What pipe to choose for the chimney: regulatory guidelines and rules

Installation of a stove or fireplace involves the installation of a smoke removal system. In this matter it is not enough to choose the right pipes for the chimney, it is also necessary to observe a lot of construction and fire prevention rules. Otherwise, the operation of heating equipment will be ineffective and unsafe.

Errors made during installation of the chimney not only reduce the return on the operation of the firebox, but can also lead to tragedy.

Regulatory requirements for the installation of chimneys

The main and only purpose of the chimney is the removal of exhaust gases from the heating boiler into the atmosphere outside the building where the stove, boiler or fireplace is installed. At the same time, the efficiency of the heat-generating equipment directly depends on its proper installation.

You can put the boiler in the house with excellent efficiency, but to prevent miscalculations when installing the chimney. As a result, excessive fuel consumption and lack of comfortable air temperatures in the rooms. The chimney must be correctly selected section, location, configuration and height.

Image Gallery

A photo of

The brick chimney is a classic of the furnace business, but a modern chimney can also be made of other materials.

The traditional brick channel can be supplemented with a steel sleeve that reduces the aerodynamic drag in the pipe.

In the arrangement of cabins and outbuildings, asbestos-cement pipes, which are not distinguished by aesthetic advantages and durability, are still often used.

The ceramic chimney assembled from modular elements is much more attractive externally, is steady against wear and atmospheric actions.

Along with building ceramics, galvanized sheet steel is used in the construction of chimney pipes, which is joined by folded seams.

Significantly facilitate and simplify the process of the device chimney finished parts of circular cross section, made of stainless steel

Pipes made of ordinary galvanized steel are not inferior to stainless steel products in terms of durability, but lose on decorative indicators

One of the most common options for the construction of a metal chimney is constructed according to the pipe-in-pipe scheme, between which there is a heater

Brick chimney

Brick chimney with steel sleeve

Asbestos cement chimney

Ceramic block chimney

Metal pipes of rectangular section

Pipes from stainless steel factory production

Chimney made of galvanized steel

Metal chimney type sandwich with insulation

If there are two boilers in the house or a stove and a fireplace in different rooms, then it is better to make separate smoke pipes for each of them. The variant with one chimney is permitted by SNiPs, but only a professional stove can correctly calculate it.

The diameter of the chimney is selected depending on the used heating equipment. When installing the boiler, it is already set by the manufacturer by the branch pipe. It is forbidden to connect pipes of smaller section to it, and more is simply not necessary. In the second case, to increase the thrust will have to mount the gearbox, which costs a lot of money.

In the case of a stove, fireplace or Russian brick stove, everything is somewhat more complicated. It will have to do engineering calculations taking into account the fuel used and the size of the furnace. It is much easier to take the finished project of a similar furnace, time-tested. Fortunately, there are many options with a well-defined order of brickwork.

The height of the chimney pipe elevation above the roof is determined by its distance from the roof ridge (+)

The higher and longer the chimney, the stronger the thrust. However, this can lead to overheating and destruction of its walls. Plus, a strong increase in thrust is a prerequisite for the onset of turbulence in the chimney, which is accompanied by hum and low-frequency noise.

With a pipe that is too low, the ridge can become an insurmountable obstacle to the smoke coming out of it. As a result, there will be a reverse thrust effect with the overturning of flue gases back into the furnace.

During normal operation of the chimney, horizontal wind flow, turning over the pipe section above the roof, turns upwards. As a result, discharged air is formed above it, which literally “sucks” smoke out of the outlet. However, this process can be hampered by a ridge-roof ridge and even a tall tree in close proximity to the house.

General requirements for the installation of smoke exhaust systems

Building codes require chimney to do as follows:

1. Its length from the grate to the top point should be from 5 meters (the exception is possible only for buildings without attics and only in conditions of stable forced traction).
2. Taking into account all possible bends, a height of 5–6 m is considered optimal.
3. The distance from the metal chimney to the structures of combustible building materials should be from a meter.
4. The horizontal tap immediately behind the boiler should not exceed 1 m.
5. With the passage of roofing, walls and ceilings inside the house should be equipped with a channel of non-combustible materials.
6. To connect the metal elements of the pipe sealant should be used exclusively heat-resistant with a working temperature of 10000C.
7. Above a flat roof chimney should rise at least 50 cm.
8. If a non-brick chimney is constructed above the roof level by 1.5 meters or more, then it must be strengthened with the help of stretch marks and braces.

