How to make a chimney for a fireplace: rules for constructing a smoke channel and comparison of designs. Internal and external decoration of the chimney pipe: a set of simple options for independent implementation Exhaust pipe for a fireplace in the house

The slightest failure in the design and construction of the chimney will most likely lead to its cracking. Through cracks, carbon monoxide can, in turn, enter the house. Over time, the chimney may simply collapse. For these reasons, it is important to approach the study of the issue with particular pedantry.

What is this article about?

Types of chimneys for fireplaces

There are many designs, but the most popular are the following types of arrangement:

With an open firebox with air heating.
With a closed firebox with air heating.
With a closed firebox with water heating.

In apartment buildings, it is impossible to install a brick fireplace, especially with a brick chimney due to the high load on the floors, fire safety rules and the impossibility of venting the pipe through the common attic space. However, it is possible to purchase and install closed metal devices with a coaxial chimney.

Fireplaces with closed firebox

A fireplace with a convection (air) type of heat supply has an efficiency of 80%, which is not so little in contrast to 20-30% of a classic device. It works on the principle of convection. Through the ash pan, the fireplace sucks in cold air from the lower part of the room and transfers it to the fireplace insert, where it is heated and sent through special air ducts to heat one or more rooms. Convection can be natural, that is, without the use of special devices that pump pressure or forced (electrically dependent), with the installation of fans inside the structure.

A fireplace with a water circuit can reach 85% efficiency due to the long cooling of the heat source. Its meaning is that a heat exchanger is placed in the firebox, which contains a liquid that is heated under the influence of fire. The liquid circulates through specially equipped channels, according to the gravitational principle, and the room is heated. The firebox of such a fireplace is also closed. There are several types of structural arrangement, thanks to which even a two-story house can be heated.

Fireplaces with a closed firebox have a complex structure, which is why their construction must be done by a professional. Here, simple care is not enough, as with a classic hearth; accurate calculations of the slopes of pipes and channels are required individual for each room, otherwise the system will not work or will not operate correctly.

Fireplace with open hearth

The classic design of the structure is not designed for high efficiency indicators. Usually it is 10–20, maximum 30%. The fireplace has an open firebox, and hot gases exit into a straight chimney to the street (a slope of only 30 degrees is allowed, no more). The heating of the air in the room is directed, coming directly from the hearth furnace; there is no heat-accumulating zone, since the walls of the fireplace do not heat up. However, this is still the most attractive type of fireplace, because access to the fire is direct, it is not hidden behind screens and provides a directed flow of heat and heat.

The chimney of such a fireplace consists of several parts:

The tooth is an inclined threshold in the upper part of the firebox, located under the attachment pipe, creating a narrowing of the chimney opening of the firebox. It prevents cold outside air from passing through the chimney into the furnace. This increases the efficiency of the fireplace, creates the optimal temperature of the exhaust gases, mixing hot air with cold masses and improves draft. It can be located on any wall of the fireplace.
The angle of inclination of the tooth is usually 20 degrees, so that it does not overlap the specified cross-section of the chimney
The head pipe is an area of the chimney laid directly above the combustion chamber, located indoors and equipped with a damper necessary to regulate the draft. It is laid out with 4–5 bricks around the outlet hole. Also as in the body of the fireplace, each row is checked for evenness using a horizontal level and vertical plumbs. Before the overlap there should be about 6 rows left for arranging the fluff.
The fluff is the next, expanded part of the chimney, passing through the ceiling and providing its fire protection. The laying of this part of the chimney is calculated taking into account that each row increases by a quarter of a brick.
Riser - running from the attic to the roof. The riser is usually placed in 5 bricks without increasing the outer diameter. Its height is 1–2 rows above the roof.
The otter is a part of the chimney from the beginning of the roof that protects the attic space from precipitation getting inside. The length of the otter is made with projections of a quarter of a brick in both directions; the size of the smoke channel is compensated by brick plates.
The neck is a pipe that goes to the head.
The cap is the final part of the chimney, laid out in the same order as the fluff. At the mouth of the chimney, a 4-slope protective cap is attached (ideally) to prevent debris and precipitation from entering the chimney.

Requirements for the pipe and its dimensions

When installing a chimney, you must be guided by the technical requirements set out in SNiP 41—01-2003.

Basic Rules:

The room in which the fireplace is installed must be at least 15 square meters. m, for optimal air circulation.
One fireplace must contain one chimney. It is not allowed to connect the device to an old chimney or to simultaneously use the outlet channels with two structures.
The cross-section of the chimney pipe is about 1/10 from the portal, or better yet 1/15, in any case, at least 14x27 cm.
The thickness of the walls of the chimney indoors can be half a brick, but when going outside, it is no less than a brick, so that heat loss is minimal.
The height of the chimney can be from 5 to 11 meters and should rise above the roof to such a height that nothing interferes with the exit of flue gases, more on this below.
The masonry is made in such a way that the seams inside the smoke channel go under the jointing. The presence of the solution on the walls of the chimney is not allowed, Also as well as the protrusions of brick “ears”.

Pipe height above roof

The chimney is located from the ridge at a distance of up to 1.5 m - the head rises from 50 cm above its level. This arrangement is considered ideal because a minimum amount of precipitation will accumulate around the chimney, damaging the pipe.

From 1.5–3 meters - it is possible to arrange it at the same level as the ridge.

From 3 meters - no more than 10 degrees to the roof slope.

If the chimney rises more than one and a half meters, fastening with ties is necessary.

In the case of a flat roof, the height of the chimney is at least half a meter.

The height is also adjusted depending on nearby traction obstacles - trees, adjacent roofs, and so on. The principle, as already mentioned, is simple - nothing should interfere with the exit of flue gases.

Projects

Laying it out is easy, even an inexperienced person can do it, just follow the order and calculate the chimney structure using simple diagrams. We have prepared several good projects with orders to choose from.

Before laying, consult a professional about the feasibility of the chosen scheme.

First, practice. The task is to use simple Lego cubes (if your children have this construction set) to build the desired fireplace. All the necessary blocks are usually included in the kit - full, halves, quarters, and so on. This will allow you to see the future model in its natural form, disassemble the chimney structure in more detail, and also check the order drawing used.

Required materials

Usually, the orders either indicate the required amount of brick, or it can be easily calculated by order. The most common solid, red stove or fire-resistant brick is used.

