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DIY brick chimney for a metal stove. How to build a brick chimney. Advantages and disadvantages of brick construction

A chimney for a stove can be built with your own hands if a diagram of its laying is at hand, and the House master has at least minimal skills in working as a mason. The construction of this department requires an approach no less serious than that of a building, since the efficiency of heating, the safety of those living in the house, and the overall service life of the entire heating structure will depend on the quality of its masonry.

When working on a chimney, you must remember that its internal surfaces must be as neat and smooth as the external ones, since this factor directly affects the creation of good draft.

Types of brick chimney pipes

Chimney pipes are divided into types depending on their installation location relative to the stove itself. So, they are root, mounted and wall.

• The most common design of a brick chimney pipe is a top-mounted one. It is installed directly on top of the heating device and is its continuation. Such chimneys are often installed during the construction of a heating or sauna stove.

• The second most popular is the root chimney. This type of pipe is distinguished by the fact that it is installed next to the furnace or is included in its structure and is placed on one of its sides.

Main pipes can be installed for both brick and cast iron stoves. In addition, one main structure is often used for several heating devices. For example, in a two or three-story house, one chimney is passed through all floors and stoves are connected to it. If you plan to use a pipe in this way, then in this case, an accurate calculation of its parameters must be made, otherwise there will be no normal draft, which means that the efficiency of the stoves will decrease and the risk of combustion products entering the premises will increase.

• The wall pipe is built into capital internal or external walls. But, in the latter case, the walls of the chimney will have to be very well insulated, since due to the large difference in external and internal temperatures, condensation will actively collect inside the channel, which will significantly worsen the operation of the stove, reducing draft and contributing to the rapid overgrowing of the chimney with soot.

It should be noted that although this construction is highlighted a separate species, it can be either root or mounted.

Brick chimney design

The chimney has several sections. To understand its fundamental design, we can take as an example the structure of the mounted pipe, since most often this is what design engineers choose when drawing up furnace layout diagrams.

So, the design of the mounted pipe with its passage through attic floor and rafter system, includes the following departments and elements:

1 – Metal cap or umbrella. It may take many forms, but its function is always to protect internal space chimney from penetration of precipitation various types, as well as dust and dirt.

2 – The head of the pipe consists of bricks protruding outward, which will protect the neck of the structure from raindrops that will flow down the protective cap. The metal umbrella is also attached to the protruding parts of the head.

3 – Pipe neck.

4 – A cemented or otherwise waterproofed inclined surface of the otter, designed to drain water that gets onto the neck of the pipe.

5 – Otter. This part of the structure has thicker walls than the pipe neck. The otter should be located where the chimney passes through the rafter system and roof. The thick walls of the otter will protect the flammable materials of the sheathing under the roof from overheating.

6 – Roofing material.

7 – Lathing of the rafter system.

8 – Rafters.

9 – Pipe riser. This department is located in the attic of the house.

10 – Fluff. This part of the chimney begins under the ceiling inside the house, passes through the attic floor and ends in the attic, slightly above or flush with the floor beams. The fluff, like the otter, has thicker walls than the neck and riser of the pipe. Increased thickness also protects against overheating wooden beams and other combustible attic or interfloor covering.

It should be noted that in some cases, instead of fluff, a metal box is installed in its place around the pipe, filled with non-combustible materials, such as sand, vermiculite or expanded clay. The function of this layer, which has a thickness of 100÷150 mm, is also to protect combustible floor materials from overheating.

11 – Floor beams.

12 - Insulation, which is most often made from asbestos, is in any case necessary to create fire safety, since the walls of the chimney will come into contact with the wood of the floor beams and other materials that make up the floor and ceiling.

13 – Smoke damper, located indoors, in the upper part of the pipe, which allows you to regulate the intensity of the exhaust flows of heated air and combustion products.

14 – Pipe neck, which starts at the top of the furnace - the roof.

Calculations of chimney pipe parameters

The principle of operation of the chimney system is the movement of air masses from the combustion chamber to the exit to the street, that is, from the lower point to the upper. This process occurs through the creation of draft, which occurs due to changes in temperature and pressure. It is thanks to all these factors that normal functioning chimney system.

To create optimal aerodynamic processes, the size of the pipe channel must correspond to the power of the furnace, which, in turn, largely depends on the size of the firebox. The surfaces of the internal chimney space must have smooth walls along which air flows will slide freely without turbulence, and due to this no backdraft will be created. That is why quite often an insert made of a round ceramic pipe is built into a square brick chimney, which has absolutely smooth surface and having no internal corners.

Sectional size

In connection with the mentioned factors, it is necessary to very carefully calculate the internal size of the chimney, taking into account its length, since the larger this parameter, the higher the draft in the pipe.

Of great importance for creating normal draft and high-quality functioning of the heating device is the correspondence of the parameters of the chimney passage and power, as well as the size and number of channels provided for by the design and passing inside the stove.

If the parameters internal dimensions chimney cross-section will exceed the calculated value, this will lead to rapid cooling of the heated air in it and the formation of condensation, and hence a decrease in draft. In this case, the necessary balance will be disrupted, and the flows cooling in the upper part of the pipe may return down, creating smoke in the room.

The size of the chimney opening is calculated as follows:

• The size of the chimney of a fireplace with an open firebox approximately corresponds to the proportions of 1:10 (chimney cross-section (f) / firebox window area (F)). This formula generally applies to both square or rectangular and cylindrical pipe types, but not directly, but taking into account the cross-sectional shape of the channel and the overall height of the chimney.
• The size of the chimney of a stove with a closed combustion chamber has a proportion of 1:1.5. In the case when the heat transfer of a heating structure is less than 300 kcal/hour, the cross-section usually has a size of 130×130 mm or half a brick (not less). When making calculations, it must be taken into account that the cross-sectional size of the chimney should not be smaller than the inlet opening of the ash-blower.