Any slopes and horizontal sections inevitably reduce the draft in the chimney pipe. If you do not make it straight, then the bends and displacements are best performed from several inclined segments at a total angle of up to 45 degrees.

In addition to compliance with purely building rules guaranteeing high efficiency of the chimney and furnace it is also necessary to take care of fire safety, for which special digits are made and screens (+)

When arranging ventilation and chimney shafts in parallel in the same construction above the roof, in no case should they be covered with a common cap. The exhaust from the furnace must necessarily rise above the ventilation pipe, otherwise the draft will decrease and the smoke will begin to suck back into the house. The same applies to the individual, but nearby located hoods and chimneys.

The choice of chimney material

The laying of the chimney in a private residential building can be done in several ways:

1. With a passage through the attic and roof.
2. With the conclusion of the external walls and exclusively inside the building.
3. With the passage only through the roof, bypassing the interfloor overlappings.
4. With a support directly on a copper or the furnace or with fastening to walls.
5. With offset vertical axis and in a strictly straightforward design.

The choice of the final configuration depends on the layout of living rooms, the location of the heating unit, as well as the individual features of the structure and architecture of the cottage. In each case, it is recommended to select your own version of the chimney. It remains only to figure out which pipe to choose for the chimney, which material is best suited for this.

The riser of the chimney can be laid in the external and internal walls of the house, behind the facade and pass through the living rooms (+)

You can make a chimney out of:

• bricks;
• iron or asbestos pipes;
• ceramics;
• concrete;
• heat resistant glass.

The section can be either round, square or rectangular. And it is the first of them that is the most optimal. Of all the materials for self-assembly only with heat-resistant glass problems may arise. Its installation will require a device of a special supporting structure, competently and with a guarantee that only a specialist can assemble.

Option # 1: Traditional brick

Chimneys of baked bricks are made not for the first century. These are traditional and well-studied designs for the discharge of flue gases by professional stoppers. But they have to be done simultaneously with the construction of the dwelling, for heavy brickwork it is necessary to pour a separate foundation.

The brick for the chimney of gas equipment should be taken exclusively corpulent and well burned, the porous analogue is capable of passing a gas dangerous to humans.

Among the advantages of a brick pipe are high fire safety, attractive appearance, design knowledge and additional heat transfer from the masonry. And among the shortcomings - the high cost of the work, a lot of weight and the need for the device foundation, as well as strong roughness of the walls.

In general, brickwork is a reliable and efficient way of organizing a chimney. And the existing drawbacks can be easily circumvented by a banal installation inside a stainless steel pipe shaft. The steel liner will prevent clogging with soot and will take over part of the heat load, thereby protecting the brick and extending its service life.

Brick chimneys are constructed primarily by using solid fuels. They are satisfied with mounted ones, i.e. installed on the stove floor, rooted in the form of a separately constructed vertical outlet, and wall-mounted - located inside the bearing wall. When using a metal liner with a round cross-section, inserted inside a brick chimney, it can serve as a chimney of gas heating and cooking units.

Image Gallery

A photo of

Optimal for the movement of flue gases in the form of a brick channel is considered a square in cross section. Brick for masonry should be without chips and cracks

Significantly greater resistance differs rectangular. Both of them are inferior to round tubes, which is why they are often supplemented with metal or asbestos cement sleeves.

The brick chimney is usually located as close as possible to the ridge edge of the roof. The location in the center of the building allows you to heat the rooms with one unit all the rooms

A pipe installed separately from the furnace on a separate or common foundation with the furnace is called a root. In the lower part of it arrange a hole for cleaning.

The chimney installed on the stove, i.e. the reinforced concrete slab laid on top of the walls, and which is essentially its continuation, is called mounted

Chimney channels built in the wall, called the wall. They are arranged mainly in walls located inside the building, but when performing insulation, they can be constructed in outdoor

If the walls are composed of gas-silicate blocks, silicate or slotted bricks, then the chimney device sections are laid out with solid red brick.

