SNiP for stoves and chimneys
Edition from 05.07.2022 Download
In order to find out the standards and technical requirements for brick stoves and chimneys established in Russia, we need to refer to the current SNiP 41-01-2003, instead of the outdated SNiP 2.04.05-91. In other countries, the rules may differ, but these rules are necessary for every stove owner for his own safety!
There is also Regulation 390 "On the fire-fighting regime", which replaces the outdated Regulations PPB 01-03 and it would also be useful to study.
Most of the rules for the brick stove are given in the schematic figure below:
There are also points that were not specified:
1. The space between the overlap (overlapped) of the heat-intensive furnace and the ceiling of combustible materials is allowed to be closed on all sides with brick walls. The thickness of the stove overlap should be increased to four rows of brickwork.
2. In buildings with stove heating is not allowed:
а) ventilation system with artificial impulse, not compensated by artificial impulse;
б) smoke extraction into ventilation ducts and use of smoke ducts for indoor ventilation.
3. The distance from the stove door to the opposite wall should be at least 1250 mm.
4. The minimum distances from the floor to the bottom of the gas turnover and ash boxes should be taken:
а) in the construction of the floor or floor made of combustible materials to the bottom of the ash tank - 140 mm. to the bottom of the gas turnover - 210 mm.;
б) when constructing a ceiling or floor made of non—combustible materials - at the floor level.
5. For connection of stoves to chimneys, it is allowed to provide flue ducts with a length of no more than 0.4 m., provided:
а) the distance from the top of the chimney to the ceiling made of combustible materials should be not less than 0.5 m. in the absence of fire protection of the ceiling and not less than 0.4 m. - in the presence of protection;
б) the distance from the bottom of the chimney to the floor of combustible materials should be at least 0.14 m.
Climatic parameters of the air
In the above mentioned SNiP in p.5 there is a reference to GOST 30494-2011, according to the definition of microclimate in residential and public areas, and for non-residential premises there is GOST 12.1.005-88, which sets the air requirements of the working area, where it is possible to determine not only the optimal indoor air temperature, but also the MAC of harmful substances in the air. The article is written on the website http://planstove.com
The climatic parameters of the cold period of the year in the various republics can be found in SP 131.13330.2012.
Norms and technical requirements for pipes
The height of the pipe is one of the factors affecting the traction force. It should be noted that the distance between the pipe head and the grate (hearth level) should be at least 5 m. The height of the pipe above the roof is determined by the distance between the pipe and the roof ridge (see Fig.). It is clear from the drawing that if the pipe is located at a distance from the ridge less than 1.5 m., then the pipe is made 0.5 m. above the ridge (or the roof parapet), as well as above the flat roof (previously indicated at least 2 m.). If the pipe is located at a distance of 1.5 m. to 3 m. from the ridge, then the pipe is brought to the level of the ridge. At a distance of more than 3 m. the head of the pipe should be at the level of the line at an angle of 10 ° to the horizontal plane below the ridge. In any case, the height of the pipe above the roof should be at least 0.5 m. If there is an extension next to the main building in which the furnace is located, then the pipe must be output 0.5 m above the level of the imaginary line that descends from the edge of the main roof down at an angle of 45 degrees (see Fig.). The dark area in the figure is called the wind support zone, in which, as a rule, there is increased air pressure. So it turns out that the pipe should be 0.5 m higher than the wind support zone. It is allowed to provide pipe bends at an angle of up to 30 degrees to the vertical with a distance of no more than 1 m, and the inclined sections of the inner section must be smooth and have a cross-section of at least the cross-sectional area in the vertical sections of the chimney.
Pipe to roof connection. When passing the outside of the chimney, it is not necessary to rigidly fasten it with the roof itself and the rafter system, because in the event of damage to the pipe by wind or other natural forces, the entire structure of the roof will be disrupted.
Pipe cap (umbrella) - the mouth of the chimney is covered with a steel cap to ensure that the wind and precipitation or, for example, fallen leaves do not fall into the pipe, as they can severely disrupt the traction or cause internal damage to the stove. There is also the opinion that the iron cap can collect condensate, or it can be demolished/damaged in a strong wind and therefore the stone cap is not only reliable, but also a calling card of a stove maker. Umbrellas, deflectors and other nozzles on the chimneys shall not prevent the smoke from leaving freely.
The otter was invented at a time when technology was not well developed and was used to protect the roof from precipitation. Today, there are many solutions that reliably protect the passage of the pipe through the roof and now the otter is not as popular as before, but do not forget that the pipe should be able to freely lengthen and expand at the time of heating.
Deflectors are a device that protects against wind. They are based on the principle of using wind energy to suck gases from chimneys.
Artificial Exhaust System – In heated rooms, ventilation with artificial impulse is not permitted without a compensated influx of air, as well as the removal of smoke into the ventilation system designed for ventilation of premises.
In addition, there are a number of recommendations and rules on the location of chimneys and their installation:
1. It is undesirable to place chimneys next to the attic windows so that random gusts of wind do not carry smoke or carbon monoxide inside the attic, if it is residential. It is also not recommended to erect exhaust pipes and ventilation ducts in the endways, so that a snow pocket does not form.
2. It is not recommended to overstate the size of the pipe too much above the specified standards, because from strong wind pressure, or snow pressure in winter, the chimney may tip over and if for technical reasons the pipe lift cannot be avoided, her position above the roof strengthens the stretch marks.
3. The most rational location of the chimney is considered to be the closest possible location of the pipe to the ridge on the pitched roof for the following reasons:
- the height of the pipe will provide the maximum height from the hearth level (the location of the grate) to the mouth of the pipe;
- the construction of the pipe will not be subjected to artificial swirls of the wind flow;
- the size of the pipe will not allow to collapse from wind pressure, or snow pressure in winter;
- for the construction of such a pipe, it is not necessary to build forests, and the material on the roof is required in a minimum amount.
4. It is important to remember that the smoke channels in the walls of foam concrete blocks or silicate bricks should be made of ceramic solid bricks. This is stipulated in the fire safety requirements.
5. In the location of the attic space, it is recommended to whitewash the chimney to determine the defective location and timely repair.
6. Chimneys for wood and peat stoves on buildings with roofs made of combustible materials should be provided with spark traps made of metal mesh with holes no larger than 5x5 mm. In bell stoves that do not have a component part of a barbecue or fireplace, such a mesh is not necessary.
7. Smoke pipes should be built above the roof of taller buildings attached to a building with furnace heating. This paragraph from clause 6.6.12, causes a contradiction with the information on the height of the pipe indicated in the figure in the area of the wind support of the extension, but on the other hand, this information was found in some scientific books, for example, in the "Rules for the production of pipe-furnace works", 2006.
8. The height of the exhaust ventilation ducts adjacent to the chimneys shall be equal to the height of these pipes.
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