When calculating a fireplace chimney, you can use the following table.

Pipe height N, m		5	6	7	8	9	10	11
		f/f ratio in %
Pipe section	Round	11.2	10.5	10	9.5	9.1	8.7	8.9
	Square	12.4	11.6	11	10.5	10.1	9.7	9.4
	Rectangular	13.2	12.3	11.7	11.2	10.6	10.2	9.8

Pay attention to the direct dependence of the chimney cross-section not only on the parameters of the firebox, but also on the height of the pipe. Probably, sometimes when making calculations it will be more expedient to start from this parameter. For example, a pipe 11 meters high on a one-story country house would look completely ridiculous.

The same dependence, but more accurately presented in graph form.

Let's say you need to calculate the cross-section of a chimney pipe for a fireplace with a firebox, the window dimensions of which are 500×700 mm, that is, the total area – 0.35 m². It is assumed that a pipe with a total height of 7 meters.

• Let's look at the graphical diagram:

- for a round chimney cross-section, the optimal ratio is f/f = 9.9%;

- for square - 11,1% ;

- for rectangular - 11,7% .

• It is easy to calculate the optimal cross-sectional area of ​​the chimney channel:

- circle: 0.35×0.099 = 0.0346 m²;

- square: 0.35 × 0.11 = 0.0385 m²;

- rectangle: 0.35 × 0.117 = 0.041 m².

• Now, using the simplest geometric formulas, it is easy to reduce the areas to linear dimensions:

- diameter round pipe: d = 2×√S/π = 2×√0.0346/3.14 ≈ 0.209 m = 210 mm.

- side of a square pipe: a = √S = √0.0385 ≈ 0.196 m = 196 mm.

- a rectangle can have different options - for example 0.130 × 0.315 m or 130 × 315 mm.

The calculation will be much simpler if you use the calculator below, which already contains all the mentioned dependencies.

Having decided to build a brick chimney with your own hands, you will follow the path of nameless craftsmen who laid stoves one and a half and two hundred years ago.

Therefore, there is no need to “reinvent the wheel” if you can take advantage of their experience.

How to make a chimney according to all the rules will be discussed further in our new article.

Despite the fact that the metal pipe is no longer exotic, chimneys continue to be laid from brick. In some ways this looks like an anachronism, but there are good reasons why you should not abandon the classic technology of laying smoke exhaust ducts.

The main one is that brick has high thermal inertia. Exhaust hot gases heat it slightly, which significantly reduces the fire hazard heating device. We must not forget about another aspect - the temperature of the smoke at the upper end of the pipe should not fall below 60–70 degrees. Otherwise, condensation will flow through it. The brick acts as the shell of a thermos and prevents the smoke from cooling down too much.

But there are two fatal drawbacks:

1. Difficulty of masonry.

The pipe with all the elements, depending on the height of the attic, takes from 400 to 800 pieces of bricks weighing 3.8 kilograms.

A column with a base area of ​​no more than 0.25 square meters. meters, its entire mass presses on the stove. This is a concentrated load. If overall height If the pipe exceeds 5 meters, it is placed on a separate base and connected to the heating device with an adapter pipe.

Brick chimney as an engineering structure

A chimney, for all its outward unpretentiousness, is a complex engineering structure, which has serious requirements. They relate to strength, fire safety, and the ability to effectively remove hot gases. Therefore, the installation of a chimney in a wooden house should begin with familiarization with its structure.

Essential elements

1. Internal chimney– is carried out from the roof of the furnace to the level below ceiling on four rows of brickwork.
2. Cutting (fluff)– expansion of the thickness of the pipe walls as it passes through the ceiling.
3. External chimney– is carried out through attic space up to the roof level.
4. Otter- another expansion of the thickness of the chimney walls, arranged to bridge the gap between it, the roof sheathing and its covering.
5. Neck– continuation of the external chimney.
6. Heading– thickening of the walls, which plays the role of a deflector.

Requirements for a brick chimney

The main one is the distance “from smoke” to combustible structures. It is equal to 250 mm - this is the full length of the ceramic solid brick.

The second requirement is strict verticality of the structure. Deviation from it by more than 3 degrees (per one meter of height) is not allowed. Also, there should be no through cracks in the brickwork.

Chimney calculation

The main criterion is the internal section. The ability to remove hot gases mainly depends on it. The more powerful the stove, the wider the chimney should be. There are three standard sizes used for one or another type of heating device.

1. “Four” - a row of which is formed by four bricks. Section 125 by 125 mm. Is used for kitchen stoves or low-power heating stoves.
2. “Five” is a rectangular chimney formed by a row of five bricks. Section 250 by 125 mm. Used for heating and heating-cooking stoves. It is not recommended to make chimneys for fireplaces smaller than this section.
3. "Six" - square pipe, a row of six bricks. Section 250 by 250 mm. It is used for fireplaces and Russian stoves - wherever minimal resistance to the movement of hot gases is required.

The second most important criterion in the calculation is height. It depends on the location of its output on the roof relative to the ridge:

1. Pipes installed on the ridge or at a distance of no more than 1.5 meters from it rise 0.5 meters above the roof.
2. Chimneys passing through the roof at a distance of one and a half to three meters to the ridge are made equal in height to it.
3. If the distance is more than three meters, then the angle between the ridge and the upper cut of the pipe should be 10 degrees.

Chimney laying

There is no fundamental difference between the laying of the solid furnace and chimneys. It is carried out on clay-sand mortar using the same tools - a furnace hammer-pick, trowel and plumb line. However, elements such as fluff and otter are laid out using a large number of brick parts measuring 1/8, 1/4, 1/2 and 3/4 of the whole.

To avoid chopping and cleaving, which are accompanied by clouds of brick dust and rarely give the desired result, it is worth using a grinder with a diamond wheel for ceramics.