To remove flue gases, each unit must be equipped with its own pipe. The combined laying of the separated ventilating and chimneys in one brick mine is allowed

The optimal shape of a brick chimney

Rectangular cross-section chimney

Priority pipe location

Root brick chimney

Specificity of the device mounted brick chimney

Wall smoke channels in the supporting structure

Laying a smoke channel with clay bricks

Ventilation and smoke ducts in the same shaft

Option # 2: Galvanized and stainless steel

Galvanization and stainless steel are resistant to corrosion and corrosive environment resulting from the combination of condensate and furnace gases. They are lightweight and do not need additional foundation; for mounting, reliable fasteners to the wall will suffice.

On sale chimney steel can be found:

1. Single wall - without insulation material.
2. Double-walled sandwiches with insulation between steel walls.

When installing a steel chimney outside the facade, it must be insulated, otherwise heat loss and abundant condensate will negate all the advantages of this option. Thermal insulation is used on chimney sections extending beyond the roof and passing through an unheated attic.

At the cost of components, a chimney made of stainless or galvanized steel will be cheaper than brick and ceramic counterparts.

Steel chimney is a designer from a set of elements that can be assembled in various ways and in a different configuration (+)

The flue channel is collected from:

• rain cap;
• tees;
• knees;
• inserts with inspection hatches;
• straight pipes;
• condensate collectors.

All this should just be mounted together by inserting one section into another and missed the joints with a heat-resistant sealant. Such chimneys are suitable for almost all types of furnaces and fuel. Galvanized and stainless steel withstand high temperatures and soot effects for decades without problems.

Smooth surface of steel walls optimizes the removal of combustion products, eliminates the accumulation of soot. Exhaust pipes made of steel pipes are suitable for gas, liquid and solid fuel stoves. Metal modules are used for the construction of a chimney fully or partially with its connection to a brick channel or installation in the form of an insert.

Image Gallery

A photo of

For the construction of a metal chimney pipe produced a full set of parts, allowing for quick installation

Round chimneys are optimally suited for removal of combustion products from gas processing units. Because they have no soot corners.

Metal smoke channels are arranged in a mounted arrangement, as the most acceptable in terms of safe operation.

The design of a metal chimney should, if possible, avoid corners. Assume a slope of 60 ° to the horizon, the length of the inclined section is not more than 1 m

Passages of metal pipe through building structures are equipped with insulating boxes like sandboxes, closed with non-combustible materials

The passage of a metal chimney through the supporting wall is insulated with non-combustible insulation and covered with a metal sheet.

When building a chimney from the outside of the building, a sandwich system is used.

Modular elements manufactured for the assembly of sandwich chimneys, provide an opportunity to build a chimney of any complexity and length

Modular parts for chimney assembly

The advantages of the round section of the chimney

Specific installation of metal pipes

Allowable flue slope

Crossing roofs and floors

Chimney passage through the bearing wall

Elements for assembling a chimney sandwich

Installation of external chimney pipes

Option # 3: Cheap Asbestos Cement

Pipes made of natural asbestos with cement as a bonding material were widely used in our country during the Soviet era. They were cheap, durable and produced in large quantities. They were mainly used in agriculture for land reclamation.

Initially, asbestos-cement pipes were not intended for the installation of chimneys. They are too fragile for this and do not tolerate high temperatures. However, the issue of price in many cases plays an important role. If there is cheap material on hand, then it must be used, leveling the problem areas in one way or another.

Asbestos cement at temperatures above 300 ° C can catch fire, therefore pipes from it are allowed to be installed only on the final section of the chimney and in no case immediately by the furnace

Asbestos pipes have another problem - the roughness of the walls from the inside. Gradually, they accumulate soot, which can ignite and simply explode. Plus, with continuous formation of condensate from a mixture of vapors and oxides of combustion inside the asbestos cement begins to break down.

This material is cheap, but using it for arranging chimneys involves a great risk. Such pipes should be cleaned more often. However, it is impossible to make a revision hole in them, it will have to be provided in the area from the furnace to asbestos cement.

Smoke ducts of asbestos-cement pipes are carried out mainly in the mounted version. The priority is the simplest scheme of the device and the vertical arrangement of all elements. If necessary, to make a bias apply nozzles of non-combustible materials.

