Brick chimneys are often installed in private homes to remove the products of combustion of fuel in stoves, fireplaces and boilers. Structures of this type are durable, but at the same time they are considered quite difficult to install. When designing and assembling a brick chimney, certain rules must be observed.
Pros and cons
The main advantages of brick chimneys, in comparison with metal ones, in addition to durability, are:
- aesthetic solid appearance;
- ability to tolerate significant temperature changes;
- good heat storage.
Brick chimneys in the vast majority of cases just fit perfectly into the interiors of almost any design. Such designs look very harmonious in rooms decorated in a classic style, loft, country, Provence, chalet and even modern.
Unlike metal chimneys, brick chimneys after heating are able to give off heat to the surrounding air for a long time,thereby increasing the efficiency of furnace equipment.
Such structures are built from a material that is not subject to rust and is fire resistant. Brick chimneys never burn out and can last up to 50-100 years.
The advantages of pipes of this variety, therefore, there are many. But such chimneys, of course, still have some drawbacks. In addition to the complexity of installation and relatively high cost, the disadvantages of structures of this type include:
- significant weight;
- ability to trap soot inside.
Brick chimneys in private houses during operation have to be cleaned from time to time. Unlike metal, the walls of such structures have a rough surface from the inside. This explains their ability to trap soot.
Since brick chimneys are heavy, they have to be built on the most solid foundations, which, of course, significantly increases the cost of installation work.
Types of chimneys
Pipes of this type can be built in private houses:
- mounted;
- indigenous.
The first type of chimney is installed directly on the stove (and sometimes on a solid fuel boiler). It is these pipes that are laid out in private homes most often. In order for the oven to support the weight of this type of chimney, its walls must be at least two bricks thick.
Root pipes are placed at a short distance from the heating equipment on the foundation. Chimneys of this variety are usually equipped for boilers or furnaces of modern design.
Sometimes in private homes, wall pipes can also be used to remove exhaust gases. Such structures are mounted inside the walls separating heated rooms. Sometimes chimneys of this type are also equipped in the external enclosing structures of private houses.
Configuration
Chimneys are built of brick according to the schemes of a special variety - orders. The design of this type of pipe is relatively simple. For fireplaces, for example, it can even be just straight smoke channels laid out using the “brick” technique.
The design elements of the outlet pipes of modern furnaces and boilers are usually:
- fluff neck with smoke valve facing the ceiling;
- fluff - thickening in the overlap, reducing the risk of fire;
- riser - the longest part passing through the attic to the roof slope;
- otter - an extended part that prevents snow, debris and rain from entering the chimney and reduces the risk of fire of the wooden elements of the truss system;
- neck and cap;
- metal cap.
The foundations for the main chimneys of furnaces and boilers are the most reliable and durable - slab foundations.
Design: section area calculation
Brick chimneys, for obvious reasons, usually have a shapesquare or rectangular. The best option for home heating equipment is, of course, a pipe with a round cross section. However, laying out a brick chimney in this way, of course, is not possible.
When designing such pipes, it is important, among other things, to determine their cross-sectional area. This indicator depends primarily, of course, on the power of the furnace equipment itself, which is determined depending on the size of the heated room and the degree of its insulation.
In any case, the section of the chimney for a brick oven or solid fuel boiler, according to the regulations, should not be less than 130x130 mm. Such pipes are usually erected for furnaces with heat output up to 3500 watts. If the house uses more powerful heating equipment, it is supposed to build a chimney with a cross section of at least 260x260 mm.
A rough calculation of the required pipe dimensions can also be made depending on the volume of the combustion chamber. It is believed that these indicators should be related to each other as 1:10. Also, when designing a chimney, one should take into account the fact that its cross section should not be less than the area of the blower hole.
Height of pipe total
This parameter should also be calculated as carefully as possible when designing a chimney. In a pipe that is too high, excessive draft will subsequently be created. And this, in turn, will lead to a significant decrease in the efficiency of heating equipment and an increase in fuel consumption.
You can not make a chimney for a brick oven or boiler in the house and too low. This is,in turn, it can lead to unnecessary turbulence in the mine and the formation of reverse thrust. Operating a furnace or boiler with such a pipe in the future can even be dangerous. The lack of draft leads to smoke in the premises when laying firewood or coal in the furnace. That is, people living in the house in this case can simply be poisoned by carbon monoxide.
According to the SNiP standards, the “correct” brick chimney, including in a low-rise building, must have a height of at least 5 m. cap).