This guarantees the accuracy of the work, eliminates tedious work and a lot of useless brickwork.

Solution

For masonry up to the roof level, a mixture of sand and clay is used, since it has a coefficient of linear expansion similar to brick, which is a certain guarantee against the appearance of cracks.

Pure clay used as a binder can be either oily or lean. In some places there are deposits where the proportional ratio of the amount of clay to sand is optimal by nature: one to three or four.

When the volumetric part of the clay increases, the solution cracks after drying, and when it decreases, it crumbles. To determine the optimal ratio of volumetric parts, you need to knead the finished solution in your fingers. It should not be noticeably slippery or rough like sandpaper.

The sand taken from the floodplains of streams and rivers is very fine and dusty. It is not suitable for masonry. It is better to use one that consists of grains of 0.8–1 mm. It feels rough to the touch.

Clay and sand are mixed in volumetric parts in a ratio of one to three or four. Water is added gradually, in small portions. The finished solution should leave marks on the trowel (but not stick to it) and should not drain from it.

To avoid errors in proportions, it is better to buy a ready-made dry clay-sand masonry mixture. Please note that those marked “fireproof” are not suitable for masonry.

Brick

Red solid burnt brick is used.

Its edges should be smooth, without cracks, and the sound produced when it is lightly struck with a furnace hammer should be clear.

The standard size used for masonry is length 250, width 125 and height 75 mm.

Laying the internal chimney

It begins immediately after the damper is installed and the furnace roof is completed. The masonry techniques are the same - applying a layer of mortar, laying the brick, “shaking” it with your hand and lightly tapping it with a pick. Verticality and horizontality are checked after laying each row. They finish it four brick heights before the ceiling.

Fluff laying

The expansion of the thickness of the chimney walls is carried out to comply with the requirement that combustible structures be located at a distance of 250 mm “from the smoke”. The usual thickness of the chimney walls is 125 mm. To double it, you need to fold four rows, each of which moves outward by 1/8 of the width of the brick relative to the bottom one - just the amount that allows the brick to lie without leaning over. The principle of masonry for all three sizes is the same:

1. The inner surface (toward the smoke) of the first row is laid out in 1/8 sections. The gaps between the outer bricks are filled in 1/4 sections.
2. In the second row, the parts increase, respectively, to 1/4 and 1/2.
3. The third row uses 1/2 and 3/4 pieces.
4. The outer belt of the fourth row of fluff is laid out with whole bricks.

Having reached the ceiling, it is placed, observing the dressing of the seams, another two or three rows higher. A gap of 2–3 cm is left between the ceiling and it to eliminate pressure from the structure on the masonry. It is covered with mineral wool slabs. Laying up to the roof is carried out in the usual manner - with bandaging of vertical seams and control of verticality.

Otter clutch

It begins after the edge of the chimney brick has risen above the roof. It is carried out outside, in compliance with all safety measures when working at height. Can be used cement mortar. They start it from the edge that is lower along the slope. The distance from the smoke on each row is equal to 1/8 of the width of the brick. There should be a total of six rows in the otter. After it they put a neck - the usual continuation of the chimney. The gaps between the roof and the chimney are covered with a “collar” made of sheet roofing steel.

Head masonry

This is a chimney deflector that prevents smoke from clogging into the chimney due to air turbulence.

It is laid out in two rows, moving the first from the smoke by 1/8 of the brick, and the second by 1/2.

Its protrusions can be used to hook the clamps of the metal cap, which prevents precipitation from entering the pipe.

How much will it cost

Over the course of three centuries, the brick chimney on the roof has become a visual constant. And a building with such a finish looks, according to subjective assessments, much more attractive.

All that remains is to determine how much compliance with the canons will cost you. If you involve third-party craftsmen, the cost of the work will also be added to the cost of the brick. And she's quite big. In St. Petersburg and the region, for example, laying one brick will cost from 50 to 90 rubles.

Solid single brick grade M 150, which is used for laying stoves, costs from 15 to 20 rubles per piece.

The solution, if you prepare it yourself, is free.

Five kilograms of ready-made masonry mixture cost 60-70 rubles. One package is enough for 10-15 rows of pipes with a cross-section of 125 by 250 mm (sixes).

Let's compare the cost of a meter metal sandwich pipe with a diameter of 250 mm and brick, having a cross-section of 250 by 250 mm. Just the kind that can be used to construct fireplace chimneys.

As you can see, the prices are almost the same. Of course, it’s worth adding the cost of laying the fluff, the otter and the head. But, given the better performance characteristics of brick pipes - lack of corrosion, greater heat resistance, it makes sense to spend money on such a purchase. And if you are planning to lay a brick chimney with your own hands, it will cost almost half the price of metal sandwich pipes.

Secrets of stove-makers' mastery

1. Before laying, the brick must be soaked - lowered into water and wait until the violent eruption of air bubbles stops. Wet ceramic blocks adhere more firmly to the solution.
2. To split and chisel bricks, use a grinder with a diamond disc for stone.
3. When laying in the attic, hang a plumb line on the rafters, between the future pipe and the workplace. This will save you from having to touch it to check. To control the verticality of the angle, it is enough to change the position of the head.

Do not forget that a chimney in a private house is not only convenience, but also technical device, requiring correct operation and care. Clean it from soot, inspect it for cracks, heat the stove or fireplace with dry wood and it will serve well for many years.

Proper construction of a chimney is a process as serious as the construction of the stove itself.

The extent to which this work is carried out correctly and accurately, the owner will protect his home and household members from fire or carbon monoxide poisoning. Therefore, the construction of this element must be taken very seriously and everything must be done as correctly as possible and according to the instructions. You can build brick chimneys with your own hands if you have experience in this work, but if it is unfamiliar, it is better to entrust it to a professional. If you are not confident in your abilities, it is better not to start.

Chimney pipes made of brick can be of two types: root and mounted. In each case, one of them is selected for construction, the one that is suitable for a particular furnace.

