The correct passage of the chimney through the attic floor, truss system and roof is no less important than compliance with all other requirements when building the stove itself. The fire safety of the house, and therefore of all those living in it, as well as the efficiency of the heater, will depend on how reliably these nodes are equipped.

The passage of the chimney through a wooden floor must be especially reliable, since in this area the heated walls of the pipe are in close proximity to combustible materials. In order to secure the floor elements, various thermal insulation materials and special devices can be used - there is no shortage of them on the market today.

The performance of such work must be treated with the utmost responsibility. Therefore, in order to understand these issues, you should familiarize yourself with the current requirements. normative documents, consider the process of conducting a chimney through ceiling to do everything strictly according to the rules established by the controlling organizations.

What do building codes and regulations (SNiP) say about this?

SNiP 41-01-2003 "Ventilation, air conditioning and heating" regulates the main aspects related to the arrangement of various autonomous heating systems. Since this publication is devoted to the analysis design features passing the chimney through the attic floor, it is necessary Special attention pay attention to section 6.6 - this is "Stove heating", and its subsections.

In some cases, these existing rules become a real problem for owners of private houses when arranging their home heating system. Such difficulties arise due to the fact that some of the requirements for modern heating systems and materials used for thermal insulation are clearly outdated. However, despite the possible obvious contradictions, the controlling organizations rely on this guideline and require the implementation of established standards.

At the same time, it must be remembered that if the stove is installed in a newly built house, then it will be necessary to legalize its presence in fire fighting services Otherwise, registering the property simply will not work. Such a permit is issued on the basis of an act drawn up by an employee of the controlling organization that accepts the building. If serious violations are found during the inspection current regulations, then, there is nowhere to go - you will have to correct the mistakes made. Therefore, it is best not to immediately deviate from the established standards.

Not everyone likes the dry language of regulatory documents, and therefore they are simply afraid to look into them. Let's try to state these rules for them in a few paragraphs:

The thickness of the walls of a brick chimney in the area of \u200b\u200bits passage through ceilings, roofs or walls (partitions) must be greater than along the main height. This thickening is called cutting.

According to existing standards, the thickness of the groove is considered taking into account the thickness of the pipe itself. The masters often use the colloquial term “from smoke” in this regard. So, standard size cutting is:

- 500 mm, if the pipe borders on a building structure made of combustible material (which, of course, includes a wooden floor).

- 380 mm - for those cases when the materials of the building structure are protected from fire by a layer of plaster of at least 25 mm with reinforcement steel mesh, or a metal sheet with an asbestos lining under it with a thickness of at least 8 mm.

The height of the chimney cut must be at least 70 mm greater than the thickness of the ceiling. By the way, SNiP does not stipulate from which side these millimeters should “look out” - from below, on the ceiling, or in the attic. Among the masters, judging by the forums, there is also no unanimity. But, as a rule, customers are asked to make a flat ceiling in the room, so a 70-millimeter step can be located in the attic. However, if you read the forums again, you can find cases when the inspector fire brigade demanded a 70-mm "side" both above and below. And it was not possible to convince them of the opposite.
It is undesirable to cut the chimney rigidly to the floor materials or to rely on any building structures. True, there is no categorical prohibition on this matter, but one should nevertheless adhere to such a recommendation that the deformation of one element that occurred for some reason does not entail the destruction of the other.
The space between the cutting and the building structure is filled with non-combustible materials. The list of materials is not specified, but in practice, those that can be classified as thermal insulators are usually used - these are expanded clay, vermiculite, mineral wool.
If the cutting of the pipe falls on the opening of a wall or partition and combustible materials, then its thickness cannot be less than the thickness of the partition itself. In this case, the cutting should be performed along the entire height of the wall.
When the pipe passes through roofing cutting is also often performed, which in this place has the name "otter". In any case, the distance from the outer walls to any elements roof structure from combustible materials should be at least 130 mm for brick pipe, and 250 mm - for ceramic without thermal insulation (when using insulation with a heat transfer resistance of at least 0.3 m² × ºС / W - 130 mm). The section of the roof at the passageway must be made of non-combustible material only.
When building a furnace and its chimney, it is important to observe the distance to walls and partitions. This gap has its own name - retreat. The amount of retreat is also regulated by the requirements of SNiP:

Chimney wall thickness, mm	Retreat type	Distance from outer surface walls of the furnace or chimney to a wall or partition made of combustible material, mm
		- non-flammable surface	- surface protected from fire
120 (ceramic fired brick)	open	260	200
120 (ceramic fired brick)	Closed	320	260
65 (heat-resistant concrete)	open	320	260
65 (heat-resistant concrete)	Closed	500	380

The surface will be considered protected from fire if the requirements already mentioned above are met - plaster desired thickness or asbestos-metal "pie". At the same time, the dimensions of the area on which such protection is made must be larger than the dimensions of the furnace or chimney by at least 150 mm in each direction.

These requirements are optional only for partitions made of materials with a fire resistance rating of REI 60 and higher (preservation bearing capacity, integrity and thermal insulation properties under 60 minutes of direct exposure to fire) and zero flame spread limit.

When installing factory-made metal furnaces, it is necessary to follow the recommendations given in the manufacturer's documentation. If not, the general rules apply.
The distance between the furnace itself (its upper wall) and the ceiling is also important. The following regulations apply here:

BUT. If the furnace ceiling consists of three continuous brick rows, then this distance should not be less than:

— for unprotected ceilings - 350 mm for periodic fires, and 1000 mm for long-burning stoves.

- for ceilings protected with a plaster layer or asbestos 10 mm + metal - 250 and 700 mm, respectively.