Laying the casing pipe, flares and part of the riser up to the roof, Also like the body of the fireplace, it is made using a clay-sand mortar mixed in a ratio of 1/1 or 1/2 if the clay is oily.

Everything that is higher than the attic space and goes out onto the street is laid out on a cement-sand mortar mixed 1/3. The cement must be of a grade not lower than M -400.

Chimney outlet through the ceiling and roof

The chimney riser is discharged through a pre-made hole in the ceiling space and roof.

Please note that if the passage in the ceiling was not cut during the construction of the house, it should not affect supporting structures such as beams and rafters.

To waterproof the chimney outlet, a special casing is made - a flange, covered with non-combustible material on the bottom. There are a lot of options for such a casing, including that you can make it yourself or purchase it in a specialized store. The penetration is closed with a flange and an iron apron, and is also coated with sealant in all joints. The main requirement is non-combustible materials, preventing precipitation and cold from entering the under-roof space.

Fireplace chimney lining

Lining a fireplace chimney is advisable in 2 cases:

For decorative purposes.
To insulate the structure to prevent condensation.

indoors, Also like the body of the fireplace, a hidden brick chimney can be lined with almost any material, since they are not subject to heating - tiles, decorative stone, plaster, plasterboard and so on.

Outside and in the attic space, the chimney is often exposed to condensation due to the difference in temperature, which contributes to the deterioration of draft and the accumulation of soot. In this case, the chimney outlet can be plastered on the outside with a cement-sand mortar, covered with artificial stone for outdoor work (which can withstand high-temperature influences), with a special heat-resistant glue, or sewn into a heat-resistant sandwich casing, purchased in a specialized store or made independently from fire-resistant insulation and a steel apron .

This is how you can quickly and with your own hands equip the most important part of a classic fireplace with an open firebox - the chimney, without the help of professional stove makers.

A fireplace is an installation that has many responsibilities. It should not only warm the room, but also bring coziness, joy, and comfort.

However, in order for the logs to burn and no acrid smoke to enter the room, it is necessary to correctly build a chimney for the fireplace with your own hands - one of the fundamental parts of the entire structure. It must be durable, reliable and safe.

What parts does a chimney consist of?
How to properly prepare for work
Basic rules for masonry
We draw the chimney through the ceiling
Arrangement of the chimney neck
Basic mistakes and expert advice

Before you start building a brick chimney, you need to understand what main parts such a structure consists of:

For those who find it difficult to install a brick chimney for a fireplace, there are always simpler, but high-quality options. You can build a structure using ceramic blocks, various pipes, etc.

Preparing for work

The fundamental stage is preparation for the work. It is necessary to familiarize yourself with the various drawings and choose the most suitable one. It would be a good idea to indicate on the diagram all the characteristics of the pipe being constructed and save it.

Watch the video preparing the solution:

Chimneys for brick fireplaces have their own characteristics, depending on the type of stove being installed:

For wood-burning models, it is enough to make brickwork
For gas models, it is necessary to place a metal pipe inside the masonry

Before laying the chimney, a rectangular foundation is erected. It is made 30-40 cm high and 15-20 cm wide in one of two options:

Formwork is installed and concrete is poured
Made from refractory solid bricks

To build a brick chimney for a fireplace, you need to prepare the following tools and materials:

Fireproof brick (grade M200 and higher)
A mortar consisting of cement, fine sand, water and clay
Hand tools (trowel, level, plumb line, etc.)
Thermal insulation materials
Steel sheets
Electric tool (grinder, drill)

Laying the mounted pipe

It is necessary to decide what the cross-section of the chimney will be for a fireplace built from brick. The smoke, rising upward, moves in a spiral. Therefore, it is customary to give preference to a round-shaped channel, but it is extremely difficult to lay it out of stone. You have to make a section in the form of a square, the size of which depends on the fireplace portal:

Closed portal – approximately 15x25 cm
Open portal – approximately 25x25 cm

It is necessary to start laying from the top, arranging the nozzle pipe. It is very important to monitor the ligation of seams between rows, vertically and horizontally. The thickness of the seams should be 1-1.5 cm. One value should be maintained throughout the entire construction.

Making a fireplace from start to finish: stages of work in order:

It is necessary to continue laying the mounted pipe until 5-6 rows remain from the ceiling. To ensure that the smoke does not have any obstacles, it is recommended to plaster the inner surface with the mortar used for joints. It is better to lay the layer not thick, so as not to greatly reduce the diameter of the chimney for a brick fireplace.

If the mounted pipe is laid directly against the wall, it must be secured. To do this, pins are installed every 25-30 cm, one end of which is driven into the masonry, the other into the wall.

Having laid the last row of the chimney pipe, it is necessary to check the vertical and horizontal, it is time to begin the most important and difficult stage of construction - the construction of the fluff, the otter and the riser located between them.

Fireplace through attic and roof

In order to pass a chimney for a fireplace built by yourself through the ceiling as safely as possible, you need to lay out the fluff. The thickness of its walls should be equal to at least one brick placed in length. In this case, the expansion is done in stages, moving by ¼ with each row.

Sometimes, instead of the classic tub of the thickened part, a concrete box is used, filled with pebbles, sand or expanded clay and installed around the chimney pipe. This option is easier to implement:

First, the wooden formwork is arranged so that it rises 7-10 cm above the ceiling; it must be secured more securely and ensure that there are no cracks
The inside of the boards is covered with a solution of sand and clay so that the formwork can be easily dismantled after the concrete mixture has hardened.
Next, reinforcement is made, rigidly connecting the rods and brickwork to each other
A solution consisting of a high grade of cement, sand and selected filler is prepared, thoroughly mixed and poured, completely hiding the reinforcing rods
After drying, the formwork is dismantled
The surfaces must be smooth so that it is possible to cover the fluff with masonry without any problems.

In order to maximally protect the structure of the ceiling, which should not touch the chimneys for stoves and fireplaces, it is necessary to make a steel edging around the perimeter of the hole, and put glass wool impregnated with clay mortar into the resulting gap. It is also recommended to lay the insulation to the sides, removing up to 20-30 cm.

Let's watch the video, the chimney through the roof slab:

After the formation of the fluff, the installation of the riser continues. In this part, the size of the chimney for the fireplace is made similar to the mounted pipe, only plastering with clay mortar is carried out simultaneously from the inside and outside. During the heating season, the attic temperature is set to low. To eliminate the big difference inside and outside the chimney, it is recommended to wrap the riser with non-flammable insulation.