• Main chimneys differ from mounted chimneys in that they are not built as a continuation of the stove structure, but autonomously, next to the place where the stove will be installed, and then connected to it with a pipe.

This chimney structure is suitable for cast iron and brick heating devices, and even two or three stoves can be connected to one main chimney. Naturally, in this case, its internal cross-section must correspond necessary parameters for a certain number of heating devices connected to it.

If a main chimney is installed, to which a pipe will be connected from cast iron stove or a gas-fired boiler, you may need to install a metal pipe inside the chimney duct.

The main chimney is installed on a foundation separate from the common building and stove. The depth of the foundation pit should be at least 30-50 centimeters, depending on the height and width of the chimney, and its perimeter should be 12-15 centimeters larger than the base of the chimney structure.

• The chimney pipe is a continuation of the stove design and is an integral part of it. Such a pipe is intended to remove combustion waste only for one furnace, of which it is a continuation.

Components of a chimney

The principle of construction of both types of chimneys is the same, but if two or three stoves are connected to the main pipe, it may have several risers and several cuts, the number of which will depend on the number of floors of the house.

In this figure you can see all parts of the chimney structure, which consists of the following elements and sections:

• The stove neck is the part of the chimney that runs from the stove to the butcher. A smoke valve is located in it, which will regulate the draft necessary for the intensity of combustion or smoldering of the fuel.
• Pipe cutting or fluffing is arranged at the pipe passage of each floor, and is intended to protect combustible floors from high temperatures. It has thicker walls compared to other parts of the smoke exhaust duct. Its thickness should be at least 35-40 centimeters, thus creating an insulation of 20-25 centimeters around the entire perimeter.
• The pipe riser is brick pillar with a smoke exhaust duct inside. It is located both before cutting and in the attic floor.
• Otter - this part is located immediately above the roof and protects the pipe from moisture - rain, snow, condensation, etc.
• The neck of the trumpet rises immediately above the otter.
• The otter having a platform, a neck and a protruding cap together make up the head of the pipe.
• A cap or umbrella is attached to the top of the cap to prevent it from getting inside the channel. various contaminants and moisture. This device is also capable of creating normal draft in the chimney channel.

Chimney laying

Scheme

The first thing you need to do is to carefully read the chimney diagram and understand how each of its rows is laid. You can choose one of many diagrams - preferably the one on which everything will be extremely clear. When laying a regular brick stove, the order for a standard brick chimney is suitable.

Construction of the superstructure

When installing the top pipe, the laying of the furnace structure itself ends 50-60 centimeters before the ceiling, and then the direct construction of the chimney duct begins. This diagram shows two options for laying a chimney: square and rectangular.

• According to the scheme of the first row, the neck of the chimney is erected before cutting. In each subsequent row, the bricks are laid in such a way that the middle of the brick overlaps the seam between the bricks of the previous row.

Having laid out three or four rows according to this pattern of the first row, the removal of the fluff of the pipe begins.

This is what the fluff looks like...

• The figure of the second row clearly shows that the bricks are laid with a shift to the outer side by one third of the brick. For a perfect fit piece material, you will have to use the division of a solid brick into two or three parts along or across.

... and this is her order

With all this, you need to remember that the chimney channel must maintain its original cross-section, since the point of thickening its walls is to increase the safety of the closure during operation. Moreover, the narrowing or expansion of the internal cavity can negatively affect draft during combustion.

• The third, fourth and fifth rows of fluff are also laid out with a shift of outside, maintaining the lumen of the canal.
• The sixth row is the same size as the fifth row and is laid out flush with the outer and inner edges of the smoke channel wall.
• The seventh and eighth rows are laid out according to the pattern of the first row.

Having finished laying the fluff, you can move on to working on the otter, and here you need to try very hard, since each row forms another step and protrudes outward, by one third.

• The first row is laid the same size as the last row of fluff.
• From the second row they begin to lay out the first step, and the chimney expands to the outside.
• Next, following the diagram, the remaining eight rows are laid out.

After completing the laying of the otter, the neck of the pipe is laid out, which is laid out according to the scheme of the first row to the top two rows of the cap, where the brick is also laid with a protrusion to the outside.

Height of pipe above ridge

The chimney pipe should rise above the roof ridge by half a meter if it is located one and a half meters from it horizontally.

If it is located lower along the slope, it is raised level with the ridge or lower no more than 10 degrees at an angle to the ridge. These parameters must be strictly observed, as they ensure the safe operation of the heating structure and have been tested by many years of experience.

Another, somewhat simplified version of the chimney

Another option for laying a chimney could be a simple straight design. It is suitable for those who have no experience in performing this type of construction.

• The entire chimney, from the stove to the head, is laid out in an even column with a channel inside, and all the elements necessary for it are made using formwork, cement mortar and reinforcement with a metal rod with a thickness of four to seven millimeters.
• In the area where the fluffing should begin, formwork is arranged, the right size and shapes.
• A metal rod or mesh is secured to the pipe.
• The formwork is coated clay mortar thin layer. It is needed so that the formwork boards can be easily removed from the hardened concrete solution.
• Then it is placed in the formwork concrete mortar and left until completely hardened.
• After the cement has hardened, the formwork is removed and all concrete parts, if necessary, are leveled to give them a neat appearance.

In this way, the complexities of masonry configurations can be circumvented. Of course, this work will take much longer, but it is impossible to make a mistake. The main thing is to arrange the formwork correctly, neatly and evenly.

Fluff insulation

Despite the thickness of the walls of the fluff, it is necessary to arrange thermal insulation around it when passing through the ceiling. It is made from asbestos, clay-impregnated felt, or a metal box is arranged, which is filled with expanded clay or sand. The fluff must be insulated over the entire thickness of the ceiling.