B. If the oven floor consists of only two continuous rows, then the above distances to the ceiling should be increased by one and a half times.

AT. For metal stoves, the clearance between their upper surface and the ceiling of the room must be at least 800 mm if the ceiling has the above-mentioned thermal protection, and 1200 mm if it is not.

The penetration of metal chimneys through any floors or walls must be carried out through sleeves made of non-hot material.

The gaps around the chimney pipes must be sealed with non-combustible materials (class NG or, in extreme cases, G1), best of all - with the lowest possible coefficient of thermal conductivity. This will provide the necessary fire resistance for fences.

The wood used to mount the truss system and attic floor, belongs to the G3-G4 group in terms of combustibility. After being treated with flame retardants, it becomes more resistant to fire, but, despite this, it remains combustible. It is naive to rely on the "magical qualities" of the advertised impregnations, which allegedly completely makes the tree non-combustible. That is why it is necessary to adhere to the norms established by SNiP, correctly positioning the chimney and other sections of the furnace at the specified distances from the structural elements of the house.

Self-activity in these matters, unauthorized deviation from existing rules, simply committed negligence can lead to tragic consequences, since overheating of adjacent furnace design elements of the building with a high degree of probability will end in their ignition.

So, a poorly equipped chimney penetration through a wooden ceiling can easily lead to a fire. To avoid tragic consequences, it is necessary to properly thermally insulate the cutting, ensuring proper level fire safety.

To figure out how to carry out these actions correctly, it is necessary, keeping in mind the recommendations of SNiP, to consider the whole process in stages.

Since the chimney can be metal or brick, it is necessary to separately consider the installation of both options.

Penetration for a metal chimney pipe

Special devices and materials for sinking a metal chimney

Box-shaped ceiling-through structures

The arrangement of the passage of a chimney metal pipe through the structure of a wooden floor can be carried out using a finished ceiling through node, or made independently, but in compliance with the standard dimensions.

If purchased ready-made version such penetration, then its size is selected according to the diameter of the chimney pipe. The convenience of using the factory box is that its design already provides for all the dimensions established by SNiP, so you don’t have to rack your brains over this. It remains only to show an opening in the ceiling for penetration, and then strengthen its thermal protection of the surfaces.

You can make a passage-box yourself. It is made of different materials - it can be a steel sheet with a thickness of at least 0.5 mm, alone or in combination with minerite, asbestos sheet, with mineral basalt wool foiled on one or both sides. If the box is purchased or made of metal, then it will need to be thermally insulated with ordinary or foil mineral wool, vermiculite, expanded clay.

If it is decided to make such a penetration on its own, then the diameter of the hole in its central part should be approximately 0.5 mm larger than the outer diameter of the pipe. This is done in such a way that the metal pipe passes freely through the box, but at the same time, the gap between them would not be too large.

For the manufacture of penetrations, you can use the dimensions shown in the illustrations and presented in the table:

Letter designation of structural elements and size in mm
d - hole diameter	L - side length of the decorative panel of the box	G - the width of the sides of the box	H - box height
205	580	370	310
215	580	370	310
255	580	450	310
285	580	450	310

If the passage box is made only of 50 mm thick foiled mineral wool, then it is best to cut the elements for it according to pre-made templates. Assembly of parts in single structure carried out using heat-resistant foil tape. Having chosen this option for cutting, you must not forget that you will also need to purchase or make one or two metal panels for it. One of them is attached to ceiling surface, flush with it, and the second (optional) closes the heat-insulating material from the side of the attic.

Another option for penetration can be a box made of a metal sheet, insulated with the same foil-clad mineral wool. This insulation is cut into strips with a width equal to the height of the resulting box and is laid along the walls on the end, with the foil side to the pipe. The space of the box free from the pipe must be densely filled with a thermal insulator.
The box can also be made of mineralite (fiber-reinforced concrete slabs) 10 mm thick. Structural elements are also cut out according to prepared templates, and then fastened together using metal corners. A smaller box made of a metal sheet 0.5 mm thick is installed and fixed in a casing made of this material.

Between the walls of the outer and inner boxes there should be a gap of 10 ÷ 15 mm wide, which is filled with basalt insulation, and the space around the pipe can be filled with vermiculite, expanded clay of fine or medium fraction, or the same mineral wool. The holes through which the pipe will pass must have the same diameter in both boxes. A metal plate can also be used to aesthetically design the penetration from the side of the living room, or the fiber cement board can be left open. After finishing installation work, the slab facing the living room will be easy to paint in the color of the ceiling.

Video - Making and installing a homemade box-shaped chimney penetration sauna stove

Heat-resistant materials for the manufacture of penetrations

A few minutes of attention deserve the characteristics of heat-resistant materials that are used to insulate the ceiling penetration. They differ in some of their qualities from conventional insulation made on the same basis.

Minerite is absolutely not combustible material, which is also called fiber cement boards in another way. It is often used for wall cladding in areas where stoves and chimneys are installed.

Minerite prices

This material is not only resistant to extremely high temperatures, but also moisture resistant, has good mechanical strength, does not contribute to the formation of mold and fungus colonies. Minerite is environmentally friendly pure material, so when elevated temperatures does not emit fumes harmful to human health.

For the manufacture of screens installed in the cutting and on the walls around furnaces and chimneys, "minerite LV" panels are used. In addition, such panels are also suitable for the construction of fire-resistant partitions.

Non-combustible slabs made of basalt wool and covered with aluminum foil, are used for fire protection of walls and passages around chimneys.

This material is made from environmentally friendly components and has a high resistance to aggressive biological and chemical effects. According to its thermal insulation data, mineral wool, of course, is many times superior to minerite, but inferior to it in mechanical strength and durability.