The most difficult stage of the instructions on how to build a chimney for a fireplace has been completed. Having reached the roof, it is necessary to proceed to the next stage - arranging the otter. The pipe is expanded, as when laying fluff, but only slightly. In this case, it is necessary to install a galvanized metal casing around the perimeter with a small protrusion on the roof, which is covered with soft waterproofing and roofing.

Finishing the fireplace

Having finished building the otter, you need to start arranging the final part - the neck of the chimney for the fireplace with your own hands.

Let's watch the video, the first firebox:

It is made similarly to a riser and rises to the selected height, which depends on the distance from the ridge:

Up to 1.5 m – 0.5 m above the highest point
Up to 3 m – at the level of the top point
More than 3 m - a straight line drawn between the top point and the pipe being erected should deviate from the horizontal by no more than 10 degrees

All that remains is to complete the head for the future chimney. Its construction is carried out similarly to fluff. Upon completion of the work, it is recommended to install the cap and weather vane.

The most common mistake is made at the calculation stage. If the fireplace is placed incorrectly, the chimney pipe may rest against one of the beams. The problem can be eliminated by installing additional elements of the rafter system.

Watch the video, installation of connections to the pipe:

Many people, in order to save money and time, combine more than one channel with one fungus. This is one of the biggest mistakes. The ventilation system ceases to fully perform its functions, as a result of which mold and condensation appear.

There is nothing difficult about how to make a brick fireplace for a chimney with your own hands. However, you cannot begin repairs or make any structural changes without permission. It is necessary to contact a specialist and carry out additional preliminary calculations.

Each fireplace or duct must exit into one chimney. If this is necessary, the common part is expanded and a cut is made in the center with a thickness of 12-15 cm to a height of one meter.

There should not be many changes in the direction of the chimney, since smoke removal should be carried out in the simplest and fastest way. The construction of complex structures with slopes of no more than 45 degrees is permitted only with a minimum chimney length of 6-7 m.

Let's sum it up

It is necessary to build stoves, fireplaces or chimneys yourself only when you have confidence in your capabilities and strengths. The finished structure must comply with technical and fire standards. Each individual case may have its own unique distinctive features.

When starting work, you should familiarize yourself with the examples by examining 1-2 chimneys visually. If they cause a lot of difficulties, do not risk the fireplace and your own safety. The seemingly expensive help of specialists will soon pay for itself, and the stove will not cause trouble, properly heating the room or the whole house.

Chimneys for brick fireplaces
Disadvantages of brick structures
Fire safety of chimneys
Stainless steel smoke exhaust structures
Block ceramic chimneys
Criteria for choosing a smoke exhaust pipe

Chimneys for hearths are very different, but their shape, dimensions of the fireplace pipe, material of manufacture and appearance do not matter, since the main requirement for the smoke exhaust structure is to ensure good ventilation of the combustion chamber.

Chimneys for brick fireplaces

It is believed that a chimney system is made with high quality only when there is no smell of smoke in the room where the fireplace is located, and the firewood in the firebox ignites immediately. If a chimney for a brick fireplace is installed in a private household, a chimney is usually built, which is combined into a single structure with a ventilation riser. Red solid ceramic bricks are used for masonry.

The creation of pipes from this material has a number of features. Both the brick chimney duct and the ventilation unit must rest on the base. You can use a slab or load-bearing wall as a foundation. Read also: “Types of brick chimneys and rules for their construction.”

When constructing a smoke exhaust structure, it is necessary to adhere to a number of rules:

To lay the masonry you need to use a lime-sand mixture.
When a chimney system is inserted into a wall, regardless of what material it is made of, it is questioned.
At the same time, they adhere to a 30-centimeter step, the anchors are inserted into the walls, adhering to a checkerboard pattern, to a depth of 20 centimeters, using reinforcement with a cross-section of 1 centimeter.
To increase the stability of the masonry of the ventilation riser and chimney, it must be reinforced every third row using class A1 reinforcement with a 6-mm cross-section.

Disadvantages of brick structures

A smoke exhaust pipe for a brick fireplace has disadvantages, the main one being the short service life of such structures, which does not exceed 7 - 10 years.

The fact is that frequent and significant temperature changes during the cold season lead to the appearance of condensation, and it either freezes or thaws. As a result, over time, the brickwork begins to collapse.

To reduce the impact of negative aspects you can:

expand the cross-section of the external chimney walls to 25 centimeters in those places where they are above the roof surface;
insulate these sections of the chimney with mineral slabs.

The chimney pipe will last longer if you install a cap on top of it, which will protect it from precipitation.

One of the significant disadvantages of brick chimney structures is the presence of a rough inner surface, since this circumstance leads to a decrease in draft efficiency compared to smooth pipe walls.

Designing smoke drainage through a chimney that has a certain reserve cross-sectional area can help cope with this problem.

The installation of galvanized steel pipes inside the smoke exhaust system will also increase the service life.

Fire safety of chimneys

When arranging a smoke exhaust structure, one should not forget about fire safety rules:

A gap of more than 25 centimeters is left between the wooden roofing parts and the inner surface of the chimney.
Wooden parts must be insulated using felt, which is moistened with a solution of clay or asbestos cardboard is laid in two layers. Read also: “How to make a spark arrester for a pipe - operating principle and installation methods.”

Stainless steel smoke exhaust structures

Chimneys for fireplaces of this type are stacked structures.

The length and diameter of a stainless steel fireplace pipe can be very different. Such products are often produced complete with ceramic ones and placed inside steel ones.

Chimneys made from galvanized stainless steel have the following advantages:

they can be installed without a foundation, since they are light in weight;
assembly and installation of the structure is permitted after completion of construction;
they are cheaper in cost than block and ceramic systems;
If necessary, replacing individual elements will be easy.

The disadvantage of steel chimneys is the need for a design solution in the case of interior design, if such a structure is installed indoors. Read also: “Which stainless steel chimney pipes are best to use - types and advantages.”

Block ceramic chimneys

The basis for the ventilation ducts in such a ceramic chimney are blocks made of lightweight concrete.

A wide range of these products allows you to easily select the required parameters.

To connect the blocks, a vertical reinforcement process is used.