Waterproofing the passage

After completing the laying of the cap, you can install the umbrella and begin waterproofing the pipe passage through the roof.

Waterproofing is very important point in the chimney structure, and the durability and efficiency of its operation depend on it.

The distance created between the pipe and the roof must be covered with an apron. Most often, roofing material is used for these purposes, which is fixed to a sealant.

On top of this layer of waterproofing is an “apron”, which is made from a wall profile or from a special waterproofing tape. It is also attached to roofing material using sealant, and is fixed on the pipe with a strip designed for this purpose.

"Apron" for the chimney pipe

In order for the chimney system to work efficiently, you need to follow some recommendations that professional stove makers always take into account.

• When laying brick rows, be sure to carefully select the excess mortar that will protrude into the chimney channel. These surfaces must be very smooth so that as little soot deposits settle on them as possible.
• The binding of bricks in the brickwork of a chimney requires special attention, since in such a design a large number of not whole bricks can be used, but their halves, plates, third or fourth parts. In order to evenly cut or chip off bricks, you can use a “grinder” (grinder). If you file the desired part with it, it will be easier to separate a fragment of the required size. The plates that are needed in some rows of masonry will have to be sawed off completely, since such thin parts can simply break.
• The seams in the chimney masonry should not be too thick - their thickness can be four to five millimeters. This must be observed because the solution, even in a frozen state, is more susceptible to destruction when exposed to external factors than hardened brick.
• And, of course, a very important measure when servicing a chimney during its operation is its timely cleaning or periodic preventive maintenance to prevent clogging.

DIY video tutorial on laying a chimney

Laying a chimney is a very difficult undertaking, as it takes place at a height and requires maximum care. Therefore, you need to realistically assess your strengths and capabilities. If there are any doubts that this work can be done independently, then it is better to entrust it to an experienced craftsman.

There is not a single stove without a chimney. Removal of carbon monoxide and smoke from the firebox - necessary condition proper operation of the stove. What should the pipe be made of and how to arrange it so that it lasts for a long time and does not create additional problems? An experienced stove maker will answer without hesitation - from the same material as the stove itself. This is due to the fact that various materials the coefficient of thermal expansion is different. And if brick and metal are heated at the same time during the fire, then a gap will form at the point of their connection over time. Smoke begins to leak through the gap, this disrupts the smooth operation of the stove, and also poses a serious threat to the life and health of household members. Therefore, if you want to build a chimney for a brick stove, you must also do it from brick.

What is a brick chimney and where is it used?

Chimneys are used to remove gaseous combustion products in stoves, fireplaces and heating boilers. Smoke, carbon monoxide and soot under the influence of draft are carried out of the furnace into the pipe and discharged outside. As they move, they cool down, giving off heat to the walls of the chimney.

To remove combustion products from a brick stove, you need to build a chimney from the same material, i.e. brick

Unlike metal pipes, brick has:

But a brick chimney also has a rather significant disadvantage. IN country houses And country cottages there is no possibility to fold pipes cylindrical, which are ideal for the passage of hot gases. The internal cross-section of a square or rectangular shape creates obstacles for the flow of smoke. As a result of this, on internal walls A layer of soot quickly forms, which reduces traction. Accordingly, they have to be cleaned more often than metal ones.

Chimney pipe design and operating principle

The classic chimney design is a vertical tower, inside of which there is a through hole that connects the furnace firebox with the open space outside the house. According to the laws of physics, air pressure decreases with distance from the earth's surface. As a result, a draft arises inside the pipe - a desire air mass to movement from bottom to top. If the air access from below is blocked, the draft disappears. Therefore, a smoke damper or view must be installed in the chimney, with the help of which it is possible to regulate the draft.

Using the damper, you can regulate the size of the smoke channel, and therefore the draft

Since the pipe is operated in residential buildings, it should not pose a fire hazard, therefore the masonry is carried out taking into account maximum protection from possible fire. A certain terminology has become established among stove makers, which reflects the structure and functional purpose of individual pipe elements.

In some cases, a combined pipe design is practiced. The brickwork ends in the attic and then a metal or asbestos pipe is mounted to it, leading to the roof. In this case, there is no need for an otter, neck and head, which significantly saves time and money. At the same time, we must not forget that the area cross section the metal pipe should not differ from the cross-section of the brick pipe in a smaller direction. The combination of pipes made of of stainless steel, embedded in an asbestos pipe.

In the upper part of the chimney, where the temperature of the flue gases is not so high, you can make a transition with brick pipe to metal

In both cases, the top hole must be closed with an umbrella (or deflector), which will prevent rain and snow from directly entering the pipe.

Calculation of main pipe parameters

All calculations for the chimney must be performed at the design stage of the stove. The project must be carried out by a qualified engineer or craftsman who is well versed in all the nuances of the furnace business. It is impossible to plan the dimensions of the pipe in isolation from the dimensions of the firebox and heat exchanger. Everything is interconnected and must correspond to one goal - the coordinated operation of the furnace equipment.

If, when building a fireplace, the “body” of the stove is missing, and the firebox is directly connected to the chimney, then the Russian stove additionally has heating ducts in the walls, and it is impossible not to make allowances for this. The presence of passages changes the draft and lengthens the path of the flue gases several times. Accordingly, the chimney must create greater vacuum so that the movement of gases is accelerated and soot does not settle inside the passage. A separate topic could be the calculation of chimney parameters in sauna stove. It is important here that the draft is not excessive, and that the burning fuel has time to transfer heat inside the steam room.

The stove maker’s task includes taking into account not only internal, but also external factors - the location of the pipe in relation to the roof, the characteristics of the local climate, and even the influence of the landscape.

The chimney draft can be affected by tall buildings and trees located nearby, as well as by incorrect choice of chimney height

For gas heating systems due to their increased fire hazard calculation of the chimney parameters is carried out by specialists who develop the boiler. Dimensions are indicated in technical passport and are binding.