High-quality basalt slabs do not accumulate moisture, and they do not create a favorable environment for the settlement of rodents and insects, the appearance of microflora colonies. This type of insulation belongs to the flammability group G1. (Yes, and this is only due to the adhesive layer that holds the foil coating, since in its “pure form” basalt insulation can be attributed to completely non-combustible materials). Basalt slabs from different manufacturers may differ somewhat in the upper limit of the operating temperature range. But in any case, it ranges from +750 to 1100 degrees, which should be more than enough for the chimney.

Prices for basalt slabs

basalt slabs

Installation of a penetration for a metal pipe

Before installing the penetration into the window cut out for it in the attic floor, it must be prepared, further strengthened, if necessary, and insulated from high temperatures.

The first step is to additionally monitor the condition of the opening and its surrounding parts. ceiling structure. This is done in order to make sure that the box in it will be securely fastened.

The box penetration must be firmly fixed to the ceiling structure. It, of course, is positioned so that it is between the floor beams (it is clear that these issues regarding the placement of the furnace in the room are always thought out in advance). Beams can become a reliable basis for fastening the penetration, located on the sides of it.

However, it often happens that the floor beams are too far apart and therefore the "pie" of the floor in the area of \u200b\u200bthe pipe passage does not have the necessary rigidity, and it will need to be strengthened. Another option, exactly the opposite, is that the too frequent step of the installed beams does not leave enough free space to accommodate the box penetration.

In any of these cases, after removing the desired section of the coating, you can mount the frame, in accordance with the dimensions of the box, using wooden beam. The crossbars of this frame are rigidly cut into the floor beams. If necessary, with too widely spaced beams, additional longitudinal support bars can be used in the frame. An example of creating such a frame is shown in the illustration.

Such a check and strengthening (refinement) of the frame will be necessary if it is mounted in an already built house. However, as a rule, the installation of stoves and, therefore, the installation of chimneys, are planned in advance. And in the process of installing floor beams during the construction of a building, such a frame is provided in advance for the subsequent installation of box-shaped penetration.

Further, all wooden details ceiling structure, located along the perimeter of the cut-out window for penetration, must be additionally treated with a special impregnation. The flame retardants included in the composition will increase the fire characteristics of the created assembly. Continue to further operations only after complete drying of the treated surfaces.

The next step is to install a penetration box into the cut-out opening from the side of the room. The edges of its bottom part are securely screwed with self-tapping screws on the ceiling surface.

But this operation should be performed only after careful control of the location round hole for the chimney relative to the heater. It is unacceptable that even a slight deviation causes unevenness, a "break" of the installed pipe. This will create unnecessary stress in its walls, which may well lead to insufficient sealing in the joints.

Precise alignment of the box passage is best done on a plumb line to ensure that the axis of the pipe being installed is vertical.

Further, the lower part of the chimney pipe is assembled, starting from the outlet pipe of the furnace (boiler).

It is very important - no matter the distance from the stove to the ceiling, and no matter what accessories are used, never, under any circumstances, the connection of two elements (pipes) of the chimney should not fall on the ceiling. Little of, minimum distance from such a connecting node to the floor surface (it does not matter, from below, in the room, or from above, from the side of the attic) should be at least 300 mm.

Requirements for correct location junctions of individual pipes are important, of course, from the standpoint of providing visual control. But the main predetermining factor of such a considerable (300 mm) offset from the ceiling is the continuing probability of a breakthrough of hot gases in these, let's be honest, the remaining most vulnerabilities prefabricated metal chimney.

The next stage of work can be carried out from the side of the attic or living space, depending on how it is more convenient to mount next section pipes. If the work is carried out from the side of the attic, then the next part of the chimney pipe is passed through the hole and fixed on the lower, already mounted section.

When the pipe is led into the attic, you can proceed to filling the penetration box with heat-insulating material. If one of the loose thermal insulation materials is selected, and small gaps remain between the pipe and the border of the round hole, they can be clogged with basalt wool or plastic clay, and then the insulation is poured from above.

From bulk heat-insulating materials, it is best to choose expanded clay or vermiculite. Ordinary sand is used for backfilling only as a last resort, as it has a too fine fraction, big weight and excessively high thermal conductivity for such a function. Expanded perlite sand is not particularly convenient to use in such conditions due to its excessively high "volatility".

The easiest way to fill the box with heat-resistant basalt wool, as it has the lowest thermal conductivity. When using a mineral wool mat, the box from the attic side should not be sealed thoroughly in order to have free access to the pipe throughout its entire length. If the pipe goes to the second floor, then the hole in its floor with insulation material around the chimney can be closed with a metal sheet, screwing it to the floor.

The selection of photographs below demonstrates the installation of a home-made box penetration made of dense slabs of foil basalt insulation.

- The first two fragments: this is a finished self-made penetration from different angles.

- The third fragment: a window was cut out in the ceiling for the installation of penetrations. Please note: to ensure maximum safety, the master filled the gap between the ceiling covering and the attic floor with mineral wool.

- Fourth photo: The penetration box is inserted into the prepared opening and fixed from below.

- Fifth fragment: After the installation of the pipe section leading to the attic, the penetration is closed from below with a metal panel. It is securely fixed on the ceiling with self-tapping screws, completely covers the edges of the window of the passage unit, holds the heat-insulating box well in the ceiling and provides mechanical protection for the mineral wool panel, which is not very durable.

- Sixth photo: Continuation of the installation of the chimney. The gap between the pipe and the box will be tightly filled with mineral wool. Since the attic in this case is “inhabited”, the passage node will be covered with a decorative metal plate.

And in the video below, the master managed without creating a box structure at all.