A ceramic fireplace pipe is inserted inside them and thermal insulation made from non-combustible materials is placed.

The technology for carrying out installation work in this case depends on the features of the structure being installed and therefore the use of generally accepted rules will be inappropriate.

The advantages of this type of chimney for fireplaces include:

quick installation and assembly;
long service life;
high efficiency;
a wide selection of blocks to give the smoke exhaust channels the desired configuration;
the ability to clean the smoke exhaust system through special openings.
Their presence at the bottom of the structure also helps condensation to drain freely.

The disadvantages of a ceramic pipe for a fireplace chimney include:

relatively low price;
long delivery times, since such structures are in most cases produced abroad.

Even taking into account the shortcomings, ceramic fireplace pipes are considered the undisputed leaders among similar products.

Criteria for choosing a smoke exhaust pipe

When deciding which pipe should be near the fireplace, first of all you should pay attention to the cross-section. The choice of this parameter depends on the type of unit or fireplace. The chimney is equipped taking into account the parameters 140x140, 140x270, 270x270, which are multiples of the dimensions of the brickwork.

The diameter of the fireplace chimney cannot be less than this parameter at the boiler outlet.

And it, in turn, depends on the type and power of the unit.

The opening of the ventilation riser is located close to the chimney structure. According to the standards prescribed in SNiP, a hood is installed for boiler rooms, which is capable of providing three air exchanges per hour. For living rooms with fireplaces, ventilation is sufficient, creating twice the value of this parameter.

The best solution would be to place the fireplace chimney surrounded by ventilation ducts.

Among other criteria, when calculating a chimney for a fireplace, the type of fuel used is taken into account. If it is liquid or gaseous, then its wall thickness should be at least 0.6 millimeters. When it is planned to use solid fuel, the required wall thickness of the structure is 1 millimeter.

When installing a chimney inside a brick shaft, single-wall components are used.

Chimney diagrams: how to make them correctly?

If the smoke exhaust structure will be located separately in the house or outside the building, it is necessary to use insulating materials that ensure fire safety. When you plan to burn a fireplace in a wooden house with coal, choose chimneys with an insulation thickness of 50 to 100 millimeters.

When purchasing elements for installing ceramic or steel smoke exhaust systems, you need to pay attention to the permissible temperature limits. If you plan to use wood or coal for the fireplace, then you cannot use pipes that are designed for fuel combustion temperatures up to 250°C - they are intended exclusively for gas or oil units.

When choosing a chimney, pay attention to the following points: can it be used in stoves operating on solid fuel, and resistance to possible ash combustion at temperatures close to 1000°C.

The chimney for the boiler should look like a vertically located homogeneous structure. The height of the fireplace pipe cannot be less than 4-7 meters with an optimal draft of 10-20 Pa (for more details: “What height of the chimney is needed above the roof - norms and rules”).

According to the operating requirements, cleaning of chimneys and monitoring their condition must be carried out by chimney sweeps at least 4 times a year.

Brick fireplace pipe

What product can be used to clean a stone chimney?

How to clean soot from a stone chimney?

The chimney needs to be cleaned if the thickness of soot on its walls reaches more than 2 mm. It can be cleaned either mechanically or chemically.

When choosing a mechanical method, you need to use a metal brush, the diameter of which should be slightly larger than the diameter of the chimney.

This brush is equipped with a cable and a weight for better movement down the pipe. This fixture is more suitable for round pipes. If your chimney is of a square or rectangular design, then it is better to use a brush with metal bristles.

The brush for cleaning chimneys is equipped with a set of holders that are fastened together when increasing the required length of the brush.

Before you start cleaning the chimney, you need to close all cleaning holes to prevent soot from entering the room.

Chemically, the chimney is cleaned using various chemicals in the form of briquettes, powder or liquid, which are added to the firebox while burning wood.

These products help to destroy soot deposits on the walls of the chimney, and it falls down.

You can also use folk remedies to clean the chimney from soot - heat the stove or fireplace with aspen wood or burn half a bucket of potato peelings.

Two methods are used for cleaning:

using a brush or a brush (as well as another device, for example, a chain with a large link, or a homemade plastic brush);
using chemical fuel.

As for chemicals, they are all added to the already lit fire inside the firebox after the chimney has warmed up.

When burned, chemical briquettes release a composition that removes soot and deposits from the walls.

The choice of brushes for cleaning is quite varied, and starts from brushes on handles, if the chimney is not very long, and ends with brushes on cables with a weight. The weight stabilizes and allows the brush pile to be pressed tightly against the chimney wall.

The difference between these methods is that with the chemical method the valve is open, but with the mechanical method it must be open.

During the operation of the chimney, these methods must be combined.

How to properly install a chimney for a modern fireplace?

Everything is exactly the opposite - these pipes are cold. And the presence of insulation in the pipes is not enough to be considered “warm” pipes.

This insulation is absolutely useless as protection for the chimney from the cold. Rather, it serves for fire safety.

Let's try to explain.

Let's take a fur coat as an example. As you know, a fur coat does not keep you warm. It just keeps you warm. That is, you need a heat source, otherwise there will be nothing to keep.

Same thing with sandwiches.

They are not “warm”. They are only able to hold back heat. That is, they are not designed to hold back cold air from outside trying to get inside. They are a heat insulator for exhaust internal hot air.

The thing is that when the fireplace is burning, there are no problems with backdraft.

When burning, the temperature in the chimney is such that no frost can stop the draft. This means that at the moment of combustion, it does not matter which pipe was installed on your chimney - “warm” or not. Conclusion No. 1: There are no problems with an already burning fireplace and there is no need for a supposedly “warm” “sandwich”. But the fact of the matter is that the main state of the fireplace is INACTION. He is idle for the vast majority of his life. Therefore, how “warm” a “sandwich” chimney is should be assessed precisely when the fireplace is not in use.

This is where the fun begins.

As we have already found out, the “sandwich” does not generate heat. It is only capable of acting as a “fur coat” that retains heat. But for this you need something that could be held, on which you could demonstrate your declared qualities and advantages. That is, warm internal air must be CONSTANTLY removed through the chimney so that the “sandwich” has something to draw heat from, otherwise it will cool down.