In private construction, where the combustion is carried out mainly with solid fuel (wood, coal, peat or fuel briquettes), you can adhere to the following rules that will ensure correct work any oven:

• internal cross-sectional area of ​​a rectangular chimney in stoves closed type should not exceed the cross-sectional area of ​​the blower;
• internal cross-sectional area of ​​pipes in furnaces open type and fireplaces is calculated in a ratio of 1:10 in relation to the firebox.

It is believed that if the chimney structure has rectangular shape, the ratio of the short side to the long side should be 1:2. In this case, the minimum permissible cross-sectional size of the channel is 14 x 14 cm.

The size of the brick chimney channel wall should not be less than 14 cm

An important factor is the height of the pipe. Correct calculation allows:

• optimize the operation of the chimney and achieve better efficiency indicators for heat transfer;
• provide safe operation heating device, eliminate the leakage of harmful gases due to weak draft;
• provide fire safety- if the draft is excessive, sparks and flames may fly out of the pipe.

IN general case height is determined in accordance with SNiP 2.04.05–91:

• the minimum distance from the grate to the top point of the chimney (excluding the protective umbrella) is 5 m;
• the optimal distance is 6 m.

Such parameters ensure stable draft, i.e. the design of the chimney allows you to create a pressure drop sufficient to operate the stove at any time of the year. But in each particular case it is also necessary to take into account:

There is such an unpleasant phenomenon as reverse thrust. This term refers to the movement of smoke in the chimney in the opposite direction - from the chimney duct into the room. There may be several reasons for this, but the main one is the incorrect position of the chimney. As a rule - underestimated.

An error in choosing the height of the chimney often leads to backdraft

Excess draft can always be eliminated by adjusting the air flow in the ash pan and smoke valves. Insufficient traction is exacerbated in several ways:

1. Pipe extension.
2. Cleaning the inner surface of the chimney duct.
3. Installing a deflector.

The deflector not only increases draft, but also protects the chimney channel from moisture, debris and birds and bats settling in it.

According to experts, by installing a deflector on a chimney you can increase draft by 15–20%

Video: how to calculate the height of the chimney

You will learn about which pipe is best to choose for a chimney, as well as the advantages and disadvantages of materials in our material:.

Making a brick chimney with your own hands

Knowing the features of chimney construction and having in hand finished project, you can begin to independently construct a smoke exhaust duct.

Materials and tools required for chimney construction

For self-construction chimney pipe you will need the following tools:

• trowel and mason's hammer;
• hydraulic level, plumb line (or construction laser level);
• construction bucket for mixing mortar;
• building rule, jointing;
• electric mixer (optional) a regular drill with nozzle);
• measuring instruments - tape measure, ruler.

To build a chimney, standard tools from a mason's kit are required.

During the masonry process, you need to make smaller building elements from brick - brick plates, a quarter of a brick, a half, etc. An experienced mason copes with the task with one well-timed blow of a hammer. A novice stove maker who does not have such skills can use a grinder with a diamond blade. With its help, cutting of any required shape becomes easily accessible, although accompanied by a large amount of dust.

Some stove makers successfully use a template made of wood or metal for masonry. The template allows you to strictly adhere to the dimensions, which is especially important for the internal hole of the pipe.

In addition, you will need materials:

• red brick (in no case white - silicate) solid, hollow, fireclay, clinker;
• cement mixture (can be ready-made or prepared independently from sand, cement and clay);
• a set of smoke valves or views;
• sheet metal or roofing.

Preparatory work before making a chimney

Before directly starting work on laying a brick pipe, it is necessary to carry out certain preparatory work:

During operation, hands come into contact with chemically aggressive solutions; it is recommended to use protective gloves to protect them.

When performing work on the roof, it is necessary to observe personal safety measures and also use scaffolding and rope belay.

At the construction site there should always be a first aid kit with first aid for wounds and bleeding. Sometimes the chimney is not located in the center of the room, but is in contact with the load-bearing wall. This situation is often observed during the construction of fireplaces. In this case, you can use wall structure chimney. It is pre-installed during the construction of the main wall. It is appropriate to note here that among stove makers there is a common classification of chimneys according to design characteristics:

1. Brick overlays. Chimneys installed directly on the stove masonry.
2. Brick root. Pipes located separately from the furnace, standing on separate foundation. They have the shape of a riser.
3. Prefabricated. Individual blocks made of refractory concrete that are stacked at the site where the chimney is installed.
4. Wall. They are built into a load-bearing wall, significantly saving space and volume of premises. However, it should be taken into account that it is not advisable to install wall pipes in external walls. Contact with cold outside air sharply reduces the efficiency of such a chimney in terms of heat transfer.

IN wooden houses the junction of the pipe with the combustible elements of the building is accompanied by a thickening of 1–1.5 bricks. To avoid fire, joints are additionally laid with asbestos or felt sheets. The felt is pre-soaked in a liquid clay solution.

Step-by-step instructions for building a brick chimney

The construction of a chimney involves laying bricks in strict accordance with the layout of the material in each row - the order. This plan must be drawn up when preparing a project for the construction of a smoke exhaust duct.

Each row of chimney masonry has a strictly defined arrangement of bricks

We can only add that for the best bonding of bricks with mortar, it is recommended to adhere to the following installation settings:

1. The mortar is applied in a layer of 1.5–2 cm, the brick is wetted and coated with the mortar. After installing the masonry in place, the brick is pressed down so that the final thickness of the seam is 1 cm.

   

   When laying each brick, it is necessary to check its position horizontally and vertically, and also maintain a joint thickness of 1 cm

2. As the masonry progresses (after 5-6 rows), it is recommended to do mopping - grouting the seams between the bricks inside the chimney duct. Smooth inner surface will provide good passage exhaust gases, will reduce the risk of soot deposits. Grouting can be done with a wet cloth.