Video: fire fluffing of a chimney pipe in a passage through a wooden floor

The passage of a brick pipe through the ceiling

A masonry chimney is usually designed to protect surrounding combustible materials from overheating. The section of the pipe, which is laid out when it passes through the ceiling, is already a cut in itself and is called "fluff".

This chimney design is traditional, long-tested, and most often chosen by stove-makers.

"Fluffing" begins under the very ceiling in the living room (three to four rows of bricks before it) passes through the entire thickness of the attic floor. Sometimes the fluff is raised to the clean floor of the attic, in other cases it is made flush with the subfloor. Both options can cause nitpicking of the inspectors - we recall the notorious “70 millimeters” already discussed above.

This structural element plays the role of the necessary thickening of the pipe walls, which protects the combustible materials of the ceiling from overheating.

In fact, the design of the “fluff” is directly affected by precisely the requirements of the SNiP that were considered in the first section of the publication. In order not to repeat yourself, you can give a diagram that clearly shows what dimensions and where must be observed:

Can I lay out a brick chimney myself?

The work, at first glance, is simple, however, a lot depends on its quality, up to the health and life of the inhabitants of the house. Detailed information you can read about it by following the recommended link - it will be easier to figure out whether it is worth taking this event on yourself, or it is better to invite specialists.

Another option for arranging the penetration of a brick pipe through the ceiling is carried out in almost the same way as a metal pipe. In this case, of course, the chimney along its entire height has the same cross-sectional size, without increasing the thickness of the walls. However, all linear parameters established by SNiP are respected.

The hole in the ceiling can be covered with a metal sheet or fiber cement board. In the middle of the thermal insulation panel, a window is marked, through which the chimney will pass. The length and width of this opening should exceed the similar parameters of the pipe by literally 3 ÷ 5 mm.

When laying the chimney, about three or four rows from the ceiling, a sheet with a prepared opening is put on it, and then the laying is carried out further to the height of the attic's clean floor.

The next step, the sheet put on the pipe is lifted, pressed and fixed to the ceiling in a way convenient in a particular case - with self-tapping screws or dowels.

Further, work is carried out from the side of the attic or the second floor. Strips of basalt wool, pieces of asbestos or fiber cement slabs are laid along the walls of the opening cut out for penetration. This "frame" should cover the entire thickness of the attic floor. If necessary, the material can be fixed on the floor beams.

Thanks to these operations, a kind of box is created around the neck of the pipe, which will be filled with heat-resistant material. As it can be used basalt wool, which densely fill the entire volume. If cotton wool with a foil layer is used, then it is turned towards the walls of the furnace.

It is quite possible to perform such thermal insulation of the pipe with expanded clay or vermiculite, but before backfilling, it is imperative to close up the gaps remaining between the pipe and the edges of the opening, especially if fine fraction material is used.

Of course, you can do exactly the same as with a metal pipe, putting a ready-made penetration made of steel sheet. This option will probably be more reliable and convenient both in terms of its installation and reliable fixation, and when filling the box with thermal insulation material. True, such a box will cost much more. Does it make sense - decide for yourself.

After filling the penetration with insulation, it is also covered from above with a metal or fiber cement sheet.

At this point, the work on arranging the safe passage of the chimney through the ceiling can be considered completed.

After reviewing the details of the arrangement of this area of \u200b\u200bthe chimney, we can come to the following conclusion:

That there are no particularly complex actions that are subject only to highly qualified narrow specialists in this process. The main thing is to scrupulously follow the requirements established by SNiP, maintaining all the necessary dimensions and following the recommendations. If you do everything according to the rules, then you can not only ensure safe operation heater, but also to avoid completely unnecessary problems with regulatory authorities.

Evgeny AfanasievChief Editor

Publication author 28.10.2016

/ How to run a chimney through the ceiling?

How to run a chimney through the ceiling?

When installing a chimney, the most important thing is to ensure reliable protection from the fire. That is why, the passage for the chimney through the ceiling must be made in accordance with all the rules. Even special sandwich pipes must be carefully insulated in places where they come into contact with the details of floors and roofs.

Basic rules for arranging a structure

By following simple instructions, you can assemble a safe and well-functioning chimney. However, if you deviate from the instructions below, the design can not only become inefficient, but also dangerous in terms of fires.

The total height of the structure should not be less than 5 meters from the heat source to the pipe head.
It is not allowed to use pipes of a smaller diameter than the outlet of the stove pipe.
The height to which the pipe rises above the roof must exceed the height of the ridge by 50 centimeters. If the chimney is located on the slope of the roof, then the distance above which it should rise by half a meter is calculated based on the following diagram:

If the device has a height above the base of more than one and a half meters, it must be strengthened with stretch marks.
Connections of structural elements should not coincide with passages through the roof or ceiling.
The length of horizontal or inclined sections of the chimney must not exceed one meter. This is necessary to prevent soot clogging of the pipes, as well as to ensure the best ratio of traction force and furnace efficiency.
If the roofing material is combustible, then it is necessary to equip the pipe with a spark arrester made of mesh, with cells no larger than 5 millimeters.

It is not difficult to take into account all these points, and the efficiency and safety of the device under construction will comply with all necessary standards and norms.

Organization of the passage

In most cases, a special sandwich pipe is used for the construction of chimneys. It is a two-pipe design. different diameter nested one inside the other. Between them, a non-combustible heat-insulating material is laid. The outer shell is made of thin metal, and the inner part is made of thicker steel.

The passage through the ceiling of such a sandwich chimney is carried out in the same way as a conventional pipe. Unless there will be a little less work on arranging the passage node. Can be used as turnkey solution already made at the factory, and independently assemble the necessary assembly.

