe must be carried out in accordance with the requirements of building codes.

Hello again!

The owners of apartments on the upper floors of high-rise buildings are often annoyed by the section of the sewer pipe that goes to the roof. It seems useless and, according to the owners, takes up too much usable space, which is why they often get rid of it without remorse.

In fact, the seemingly unnecessary fan pipe has a very specific purpose. What is its function and is it really impossible to do without it?

The fan pipe is a continuation and belongs to the class of gas outlet ventilation equipment.

Purpose and functions

The fan riser is designed to remove fetid gases accumulated in the circuit outside the boundaries of the household.

But this is not its only function, it:

It normalizes the pressure in the system, which prevents the failure of hydraulic locks in the siphons of plumbing fixtures while draining a large amount of wastewater.
Attenuates the sounds of sewage movement in the pipeline.

Device and principle of operation

From a technical point of view, the fan riser is a natural extension of the waste pipeline. In fact, this is a pipe segment connected to the sewer line and extending beyond the boundaries of the roof structure of the house.

The contour and layout of the outlet of the fan pipe is determined by the features of the structure.

The principle of operation of the fan riser is based on the difference in atmospheric pressure inside the sewer circuit and on the street. Formed in the process of biological decay gases naturally rush up and down. Since the design of the siphons of plumbing fixtures provides for a kind of barrier in the form of a water seal, they go outside along the path of least resistance - through the fan pipe. If it is absent or blocked, these gaseous emissions will be carried out through the water seal and enter the room.

How to determine if a vent pipe is required

There is no need to guess in this matter: everything is clearly regulated by the norms of SNiP 2.04.01-85. If the house does not belong to the categories "one-story" and "private", it must be equipped with a fan riser.

Do I need a fan riser in a one-story and two-story house

As we have already decided, if the house is two-story and also multi-apartment, a ventilation sewer circuit is a must.

But with a one-story, even a private house, everything is not so simple. A fan riser in a private one-story house may be required if, with a single discharge of wastewater, the liquid completely, albeit for a short time, blocks the cross section of the sewer pipe. In this case, there is a high probability of failure of the hydraulic seals of sanitary equipment and the release of waste gases into the room.

The designated risk zone includes houses in which:

More than one floor and at the same time each is equipped with a bathroom, even with a separate sewer branch.
The diameter of the waste risers is less than 110 mm.
Jacuzzis or pools are connected to the public sewerage system.
The septic tank is removed from the house at a distance of less than 8 meters.
Not sustained.

Even if you have a one-story house, but at the same time it has several bathrooms, it is necessary to connect a fan pipe.

How to check if there is a sewer pipe in the house

There is nothing easier:

If you are a happy owner of an apartment located on the top floor of a multi-storey building, just go to the bathroom where the sewer riser is located. If a pipe goes up from it, everything is fine. By the way, it would be useful to go up to the attic and make sure that this pipe is brought out of the roof.
If you are not so lucky and the apartment is located a little lower, just listen to the sounds made by the sewer. A characteristic squelching is a signal that the fan pipe is either not there at all, or it is clogged.
The systematic failure of water seals and a fetid odor will also indicate problems with the sewer ventilation system.

Is it possible to do without it

In very rare cases, yes. But then the sewer line should be equipped with a check or vacuum valve (aerator). Which is better, consider below.

What materials is it made from

What is a fan, what is a sewer - this is the same type of pipes. This means that they are made from the same materials - plastic or cast iron:

more convenient to install and operate.
Cast iron is stronger and more durable, but it is harder to work with them due to their impressive weight and fragility. In addition, cast iron quickly become contaminated during operation.

Types, sizes and diameters

There are 2 types of fan pipes:

Rectilinear (rigid).
Offset (corrugated).

The offset pipe is mobile and allows you to connect to a toilet with any outlet location.

The standards regulate the diameter of the fan pipes of 110 mm. This value is the same for both cast iron and plastic models.

The length of the fan pipe can be different: it depends on the height of the ceiling and attic spaces, as well as the level of output outside the roof.

Which view is better

Cast iron is gradually giving way to plastic, so if possible it is better to replace the cast iron model with a plastic one. This is not at all difficult to do: you can use special cuff adapters for tie-in.

When choosing between plastic products, give priority to polymers based on polypropylene (PP) or polyvinyl chloride (PVC). They are:

They provide sufficient fastening rigidity, resistance to vibration and mechanical loads.
Able to withstand the aggressive environment of condensate accumulating on the walls of the pipeline during the release of malodorous gases.

