The rules for the production of pipe and furnace works were agreed upon in a letter from the Department of State Supervision of the Ministry of Emergency Situations of Russia. Smoke and ventilation ducts
Safe operation of household gas appliances and heating devices can be ensured with proper removal of combustion products and constant air exchange in the rooms where gas appliances are installed.
The removal of combustion products from water heaters, heating boilers and furnaces and air exchange in the premises are carried out through chimneys and ventilation ducts due to natural draft created by the temperature difference between the outside (cold) and heated air of the room. With an increase in the height of the chimney or ventilation duct and the temperature difference between the outside and exhaust air, the vacuum (draft) in the duct increases. Therefore, greater draft is observed in the channels of the first floor and in winter.
When water heaters are operating, the temperature of combustion products in front of the gas exhaust device is 180-200 °C. In the initial period, as well as with significant air leaks through the gas exhaust device, the temperature of the combustion products may be lower than the specified values. In ventilation ducts, where the temperature of the exhaust air is 20-25 °C, the draft is very low. IN summer periods, when the air temperature in the duct is lower than the outside air temperature, reverse draft may occur (draft reversal) when air flows from the duct into the room.
Rice. 1. Layout of the wind pressure zone: I - the chimney is located in the wind pressure zone; II - the chimney is located outside the wind pressure zone
When combustion products (air) move through a channel, part of the flow energy (pressure) is spent on overcoming the frictional resistance of the flow on the surface of the channel walls, on local resistance (turns, narrowing of the channel, etc.), on creating an output speed. The amount of pressure loss due to friction depends on the length of the channel, the material of its walls and their condition. For large roughness and surface contamination interior walls When the channel is closed, its resistance is greater, so the smooth surface of the inner walls of the channel and its timely cleaning improve traction.
The draft in channels with an increased cross-sectional area deteriorates, since a large cooling surface causes a decrease in the temperature of the combustion products. A weakening of draft occurs when significant air leaks occur through leaks in the channel and connecting pipes, as well as from neighboring channels, the isolation of which is broken. Air leakage leads to an increase in the volume of gases passing through the channel and a decrease in their temperature. For these reasons, cleaning doors must not be left open while the devices are operating.
The magnitude of the vacuum (draft) in smoke ducts during operation of water heaters and heating furnaces is usually 10-15 Pa, and in ventilation ducts it is an order of magnitude less. The draft changes significantly when the window or transom is opened. The operation of smoke and ventilation ducts, and therefore the air exchange in the room, is influenced by the wind, as well as the location of the house relative to neighboring buildings and structures. The chimney should not be allowed to be in the area of wind pressure. The wind pressure zone is the zone located below the line drawn from the highest point of the building closest to the chimney; structure or tree at an angle of 45° to the horizon (Fig. 1).
In order to prevent a drop in the temperature of combustion products at the outlet of the chimney, condensation of moisture from exhaust gases and freezing of chimneys, their installation should be provided in the internal walls. It is allowed to place smoke ducts in external walls made of. non-combustible materials when insulating them with outside. Chimneys must be vertical without ledges (horizontal sections) made of clay bricks with walls at least 120 mm thick or heat-resistant concrete at least 60 mm thick.
Rice. 2. Correct location the head of the chimneys on the roof relative to the ridge
In their bases, pockets 250 mm deep and holes with doors for cleaning, lined with bricks placed on the edge, should be provided.
For the manufacture of chimneys, it is not allowed to use thermally fragile or coarse-grained materials (slag concrete), as well as sand-lime brick, which has sufficient heat resistance, but is quickly destroyed in the presence of moisture and carbon dioxide dissolved in it. If it is necessary to use such materials, lining of red brick with a thickness of 130 mm is made inside the channels.
It is allowed to deviate chimneys from the vertical at an angle of 30° to it with a sideways displacement of up to 1 m. Sloping areas must be smooth, of constant cross-section, with an area not less than the cross-sectional area of the vertical sections.
Chimney height from gas water heaters and gasified stoves must be at least 0.5 m above flat roof; at least 0.5 m above the roof ridge when the pipe is located at a distance of up to 1.5 m from the ridge; not lower than the ridge of the roof when the chimney is located at a distance of 1.5 to 3 m from the ridge; not lower than a line drawn from the ridge downwards at an angle of 10° to the horizon, when the chimney is located from the ridge at a distance of more than 3 m (Fig. 2).
The height of exhaust ventilation ducts located next to chimneys must be equal to the height of these pipes. The mouths (heads) of brick chimneys to a height of 0.2 m must be protected from precipitation by plastering with cement mortar. The installation of umbrellas, deflectors and other attachments on chimneys is not allowed.
Structures made of flammable or slow-burning materials adjacent to stoves and chimneys, as well as ventilation ducts located next to chimneys, must be protected from fire by partitions made of non-combustible materials that meet fire safety requirements.
In houses under construction, combustion products must be removed from each appliance or stove through a separate chimney. IN existing houses It is allowed to connect to one chimney no more than two water heaters or heating stoves located on the same or different floors, provided that combustion products are introduced into the chimney at different levels (at least 50 cm from each other) or provided that cuts are installed in the chimney at a height of 50 cm 120 mm thick. In some cases, if there are no chimneys in existing houses, the installation of attached chimneys is permitted, the need for thermal insulation of which is decided at the design stage.
The cross-sectional area of the chimney should not be less area cross-section of the gas appliance or stove pipe connected to the chimney. When connecting two appliances or stoves to a chimney, the cross-sectional area of the chimney is determined taking into account their simultaneous operation.
Gas appliances are connected to chimneys using metal pipes. The length of the vertical section of the connecting pipe, counting from the bottom of the smoke exhaust pipe of the gas appliance to the axis of the horizontal section of the pipe, must be at least 0.5 m. In rooms with a height of up to 2.7 m for devices with draft stabilizers, the length of the vertical section may be reduced to 0.25 m, without draft stabilizer - up to 0D5 m. The total length of horizontal sections of the connecting pipe in houses under construction should be no more than 3 m, in existing houses - no more than 6 m.
The slope of the pipe towards the gas appliance must be at least 0.01. The suspension and fastening of connecting pipes must exclude the possibility of their deflection. The links of connecting pipes must fit tightly, without gaps, into one another along the flow of combustion products by at least 0.5 of the pipe diameter.
The connecting pipe must be tightly connected to the smoke duct. Its end should not protrude beyond the channel wall, for which a limiting device (washer or corrugation) is used.
Connecting pipes made of ordinary sheet steel should be coated with fire-resistant varnish.
They are connected to the chimney so that there remains a “pocket” with a depth of at least 250 mm below the pipe entrance, which has a hatch for cleaning.