The diameter (section) of the chimney depends on the size of the firebox. Usually the most common chimney diameters are: 180 mm, 200 mm. There are 250 mm., 300 mm. Sometimes you come across simply huge ones: 400 mm, 500 mm. In any case, even the smallest chimneys are quite impressive channels through which a decent amount of air (i.e. heat) can escape. Agree, it is very unreasonable during the cold period to literally throw away precious heat into a not very small pipe.

And if so, then on the chimney, in case the fireplace is down, a valve (gate) is provided. That is, when the damper is closed, heat does not escape into the chimney. That is, the “sandwich” instantly cools down. Conclusion No. 2: when the fireplace is not lit and the damper is closed, the “sandwich” is again useless.

But that's not all. Ready-made fireplace inserts have a standard damper, which the fireplace manufacturer deliberately makes loose, with cracks.

The air that goes into the chimney through these leaks in the standard damper is sorely not enough to warm up the “sandwich”. Our climatic conditions are not the same.

The metal pipe cools down very quickly and the draft in it overturns. Well, where is that “warm” pipe that sandwich manufacturers keep talking about? Why doesn't she save in such a situation? Yes, because metal has very little thermal inertia and because of this it is not able to retain heat for a long time under the influence of cold outside air.

If you want to protect yourself as much as possible from the draft tipping over during the cold period, forget about the “sandwich” as a fireplace chimney. If you use it as a fire safety element when passing inside the house, then at least do not place the “sandwich” above the roof - leave it warm, within the house, and make the street part of the chimney out of brick (with a cross-section as close as possible to the internal diameter ).

Or, if this is not possible, do as our ancestors did. They made the chimney pipe: firstly, not with metal pipes, but with pottery (ceramic) pipes, and secondly, they did not line it with insulation, but filled it (coated it) along the contour with a heat-intensive material.

In particular, lime mortar.

In order to minimize the risk of the chimney draft overturning, it (the chimney) must very slowly release the heat it has gained. That is, it must have greater thermal inertia. “Sandwich” does not have this quality, and therefore cannot be considered a “warm” pipe.

All of the above is not an attempt to “hit” the “sandwich” as a product.

This is elementary indignation from illiteracy, misunderstanding, or greed of the sellers of this product. It’s time for them to realize that there are conditions and places in which it cannot be used. This product is a good solution as a chimney for gas boilers. For a fireplace - THE WORST.

4. Do not place deflectors or umbrellas at the chimney outlet.

This impairs the performance of the fireplace.

If, in addition to the chimney, there are also ventilation ducts in the pipe (head), then you can cover this pipe with a common umbrella. But then the fireplace chimney MUST PASS THROUGH THE UMBRELLA. If this is not done, then if there is insufficient inflow, the smoke coming out under the common umbrella will be sucked back into the room through the ventilation ducts that go under the same umbrella and the smell from the fireplace will appear in various rooms (in the kitchen, in the bathrooms, wardrobes).

Deflectors are designed to enhance traction.

They increase traction if there is wind. Which means when there is no wind, the deflector is an obstacle. And how could it be otherwise, if the design elements of the deflector interfere with the free exit of smoke from the chimney.

5. Without an inflow, the fireplace will not work.

The larger the fireplace, the larger the chimney. The larger the chimney, the greater the chance that difficulties may arise with it.

A large chimney removes a fairly impressive volume of air during operation. This means that exactly the same amount of air must be replaced. During the warm season this is not a problem - you can simply open the window. But in winter this trick will not work - you can get a strong draft. Therefore, the inflow for a fireplace is the most important component of its normal functioning.

The influx can be made general or local, i.e.

e. serve in the rooms, or directly into the fireplace.

6. An open fireplace is better than a closed one.

A fireplace with a closed firebox (a fireplace that has a glass door) is less predictable of backdraft.

The thing is that if warm air does not constantly pass through the chimney, then the channel cools down and reverse draft comes from it. When the fireplace is lit, everything is fine, but when it is not in use, the presence of a glass door results in trouble for the owners. A fireplace with a closed firebox has factory supply slots on the front side of the portal, which can be used to regulate the combustion process.

These cracks are small, but they are enough for working fireplace. But when the fireplace is not used, then the sum of these gaps(relative to the dimensions of the chimney) too small in order to ensure heating of the chimney.

As a result, the chimney channel cools down and reverse draft flows through it. Well, since almost all such fireplaces have a damper (damper) that is made loose, with cracks, it cannot be used to stop the penetration of cold air into the room. Here you need either an additional tight gate, or door always ajar fireplace with constant supply.

These are some of the basic rules that it is advisable to listen to.

There are still many different nuances that affect the operation of the fireplace, but if you at least follow these recommendations, you can subsequently avoid many problems.

Furnace chimneys

Installing individual heating and cooking sources has become commonplace for private homeowners. Someone builds a classic Russian stove in their home, on which they can cook food and heat the whole house. Some people prefer a miniature household oven that heats up in minutes and is convenient for cooking, and use the heating stove to warm up the living room.

There are many options for solving the problem, but each of them combines one furnace oven. In fact, they are separate structures that are subject to their own construction rules and, although structurally connected to the main body of the furnace, have structural and structural features.

Why build a chimney

In superficial thinking, it seems that the chimney is only intended to fulfill one function of exhaust gas evacuation and is no longer suitable for everyone.

However, this is far from the case and is in fact involved in some rather complex processes that, at first glance, are not completely invisible. (See also: do-it-yourself chimneys for boilers)

The main thing, of course, is to take the exhaust from the place where the fuel is burning.
Regulating the speed of the generated current to minimize this and prevent condensation of the deposition of active substances;
Ensure maximum heat transfer from exhaust gases, which increases the efficiency of the furnace.

The special shape of the chimney facilitates the fulfillment of these tasks, while additional solutions are being developed to facilitate their implementation.

For example, to increase heat dissipation, an air labyrinth was invented in which the exhaust gases were kept longer in the chimney for a longer time, thereby heating up further.

What parts make up a chimney?

A brick or stone chimney is a classic design, which is divided into parts according to the stages of construction and in accordance with their purpose.

(See also: DIY carbon stoves)

When the stove is installed, a vertical or horizontal labyrinth is made on the floor of the stove. Each of them has its own disadvantages and advantages.

The vertical smoke labyrinth provides a higher velocity of exiting gases and is therefore degraded.
But its design allows you to reduce cleaning time and effort. To cleanse this labyrinth, windows are made from which ash falls.
The horizontal design of the labyrinth can significantly reduce the speed of exhaust gases.
But at low speed, soot and active formations are released. When cleaning an air labyrinth, it is necessary to collect only falling soot, but almost with the help of a special tool to overcome it from the walls of the chimney.