Height of the pipe on the slope of the roof
Metal chimneys of stoves and boilers can be brought out into the street, including through the walls of the house. Brick structures of this type, in the vast majority of cases, are laid during installation, of course, through the ceiling and the roof slope. When using this technology, among other things, you should adhere to the following standards:
- if the distance between the pipe and the ridge does not exceed 1.5 m, it should rise above the latter by at least 50 cm;
- with a distance between the pipe and the ridge from 1.5 to 3 m, a brick chimney on the roof can be erected at the level of the latter.
If the pipe is located further than 3 m from the ridge, it is assembled in such a way that its upper edge is on a conditional line drawn through the vanishing point of the slopes at an angle of 10 degrees to the horizon. Above flat roofs, a brick chimney is laidto a height of at least 50 cm.
Choice of masonry material
Sometimes chimneys in private houses are built from fireclay bricks. However, such material, unfortunately, is very expensive. Therefore, more often such pipes are still assembled from ordinary solid burnt red bricks. Such a stone is able to withstand fairly high temperatures, is relatively inexpensive and lasts a very long time. Brick chimneys are mounted from this type of material in a bathhouse, in small private houses, cottages.
It is believed that burnt stone of only the first grade should be chosen for exhaust gases. In this case, the pipe, which during operation is exposed to various kinds of adverse environmental factors, as well as strong temperature fluctuations, will subsequently serve as long as possible. In terms of strength for assembling the chimney of a private house, you should choose a brick of a brand not lower than M150 / 200.
In some cases, for some reason, the exhaust gas pipes, the owners of suburban residential buildings, have to be built from second-class material. In principle, the regulations allow this. However, such a pipe at the final stage must be additionally plastered (part of the structure above the slope). Before performing the actual masonry itself, such a brick should be soaked in water. In this case, he will subsequently not draw water from the bonding mixture and, accordingly, the masonry will turn out to be more durable.
Which solutions can be used
Masonrymixtures for the installation of brick chimney pipes must also be selected with the utmost care. Such structures are usually mounted using three types of solutions:
- clay;
- cement;
- clay-cement.
Mixtures of the first variety are used where the pipe is very hot during operation. With the use of such a solution, laying of the lowest part of the chimney is usually done on the last rows that cover the furnace. Fluff is also often collected on such a mixture.
For laying the riser, otter and all other parts of the pipe, clay-cement mortar is usually used. In these places, the chimney can also warm up, but not too much.
Purely cement mortar is usually used if the pipe is being built not on the furnace itself, but on a separate foundation. In such structures, the lower rows are always subjected to serious loads due to the large weight of the brick. The cement mixture in such chimneys, called, as we found out, indigenous, is used for laying the first two rows. The remaining parts of the pipe are assembled according to the same rules as when erecting directly on the furnace.
Mixing
Clay for the solution, when it is kneaded, is pre-broken and soaked. Sand is necessarily sifted to remove particles of debris, stones, organic inclusions. These two ingredients are mixed in proportions depending on the fat content of the clay in this particular area.
Sometimes masonry is performed on suchindustrial solution. A clay mixture of this variety can now be purchased at almost any building supermarket. The only thing is that in this case you need to buy material designed specifically for laying furnaces. Such mixtures, among other things, are able to withstand significant temperatures.
Cement mortar in most cases is prepared in proportion with sand as 1/3 or ¼. For plasticity, a little slaked lime is most often added to such a mixture.
Cement-clay mortar for installing a brick chimney is usually prepared according to this recipe:
- 10 l sand/clay mixture;
- 1 liter of grout.
Chimney foundation
Ordinary exhaust pipes are laid out as a continuation of the furnace, according to the rules. Indigenous chimneys, as already mentioned, are assembled on a solid foundation. The foundation is poured under such pipes using standard technology.
First, a foundation pit is dug to erect a concrete slab. If the chimney is laid out inside the house, the depth of the latter is usually 50 cm. If the pipe is being built on the street, the pit is dug below the freezing level of the soil.
Further, in any case, the foundation is poured using the following technology;
- the bottom of the pit is covered with a mixture of crushed stone and sand;
- formwork is installed in the pit;
- rebar cage being installed;
- concrete is being poured.
Installation of a brick chimney, according to the regulations, must be carried out on a foundation, the height of the plinth of which is at least 30 cm.
How to make a brick chimney: masonry rules
When assembling the pipe itself, certain recommendations should be followed. The masonry should be carried out first of all in such a way that there are no protrusions and depressions inside the shaft. The seams during the construction of the pipe should be flush with the wall. If the home master does not have experience in assembling chimneys, he should use special steel or wooden templates when laying. Such elements are simply inserted inside the pipe and lifted by the handles higher and higher as it is erected.