Chimneys from appliances that do not have draft stabilizers must be equipped with dampers (dampers) with holes with a diameter of at least 15 mm; if draft stabilizers are installed, the installation of dampers is not allowed. The fireboxes of idle furnaces are ventilated through the holes in the dampers. The dampers should be located on the same wall of the furnace as the firebox.
To determine the possibility of connecting gas appliances to chimneys or when converting stoves to gas fuel, chimneys are checked for compliance of their design and the materials used with the requirements of regulatory documents; presence of normal traction and absence of clogging; density and isolation (a chimney is considered dense if the smoke from it does not penetrate into the room or ventilation ducts); the presence and serviceability of partitions protecting combustible and non-combustible structures; serviceability and correct location of the head relative to the roof, nearby structures and trees.
The absence of clogging of chimneys is checked by lowering a special spherical weight weighing up to 3 kg and a diameter of 80-100 mm to its entire depth (from the head to the cleaning pocket). The density and isolation of channels is checked using the smoke method. To do this, insert a lit rag soaked in petroleum products or other highly smoking material into the cleaning door. The outlet of the channel in the head is tightly covered with a sheet of plywood or iron. The appearance of smoke in channels adjacent to the one being tested or in rooms adjacent to the wall where the channel is located indicates that the channel is not isolated or leaking. The density and cleanliness of channels of small height can be checked by lowering a switched-on portable electric lamp with a power of up to 500 W into them. In this case, the channel being tested and the channels adjacent to it, in which there should not be a light beam, are viewed.
Smoke and ventilation ducts
Types of chimneys and channels. Chimneys are made of ordinary clay bricks (solid), asbestos-cement or pottery pipes, as well as blocks of refractory concrete. To remove fuel combustion products, pottery or asbestos-cement pipes with a smooth surface of the inner walls are used, which significantly reduces the resistance to the movement of flue gases and maintains the density of the outer walls longer compared to brick ones.
Mounted chimneys are supported on stoves or fireplaces with a wall thickness of at least 0.5 bricks. Heavy mounted pipes are installed on reinforced concrete slab, mounted on the furnace ceiling. It is most rational to install asbestos-cement pipes: they are lighter than brick ones and major renovation furnaces there is no need to disassemble these pipes; they can be firmly fixed in the attic of the building.
In one-story buildings, brick and asbestos-cement chimneys attached to the internal or external walls of the building are used to remove fuel combustion products and air exchange in the premises.
Internal and external brick chimneys are installed on separate foundations. The depth of the foundation must be no less than the depth of soil freezing. At the junction of the existing wall of the building and the brick chimney, a layer of asbestos is laid to create a sedimentary joint. Attached asbestos-cement external and internal chimneys are attached to the walls of the building using the type of fastening of drainpipes or supported on a console.
When constructing low-rise buildings, prefabricated chimneys are widely used, which are installed in the form of separate risers or built into the wall of the building. Blocks of such pipes are made of refractory concrete.
Where the chimney exits through the roof, an air gap of at least 130 mm wide is left. The chimney covering is connected to the existing roof of the building using special aprons made of galvanized steel.
When installing channels in external walls, it should be taken into account that in order to avoid hypothermia flue gases and condensation on the inner walls of the channels, which leads to saturation of the masonry with moisture and weakening of draft, the distance from the inner surface of the channels to the outer surface of the walls should be 1.5 bricks at an estimated outside air temperature of - 20 ° C and above, 2 bricks from -20 up to -30 °C and 2.5 bricks - at temperatures below -30 °C.
The construction of channels from slotted, perforated or silicate bricks, as well as from slag concrete and other thermally fragile or coarse-grained materials is strictly prohibited. If the masonry of the walls of the building is made of cinder blocks, perforated, slotted or sand-lime brick, then sections of walls with channels are laid out from ordinary clay bricks. It is especially effective to line smoke ducts with asbestos-cement pipes, which have increased density.
Basic requirements for pipes and channels. Chimneys and channels are laid out without bends or ledges. Their inner surface should be flat and smooth. This surface is obtained by careful masonry using wooden or metal buoys and subsequent mopping of the walls with a damp cloth.
The density and isolation of the smoke channel is determined by smoke. To do this, in its lower part (cleaning) they burn a resinous substance (tar paper, roofing felt, rags soaked in fuel oil). When smoke appears above the mouth of the chimney, the channel is tightly closed with a bag of sand or a piece of plywood. The appearance of smoke in adjacent channels or in rooms adjacent to the channel being tested indicates its leakage. A channel is considered separate if the smoke from it does not enter adjacent or higher-lying rooms through the connection of the stoves.
The most important requirement when installing smoke channels is to maintain their density.
If there is a blockage in one of the channels located in the chimney array, exhaust gases through leaks can penetrate into adjacent ventilation ducts or into rooms on other floors and cause poisoning from combustion products. If there is a violation of the density at the joints of asbestos-cement or pottery pipes and in brickwork cold air is sucked into the smoke duct from ventilation ducts or from adjacent ones that are not operating in this moment chimneys. This leads to a sharp drop in the temperature of the flue gases, and consequently to a decrease in vacuum.
The cross-sectional area of the chimney must correspond to the cross-sectional area of the furnace outlet pipe. Minimum size pipe sections made in brickwork - 140X140 mm (0.5x0.5 bricks), round pipe - 150 mm.
For laying chimneys, as well as smoke and ventilation ducts in the walls of buildings, lime-sand or lime-cement mortar is used. The heads of chimneys (above the roof) are laid out on cement mortar. The outer surfaces of chimneys in attics are rubbed or plastered and then whitewashed. The thickness of masonry joints on lime-sand or complex mortar is no more than 10 mm.
Connecting two devices to one smoke channel. When using a chimney to remove fuel combustion products from two or more appliances, the air exchange of rooms is carried out through smoke and ventilation ducts formed by dividing the cross-section of the chimney with partitions. The thickness of the partitions between the smoke and ventilation ducts in the chimney is at least 0.5 bricks. This division of the chimney into separate smoke and ventilation channels allows them to be used as separate chimneys.
According to the requirements of the Safety Rules in the gas industry, fuel combustion products must be removed from each furnace or other heat generator through a separate smoke channel. As an exception, in old buildings it is allowed to operate two furnace devices connected to one smoke channel, when venting combustion products at the same or different levels. In the case of removal of combustion products from two devices at the same level in the smoke channel, a cut is performed. Its height when connecting two gasified stoves into one channel is at least 0.5, and when connecting two stoves operating on solid fuel, - not less than 0.75 m.
If fuel combustion products from two gasified stoves must be removed at different levels, then the distance between connections must be at least 0.5 m. When connecting two stoves operating on solid fuel at different levels, the distance between connections must be at least 0.75 m.
Connecting two furnace devices into a common smoke channel at different levels is not recommended, since when they operate simultaneously, the lower furnace, which has a stronger draft, will prevent the formation of a normal vacuum in the upper furnace. Therefore, a significant weakening of draft may be observed in the upper furnace, which usually leads to smoking of this furnace. To avoid smoking, it is recommended to heat stoves in different time days.