Also: how to clean a chimney pipe)

The flue usually begins at the stove neck, which is the part structurally connected to the body of the flue gas labyrinth without flue gases.
A smoke damper is installed directly behind the oven door, which allows the adjustment bar (increasing or decreasing the exhaust gas through the chimney), and if it is necessary to completely prevent the formation of a reverse air flow Street - not to cool the space and not to increase the cooling rate of the oven.

When the door begins to smoothly switch to interweaving interconnects.
To do this, the chimneys for the stove are thickened and at least 2 bricks are laid. As in this section, the escaping gases begin to move at a significant speed; this measure makes it possible to reduce the heating of the outer wall of the chimney, thereby significantly reducing the likelihood of a fire. The spray is applied to 1-2 bricks above the overlap of the intermediate layer.

See also: Repairing a Russian oven with your own hands)

At the intersection of the boundary ceiling, it is advisable to additionally install thermal insulation between the chimney and the external combustible coating. It is best to use modern materials, such as a sandwich panel with mineral wool filling.

After firing into the chimney structure, a lever which, depending on the internal diameter, can significantly increase the flow rate or reduce it slightly.
Although it is not particularly important to reduce the flue gas velocity characteristics, there is no reason to heat up the attic space.
The transition between the attic and the outer part of the roof is made by a special structure called an “otter”. When installing fireplaces and chimneys from stoves, you must strictly follow the technology and complete all structural elements. For example, if it was not "open", which is an extension of the chimney and does not allow a change in standing position, sediment will be applied to it by the outer wall and fall towards the front of the stove, thereby disturbing the outside of the structure.

Also: how to clear tea from a chimney)

Above the structure is the otter of a classic chimney, if the hose for the door, which must be fixed in height, that the chimney itself is above the ridge of the roof or when it is located side by side, no more than 10 degrees if the line is reduced in accordance with the top edge of the roof.
This is necessary so as not to create reverse draft, but the chimney worked in the desired direction - the release of gases from the outside, and not the ventilation of air in the room. If the stove smokes inside the room, it is necessary to slightly increase the height of the chimney neck.
The chimney ends with a head covering it on top.
It is usually made of tin or thin sheet metal, in the village you can find old cast iron which is located on the top of the pipe.

Fireplace installation and chimney installation

The main purpose of the head is to prevent precipitation from entering the chimney and to prevent foreign objects carried by birds from entering.

What are the non-standard uses of a chimney?

Chimneys are not commonly used today.

It is true that they must have a slightly non-standard configuration, but such models are still used successfully.

For example, attention can be drawn to fairly frequent structures in chimneys, rather than to some vertical chamber on all sides that goes around the chimney. In this area it is very suitable for dry or smoked products.

Another unusual use for a chimney is a camping portable smoke stove. This is essentially a versatile and compact design that includes both ovens for cooking where you need to stew, plates that can be fried foods and water boils, and finally wet and damp things can be dried on this oven.

The most interesting thing is that most of the functions of a smoke stove are available thanks to the special design of the chimney.

Like a conventional stationary stove, the "smoke" contains the stove, but to miniaturize the design it does not offer separate ash, just below the neck for storing the fuel, several holes are made through which the air required for combustion is supplied.

Inside the furnace body, which opens into two parts, a steel mesh is perforated, through which waste ash and coal are extracted.

Separately, it should be noted the design of the chimney, which is actually straight, and the gases escaping into it only accelerate.

On the first elbow, which is directly mounted on the body of the stove, there is a platform on which you can place a dish or a kettle. It fits over the top of the chimney, but if it's still holding the radial rods, then it's entirely possible for damp things to dry out quickly due to the warm exhaust gases and because they're high above the stove so they don't burn.

Chimney maintenance

There are many models and types of chimneys, but there are practically no stoves that do not have them.

Being one of the main structures of chimneys that require constant care and maintenance. It consists of regular cleaning of the internal channel from the application applied to it and the salts of the active components. At least once a year it is necessary to clean a special device that resembles a regular washing brush.

Also, don't forget that you need to remove and test the air labyrinth, otherwise the exhaust gas flow will be greatly reduced, the pattern will be lost, and the furnace will not be able to operate.

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Our ancestors, living in almost the coldest country on the planet, heated their homes in winter with wood-burning stoves. In an era when every residential building is equipped with a gas boiler, stoves and fireplaces have become exotic, the installation of which serves as a decorative element rather than a practical necessity. However, these devices are still heating devices, and therefore require smoke removal. In this article we will tell you how to construct a chimney for a fireplace.

Chimneys for fireplaces or stoves are channels through which a mixture of gases, which are products of fuel combustion, is removed from the furnace of a heating device into the atmosphere. The design of these elements of the heating system is made in the form of a pipe or a brick shaft, the tightness of which determines whether the system works correctly. Chimneys for fireplaces and stoves are necessary, since without them it is impossible to operate heat-generating devices, the operation of which is as follows:

Fuel is placed into the furnace of heat-generating equipment (stove, fireplace, boiler). Basically, the devices operate on wood, gas, compressed or hard coal, and fuel oil.
The fuel is ignited using an open flame source, as a result of which the system generates a large amount of heat, which is used to maintain the optimal temperature in the room, and smoke.
Smoke, which is a product of fuel combustion, consists of a mixture of carbon dioxide and carbon monoxide, ash, soot, and other aggressive chemicals. The temperature of the smoke entering the chimneys for fireplaces or stoves reaches 400-500 degrees, therefore, obeying the law of convection, it rises, freeing up space in the firebox for cooler air.
The design of the smoke removal channels is a vertical sealed shaft through which hot smoke rises only upward. Thanks to this process, fresh oxygen-rich air enters the firebox, which is necessary to maintain combustion.

The process of drawing oxygen-rich air into the firebox is called draft. To check chimneys for fireplaces for the presence of draft, you need to bring a lit match or candle to the firebox: if the flame deviates towards the smoke exhaust channel, then the system is working correctly. If the candle flame burns evenly, there is no draft. But the most dangerous situation occurs when backdraft occurs; it is signaled by a flame deviating in the opposite direction from the chimney.