Option # 4: Exotic ceramics and concrete

Ceramic chimneys have unsurpassed durability and high price. They are not afraid of overheating, aggressiveness of soot and corrosion. These pipes have very smooth walls, soot on which does not even linger.

When installing pipes made of ceramics are collected in the same way as steel. Only around them is formed a box of expanded clay. Such chimneys practically do not heat up. Even that small part of the heat that is given to inert ceramics is absorbed by expanded clay concrete walls. The fire in the house due to the burning of such a chimney is nonsense.

Modular chimneys made of ceramic pipes are reliable and durable, but they are practically not produced in Russia, so they have a rather high cost (+)

The chimney construction of ceramics and expanded clay concrete weighs much less than the brickwork of a similar purpose. But even in this case, it is necessary to make a separate small foundation for it.

An even more massive monolithic foundation will have to be made for a concrete chimney. This variant of smoke discharge is rarely used precisely because of the complexity and laboriousness of manufacturing the structure. It will be necessary to install the formwork, and after waiting for the concrete solution to solidify.

Image Gallery

A photo of

Ceramic chimney is constructed according to the pipe-in-pipe. Gas silicate blocks are located outside, inside a layer of insulation and heat-resistant ceramic elements

The protective gas-silicate casing of the ceramic sandwich system can be produced with an additional channel for organizing the ventilation riser

Ceramic elements mainly collect radical chimneys for boilers and stoves, mounted in the case of arranging fireplaces

The principle of a sandwich chimney allows arranging external chimneys of ceramic elements without additional insulation

Ceramic Chimney Sandwich

Protective cover for the smoke and ventkanal

Type of chimneys being built

Ceramic pipe on the facade

Common mistakes beginners and self-taught

In the first place among the misstep - the wrong height of the chimney. Too high an option creates excessive craving for the likelihood of tipping over by pulling smoke back into the firebox and the room with the stove. 5–6 meters are considered optimal, but much depends on the size of the combustion chamber and the configuration of the chimney.

A constant flow of air into the furnace is a mandatory guarantee of good traction in the chimney, so it is important to equip quality ventilation in a room with a fireplace or stove (+)

It is not allowed to overcool the chimney and to overheat it too much as a result of intense burning of fuel in the firebox. Everything should be in moderation, otherwise the pipe may crack. To facilitate the identification of these cracks, you should whitewash the chimney section in the attic. On a white background, all soot soils will be noticeable.

Often, newcomers when installing a steel chimney forget to ensure the removal of condensate. To do this, you need to make a special collection and insert hatches for the audit into the pipe. Errors are made in the choice of steel grade.

With the usual burning of wood, gas or coal in a fireplace or heating boiler, the chimney heats up to 500-6000С. However, the temperature of the smoke, albeit briefly, can rise to 10000С. At the same time after a few meters from the furnace, they cool down to 200-300 degrees and do not pose a threat to the pipe.

But its initial meter section from the boiler has time to heat up very strongly. Steel must be heat resistant and able to withstand these loads. And the steel pipe should be insulated only a couple of meters from the firebox to prevent overheating of this chimney segment.

To improve fire safety, passages through ceilings and walls are made through special non-combustible inserts, direct contact of hot pipes and flammable building materials is unacceptable

When brick laying by an inexperienced craftsman, vertical rows of their rows are often allowed to move relative to each other. When building walls, this is allowed, but in the case of the chimney it is absolutely unacceptable. This greatly reduces the effectiveness of the chimney channel, as it begins to form turbulence and soot precipitation on the walls.

The foundation under the brick chimney must be super-reliable, otherwise the pipe may be moved to the side with its subsequent partial or complete destruction. And if the smoke is diverted to a gas boiler, then it is better to exclude a brick. It quickly collapses under the influence of the alkaline environment formed during the combustion of natural gas.

Useful video on the topic

What mistakes are most often made when installing furnaces and chimneys to them:

How to put brick chimney pipes:

How to make a stainless steel chimney:

Reliable chimney pipes can be made of various building materials. The choice of options is quite extensive. The easiest way to do the chimney out of steel, and cheaper than brick. But if you need the most durable and safe system for removing furnace fumes, then the undisputed leader here is ceramics. It is expensive, but will last more than one decade. The main thing when installing all the options to comply with construction and fire regulations.