Pocket device for cleaning. In the walls of chimneys below the connection point of the roofing steel chimney or below the connection point of the furnace, a cleaning pocket with a depth of at least 0.25 m is installed. Cleaning sheets are provided in asbestos-cement pipes. In the lower part of each chimney, where accumulation of soot and ash carryover is possible, cleanout holes are installed, closed with cleanout doors or tin cleaners, and sealed with bricks on the edge. Bricks are laid only on clay mortar.
The pocket design ensures safer operation of smoke ducts: in the event of a fall out internal partition the brick usually falls into the bottom of the channel and does not cover the inlet (connection). Debris generated as a result of brick decomposition and mortar spalling also collects in the pocket. Without a pocket, debris will clog the connection point of the device into the smoke channel or significantly reduce its cross-section, which will lead to the cessation of draft and the accumulation of combustion products in the room.
Most accidents when using stoves occur from blocked chimneys. Therefore, a pocket device must be mandatory for all channels intended for the removal of combustion products.
Requirements for ventilation ducts. Ventilation ducts are located in rooms where heating devices are installed. In old residential buildings Usually, chimneys of idle furnaces are used as ventilation ducts and kitchen stoves. If the location of the channel does not coincide with the installation location heating device, for example, in the adjacent non-residential premises, exhaust is carried out using air ducts made of roofing steel. In this case, the ventilation grille is fixed in the branch pipe from the side of the ventilated room, the other end of the branch pipe at the point of entry into the channel is hermetically sealed.
When using old channels that were previously used to remove combustion products from solid fuel stoves, take into account that the operation of the smoke or ventilation channel from gasified stoves has its own characteristics and differs from the operation of the smoke channel that removes combustion products solid fuel. Often, in channels that worked well from heating stoves or kitchen hearths, insufficient vacuum is created when used under smoke (from gasified stoves) or ventilation channels, since the vacuum created in the smoke channel during the combustion of solid fuel is much higher than the vacuum in the same channel during combustion of gaseous fuel. In addition, the long duration of combustion of solid fuel stoves ensures good heating of the smoke channel, as a result of which residual heat is retained in it for a long time.
The bottom of the ventilation duct inlet should be located at a distance of no more than 0.5 from the ceiling and no less than 1.8 m from the floor in rooms with a height of 2.7 m. A ventilation grill measuring at least 150x150 mm is installed at the inlet of the ventilation duct.
In the lower floors of multi-story buildings, ventilation duct grilles are placed as high as possible, and in the upper floors they are arranged at the usual height (0.3...0.5 m from the ceiling). Ventilation ducts located next to the smoke ducts lead above the roof at the same level as the smoke ducts. The cross-sectional size of ventilation ducts made in brickwork must be at least 140x140 mm (0.5x0.5 bricks), and the diameter of round ducts must be at least 150 mm.
The ventilation duct must provide three air exchanges in the room within an hour.
In kitchen areas where gasified stoves are installed and there is a ventilation duct, additionally install mechanical ventilation not allowed. When the fan operates, a high vacuum is created in the room, and a reverse draft is formed in the smoke ducts where the stove devices are connected. This can lead to poisoning by fuel combustion products.
It is prohibited to install mechanical ventilation through non-separated ventilation ducts, since when the fan is running, a reverse draft will form in the ventilation ducts located above or below.
If there is a weak or unstable draft in the smoke duct, a conventional ventilation duct can create a sufficiently strong vacuum in the room and upset the draft. Backdraft in the smoke duct can also occur when in the room where it is installed furnace device, will not be provided constant influx air.
Characteristic features poor performance of the ventilation ducts are the absence of deposits and dust adhesion on the ventilation grille, sootiness of the ceilings and walls in the room, the presence of condensation or wet spots on the walls and ceilings in utility rooms, a feeling of persistent foreign odors.
The Bezdyma company provides services for the design and installation of chimneys and ventilation ducts in buildings of various architectures.
Chimney installation
Our specialists perform the following work:
- calculation of smoke removal systems;
- design and assembly of brick chimneys;
- repair of brick chimneys;
- installation of single-circuit and double-circuit metal chimneys;
- installation of ceramic chimneys;
- calculation and installation of ventilation ducts.
Advantages of cooperation with the company “No Smoke”
Great experience
Our specialists have been providing chimney and ventilation installation services for many years. Extensive experience allows us to create effective, safe and inexpensive solutions.
Qualified specialists
We take recruitment very seriously and invite only the best engineers and installers to work.
Professional tool
Using powerful professional tool allows you to perform all technological operations quickly and with high accuracy. This ensures high quality installation of chimneys and ventilation ducts with minimal labor costs.
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All systems installed by our specialists are guaranteed for 1 year.
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We do not claim that our prices are the lowest, but many clients come to us repeatedly. This is the best confirmation that our prices for installation of chimneys and ventilation correspond to the quality and level of service.
More detailed information You can get information about our services by calling 8 (495) 972 - 58 - 42
D.1 This appendix provides recommended provisions for the design of smoke and ventilation ducts for gas-using equipment, household heating and heating and cooking stoves.
When designing smoke ducts from gas-using installations industrial buildings and boiler houses should be guided by the requirements of SNiP II-35.
When converting existing boilers, industrial furnaces and other installations from solid and liquid fuel to gas fuel, a verification calculation of the gas-air path must be performed.
D.2 The installation of smoke and ventilation ducts must comply with the requirements of SNiP 2.04.05. D.3 Smoke ducts from gas-using equipment installed in enterprise premises Catering, trade, consumer services, offices built into a residential building are prohibited from being combined with smoke ducts of a residential building. Ventilation of the above premises must also be autonomous.
D.4 The removal of combustion products from gas-using equipment installed in office premises located within the dimensions of one apartment, as well as the ventilation of these premises should be provided for as for residential buildings.
D.5 The removal of combustion products from household stoves and gas-using equipment, the design of which provides for the removal of combustion products into a smoke channel (chimney) (hereinafter referred to as the channel), is provided from each stove or equipment through a separate channel into the atmosphere.
In existing buildings, it is allowed to provide for the connection to one duct of no more than two furnaces, appliances, boilers, apparatus, etc., located on the same or different floors of the building, provided that combustion products are introduced into the duct at different levels (no closer than 0.75 m one from the other) or at the same level with the device in the cutting channel to a height of at least 0.75 m.
In residential buildings, it is allowed to provide for the connection of more than one gas-using device to one vertical smoke duct. heating equipment with a sealed combustion chamber and a built-in device for forced removal of flue gases. This equipment is located on different floors of the building. The amount of equipment connected to one channel is determined by calculation.
It is not recommended to connect household equipment to the channel heating stove long burning.