To correctly make a smoke exhaust duct for a stove or fireplace, you need to carefully study the information about the heating device specified in the instructions, and also calculate the volume of gas in the firebox. It is quite difficult to install a chimney for a fireplace with your own hands, since this complex design requires special knowledge and experience, which only experienced craftsmen can boast of.

Placement methods

Assembly and connection of the smoke exhaust duct occurs after installation of the heating device. However, you need to select a location and calculate the cross-section and pipe before starting installation. Chimneys for fireplaces or stoves are placed in two ways:

Note! Calculation of the smoke exhaust duct of a heating device determines the recommended cross-section and height of the pipe, and calculates the required level of draft to maintain combustion. When calculating these parameters, the power of the device, the type of fuel used, location and climatic conditions in the construction region are taken into account. Chimneys for fireplaces are built on the basis of a design that takes into account all of the above factors, and the connection is made under the supervision of a professional craftsman.

Materials

Chimneys for fireplaces are made from various materials that have high heat resistance, low thermal conductivity, excellent fireproof properties, do not enter into oxidative reactions with water, and do not interact with aggressive chemicals contained in combustion products. To make a durable and reliable smoke exhaust duct for the stove, use the following materials:

Important! The material for assembling the chimney is chosen based on the type of fuel on which the heat-generating device operates: brick and ceramic pipes are better suited for fireplaces and stoves operating on solid fuel; steel sandwich pipes do a good job of removing smoke from gas models.

Requirements for smoke exhaust ducts

The use of heating ducts is associated with the risk of fires and carbon monoxide poisoning, therefore strict requirements are imposed on smoke exhaust ducts, the purpose of which is to protect users. To ensure that the operation of the equipment does not cause problems, the following conditions must be met when installing the chimney:

Important! Experienced stove craftsmen advise, when discussing a fireplace project, to insist on placing the chimney inside the house, and always near the inner and not the outer wall. With this installation scheme, the channel turns out to be warmer, there is no draft deficiency and vapor condensation in it.

Video instruction

Installing a fireplace requires experience and certain instructions; installation is especially difficult if you plan to assemble not only a heavy solid fuel stove, but also a chimney, without which the full and safe operation of such a solid fuel heating unit is impossible.

If you plan to install a fireplace that burns wood or another type of solid fuel, you need to take care not only of its place and location, design features, but also how and how the hood or chimney itself will be installed and assembled, which is necessary for timely removal of combustion and decay products.

Fireplace installation criteria

Installing a fireplace stove requires compliance with a number of rules and basic requirements that will help you to be sure to cope with this task yourself, thereby saving money that could have been spent on the services of a professional craftsman or stove maker:

The fireplace insert is installed only in a pre-prepared portal, and the opening of the frame must correspond to the hearth in its depth, shape, width, height and other parameters;
The fireplace insert is installed only in a stable portal made of a fire-resistant frame, sheathed and lined with materials of appropriate quality and characteristics;
Cast iron and steel fireplace inserts have an average weight of up to 200-300 kilograms maximum, due to their low weight, such fireplaces can be installed in a brick and wooden house, on the first or second floor. Reinforcement of the floor and walls is sometimes necessary, but installation of a foundation in this case is not required, since the mass of such a cast iron or steel hearth is small. Unlike a brick oven, the weight of which can be more than 1000 kilograms, which in turn requires the mandatory construction of an additional foundation that will not be connected to the house;
A cast iron fireplace, as well as classic brick stoves, become very hot during operation and kindling, which is why, for fire safety purposes, it is necessary to install such stoves and fireplace inserts only on an insulated floor and near fireproof walls. Floor insulation is cheaper and best done with a sheet of metal or by building a low concrete podium; metal sheets can also be used to protect the walls, which can be replaced with heat-reflecting foil, tiles, natural or artificial minerals;
Do-it-yourself brick fireplace can only be assembled if you are clearly and one hundred percent confident in your skills and strengths. To facilitate the masonry process, you need to draw or take from trusted sources a high-quality order, a diagram with which you can accurately calculate the required amount of materials, mortar, fittings. The order also shows in detail each row of masonry, how many bricks it consists of, when it is necessary to install a firebox, ash pan, grate;
A fireplace, the firebox for which can be either purchased or assembled from brick, must be installed in the right location and room to achieve maximum efficiency and efficiency of up to 95 percent. It is best if the fireplace stove is installed in the central room of the house, so you can get maximum and uniform heating of all rooms in the house. Do not install the fireplace near load-bearing walls, since with this arrangement, 90 percent of the heat will go outside and will not warm the house. Also, you should not install the fireplace near windows and doors, since when they are opened, a draft will be created, which will cause a decrease in efficiency and deterioration in draft performance, which can lead not only to inefficient operation, but even to smoke.

A stove, the masonry of which is carried out by hand, must be laid only from high-quality bricks, which will be perfectly smooth, without chips and cracks, through which smoke and decay products may subsequently escape into the room.

A fireplace, the price of which depends on the chosen manufacturer, model and its functionality, is best to buy a cast iron one, since cast iron is capable of producing good accumulation of thermal energy, warming up rooms well, and in addition, such a material is durable. The disadvantages of cast iron fireplaces include the average strength of the material and the need for such a device to completely cool, since if cold water gets on the hot surface, the material can become deformed and deteriorate.

A do-it-yourself fireplace made of steel has a more affordable price; such a firebox heats up quickly, but is not durable, wears out quickly, and when the fuel burns out, it immediately cools down; the average service life of this option will be no more than 7 years.

If you still decide to assemble it with your own hands from brick, for the main frame, the surface of which does not heat up much, you can use the simplest solid brick, but as for the firebox and chimney, you will need a more expensive fire-resistant stove brick.

According to stove makers, it is better to assemble the entire fireplace stove from one brick and not combine different types with each other, since different categories of materials have not only different sizes, shapes and characteristics, but also the coefficient of thermal expansion. This, in turn, can cause cracks to appear on the surface of the heating unit, violating its tightness. The adhesive solution itself for assembling brick fireplace stoves must be used the same for any brick; it must contain clay.

A foundation is necessary for brick fireplaces or cast iron or steel fireboxes, the total mass of which, together with the portal, exceeds 500 kilograms; it is especially important to assemble an additional foundation if the house is old or wooden.