In any case, it is necessary to first prepare the place where the entire device will be installed. cut into the ceiling square hole, with a side of about 45 centimeters. This size is enough to pass a standard chimney through it.

The ceiling assembly itself for the passage must be laid out on the outside and inside with a heat insulator that can withstand high temperatures. The most popular for such purposes is a special basalt wool.

According to the size of the square part of the node, reference lines are drawn on the ceiling. The opening must be located strictly above the furnace nozzle. The hole itself is sawn slightly smaller than the connecting square plate. It is necessary to leave such a gap so that it is possible to attach it to the ceiling with self-tapping screws. The finished opening is laid out with the same heat-insulating material as the passage assembly.

Insert a finished assembly into this hole to check all connections. Before you bring the chimney through the ceiling and finally fix it, you need to make sure that the pipe is vertical and that it is exactly in the center of the opening.

If you look from the side of the upper floor or attic, you can see that there are voids in the passage node. They are filled with non-combustible heat insulator. You can use expanded clay, clay or the remains of basalt wool. The main thing is to fill the void very tightly.

To have a better idea of what the whole assembly looks like in section and what the chimney passage looks like through the ceiling, you can look at the drawing below.

The diagram shows the main elements of the chimney and the passage unit, as well as the parts of the ceiling through which the passage was carried out. Through the roof, the pipe is carried out in a similar way. The only difference will be a hole in a square metal plate - it will not be round, but oval, as it will be located at an angle.

Self-manufacturing of the transition node

It is not necessary to buy a finished product if you want to do everything yourself. The design of this practically does not change. It is also necessary to cut a square hole in the ceiling.

The next stage is the preparation of a plate of non-combustible material, which will be attached from the inside of the room. It cuts a hole round shape equal to the outer diameter of the sandwich pipe.

The inner surface of the cut out opening is lined with a heat insulator and sewn up with metal strips. Through it, a sandwich pipe is passed, with a prepared mounting plate put on it. It must be securely fixed in the opening with spacers made of a material that can withstand high temperatures and does not burn.

Between the mounting plate and the plane of the ceiling, a sheet heat insulator is often laid to prevent heating. This is not the most mandatory measure, but it certainly will not be worse from such a precaution.

From the side of the upper room, the void in the ceiling is filled with a heat insulator. As in the previous case, it can be expanded clay, clay or special basalt wool. Some use sand, but it’s better not to do this - its thermal conductivity is higher than even that of expanded clay, and the loose structure will lead to the fact that sooner or later it will begin to fall asleep.

You can also read about how to close the chimney passage on the ceiling.

This material contains only general information regarding how to run the sandwich chimney through the ceiling. There are also more complex technical terms designs. However, general principles ensure fire safety and the effective operation of the chimney will not change.

The Russian bath is usually heated with firewood, which means that it is necessary good chimney to remove combustion products. Only certain types of chimneys can work flawlessly on a sauna stove, so the choice of material must be approached responsibly. The issue of installing a chimney, which is allowed to pass through the ceiling or wall, should be taken just as seriously.

Types of chimney for a bath

A chimney is a device that improves draft in the furnace and removes gases into the atmosphere. This channel has a rectangular or circular section and consists of vertical and sometimes horizontal elements.

The first chimney consists of only vertical parts, and the second has one horizontal element

Between themselves, chimneys differ in the material of manufacture and design.

What material is suitable for the chimney

Most often, smoke channels are constructed from bricks, ceramics and steel. The last material can be black, galvanized or stainless steel.

Combined chimneys are widely used. The most popular are two options: a brick channel with steel pipe inside and a ceramic pipe in a steel case.

Combined chimneys combine metal and material with poor thermal conductivity

The advantages of brick, ceramics and steel - they perfectly resist fire, are not toxic when heated. Asbestos-cement and aluminum pipes do not have such advantages, therefore they cannot be used to build a chimney for a sauna stove.

by the most practical material metal is considered for the manufacture of the chimney

To make it easier to choose between brick, ceramic or steel, I can give a simple but useful advice: it is better to take the raw materials with which you have experience. For example, someone who once posted brick wall, it will not be difficult to assemble a brick chimney. True, such a product is gradually becoming a thing of the past, freeing the way metal devices. I, like many other owners of baths, boldly prefer a stainless steel sandwich pipe.

A chimney made of sandwich pipes is preferred by most bathhouse owners, since these structures are made with a thick layer of insulation inside and no longer require modification during installation.

Sandwich pipes (double-walled metal constructions) are in demand due to the following characteristics:

easy and fast installation;
material strength;
low risk of fire - they do not heat up to the limit.

The chimney from a sandwich pipe is assembled simply, as from a designer, and does not require special building skills

Sauna chimney design

According to the design or installation method, the chimney can be of two types:

Subsequently, they usually regret installing an external chimney in their bath. Such a chimney is safer, but it gives off heat not to the room, but to the street. Therefore, it is better to build an internal smoke channel in the bath: it does not need to be insulated, it is easier to clean during operation.

The inner pipe goes through the ceiling and the outer pipe goes through the wall.

Calculation of the size of the pipe in the bath

When choosing a chimney, you should pay attention to the cross section (diameter) of the pipe and determine overall height channel.

Chimney section

The cross section of the chimney is round, rectangular and square. And its size depends on the power of the sauna stove.

Usually, round-shaped pipes are taken for a stove in a bath. In them, traction is as good as possible, because air flows do not encounter serious obstacles in their path.