It is better to use the same type of plastic that was chosen for the main sewer. So it will be easier to choose a sealing composition.

Structural features are determined by the installation method and personal preferences of the owner. If the design is straight, it is wiser to use rigid products. If it is planned to bend the contour, it is allowed to perform part of the elements in the corrugation.

How to choose the right

The main issue in choosing a fan pipe is determining the optimal diameter, especially when it comes to apartment buildings with a large number of drains.

The size of the cross section of the fan pipe should not be less than the same value of the interfloor sewer riser to which it is connected.

approximate price

The cost of fan pipes is determined by a number of parameters:

Dimensions (section, length, wall thickness).
Manufacturing material.
structural features.
Manufacturer and brand name.

The estimated cost of PVC models is given in the table:

Outer diameter, mm	Wall thickness, mm	Pipe length, m	price, rub.
90	5	3,06	500
90	8	6	1850
113	5	2,07	560
113	5	3,07	830
113	5	5,07	1360
113	7	2,07	760
113	7	3,07	1125
113	7	5,07	1855
125	5	2,07	605
125	5	3,07	900
125	5	5,07	1480
125	6	3,07	1050
125	6	5,07	1735
125	7,5	3,07	1320
140	6,5	2,07	890
140	6,5	3,07	1320
140	6,5	5,07	2180
140	8	3,07	1600
140	8	5,07	2630
165	7,5	3,07	1740
165	9,5	3,07	2150
195	8,5	3,08	2195
195	11,5	3,08	3050
225	10	3,09	3170
225	13	3,09	4005

Installation rules

The installation of the vent pipe is carried out inside the heated room strictly from the bottom up in the following sequence:

Preparation in the bearing elements of the construction of technological holes.
Installation of plumbing fixtures, assembly and connection of their sewer circuit to the riser.
The system is assembled at the lowest point of the circuit. To connect all the elements, a tee is used, one of the holes of which should “look” up.
A section of the fan pipe of the required size is installed in the branch pipe of the tee, so that the connecting section does not fall out onto the attic floor.
Silicone sealant is used to seal the joints.
Every 1-1.5 meters, the pipeline is fixed to the wall by means of clamps: rigid - in the places of the socket connection, floating - in straight sections. It is advisable to use clamps with a rubber seal, they will better hold the pipe in a given position and compensate for the vibration load.

How is the outlet pipe through the roof and how to determine the desired height

The contour of the fan riser is erected along the inner wall of the building, is carried out through the attic and without fail is taken out of the roof.

In this case, the following conditions must be met:

To prevent the collapse of the structure in the attic, a fastening system is provided.
The minimum level of elevation of the fan pipe above a flat roof is 30 cm, above a pitched roof - 50 cm.
When the fan pipe is placed in parallel with the ventilation circuit of the house, the edge of the fan pipe is set at least 15 cm higher than the edge of the ventilation pipe.
With a gable roof, the fan pipe should be taken out from the leeward side.
The distance between the edge of the vent pipe and the nearest window or balcony is at least 4 m.
To prevent contamination, the head is equipped with a special protective deflector. Installing another type of equipment will inevitably worsen the quality of the sewer ventilation circuit, as well as provoke the formation of condensate.
When the head rises above the roof level to a height of more than 50 cm, a bracing system is installed that firmly fixes the position of the pipe on the roof.

Sometimes you can lead the fan pipe through the gable part of the roof, this will preserve the integrity of the roofing. In addition, technically, such installation is easier to perform, the main thing is to comply with the requirements for the remoteness of the head from the window and balcony structures of the house. Otherwise, fetid aromas will be drawn into the house.

How is the output through the roof

For output through the roof, a mounting hole is made in the roofing pie, 1-2 cm larger than the diameter of the fan pipe. After the pipeline is assembled, it is necessary to carefully seal the through hole.

For this, special polymeric elastic linings are used, the so-called master flashes. They are:

Easily installed.
Provides a tight seal.
Reliably protect the place of passage from leakage.

Along the edges of the lining, you should additionally walk with sealant.