   

   Internal seams are leveled and rubbed with mortar as the masonry progresses.

3. The installation of a smoke damper is usually carried out between the second and third rows of bricks. But this is not a strict rule - you can adjust the installation location depending on the situation. Immediately after installation, the valve is closed so that the cement mortar does not fall into the furnace.

   

   For each smoke channel a separate valve is installed

4. In the external masonry - on the roof - a mortar with increased strength and moisture resistance characteristics is used. To do this, the mixing proportion is changed, increasing the cement content (instead of 1/4, make 1/3). Moreover, the cement selected is grade M 500 or M 600. For the head they are often used not cement-sand composition, but cement-clay. It is made by adding 1 liter of cement to 10 liters of sand-clay mortar, which is used for laying the furnace.

   

   When using hollow bricks internal cavities filled with cement mortar

5. It is important to keep the solution clean. It is unacceptable for debris, especially of organic origin, to get into it.
6. Straight sections of the chimney are laid out plumb. To do this, strong silk threads are pulled in each corner and aligned vertically. The right angle is controlled using a square every 4-5 rows.

   

   It is convenient to control the vertical position of the chimney walls using cords stretched in each of the four corners

Video: DIY chimney for a fireplace

Features of the operation of brick chimneys

After the construction of the chimney is completed and the pipe is successfully put into operation, it is advisable to familiarize yourself with the features of use brick stove. In order for the heating unit to serve for a long time and without accidents, it is necessary to follow simple but important rules.

1. The main enemy of brick is sudden temperature changes. It is better to heat more often, but for short periods of time. It is not recommended to make more than 2 fuel loads per firebox. This is especially true for coal, the combustion temperature of which exceeds 1000 degrees.
2. Timely cleaning of the pipe from soot unlimitedly extends the service life of the chimney duct.
3. If cracks occur on the stove body and chimney in particular, measures should be taken immediately to eliminate them. Neglected cracks tend to progress quickly and pose a threat not only to the integrity of the brickwork, but also to human health. Carbon monoxide, which is colorless and odorless, but poisonous to all living things, penetrates into the living space through small cracks.
4. The slightest malfunction in the doors of the firebox or ash chamber (ash chamber) first significantly reduces the heat transfer of the stove, and then leads to an avalanche-like accumulation of soot on the chimney channels. If you find a door, view or valve that does not close tightly, you should immediately repair or replace it.
5. At least once a year it is necessary to carry out preventative maintenance on the furnace. It is best to do this at the end of summer, before the start heating season. A daily preventative procedure includes opening the blower door for 15–20 minutes. This simple action will allow you to briefly create maximum draft, which will pull the soot deposited on the walls into the external environment.
6. The use of damp firewood has an adverse effect on the cleanliness of smoke ducts, especially in winter time. It is more rational to use fuel briquettes, the humidity of which is much lower. Firewood should be prepared ahead of time - wood drying in a natural way- the process is long (from a year to two).

Chimney cleaning and repair

For cleaning pipes they are used as traditional ways, and modern, based on the achievements of technological progress.

From time immemorial, stove maintenance was carried out by people whose profession was called chimney sweep. Today, finding a professional chimney sweep is problematic. They were replaced chemicals, which, however, are also often called “Chimney Sweep”.

Finding a professional chimney sweep today is very difficult; this profession is a thing of the past.

Thus, a product called “Log Chimney Sweeper” has proven itself well. It contains salts copper sulfate and other active chemical compounds. Burning in the firebox, the vapors of these substances interact with carbon deposits deposited on the walls of the pipe. Under the influence of heat, the reaction continues for several weeks and leads to the fact that the solid structure of the soot crumbles and, falling back into the firebox, burns. According to manufacturers, using “miracle logs” twice a year allows you to completely remove soot from the pipe. The consequence of this is good traction and a high percentage of heat transfer from the furnace.

Manufacturers of the “Log Chimney Sweeper” product claim that its use twice a year allows you to completely clean the chimney of soot

From folk remedies You can note such effective methods of prevention as burning salt or soda once every 2 months (about 0.5 kg per firebox). The powder is poured into the combustion chamber at the moment when the firewood is well lit and the temperature is at its maximum. After this, you need to close all the doors tightly, as the reaction can be quite violent.

Dry aspen firewood helps clean the chimney well. The fact is that aspen burns with a large release of heat, the flames are long and penetrate deeply into the passages.

If there is no aspen or soda, you can use potato peelings. To do this, you need to accumulate about half a bucket of potato peels. When burned in a firebox, the released substances bind the soot and cause it to burn to the end.

The combustion temperature of aspen firewood reaches 800 degrees, so the soot on the walls of the chimney burns out

When performing work on installing chimneys, especially in the area of ​​installation of the neck, otter and cap, you should carefully observe safety standards. If you work carefully and follow the necessary instructions and technologies, you can easily build a brick chimney with your own hands.

Nowadays there are a large number various chimneys, suitable for solid fuel or gas boiler. The latest developments in this area and the emergence of new materials allow manufacturers to produce chimneys, which in their design are separate complex units that can successfully resist corrosion, soot deposits and condensation. But still, despite this, many prefer to build a brick chimney with their own hands.

Recently construction country houses has become widespread. Along with this, interest in fireplaces and stoves has increased. People try to build stoves according to old, proven recipes inherited from their fathers and grandfathers. But the art of stoves was almost completely lost in certain regions during a certain period of development of our country. Today we will try to help you build a chimney with your own hands.

Chimney - what does it consist of?

Before you build a brick chimney, you need to figure out what parts it consists of. After all, many people think that brick chimneys are an ordinary rectangular pipe made of brick laid on mortar. This is not entirely true. But let's take things in order.

At the beginning . This part of the pipe is installed directly on the stove. A valve can be installed in it. The mounted pipe must be laid out, ensuring that the bricks are tied in each row. The attachment part is not brought to the interfloor ceiling of 5 or 6 rows. It all depends on the height of the stove, the room and the thickness of the interfloor ceiling. This place is called the neck of the fluff.