The diameter of the pipe for the furnace in the bath is calculated as follows:

First, it is calculated what volume of gases will be released during the operation of the furnace: V gas \u003d B * V fuel * (1 + T / 273) / 3600. Where V gas is the volume of gas passing through the pipe in 1 hour (m³ / h), B is the maximum mass of fuel burned within an hour in the combustion chamber (kg, depends on the power of the furnace and the density of the fuel), V fuel is the coefficient of the volume of gases formed during the combustion of fuel (m³ / kg), and T is the temperature of the gases at the exit from the pipe (°C). The value of V fuel when using dry firewood is 10 m³ / kg, which is indicated in a special table. If the chimney is carefully insulated, the T value is in the range from 110 to 160 °C.
Substituting the necessary numbers into the formula: S smoke \u003d V gas / W, determine the required cross-sectional area of \u200b\u200bthe pipe. S smoke is the cross-sectional area of the chimney (m²), V gas is the volume of gases per hour (m³ / h), and W is the speed of movement of combustion products inside the chimney, is 2 m / s.
Calculating the area of the circle, find the diameter of the pipe. To do this, use the formula D \u003d √ 4 * S smoke / π, where D is the inner diameter of the round pipe (m), and S smoke is the area of \u200b\u200bthe internal section of the chimney (m²). P - mathematical constant (3.14).

Table: dependence of the temperature of the gases in the chimney on the fuel

Fuel			The volume of combustion products at 0 o C and 760 mm of pressure, m 3 / kg,V fuel	Temperature of gases in chimneys, oC
Type of fuel	Qph kcal/kg	Density kg / m 3		First T1	Intermediate T2	Last T pd	Exit to the pipe T uh
Firewood with 25% humidity	3300	420	10	700	500	160	130
Air-dried lump peat with a moisture content of 30%	3000	400	10	550	350	150	130
Peat briquette	4000	250	11	600	400	160	130
Coal near Moscow	3000	700	12	500	320	140	120
Brown coal	4700	750	12	550	350	140	120
Coal	6500	900	17	480	300	120	110
Anthracite	7000	1000	17	500	320	120	110

So that the calculation of the pipe diameter does not seem too complicated, you can consider it with an example:

It has been established that 8 kg of firewood burns in an oven in an hour.
For T we take the value of 140 ° C.
During the operation of the furnace, gas will be released in a volume of 0.033 m³ / h (V gas), since 8 * 10 * (1 + 140 / 273) / 3600 = 0.033.
According to the second formula, we get the number 0.017. This cross-sectional area (in m²) is required for the chimney.
It was found that the furnace needs a chimney with a diameter of 0.147 m (since √ 4 * 0.017 / 3.14 = 0.147).
We translate the diameter value from meters into millimeters and round it up (i.e., it turns out 150 mm).

Chimney height

The height of the chimney is primarily affected by the type of roof.

Above the surface of a flat roof, the pipe should rise at least 50 cm. If more than one and a half meters of the smoke channel comes out, then special extensions are used to fix this structure.

On a flat roof, it is better to build a brick chimney, but usually a bathhouse is made under a pitched roof.

Of particular importance when calculating the height of the pipe is the distance from the place of its installation to the ridge beam of the pitched roof. Namely:

if the pipe is more than 3 meters away from the ridge, then its upper edge should be at the level of the line conventionally drawn from the ridge down at an angle of 10 degrees to the horizon;
when the distance between the ridge and the chimney is in the range from 1.5 to 3 meters, the pipe is placed at the same height as the ridge;
reducing this distance to 1.5 meters, the pipe is raised at least 50 cm from the level of the ridge.

The height of the chimney depends on the type of roof and the distance from the chimney to the roof ridge

Pipe output options

The pipe from the sauna stove is allowed to be led out into the street both through the roof and through the wall.

Through the ceiling and roof

Installation of a chimney through the ceiling is conditionally divided into the following stages:

Preparation of the opening - a hole 45x45 cm in size is cut out in the ceiling of the bath. Another similar opening is made above it in the roof. Both windows are created so that the chimney passes exactly in the middle of the hole.
The hole for the passage of the pipe through the ceiling is made square
Welding of the passage unit - 5 square blanks are cut out of a steel sheet with metal scissors: one is 50x50 cm in size, and the rest are 5 cm smaller. A round hole is cut in the middle of a large piece (the diameter is equal to the outer section of the chimney). Holes for fasteners are drilled in the corners of the product. welding machine a box is welded from four other (small) blanks. It is then connected to a large piece of metal with a hole. Or you can simply buy a chimney pass-through at the store.
The metal box will protect the ceiling from overheating during the operation of the sauna stove
Mounting the feed-through to the ceiling - prepared metal box inserted into the ceiling hole inside baths and fixed.
The pipe passes through the ceiling, being in a firmly fixed metal box
Making a box for passing through the roof - another metal box is made using the same technology. But a hole is not cut in itround instead of oval. After all, the box will be mounted on a pitched roof, so it will turn out to be inclined relative to the pipe. However, it is difficult to accurately determine the cross section of the resulting ellipse, so it is better to purchase such a product in a store. This box is mounted to the roof from the side of the attic.
The passage of the pipe through the roof also requires the installation of a metal box in order to protect the truss system of the bath from overheating and fire
Assembling the chimney - an element with a gate (a valve to adjust the thrust force) is put on the furnace pipe. It must be made from a single-walled strong pipe, even if the entire channel is made of sandwich pipes: so that they do not catch fire internal insulation. The first section of the chimney is fixed to the furnace with metal fasteners. The second link is mounted on it. If it is thinner than the outlet of the first element, then an adapter is installed on the first element. Then the two parts of the smoke channel are welded and fastened with a clamp.
The link with the gate is attached directly to the furnace and is the beginning of the chimney
Pipe insulation inside the box - the box in the ceiling is completely filled with expanded clay, clay, asbestos or mineral stone wool. The top is covered with metal foil. Or you can put a metal sheet with a hole in the middle.
The space between the boards and the pipe is filled with insulating material.
Creating the necessary pipe bend - if the hole in the roof is not located directly above the stove, then a knee is installed on the second fragment of the chimney. This is an adapter to change the direction of the pipe. Another link is mounted on it, which is brought out of the roof through the box.
The elbow allows you to change the direction of the pipe and lead it exactly between the rafters
Making the passage for the pipe on the roof - a box mounted in the roof is filled with mineral wool. The area with the outgoing pipe is covered with roofing material. An elastic roof is put on top of the chimney. It is glued to the roof surface with a moisture-resistant sealant and fixed with self-tapping screws. Sometimes, instead of an elastic kryzy, a metal one is placed.
The metal lid is as effective as the elastic one.
The top of the pipe is supplemented with a fungus that protects against precipitation.
Installation of the chimney is completed by attaching the umbrella