D.6 Channels from gas equipment should be placed in the internal walls of the building or provided with attached channels to these walls. In existing buildings, it is allowed to use existing smoke ducts made of non-combustible materials in the external walls or provide extension ducts to them.
D.7 It is allowed to connect periodic gas-using equipment ( instantaneous water heater etc.) to the channel of a heating furnace with periodic combustion, provided that they operate at different times and the channel cross-section is sufficient to remove combustion products from the connected equipment. Connecting the connecting pipe of gas-using equipment to the chimney revolutions of a heating stove is not allowed.
D.8 The cross-sectional area of the channel should not be less than the cross-sectional area of the pipe of the connected gas-using equipment or furnace. When connecting two devices, apparatus, boilers, furnaces, etc. to the channel. its cross section should be determined taking into account their simultaneous operation. The structural dimensions of the channels are determined by calculation.
D.9 Removal of combustion products from restaurant stoves, food boilers, etc. It is allowed to be provided both in a separate channel from each equipment, and in a common channel. The removal of combustion products from gas-using equipment installed in close proximity to each other can be carried out under one umbrella and then into a collection channel.
It is allowed to provide connecting pipes common to several devices (equipment).
The cross-sections of channels and connecting pipes must be determined by calculation based on the condition of simultaneous operation of all equipment connected to the channel and connecting pipes.
D.10 Smoke ducts should be made from ordinary ceramic bricks, clay bricks, heat-resistant concrete, as well as steel and asbestos-cement pipes for one-story buildings. Outer part brick channels should be made of brick, the degree of frost resistance of which complies with the requirements of SNiP II-22.
Smoke ducts can also be factory-made and supplied complete with gas equipment.
When asbestos-cement and steel pipes are installed outside a building or when passing through the attic of a building, they must be insulated to prevent condensation. The design of smoke channels in external walls and channels attached to these walls must also ensure that the temperature of the gases leaving them is above the dew point.
It is not allowed to make channels from slag concrete and other loose or porous materials.
D.11 Channels must be vertical, without ledges. A slope of channels from the vertical is allowed up to 30° with a side deviation of up to 1 m, provided that the cross-sectional area of the inclined sections of the channel is not less than the cross-section of the vertical sections. To remove combustion products from restaurant stoves, cooking boilers and similar gas appliances, it is allowed to provide horizontal sections of channels placed in the floor with a total length of no more than 10 m, provided that fire-proof cutting is installed for combustible and non-combustible floor and ceiling structures. The channels must be accessible for cleaning.
D.12 The connection of gas-using equipment to the ducts should be provided by connecting pipes made of roofing or galvanized steel with a thickness of at least 1.0 mm, flexible metal corrugated pipes or standardized elements supplied with the equipment. Total length horizontal sections of the connecting pipe in new buildings should be no more than 3 m, in existing buildings - no more than 6 m.
The slope of the connecting pipe should be at least 0.01 towards the gas equipment. On connecting pipes it is allowed to provide no more than three turns with a radius of curvature not less than the diameter of the pipe. Below the point where the connecting pipe is connected to the channels, a “pocket” device with a cleaning hatch must be provided, to which free access must be provided. Connecting pipes laid through unheated premises, if necessary, must be thermally insulated.
D.13 It is not allowed to lay connecting pipes from gas-using equipment through living rooms.
D.14 The distance from the connecting pipe to the ceiling or wall made of non-combustible materials should be at least 5 cm, and from combustible and non-combustible materials - at least 25 cm. The distance can be reduced from 25 to 10 cm, provided that combustible and non-combustible structures are protected with roofing steel on an asbestos sheet with a thickness of at least 3 mm. Thermal insulation should extend beyond the dimensions of the connecting pipe by 15 cm on each side.
D.15 When connecting one gas-using device (equipment) to the channel, as well as equipment with draft stabilizers, gates are not provided on the connecting pipes. When connecting gas-using equipment that does not have draft stabilizers to the prefabricated chimney, dampers with a hole with a diameter of at least 15 mm must be provided on the connecting pipes from the equipment.
D.16 When installing a periodic gas burner device in a heating furnace, a gate must be provided in the furnace design. The installation of dampers in a furnace with continuous combustion is prohibited. When switching to gas fuel, a heating and cooking stove must have three dampers (one for summer operation, another for winter operation, and a third for ventilation).
D.17 Smoke ducts from gas-using equipment in buildings must be removed (Figure D.1):
- not less than 0.5 m above the ridge or parapet of the roof when they are located (counting horizontally) no further than 1.5 m from the ridge or parapet of the roof;
- level with the roof ridge or parapet, if they are located at a distance of up to 3 m from the roof ridge or parapet;
- not lower than a straight line drawn from the ridge or parapet downward at an angle of 10 ° to the horizon, when the pipes are located at a distance of more than 3 m from the ridge or parapet of the roof;
- at least 0.5 m above the boundary of the wind support zone, if there are higher parts of the building, structures or trees near the canal. In all cases, the height of the pipe above the adjacent part of the roof must be at least 0.5 m, and for houses with a combined roof (flat) - at least 2.0 m. The mouths of brick channels to a height of 0.2 m should be protected from precipitation with a layer cement mortar or a cap made of roofing or galvanized steel. It is allowed to provide windproof devices on the channels.
D.18 Smoke ducts in walls may be installed together with ventilation ducts. At the same time, they must be separated along the entire height by sealed partitions made of wall material with a thickness of at least 120 mm. The height of the exhaust ventilation ducts located next to the smoke ducts should be taken equal to the height of the smoke ducts.
D.19 Discharge of combustion products into ventilation ducts and installation of ventilation grilles on smoke ducts are not allowed.
D.20 It is permitted to discharge combustion products into the atmosphere through the outer wall of the gasified room without installing a vertical channel from gas-fired heating equipment with a sealed combustion chamber and a device for forced removal of combustion products.
D.21 The openings of smoke ducts on the facade of a residential building when venting combustion products from heating gas-using equipment through an external wall without installing a vertical duct should be placed in accordance with the installation instructions for gas-using equipment of the manufacturer, but at a distance of not less than:
- 2.0 m from ground level;
- 0.5 m horizontally to windows, doors and open ventilation holes(grids);
- 0.5 m above the top edge of windows, doors and ventilation grilles;
- 1.0 m vertically to windows when placing holes underneath them.
The specified distances do not apply to window openings filled with glass blocks. It is not allowed to place duct openings on the façade of buildings under the ventilation grille. The smallest distance between two channel openings on the facade of the building should be at least 1.0 m horizontally and 2.0 m vertically. When placing a smoke channel under a canopy, balconies and roof eaves of buildings, the channel must extend beyond the circle described by radius R (Figure D.2). It is not recommended to provide a smoke channel outlet through the outer wall into passages (arches), tunnels, underground passages, etc.