At the end of the laying of a brick chimney, plastering work is usually carried out only from the outside. Inside, the surface of such pipes in most cases is left unfinished. In the plastered shaft in the chimney, various kinds of chemical reactions will subsequently begin to occur, contributing to the destruction of the masonry. In addition, such a finish in the future will most likely collapse and clog the pipe.
Sometimes, in large houses, brick chimneys with several channels are erected at once. The thickness of the partitions in such structures, according to the regulations, should be at least 12 cm. That is, they need to be erected using the half-brick method.
Very often the chimney trunk in a private house passes throughunheated attic. In this case, it is supposed to be erected according to the technique in a brick. That is, the wall thickness of such a chimney should be at least 25 cm.
Assembly rules in foam block buildings
Sometimes brick chimneys in houses have to be erected next to walls assembled from such material. Foam and aerated concrete blocks are currently very popular with owners of suburban areas and are used to build houses quite often.
With such walls, the chimney is usually connected using 6 mm wire or 1.5x20 mm steel strips. Lay these elements most often in every second row of the pipe or in each row of the building envelope. At the same time, the wire or plates are brought into the masonry to a depth of at least 20 cm.
Installation in a wooden house
In such buildings, flue pipes should be laid with the utmost care. Wood lights up already at a temperature of 300 ° C. Inside the chimney, the air temperature can reach 500 ° C. Sometimes open fire is even observed in such pipes.
In wooden houses, therefore, chimneys should be insulated not only in places where they are laid through floors and slopes, but also near walls. According to the regulations, such pipes are supposed to be located at a distance of at least 25 cm from the log cabins when using two layers of asbestos gasket and 38 cm in the absence of the latter.
How to spendthrough the floor and slope: standards
Fire safety standards when laying chimneys in private houses built from any materials must, of course, be observed without fail. Through ceilings and roof slopes, such pipes should be carried out correctly. If the brick chimney comes into contact with the wooden elements of the ceiling of the house and the roof, this can lead to the ignition of the latter and a fire.
When passing through the floor, it is important to first of all correctly calculate the thickness of the joint. This parameter is determined taking into account the cross section of the pipe itself. According to the standards, the jointing is assembled in such a way that its height is at least 70 mm greater than the thickness of the ceiling. Very often, the “step” of the transition between the chimney itself and the cutting of the master is equipped in the attic. This allows you to make a flat ceiling in the house. However, some experts still do not advise doing so. The fact is that fire services often require that the chimney joint protrude both at the bottom and at the top of the ceiling. Remodeling the pipe in the future, if necessary, of course, will be extremely costly and time-consuming.
The brick chimney jointing cannot be rigidly fixed to the floor materials. It is also not recommended to rely on any building structures. Free space is left between the cutting and floor structures, which is subsequently filled with non-combustible materials. Most often, mineral wool is used to insulate pipes in our time.
The distance from the walls of the chimney otter to the structures of the roof slope, according tomust be a minimum of 13 cm. This space must also be sealed with non-combustible material.
Direct driving
In small private houses, brick chimneys for boilers or stoves can be carried through ceilings without jointing. In this case, the work of laying the pipe through the ceiling is usually done as follows:
- 3-4 rows before the ceiling level, a fiber cement sheet with a hole cut in the center is put on the chimney being erected;
- pipe is being laid up to the height of the finished attic floor;
- sheet put on the pipe rises and is fixed on the ceiling with self-tapping screws;
- from the side of the attic, strips of bas alt wool are laid on the base sheet.
The layer of heat insulator in the opening in this case should be equal to the thickness of the ceiling. From above, from the side of the attic, at the final stage, the bas alt wool is covered with a second sheet of non-combustible material.
Important
Today, for the assembly of roofs and ceilings, lumber treated with special fire-fighting compounds is usually used. Means of this type, of course, significantly increase the fire resistance of wood. However, the bursa and the board, even when using such compounds, still remain, of course, combustible. Therefore, the standards discussed above should be observed, including when laying chimneys through ceilings and slopes assembled from sawn timber processed in this way.
What caps can be installed on brick chimneys
Main purposeof these upper elements of the pipe design is to protect the shafts from the ingress of debris and water. Such caps of brick chimneys are called deflectors. Among other things, these elements create a certain vacuum at the top of the pipe, which ensures the suction of air from the furnace.
Most often, caps made of sheet steel are installed on the exhaust pipes in private houses. Such deflectors are reliable and long-lasting, and at the same time they are relatively inexpensive.