Video: how to run a chimney through the ceiling and roof

Through the wall

When it is necessary to bring the chimney of the furnace through the wall, sandwich pipes are used. The installation process is as follows:

A hole is made in the wall opposite the furnace nozzle. If the bath is brick, then so many bricks are knocked out of the masonry with a perforator to form a square opening 40x40 cm. As a result, a clearance of 20 cm should be obtained between the chimney and the wall. If the bath is wooden, then a square hole is cut with an electric saw.
A metal box is placed in the sawn window, through which the pipe is brought out.
The inner walls of the opening are sheathed with basalt cardboard. A factory-made or home-made metal box is inserted into the hole on the inside of the bath, which is fixed with self-tapping screws. From the side of the street, the box is densely filled with basalt mineral wool. A heat-resistant sealant is squeezed into the gaps between it and the wall. Outside, the passage block is sealed with a metal plate or a decorative rosette, which is attached to the factory product.
An adapter is mounted on the furnace pipe, treated with sealant, which can withstand temperatures up to 1500 degrees. The junction of the two elements is pulled together with a metal clamp.
The metal clamp is reliable connecting element for chimney pipe parts
A horizontal section of the smoke channel is attached to the adapter. In length, it should not be more than a meter. A horizontal pipe is passed through a ready-made hole in the wall, and a tee is put on its end.
Brackets will not allow a tall chimney to move from its place
From the side of the street, a bracket is attached to the wall. It will stabilize the position of the vertical element of the chimney.
A vertical section of the chimney is assembled - the upper element of the pipe is mounted on the lower one with a wider socket. The places where the tee and two sections of the chimney are combined are coated with sealant and tightened with clamps.
To the first vertical element pipes alternately join the rest. Brackets with clamps are fixed on the wall at equal distances to help the chimney stay upright. To move the chimney away from the roof, a special tubular element is used - a branch. On the assembled structure an umbrella is mounted.
Among the elements of the chimney through the wall, there must be a branch

Video: how to run a chimney through a wall

Sauna chimney insulation

The part of the internal chimney located above the ceiling and the entire external chimney that extends beyond the bath needs additional insulation. Typically, chimney insulation is used:

basalt wool or glass wool - equally fire resistant, keep heat well, do not emit harmful substances and are not afraid of moisture, rodents, or high temperatures;
Thermal insulation is often used due to its low cost.

In most cases, the chimney from a single-walled pipe is insulated with cotton pads. Insulation technology:

Video: how to isolate the chimney

The chimney for the bath must be built in such a way that later there is no doubt about its safety. The builder needs to take into account many things: appearance, correct dimensions smoke channel and the nuances of bringing the pipe out.

In a private house or in a bath with furnace heating there is always an increased risk of fire due to the close proximity of the heat source to combustible materials. Therefore, the installation of stoves and fireplaces and, in particular, internal chimneys provides for compliance with fire safety rules established in SNiP. Most dangerous area furnace heating system in the house is the place where the chimney pipe passes through the ceiling, ceiling and roof truss system. Since the chimney pipe becomes very hot when smoke and gases pass through it, if combustible materials are close, they can ignite and cause a fire. You can avoid a dangerous situation by observing the requirements for the installation of the chimney and using special ceiling-through units.

The ceiling-through unit is a protective box that is installed in a provided or specially cut hole in the ceiling and roofing cake. Inside the box there is a hole through which the chimney pipe is brought out. The main task of the protective ceiling-through unit is to isolate the chimney, preventing it from coming into contact with combustible roofing materials or heating them to dangerous values.

Ceiling ducts can be purchased from ready-made or make it yourself in accordance with SNiP and fire safety standards. Finished products - best option, because their design already provides opportunities for thermal insulation of the chimney. For installation, it is enough to choose a box that matches the size and geometry of the chimney.

Important! Before installation in the ceiling, the node must be isolated heat-insulating material. Basalt mineral wool and foil screens are best suited for this purpose, which withstand high temperatures and are characterized by low thermal conductivity.

Regulatory requirements and fire safety rules

The exact requirements and figures governing the rules for installing a chimney and its passage through the roof-rafter system are contained in SNiP 41-01-2003, namely, in section 6.6. Key condition, which determine the safety of the chimney pipe wire through the roof - the maximum heating temperature of the surrounding structures and materials should not exceed 50 ° C.

FORUMHOUSE users are well aware that the quality installation of a metal chimney directly affects the safety of living in a cottage. We have already written about. It's time to talk about the features of installing a steel chimney.

1. What is a sandwich chimney

In spite of big choice materials for the installation of smoke exhaust systems, reliable steel sandwich chimneys are most widely used in private housing construction.