D.22 The length of the horizontal section of the smoke duct from gas-fired heating equipment with a sealed combustion chamber when exiting through the outer wall should be no more than 3 m.
D.23 Gas-using equipment with a thermal power of up to 10 kW with exhaust of combustion products into the gasified room is placed in such a way as to ensure free exit of combustion products through exhaust ventilation devices (duct, axial fan) of this room.
D.24 In residential buildings, ventilation ducts from rooms in which heating gas-using equipment is installed for apartment heating, it is not allowed to combine with ventilation ducts of other rooms (bathrooms, storerooms, garages, etc.).
D.25 Existing smoke ducts that are not connected to other existing smoke ducts can be used as ventilation ducts. Grilles with devices for regulating air flow, excluding the possibility of their complete closure, are provided on the exhaust ventilation ducts of gasified premises.
6.1. General requirements
6.1.1. When designing and laying (installing) chimneys (ducts) from heat generators and solid fuel stoves, it is necessary to provide for the solutions set out in SNiP 2.04.05-91* “Heating, ventilation and air conditioning”, and for gas-using equipment and household stoves - SP 42 -101-2003 " General provisions on the design and construction of gas distribution systems made of metal and polyethylene pipes"(Appendix 7) and SP 41-108-2004 "Apartment heat supply of residential buildings with gas-fueled heat generators", as well as these rules.
6.1.2. Chimneys (channels) must ensure complete removal of combustion products into the atmosphere.
To remove combustion products from stoves, fireplaces and heat generators, pipes made of clay (ceramic) bricks with walls at least 120 mm thick or heat-resistant concrete at least 60 mm thick should be provided.
It is allowed to use chimneys:
ceramic from prefabricated products - for removing flue gases with temperatures up to 1000 ° C;
double-circuit from various grades of steel with thermal insulation from non-combustible materials - for removing flue gases with a temperature of 500-900 ° C;
asbestos-cement - for removing flue gases with temperatures up to 300 °C.
Application of asbestos cement pipes and pipes from of stainless steel not allowed for coal-fired stoves.
The use of smoke ducts made of steel, ceramics and other materials is allowed only with certificates fire safety or the conclusion of a specialized organization.
6.1.3. Chimneys must be made smooth and gas-tight class P from structures and materials that can withstand mechanical loads, temperature and corrosion effects of combustion products without loss of tightness and strength.
6.1.4. Chimneys must have devices that ensure cleaning of the internal surface from soot and other deposits along the entire height.
6.1.5. Chimneys must be installed vertically without ledges or reduction in cross-section. Pipe deviations are allowed at an angle of up to 30° to the vertical with a horizontal deviation of no more than 1 m. It is prohibited to lay chimneys through residential premises.
6.1.6. The cross-section of chimneys for solid fuel stoves should be taken depending on the thermal power of the stove, not less than:
140x140 mm - with thermal power up to 3.5 kW;
140x200 mm - with thermal power from 3.5 to 5.2 kW;
140x270 mm - with thermal power from 5.2 to 7 kW.
The cross-section of chimneys of heat generators and fireplace inserts is taken into account the requirements of factory instructions and should not be less than the cross-sections of chimneys.
Cross-sectional area round pipes must be no less than the cross-sectional area of rectangular channels.
6.1.7. Smoke ducts in internal or external walls may be installed together with ventilation ducts. At the same time, they must be separated along the entire height by sealed partitions made of ceramic bricks with a thickness of at least 120 mm.
6.1.8. The height of the smoke channels (pipes) of solid fuel stoves and heat generators, counting from the grate to the mouth, should be at least 5 m.
The placement of smoke ducts (pipes) above the roof of buildings must take into account the requirements of SNiP 2.04.05-91* and SP 41-108-2004.
6.1.9. As a rule, a separate chimney should be provided for each stove, each heat generator and fireplace. It is allowed to connect two stoves to one pipe, located in the same apartment on the same floor. When connecting two chimneys in a pipe, a cut should be provided with a height of at least 1 m from the bottom of the chimney.
In residential buildings, it is allowed to install a collective smoke duct with the connection of gas-fuelled heat generators, taking into account the requirements of SP 41-108-2004 and SP 42-101-2003.
6.1.10. Connection of heat generators to chimneys is carried out by chimneys no more than 0.4 m long, made of roofing steel with a thickness of at least 1 mm, or standardized elements supplied complete with heat generators.
It is allowed to use flexible metal hoses as smoke exhaust systems, consisting of two layers of stainless steel, for which there is a conclusion (technical certificate) on the possibility of their use for removing combustion products.
6.1.11. On the chimneys of solid fuel stoves, valves should be provided with a hole in them measuring at least 15x15 mm.
6.1.12. Chimneys for wood and peat stoves in buildings with roofs made of combustible materials should be equipped with spark arresters made of metal mesh with holes measuring no more than 5x5 mm.
6.1.13. The mouths of chimneys should be protected from precipitation with umbrellas, deflectors and other attachments that should not interfere with the free release of smoke into the atmosphere. The distance from the plane of the pipe head to the lower horizontal edge of the umbrella is taken to be equal to half the diameter of the pipe, and the diameter of the umbrella is equal to two pipe diameters.
6.1.14. When laying (installing) smoke channels (pipes), solutions should be provided to ensure their cleaning throughout their entire height.
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6.2. Brick smoke channels
6.2.1. When designing and laying brick smoke ducts, the solutions given in the album of standard building structures of the 5.905-27.01 series “Smoke and ventilation ducts for gasified premises” must be provided. Issue 1.
Smoke and ventilation ducts, as a rule, should be provided in the internal walls of brick buildings (Fig. 6.1). For areas with a design outdoor temperature below -40 °C, ducts should be installed only in internal walls.
To remove combustion products, smoke channels attached to the internal wall can be used (Fig. 6.2).
It is allowed to place smoke ducts in external walls made of non-combustible materials (Fig. 6.3) or provide smoke ducts attached to external wall(Fig. 6.4). The thickness of the walls from the channels to the outer surfaces of the wall is taken taking into account the calculated outside temperature.
When smoke ducts are located outside buildings, the thickness of the walls made of bricks should be at least 380 mm at a calculated outside air temperature of up to -20 °C, 510 mm at temperatures from -20 to -30 °C and 650 mm at temperatures from -30 to -40 °C.
If there are no walls in which smoke ducts can be placed, mounted or root pipes should be used.
Rice. 6.1. Placement of channels in the internal wall:
1 - smoke channel; 2 - ventilation duct. 
Rice. 6.2. Attached channels to an internal brick wall:
1 - ventilation duct; 2 - anchor rod at 1 m height through 6 rows of masonry;
3 - smoke channel. 
Rice. 6.3. Placement of channels in an external brick wall:
1 - outer surface; 2 - smoke channel; 3 - ventilation duct. 