Chimney installation criteria

Installation of a chimney is necessary if you plan to install in your house or dacha a classic solid fuel stove-fireplace that runs on wood, coal or pellets, during the combustion process which emit harmful and dangerous decomposition products when inhaled, requiring timely removal to the street.

Chimneys, in turn, can belong to a certain type, based on their characteristics and materials of manufacture:

A brick chimney stove is a classic option, which is used extremely rarely today due to a lot of disadvantages, which include the heterogeneity and roughness of the inner surface of the chimney. In turn, a large amount of condensate, soot and soot begins to form in these cracks, which is quite difficult to clean. Also, brick chimneys are difficult to construct and very expensive, since they require a large amount of brick;
Installation of a sandwich chimney is more justified due to the fact that such pipes can be installed both inside and outside the house; a sandwich hood consists of steel and insulation, which is placed between two pipes;
Steel chimneys are assembled and joined according to the principle of a designer, they have an affordable cost and low weight, a steel hood gets very hot, which is why it is often lined and enclosed in a box;
A ceramic chimney is something between a brick and a steel hood in terms of its features and characteristics; this design is a pipe that is enclosed in a ceramic box that acts as protection against overheating.

When installing a chimney, you need to familiarize yourself with the basic rules and requirements for this process:

A chimney with a large mass is installed only in a house with a stove that has an additional foundation or high-quality reinforcement of the floors;
If the chimney is installed and fixed on the facade of the building, it must be insulated, this will not allow it to freeze in the winter and cold seasons and a large amount of condensate will form inside the pipe;
The fireplace hood is lined only with refractory materials, and to collect condensate, one or more collectors are installed inside, their number depends on the length of the pipe;
The angle of inclination of the chimney should not be too large; if possible, the number of bends and transitions should be minimal and no more than 2-3, a large number of them will lead to a deterioration in draft performance;
The walls near which the chimney passes must be insulated with sheets of metal, ceramic tiles or stone - this will ensure the necessary level of fire safety;
The hood can be enclosed in a box, which is assembled from heat-resistant materials, metal, brick and performs not only the role of protection and an additional accumulator of thermal energy, but also, if there is cladding, a decorative function;
When a chimney passes through a wall or ceiling, it is necessary to install a fluff and isolate the space through which the hood will pass with special steel inserts, which can be purchased at any specialized store.

The chimney is one of the main structural elements of any wood-burning stove-fireplace, the incorrect operation of which can cause not only certain inconveniences, but also cause a fire or reverse operation of the exhaust mechanism.

The chimney exits through the facade or interior of the building onto the roof; for proper and proper operation, it must be 0.5-1 meter higher than the highest section of the roof and all nearby buildings, to protect against debris and precipitation getting into the pipe, on top of it put on the spark arrester and cap.

If you are planning to install a gas stove or boiler in your home and do not want to experience difficulties in installing a chimney or invest large sums of money in it, you can limit yourself to installing a simple coaxial chimney. A coaxial chimney is a ceramic pipe passing horizontally through the wall of the house, which has no turns or bends. However, installing a coaxial chimney is possible only in houses in which the equipment is heated without interruptions and downtime, since in severe frosts, a large amount of condensate begins to form in such an exhaust hood, as a result of which it begins to freeze.

If you want to install a fireplace insert or a fireplace stove with a chimney in your country house or in your home with your own hands, we recommend watching this video:

The proper functioning of the fireplace depends not only on the installation of the firebox, but also on the competent design and installation of the chimney. Everything is important: from calculations of the pipe cross-section to the nuances of thermal insulation. Only a high-quality chimney will best suit its purpose.

Do you want to build a chimney duct, but don’t know which pipe to choose and how to install it? We will help you deal with this problem - in the article we looked in detail at how to make a chimney for a fireplace, paying attention to the pros and cons of pipes made of various materials.

They also provided important requirements for arranging fireplaces and drawing up a project. The article material was supplemented with detailed instructions for installing a chimney, providing it with step-by-step photos.

The purpose of the fireplace chimney, as well as the main function of the chimneys of stoves or boilers, is to remove the products of fuel combustion to the atmosphere. Gases along with soot flow from the furnace into the chimney under the influence of draft.

The correct formation of a chimney consists in choosing and constructing a structure in which a minimum of soot remains on the walls of the pipe, and the draft prevents the flow of gases into the room.

Chimneys made of different materials have their own characteristics and may differ in design. For example, a traditional brick chimney consists of the following parts.

Modern chimneys made of steel or ceramics do not have such fragments as otter or fluff, but for the normal removal of smoke in brick pipes and to protect the ceilings from heating, they are simply necessary

When choosing a material, it is necessary to take into account the temperature of the gases: in the furnace it is higher, at the outlet it is lower, but even at the highest point it can reach +100 ° C. The creation of draft is based on the temperature difference - hot air is replaced by cold air.

Also important are indicators such as the height and internal diameter of the chimney - they are calculated when drawing up the project.

Step-by-step instructions for laying a chimney

The prepared project is a guide to action: it contains a masonry diagram, an estimate, and a list of construction activities. Laying a brick chimney is the final part of building a fireplace.

Step 1– preparation of materials and tools. To prepare the solution you will need sand, cement, lime (or special clay), and a container; for masonry construction - jointing, trowel, hammer, level.

Step 2– preparation of the solution. Craftsmen usually know special secrets on how to make the solution more elastic and non-cracking. For example, add a little lime to it. The consistency of the mass should resemble sour cream, be thick, but easy to separate.

Step 3– masonry. The ready-made order makes the work easier - each row must be laid according to the diagrams. If a ceramic or steel pipe will pass inside the brick body, this must also be taken into account when choosing the layout and section size.

Step 4- fluff. This element - the expansion of the pipe - is installed when passing through the ceiling. The brick is shifted ¼ towards the outer edge.

As a result of the shear, the thickness should reach 0.5 m. A sheet metal sleeve and pieces of basalt thermal insulation are inserted into the gap between the masonry and the ceiling.

If you find it difficult to choose a material or pipe design, we recommend turning to experienced stove makers who know many secrets of high-quality fireplace construction.

Have you decided to build a chimney for your fireplace yourself, but in the process of studying the information you still have some unclear points? Ask our experts and other site visitors for advice - we will try to clarify complex issues.

Or maybe you have practical experience in installing chimneys and want to point out some inaccuracies or shortcomings in the material presented? Or do you want to supplement the material with useful tips from a professional? Please write to us about this in the comments block.