When laying a brick pipe, the cross-section of the smoke channel in the top pipe and the head should be the same. Thus, the cross-section of the entire smoke channel anywhere in the chimney has the same size.

The fluff or cutting should be laid out in several rows, widening the outer part of the chimney at 250 – 400 mm.

Then you should lay out another cut called otter. The otter forms an extension on the chimney on all four sides, not less than 100 mm. This expansion prevents precipitation from entering through the cracks between the chimney and the roof directly into the attic space. The absence of an otter causes moisture to penetrate into the attic, leading to the destruction of the load-bearing structures of the roof and ceiling.

Above the otter, the chimney should be placed in the same way as the riser. This place is called the neck of the tube.

After the neck, the outer masonry expands again, forming the head of the chimney. You can install a weather vane or a metal cap on the head, which will protect the inside of the chimney from precipitation.

A well-chosen weather vane or cap can significantly increase the draft in the chimney.

Do-it-yourself chimney laying

We have looked at all the main parts and their names, it’s time to tell you how to build a brick chimney with your own hands.

Basic preparation completed

Today we will not mention materials, tools or which brick to use for the chimney; a lot has already been said about this on the pages of our resource. Let's assume that we have everything ready. Our task today is to look at how to properly build a brick chimney.

The first stage is familiarization with the drawings

Before us is a drawing of a brick chimney. Although there are many other options, this standard scheme brick chimney for a stove, solid fuel boiler or fireplace. Using a metal pipe made of a special alloy inside such a chimney can easily turn it into. Since the requirements for the smoke exhaust conditions of a solid fuel and gas boiler are somewhat different.

The numbers on the drawing indicate:

1. Wind vane.
2. Pipe neck.
3. Cement mortar.
4. Otter.
5. Roof.
6. Lathing.
7. Rafters.
8. Riser.
9. Cutting (fluffing).
10. Overlap.
11. Insulation.
12. Smoke damper.
13. Kiln neck.

It is important to know: fluff and otter can be placed a little differently, it all depends on the location of the chimney relative to the roof and on the angle of its slope.

The size of the channel directly depends on the thickness of the masonry joints - remember this.

Chimney laying - first steps

Formation of cutting

Looking from the inside, it becomes clear that the fluff is beginning to take its shape.

• In the next row, the outer dimensions are already 570x710 mm.
• Bricks of 90 - 100 mm thickness are inserted inside.

Finishing the cutting

• The fifth row is laid out with a whole brick.
• The sixth row must be laid out in exactly the same way as the fifth, but strictly observing the dressing.

If necessary, to make the fluff higher, you can lay another row, tying it under the underlying masonry.

Work in the attic

• The riser is carried through the roof.

This completes the work in the attic, then you need to begin installing part of the chimney on the roof.

"Roof work"

We continue to lay out the riser on the roof. Pay close attention to the bonding of the brickwork.

• The riser is displayed 1 – 2 rows above the roof, then the otter begins laying out.

Otter - making protrusions

• The otter is laid out in nine rows.
• Each next row is larger than the previous one in outer size by one-fourth of a brick.
• At the same time, do not forget about maintaining the size of the smoke channel.
• Select internal brick plates so that the smoke channel does not expand or contract.

As we see, in this row brickwork forms only one protrusion, forward. At the edges, the outer size of the chimney remained unchanged.

Thus, we have a front and two side protrusions. All that remains is to lay out the rear ledge.

Finishing the otter

Lay out the neck

You can view all dimensions of the height of the chimney above the roof on our resource. This applies to all chimneys, whether chimneys for brick boilers or other heating units.

The final stage is the head

Inexperienced builders believe that laying a brick chimney is the same as building walls. However, the design of the chimney has its own nuances. In particular, experts do not recommend using cement-sand mortar. Such a solution will not withstand sudden temperature fluctuations that occur in the wall of the chimney pipe. In addition, the usual solution will be destroyed by condensation, which inevitably settles on the pipe wall.

Therefore, it is necessary to lay a brick chimney using a thermally efficient and chemical-resistant solution. You can prepare a solution using already ready-made mixtures. But this is expensive, so many people prefer to prepare a thermally effective solution on their own; such a solution consists of cement, sand, lime and fireclay. Some experts recommend using clay mortar.

If the boiler is gas

If for wood stove and for a solid fuel boiler, installing a brick chimney is justified, but for a gas boiler this is not the best option smoke removal It's all about the different operating modes of the stove, solid fuel and gas boiler. If solid fuel equipment does not require high draft, then using a rectangular brick pipe for a gas boiler will lead to reduction in efficiency heating unit.

When using a gas boiler, the requirements for the chimney installation are different than when installing solid fuel equipment. Therefore, if a house is being built, then a chimney made of a metal pipe is necessary for a gas boiler.

If a gas boiler is installed instead of a solid fuel or wood stove, then the construction of a new chimney is impractical. However, the requirements for the chimney of a gas boiler must be met. In this case, the brick chimney is lined, that is, a metal pipe is installed inside the existing brick chimney. Thus, the requirements for the smoke exhaust device will be met and there will be no need to disassemble the old pipe.

Nothing is impossible

By and large, making brick chimneys with your own hands is a completely doable task for any person who loves to work with his hands for his own pleasure. Sometimes it is believed that brick chimneys are becoming a thing of the past. This is not true, for example, lining a brick chimney with pipes with a special coating, but the device of a brick chimney allows this to be done, allowing them to be used in work with the most modern boilers heating. We hope that after reading this article you no longer have the question of how to properly make a brick chimney for a fireplace or stove with your own hands. Try, practice, and the brick chimneys built by your own hands will delight you and your loved ones with ideal work under any conditions. Good luck to you!