Rice. 6.4. Attached channels to an external brick wall:
1 - outer surface; 2 - smoke channel; 3 - anchor rod at 1 m height through 6 rows of masonry; 4 - ventilation duct.
6.2.2. For laying the foundation for the main pipes, the same materials are used as for the foundation of buildings (stone, concrete, etc.).
For laying channels, it is necessary to use solid ceramic brick (red) of the highest quality, normal firing without cracks and foreign impurities, grade not lower than M100.
It is prohibited to use burnt or unburned, hollow, lightweight, or silicate bricks for laying smoke ducts.
When laying brick smoke ducts, the following solutions should be used:
lime or lime-cement - for masonry in the walls of buildings;
lime-cement - for masonry above the attic floor;
cement - for masonry above the roof.
6.2.3. The laying of smoke channels must be carried out taking into account the procedures given in the working drawings.
The top of the head of a brick chimney should be protected from precipitation with a layer of cement mortar (Fig. 6.5) or a cap made of roofing steel. 
Rice. 6.5. Head device:
1 - cement-sand mortar composition 1:2.
The free space between the smoke channel and the roof structures should be covered with a roofing steel apron placed under the otter.
6.2.4. The internal surfaces of brick smoke ducts must be thoroughly cleaned of excess mortar using a wet mop. Plastering of internal surfaces is not allowed.
6.2.5. Within the attic, the outer surfaces of the smoke ducts should be plastered and whitewashed.
6.2.6. To ensure the density and smoothness of the internal walls of existing or constructed smoke brick channels, it is allowed to lay flexible or rigid metal pipes, ceramic pipes or pipes made of other non-combustible materials in them. The choice of material for pipes is carried out taking into account permissible temperature and the composition of removed combustion products.
Installation of pipes in brick smoke channels must be carried out taking into account the requirements of the manufacturers' instructions.
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6.3. Metal chimneys
6.3.1. To remove combustion products from heat-generating installations, it is allowed to use metal chimneys from prefabricated elements and chimneys that have a fire safety certificate.
Steel grades for chimneys are given in appendix. 12.
6.3.2. Dual-circuit steel pipes(TU 4863-001-45905715-2003) are intended for removal of combustion products from stoves, fireplaces and other heat generators operating on solid, liquid and gaseous fuels. The prefabricated elements of the smoke removal system consist of an internal welded pipe made of stainless steel 1 mm thick, certified to an operating temperature of 900 ° C, and external pipe larger diameter made of galvanized, stainless or polished stainless steel 0.5 mm thick. Inner layer must be made of non-combustible material based on basalt rocks with a thickness of 30 mm.
Installation of chimneys is carried out from sections of air ducts 500 and 1000 mm long and elements (tees, bends, adapters, umbrellas, etc.).
The characteristics of straight sections of a double-circuit pipe are given in the appendix. 13.
The pipes are installed from the heat generator from the bottom up. When installing the system, pipes are placed on top of each other to a depth of at least half the diameter of the pipes. The joints of pipes, as well as prefabricated pipes and system elements should be secured with clamps.
To clean soot from pipes, it is necessary to provide removable cups or holes in the base that are closed with doors.
Fire-proof cuts should be provided at the intersection of floors and roofs.
Where the chimney crosses the floors of the building, pipe joints are not allowed. The chimneys should be secured using wall brackets every two meters and support brackets to secure the tees to the wall.
When using single-circuit metal pipes, it is necessary to provide thermal insulation to protect against condensation.
6.3.3. It is allowed to use metal chimneys and prefabricated elements, as well as metal chimneys supplied by foreign companies, to remove combustion products.
Characteristics of single-circuit and double-circuit chimneys with fire safety certificates are given in the appendix. 14 and 15.
Installation of chimney elements must be carried out taking into account the requirements of the manufacturers' instructions.
6.3.4. Chimneys should, as a rule, be placed near internal walls and partitions made of non-combustible materials. In the absence of walls and partitions where pipes can be placed, mounted chimneys should be used.
When laying metal pipes in brick channels (Fig. 6.6), it is necessary: 
Rice. 6.6. Laying a pipe in a brick channel:
1 - umbrella; 2 - roofing slab; 3 - metal pipe; 4 - mounting hooks; 5 - tee;
6 - door; 7 - cleaning hatch with condensate drainage; 8 - heat generator.
disassemble brick wall a channel at the installation site of the heat generator in a section of length required to accommodate elements for collecting condensate, a cleaning hatch and a smoke exhaust pipe;
install the specified elements in the brick channel;
attach to straight section pipes with mounting hooks, ropes of appropriate length and strength;
place the inserted pipe in the brick channel at a height that allows another pipe to be inserted into it;
by changing the height of the pipes by lowering the rope, set the required number of pipes;
fill the space between the walls of the brick channel and pipes with non-flammable heat-insulating material;
install a slab on the head of the brick channel and an umbrella on the pipe to protect against precipitation;
fill the opening in the wall of the smoke channel with bricks.
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6.4. Ceramic chimneys
6.4.1. Ceramic chimneys are designed to remove flue gases with temperatures up to 1000 °C from any heat-generating installations operating on solid, liquid and gaseous fuels.
The pipes have a Russian fire safety certificate, a GOST R certificate of conformity and a hygienic certificate of the Russian Federation.
6.4.2. Chimneys are assembled from commercially produced modules with a height of 0.33 m and sets of doors, cover and console plates, heads, etc., which are fully factory-ready, which, when assembled, exactly match each other in shape and size.
The standard sizes of chimneys, as well as combined chimneys and ventilation ducts are given in the appendix. 16.
Straight pipe sections are three-layer construction. The inner pipe is made of high-quality fire-resistant fireclay with a thickness of 15-25 mm and covered with non-flammable heat-insulating material with a thickness of 45-50 mm. The outer shell is made in the form of a block of lightweight concrete, having holes for installing anchors to secure the blocks and create channel stability (Fig. 6.7). The design diagram of the chimney is shown in Fig. 6.8. 
Rice. 6.7. Smoke ceramic pipe:
1 - shell made of lightweight concrete; 2 - thermal insulation; 3 - ceramic pipe.
Rice. 6.8. Ceramic chimney design:
1 - base; 2 - container for collecting condensate; 3 - ventilation grille; 4 - door for inspection and cleaning; 5 - tee for connecting a heat generator; 6 - mineral fiber panel; 7 - concrete block; 8 - channel for installing fasteners; 9 - channel for ventilation;
13 - gap for air outlet; 14 - mouth.
6.4.3. Before starting installation, you should determine the location of the doors for inspection and cleaning of the pipe, as well as the location and height of the connection of the heat-generating installation.
Assembling the chimney starts from the bottom up. An element is installed at the base of the chimney, which contains a ceramic pipe with a container for collecting and discharging condensate, as well as a ventilation grille to provide ventilation to blow the thermal insulation along the entire height of the pipe.