The main mistakes during installation

Everything that is prohibited by the norms of SNiP, but for some unknown reason is often ignored by craftsmen, can be safely attributed to the number of errors:

Unauthorized removal of the fan line.
Reducing the cross section of the fan pipe compared to the main sewer riser.
Conclusion of the head to the attic.
The erection of a fan circuit along the outer wall of the building.
Conclusion of the fan pipeline to the standard general house ventilation system.

Combining a fan circuit with a chimney can cause a fire due to the ignition of sewer gases.

Is soundproofing and insulation required?

Soundproofing the fan pipe is not a mandatory requirement, but it is not forbidden either. This issue becomes especially relevant when the pipeline passes through living rooms. The noise of sewage, air pops and vibrations can cause discomfort.

The following materials are used for soundproofing:

Mounting foam. The surface of the fan pipe simply foams with it. However, it should be noted that such a design will look unattractive, and it is also quite problematic to dismantle it later, and you can forget about repairs altogether.
Special slab materials made in the form of a rigid shell that exactly repeats the configuration of the pipeline. They are easy to install, hold well and do not cause difficulties during dismantling.
Soft rolled soundproofing canvases, with which the highway is usually wrapped in 2-3 layers (depending on the thickness and sound-absorbing qualities of the material). The inconvenience of using soft sheets lies in the need to ensure their sufficiently rigid fixation, which prevents the material from rolling along the vertical plane of the pipeline.

The use of thick-walled polypropylene pipes can reduce the noise effect of a working sewer.

But the insulation of the fan pipeline is not an idle question, especially when it comes to an unheated basement, upper floors and an attic. The temperature difference provokes the formation of condensate and its freezing in the pipe circuit, reducing the efficiency of the ventilation system. For insulation, as a rule, the same materials are used as for sound insulation.

Rules for replacing a pipe

The need to replace the fan riser arises when the old design:

Obviously worn out, and the connections loosened.
Has damage.
Made from old cast iron pipes, long outdated.

Replacement work should begin with disconnecting the obsolete structure from the sewer riser, which should be temporarily closed with a plug during the repair. This will prevent the release of fetid odors into the room, and will also prevent the remnants of the old pipe from entering the sewer circuit.

After dismantling the old structure, you can proceed to install a new one. The sequence of these works is described above. Do you have any questions? Watch the video.

Repairing a plastic fan pipe is a simple matter. It is enough to replace the damaged area with a new one or install a special crimp repair sleeve in this place.

With cast iron pipelines, everything is much more complicated, especially when it comes to the old fund. Over time, cast iron becomes more brittle, and it is almost impossible to disassemble a battered cast-iron joint without damage. Better to do a complete replacement.

Fan pipe alternative

Some alternative to the fan line are special devices - aerators. In their people.

In order for the drainage system to work properly, without causing inconvenience in the form of unpleasant odors, plumbing fixtures are equipped with siphons, and the sewage system itself is equipped with a fan pipe. In small houses, this design can be dispensed with, but sometimes it is still necessary. It is not difficult to equip a fan pipe, but you need to take into account all the requirements for it and the subtleties of installation.

This is a fairly simple device - a separate, usually straight, branch of a sewer pipeline, brought vertically up to the street and connecting the sewage network with the atmosphere.

In cottages with bathrooms on several floors, the fan pipe is a continuation of the riser, brought out above the roof. In houses where the drainage system is located on one floor and does not have a riser, the fan pipe is led out from one side of the transition node connecting the internal network with the external one, or from the place where the largest number of branches are connected to the main.

Note! The ideal shape of the fan pipe is a vertical straight line, but when installed inside the house, this vertical will have to cross the floors and roof, which is not always feasible. To simplify installation work, it is necessary to change the shape of the structure: bring the turn to 90 degrees with the help of 2-3 fittings-bends when passing through the wall and again direct the pipe up.

The purpose of the fan pipe

The fan pipe is used to ventilate the sewer network, that is, to remove the gases formed in the pipeline and supply fresh air if necessary.

When moving and mixing sewage discharged into the sewage system, a variety of volatile substances are released that have an unpleasant odor, in addition, they are hazardous to health.

Installation of sewer ventilation solves the problem of gas removal, preventing gases from accumulating in the pipeline.

Note! There is another, more important purpose of the fan pipe - maintaining the pressure balance in the drainage system.

When flushing water from a bathtub, a pool, or using several sinks and a toilet at the same time, residents simultaneously pass a large volume of liquid through the pipeline. In this case, the volume of air in the system is critically small and a rarefaction occurs - a decrease in pressure in the network.