A sandwich chimney consists of two pipes of different diameters inserted into each other, and all the free space between them is a place to fill with non-combustible insulation - mineral wool.

Mineral wool simultaneously plays the role of a heater and an insulator.

Sandwich chimneys have the following main advantages:

High installation speed and low cost compared to brick chimneys;
Light weight of the smoke exhaust system;
Smooth inner walls of the chimney provide good draft and help reduce soot formation;
The use of acid-resistant grades of stainless steel guarantees a long service life of the chimney.

The flue gas temperature directly depends on the type of heating boiler and the type of fuel used. The higher the temperature of the flue gases, the stronger the pipe and, accordingly, all the structural elements through which it passes. The following table will help you understand the dependence of the flue gas temperature on the type of boiler and the type of fuel used.

It should be remembered that unprotected wood begins to char at a temperature of 200 ° C. Well-dried wood can ignite from an open flame source at a temperature of 270-290 ° C. And if wooden surface exposed to constant heating for more than 24 hours in a row, it can ignite spontaneously already at a temperature of 170 ° C. Therefore, when installing a sandwich chimney, it is important to observe all fire safety measures. And any mistake made at this stage can lead to sad consequences - a fire and loss of property.

Urban:

- Two of my friends' houses burned down due to an incorrectly installed sandwich chimney. Moreover, in both cases, the fire occurred in the place where the chimney exits through the wooden ceiling.

According to statistics, up to 80% of fires occur precisely because of improperly installed chimneys. Therefore, when choosing and installing a chimney, it is necessary to adhere to SNiP 41-01-2003 "Heating, ventilation and air conditioning".

2. Chimney: distance to the floor slab and correct penetration

As practice shows, the greatest number of questions arise when calculating the distances from the chimney to the wooden floors.

VadimPro:

- I built a house with a distance between the rafters of 60 cm. And only later I found out that, according to existing standards, my chimney does not fit into this distance.

And again, SNiPs come to our aid:

vova230:

– According to the norms, when driving through wooden floors, it is necessary to maintain a distance of 38 cm from the inner tube of the sandwich to combustible structures. All this space must be filled with non-combustible material. If the standard passage does not provide this distance, then the dimensions of the furnace passage must be further increased.

If the chimney is laid through protected wooden structures, then the distance can be reduced to 25 cm.

Protection wooden structures- log, rafter ends, battens - provided by a galvanized sheet with an asbestos sheet at least 5 mm thick laid between it and the tree.

Galvanization performs the following functions:

Prevents the spread of fire in the ceiling;
Provides uniform heat dissipation;
Shields and reflects heat radiation coming from the pipe.

In the case of penetration of interfloor ceilings with single-pipe steel chimney the distance to unprotected wooden structures must be at least 50 cm!

Also, the parameters of the chimney should be calculated in such a way that the chimney pipe passes through the ceiling as a whole - without joints with other elements. The chimney itself is installed through a passage pipe-cutting, which is a metal box.

Portal Site Specialist Alexey Telegin from Moscow recommends:

- According to the norms, the thickness of the groove (metal box) should exceed the thickness of the ceiling by 7 cm.

Seal of floors in the place of passage metal pipes from the stove with basalt-fiber cardboard

Installation of PPU chimney

The very process of mounting the cut in hardwood floor can be broken down into a number of successive steps:

1. We cut a hole in the ceiling with a size of at least 700x700 mm.

2. If necessary, remove or strengthen the floor beams.

3. We sew up the perimeter of the cut out opening with fireproof materials, superisol, etc.

4. For tightness, we put a sheet of basalt cardboard under the superisol.

5. Doing load-bearing frame from a galvanized profile, which is used for the installation of GKL.

6. The dimensions of the frame are calculated for the fastening points of the PPU (ceiling-through node).

7. We close the opening with sheets of mineralite or superisol with a hole for the passage of the inner part of the PPU.

8. We fix PPU.

9. Install the sandwich pipe.

10. We warm lower part PPU and the space around it with non-combustible insulation, this will avoid freezing and the formation of frost and condensation.

It is better to lay down and calculate the smoke exhaust system at the design stage of the house!

It is also important to pay attention to how the pipes are connected to each other. There are two ways - "by smoke" and "by condensate".

Docking "in the smoke" - the pipe of the lower bend of the sandwich goes inside the pipe of the upper bend of the sandwich. In this case, flue gases move freely up the walls of the pipe;
Docking "by condensate" - inner tube sandwich: the top is inserted into the bottom, outer pipe sandwich: the bottom is inserted into the top. With this installation, the pipe allows condensate to pass through, it flows down unhindered and does not flow out along the outer part of the chimney, which can lead to a fire.

Kotlasky:

– The condensate pipe is usually installed on modern gas boilers, because they have a low temperature of outgoing smoke.

In metal stoves, cast iron potbelly stoves, the smoke temperature is about 300 ° C, the steam that is released during the combustion of firewood begins to condense at a temperature of less than 100 ° C. At the moment of kindling, steam, falling on the cold walls of the chimney, is deposited in the form of water droplets, which roll down the smooth walls of the chimney into the condensate collector.

The condensate collector is installed outdoors. It is better to collect a sandwich chimney "by condensate".

3. Features of penetration through the roof

Penetration through the roof is done according to the same principles as penetration through the ceiling. Let's find out if it is correct that when driving through the rafters, the distance to the protected wooden structures can be reduced to a size of 150 mm.

Alexey Telegin:

- It is assumed that the chimney cools down when passing through the roof, and the space around it is well ventilated, so you can reduce the gap to the protected rafters. In my opinion, this may be true for a cold roof, and for an insulated one, it is necessary to apply the norms and distances, as for interfloor floors.