Next, the revision element is installed. Behind the inspection hole door, a metal plate with a sealed seal is installed to prevent smoke from escaping through the door. The heat generator is connected using a ceramic tee. The front panel of the tee, made of mineral fiber, allows you to adjust the position of the tee relative to the chimney.
After installing the service elements and connecting the heat generator, the chimney blocks are installed. To lead the pipe above the roof, use the upper kit, which is part of the chimney elements.
To enhance the static stability of the free-standing part of the chimney under or above the roof, it is necessary to use a special set of fasteners.
6.4.4. Installation of chimney elements must be carried out taking into account the requirements installation instructions manufacturer.
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6.5. Smoke pipes made of ceramics and steel
6.5.1. Chimneys are used to remove combustion products from boilers, stoves, fireplaces and other heat-generating installations operating on any type of fuel.
6.5.2. The chimney is a three-layer structure, including an inner ceramic pipe 6.5-12 mm thick, a 60 mm thick mineral fiber thermal insulation layer and an outer stainless steel pipe 0.4 mm thick.
The characteristics of pipes made of ceramics and steel are given in the appendix. 17.
6.5.3. Installation of the chimney must be carried out taking into account the requirements of the manufacturer's instructions.
Before installing the chimney, it is necessary to clearly determine the location of its installation and the order of laying, as well as the number and location of supports, wall mounts and consoles.
When performing work on installation of mounting holes, damage to walls and ceilings must be avoided.
Installation of a chimney on the floor should begin with the preparation of the basement base.
At external laying When installing a chimney against a wall, the lower element for wall mounting, included in the chimney kit, is first installed and secured. Then, an element with condensate drainage is installed on the base or lower element for wall mounting.
When installed on the floor, the lower element of the chimney is attached to the base.
Before installing the following chimney components, sealant must be applied to the bottom edge of the inner ceramic pipe. Excessive amount of sealant is removed from the inner surface of the pipe with a damp sponge.
The socket of the internal profiled ceramic pipe should always be directed upward towards the mouth.
The chimney elements must be fastened using a socket connection using sealant and clamps, which are tightened using a clamping screw. The tightened clamp should press the pipe tightly (Fig. 6.9) 
Rice. 6.9. Chimney joint joint detail:
1 - outer pipe stainless steel; 2 - thermal insulation; 3 - heat-resistant sealant;
4 - clamp; 5 - ceramic inner tube.
When crossing the roof with a chimney, elements are used to cross the roof, taking into account the angle of inclination, which should be attached to the attic structure.
Installation of wall mounts must be provided no more than 4 m apart. Maximum free height standing plot the chimney from the last wall mounting should not exceed 3 m, and the maximum height of the pipe with wall mountings is 15 m. When installing a chimney with a height of more than 15 m, additional wall consoles must be provided.
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6.6. Chimneys LAS
6.6.1. Chimneys are designed to remove flue gases from several gas-fueled heat generators, as well as supply outside air to them for combustion. Chimneys "air - flue gases" have the international designation LAS.
6.6.2. The pipe structure is ceramic inner tube, which, with the help of spacer elements, is centered inside the concrete shell (Fig. 6.10). The flow of outside air to the heat generator is carried out through a free opening between the walls of the pipe and the concrete block.
The parameters of the LAS pipe are given in the appendix. 18. 
Rice. 6.10. Chimney LAS:
1 - light concrete block; 2 - spacer element; 3 - opening for air movement
6.6.3. The design of the pipe allows the heat generator to be connected from four sides.
The pipe elements and individual sections are connected using a fire-resistant sealant, which ensures the gas tightness of the structure.
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6.7. Asbestos cement chimneys
6.7.1. To remove combustion products with temperatures up to 300 °C, it is allowed to use asbestos-cement pipes (GOST 1839-80) without chips and cracks.
6.7.2. The cross-sectional area of the chimney should not be less than the area of the heat generator pipe.
6.7.3. When joining asbestos-cement pipes, the gap between the pipes and the walls of the couplings should be sealed with asbestos cord in accordance with GOST 1779-83* to a depth of 30 mm.
6.7.4. When designing and installing asbestos-cement chimney pipes for domestic heat generators, the solutions set out in the album series 5.905-28-01 “Smoke and ventilation ducts from asbestos-cement pipes in gasified premises” should be taken into account. Issue 1.
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6.8. Requirements for the operation of chimneys (channels)
6.8.1. Chimneys (channels) of heat generating installations must meet the requirements of SNiP 2.04.05-91* “Heating, ventilation and air conditioning”; SP 42-101-2003 “General provisions for the design and construction of gas distribution systems made of metal and polyethylene pipes”, SP 41-108-2004 “Apartment heat supply of residential buildings with gas-fuelled heat generators”, MKD 2-03-2003 “Rules and Standards” technical operation of the housing stock", these rules and instructions from manufacturers.
6.8.2. Services for inspection (checking) of chimneys (channels) must be provided taking into account the requirements of regulatory documents under an agreement with specialized VDPO organizations.
6.8.3. When accepting chimneys (ducts) of heat generators, stoves and fireplaces, it is necessary to check:
availability of the necessary executive and technical documentation (channel orders, acts for hidden work, certificates for chimneys, etc.);
compliance of completed (installed) pipes (channels) with design materials;
quality of masonry of brick channels (presence of bandaging, thickness of seams, verticality of corners, presence of cracks, etc.);
compliance of the cross-section of chimneys (channels) with design materials and passports for heat generators and fireplace inserts;
quality of installation of chimneys;
availability and sufficiency of devices for cleaning pipes (channels) and their location;
location of chimney pipes (channels), necessity, availability and thickness thermal insulation material;
type of chimneys and chimneys and the possibility of their use;
presence and size of fireproof cuttings;
the need, availability and size of fire safety setbacks;
no blockages in pipes (channels);
isolation of chimneys (channels);
presence of draft in pipes (channels);
serviceability of the heads and their elevation relative to the roof and the wind support zone.
6.8.4. Periodic inspection of chimneys (ducts) should be carried out:
before the heating season;
after renovation;
at least twice a year during the first two years from the date of commissioning of gas-using equipment and furnaces, subsequently - at least once a year;
taking into account the requirements specified in the manufacturer’s passports.
Furnaces and smoke ducts must be cleared of soot before and throughout the entire heating season at least:
once every three months for heating stoves;
once every two months for continuous stoves and fireplaces;
once a month for cookers and other continuous (long-term) combustion stoves.
IN winter time at least once a month, and in the northern regions climate zone The heads of smoke and ventilation ducts must be inspected at least twice a month to prevent freezing and blockage. Based on the results of the inspection, there must be an entry in a special journal indicating all the faults identified and the nature of the work carried out to eliminate them.