If desired, such a cap, of course, can be easily made with your own hands. Deflectors can be installed on brick pipes:
- hips;
- conical;
- tented.
Also often mounted on a brick chimney pipe and spire caps, gable, semicircular, etc.
Roof sealing
When laying a chimney through a slope, a hole of the corresponding area is cut out in the roofing material. Subsequently, moisture can, of course, penetrate into the space between the pipe walls and such sheets. To prevent this from happening, such a gap, of course, needs to be repaired.
To seal the space between the brick pipe and the edge of the roofing material in the classic version, a steel apron is used. In this case, the work is carried out as follows:
- the pipe is driven at a small height from the ramp plane;
- a wall inner profile is placed on the waterproofing along the perimeter of the pipe;
- the upper part of the slats is driven into a strobe;
- treat the joint with sealant;
- the lower part of the planks is brought under the roofing material;
- fix a waterproof tie with gutters under sheets of roofing material;
- close the entire structure from above with a decorative steel apron.
At the final stage, the apron is attached to the sheets on the slope with roofing screws. After this element is fixed on the roof, proceed to install the cap on the brick chimney pipe.
Insulation
This procedure is usually carried out to reduce the heat loss of pipes. Most often, such insulation of chimneys of private houses is done by plastering. Perform pipe insulation in this case as follows:
- reinforced mesh is fixed on the surface of the chimney;
- prepare liquid plaster mixture;
- cover the chimney with plaster in 3-5 layers.
At the end of the work, the walls of the chimney, insulated in this way, must be covered with a layer of plaster by 4 cm. This method of insulation reduces the heat loss of pipes by 25%. At the final stage, the completed plaster layer is sanded with a paint float in order to give the chimney an aesthetic appearance.
In a cold attic, as well as above the roof, chimneys can be insulated, including using bas alt wool slabs. In this case, the wall of the pipe is first attachedthe heater itself. Next, the chimney is sheathed with asbestos-cement sheets and plastered.
Arrangement of the discharge channel inside the building envelope
Internal chimneys are very often used for solid fuel and gas boilers in large houses. In this case, an unlaid shaft is simply left in the building envelope. Its cross section is calculated in accordance with the fact that 0.08 m2 should fall on 1 kW of the boiler. For example, for a heating unit with a power of 10 kW, it will be necessary to leave a shaft with a section of 0.8 m inside the wall 2 (about 300x300 mm).
Connect boilers to chimneys in brick walls by means of segments of ordinary steel pipes. The same elements are often inserted inside the mine. Pipes in such chimneys are usually insulated using mineral wool. Sometimes bas altin is also used for this purpose. The pipe is wrapped with an insulator before installation in the shaft.
Pipes for heating units operating on blue fuel
For gas brick chimneys when installed in private homes, of course, special requirements are imposed. Designs of this type should be as safe as possible in operation. After all, the accumulation of gas in the premises can lead to tragic consequences. Among other things, the outlet pipe of blue fuel heating equipment must be designed to allow easy inspection and cleaning.
The required cross-sectional area of a metal or brick chimney for a gas boiler is separately specified in the instructions for the latter. But in any case, such a pipe must have a cross section of at least 5.2 cm2 per 1 kW of power. In this case, the ratio of the sides of a brick pipe of such an assembly or shaft inside the wall should not be more than 1 to 2.
Connecting multiple heaters
Sometimes the owners of country houses connect a stove, a boiler, and, for example, a fireplace to the chimneys at the same time. This is allowed, but not in all cases. Any additional heating equipment can only be connected to brick chimneys for solid fuel boilers. If there is a gas heating unit in the house, only a separate chimney is supposed to be assembled for it.
A little about metal pipes
Stoves and fireplaces in most cases in country houses are equipped with brick chimneys. For boilers, gas or solid fuel, metal structures of this type are most often used. It can be either simple steel pipes or modern, durable and easy-to-use sandwich structures.
Metal chimneys of both these types can be brought out into the street or through the roof or through the walls. In the first case, the pipe is passed through the ceiling and the slope in special passage units, which are a box insulated with mineral wool.
Through a brick wall, metal chimneys are most often passed as follows:
- a hole of the appropriate diameter is drilled in the wall;
- on the outer facade of the house, elements are being installed forsupport of the chimney in a predetermined position;
- assemble part of the chimney from the boiler to the hole;
- assembling an external chimney with fastening to the wall with clamps.
After the installation of such a pipe, it is mandatory to check its performance.