Taking into account territorial conditions, other dates for periodic inspections of smoke ducts may be established.
During periodic inspections of chimneys (channels), the following is determined:
presence of blockages and soot deposits;
isolation of channels and wall density;
condition of thermal insulation material and fireproof cuts;
presence of traction;
appearance.
The results of periodic inspections of smoke ducts (pipes) are documented taking into account the requirements of clause 4.3.8 of these rules.
6.8.5. The condition of the internal surface of chimneys (channels), as well as the presence of foreign objects, can be assessed by using black-and-white or color video equipment. To inspect the surfaces of channels and pipes, miniature video heads are used, providing an image of the surface on the control panel screen.
The presence of foreign objects in chimneys (channels) is detected by lowering a metal ball with a diameter of 80-100 mm through the mouth on a cable. When lowering the ball, be careful not to damage the walls. Free movement of the ball indicates the absence of blockages.
6.8.6. Chimneys (channels) are checked for density using smoke by burning material that produces a large number of smoke (sawdust, rags, etc.). The mouth of the smoke-filled channel or pipe is tightly closed. The appearance of combustion products in the attic, in heated rooms or in nearby ventilation ducts indicates insufficient density of the walls of the smoke duct (pipe).
The density of the smoke channel can be checked by closing the entrance and exit of the channel with a sealing inflatable chamber and creating excess pressure in it with a fan unit. The volume of air leakage through leaks is determined by the readings of the device.
6.8.7. The isolation of the smoke duct from neighboring smoke or ventilation ducts is also determined by the smoke method. The appearance of smoke in adjacent channels indicates the presence of leaks in the walls of the smoke channel being tested.
6.8.8. The presence of draft in stoves, heat generators and fireplaces using solid fuel is checked with a lit match, which is brought to the open combustion door (inspection hole). The deviation of the match flame from the vertical towards the firebox indicates the presence of draft.
The draft value can be determined by measuring the vacuum with an electronic micromanometer or the air velocity in the firebox opening with an electronic hot-wire anemometer. The resulting vacuum value in the chimneys (channels) of heat generators and factory-made fireplaces must be no less than the values given in the operating instructions or data sheets.
6.8.9. When checking the heads of smoke channels (pipes) in winter and detecting freezing and disruption of normal operation, it is necessary:
check the serviceability of the smoke channel along its entire length;
punch a hole in the wall of the smoke duct in the attic;
insert a sheet of iron into the channel;
break off the ice with a crowbar or other tool (without damaging the canal walls) and remove it from the canal;
light a fire on a sheet of iron and heat the channel until freezing is completely eliminated;
seal the hole in the channel with brick and mortar;
check the channel for passability using a ball and rope;
check the presence of traction in the channel.
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6.9. Fire safety requirements for smoke ducts (pipes)
6.9.1. When laying and installing channels (pipes), the fire safety requirements set out in SNiP 2.04.05-91* “Heating, ventilation and air conditioning”, SP 42-101-2003 “General provisions for the design and construction of gas distribution systems made of metal and polyethylene” must be met pipes", SP 41-108-2004 "Apartment heat supply of residential buildings with gas-fueled heat generators", albums of standard building structures, products and components of the 5.905-27.01 series "Smoke and ventilation ducts of gasified premises" and series 5.905-28.01 "Smoke and ventilation channels from asbestos-cement pipes of gasified premises”, as well as in the instructions of manufacturers.
6.9.2. Building structures made of combustible materials adjacent to smoke ducts (pipes) must be protected from fire by installing indentations or cuts.
6.9.3. The dimensions of the setbacks and methods of protecting structures made of combustible materials when using smoke brick ducts should be taken in accordance with clause 3.8.4 of these rules.
The dimensions of the setbacks and the method of protecting structures made of combustible materials when laying chimneys (ducts) from heat generators using gas fuel are shown in Fig. 6.11. 
Rice. 6.11. Retreat device:
1 - wooden wall; 2 - plaster 25 mm thick asbestos cardboard 8 mm thick or felt impregnated clay mortar; 3 - ventilation duct; 4 - smoke channel.
6.9.4. When smoke brick ducts cross a floor structure made of flammable materials, it is necessary to arrange horizontal cuts by thickening the walls of the smoke duct. When masonry is used, the thickening is carried out with an overhang of no more than 1/4 of the length of the brick in each row of masonry (Fig. 6.12). 
Rice. 6.12. Horizontal cutting:
1 - ventilation duct; 2 - smoke channel; 3 - thermal insulation; 4 - wooden beam.
The dimensions of the grooves, taking into account the thickness of the walls of the brick channels, should be taken according to paragraph 3.8.13 of these rules.
6.9.5. The height of the brick grooves should be greater than the thickness of the ceiling so that the top of the groove protrudes above the floor or backfill in the attic by 70 mm.
6.9.6. Wooden beams embedded in the walls of smoke brick ducts must be located from the inner surface of the duct at a distance of at least 380 mm if the beam is protected from fire, and at a distance of at least 500 mm if it is not protected.
Options for cutting from smoke ducts to wooden beams and crossbars are shown in Fig. 6.13. 
Rice. 6.13. Placement of wooden beams and crossbars:
1 - beam; 2 - solution with thermal insulation of the end of the beam; 3 - smoke channels; 4 - cutting;
5 - crossbar; 6 - thermal insulation.
6.9.7. The distance from the outer surfaces of smoke ducts to metal and reinforced concrete beams should be at least 130 mm.
6.9.8. Combustible roof structures (rafters, sheathing, etc.) must be located at a distance of at least 130 mm from the outer surface of the smoke duct.
6.9.9. The distance from the inner surface of the smoke ducts (pipes) of furnaces and gas-using equipment to structures made of combustible materials (cut size) should be taken no less than those indicated in the table. 6.1.
Table 6.1.
| Channels | Dimensions of grooves, mm, if structures are available |
|
| not protected from fire | protected from fire |
|
| From a heating and heating-cooking furnace with burners UGOP-NP-8, UGOP-N-14, UGOP-P-19, UGOP-P-25 and with periodic combustion duration: | ||
| up to 3 hours | 380 | 250 |
| more than 3 hours | 510 | 380 |
| From household gas flow-through, capacitive, heating devices with a water circuit, firebox with burner UGOP-N-4 | 250 | 250 |
Note: Protection of structures from fire must be done with fireproof material that provides a fire resistance rating of at least EI45.
6.9.10. When metal or other chimneys cross floors made of flammable materials, fire-proof cuts should be provided (Fig. 6.14). The thickness of the cutting material must provide a thermal resistance (the ratio of thickness to the thermal conductivity coefficient) not less than the thermal resistance of a fire-resistant ceramic brick cutting. 
Rice. 6.14. Fire cutting diagram:
1 - thermal insulation; 2 - wooden structures.