The chimney in a private house is an integral part of the heating and water heating system. These designs ensure the removal of combustion products from fireplaces, water heaters, gas and solid fuel stoves, which are installed in residential buildings, garages, baths and other outbuildings. The speed of fuel combustion, the draft in the furnace, the safety of the building and its owners depend on the correct assembly of the structure. There is a wide range of products of this type on sale. With construction skills, it will not be difficult to make a chimney with your own hands. To do this, you need to familiarize yourself with the structure of these structures and the principles of their assembly.
Chimney requirements
The rules for the construction and operation of combustion products removal systems are prescribed in SNiP 2.04.05–91 and SNiP 41-01-2003. Their observance when planning and carrying out installation is one of the conditions for putting the facility into operation. Arrangement of a structure is a multi-stage process, which involves lifting it from the bottom up, competently performing joints and passing through the supporting structures.
A correct chimney must meet the following requirements:
- the minimum channel length is 500 cm;
- pipe clearance - not less than the size of the outlet pipe;
- the maximum number of knees (turns) - 3;
- length of horizontal runs - up to 200 cm;
- gas velocity along the channel - 15-20 m / s;
- niche height for cleaning and collecting condensate - from 25 cm;
- height above a flat roof - 50 cm;
- height above the ridge - 50 cm or level if the exit is more than 250 cm from its level;
- radius of curvature - larger than the channel section;
- minimum design temperature - 1000º.
It is forbidden to combine outputs from several boilers into one channel. It is not allowed to connect flue and ventilation pipes together.
Chimney design
In order to easily assemble the gas exhaust system from the stove, you should understand its design and principle of operation. The efficiency and safety of the entire heating system depends on the correct design and consideration of all the nuances.
Standard chimney device:
- Boiler. It has a firebox, a device for adjusting the intensity of combustion, a branch pipe for exhausting gases departs from the body. A pipe is connected to it.
- The channel itself. Depending on the laying conditions, it can be strictly vertical or have turns. These fragments correspond to the parameters of the main channel.
- Fluffs. They are extensions that are made at the intersection of the ceiling and the roof by the pipe. The fluffs are equipped with heat-insulating material.
- Head. It is a protective device against water, snow, debris and small animals getting into pipes.
- Chimney fixing. By type of use, it is carried out along the walls and on the roof to withstand strong wind loads and wet snow sliding down.
Each structural element performs a specific function and requires careful consideration when planning.
Material selection
The correct choice of materials is one of the components of the quality of construction. Each of them has its own advantages and disadvantages, cost and service life.When making a decision, you should carefully consider all aspects and not miss a single nuance.
The pipe from the boiler can be made of the following materials:
- Brick. The blocks are distinguished by their fire resistance, heat capacity and durability. They can even be installed on a cast iron boiler fired with coal. This is where the advantages of bricks end. There are many more disadvantages - the structure is very heavy. The rectangular clearance can form internal vortices. The walls are porous and rough; soot accumulates more intensively on them. Water absorbs the surface, and when solidified in frost breaks it.
- Iron. The use of round pipes is the best solution. A chimney made of a metal pipe can be quickly and easily assembled by means of sockets or by welding. Steel has sufficient strength. However, ferrous iron is susceptible to corrosion, and the acids formed inside the channel quickly corrode it.
- Asbestos cement. Inexpensive material from which it is easy to assemble a straight chimney. The difficulty lies in sealing joints, for which it is difficult to choose a seal with the required characteristics. In addition, the asbestos-cement channel is porous inside; soot quickly accumulates on its surface.
- Ceramics. An excellent solution for those who have sufficient funds for an expensive purchase. The ceramics are durable, heat-resistant, and soot practically does not settle on the smooth inner walls.
- Tinplate with insulation (sandwich). The presence of filler between the pipes eliminates the dew point and prevents the formation of condensation. The product does not need to be additionally insulated; soot accumulates inside extremely slowly.
It is necessary to assemble chimneys from one material, since each of them has its own coefficient of thermal expansion.
Step-by-step instructions and do-it-yourself installation nuances
To achieve a high-quality result, at the first stage of construction, a chimney diagram is drawn up and the necessary calculations are made.
The most difficult thing is to build a channel from bricks. The process is long, difficult, requiring interruptions for the masonry to shrink. If the chimney is light, it is placed on top of the stove. When the structure passes through several floors, it is placed next to the oven and connected with an adapter.
Do-it-yourself brick chimney is done in the following sequence:
- Solution preparation. Clay, lime and cement are used.
- Laying out the attachment base with tying each row.
- Inner pipe outlet with opening for damper.
- Passing the ceiling, making fluff.
- Laying out the external channel, arranging the second extension (otter).
In conclusion, the gaps are sealed and the head is installed.
It is much easier to assemble ceramic flue pipes. The assembly uses ready-made elements that need to be connected, sealed and securely fastened. The work is carried out in the following sequence:
- Manufacturing of a refractory base with a branch pipe.
- Phased installation of the pipeline in the socket. At the same time, the joints are sealed with a heat-resistant sealant.
- Securing the highway to walls and attic structures.
- Thermal insulation application.
- Installation of external finishing, installation of the head.
When building from ceramics, the general rules for chimneys must be observed - to install inspection hatches, condensate collectors, protection of floors with a special apron.
A sandwich-type pipeline is also made from ready-made links, which are inserted into one another.
The assembly of a stainless steel chimney is carried out in the following order:
- Manufacturing of a base with a branch pipe.
- Assembly of the line with simultaneous isolation of the connection points. A sealant or clay-impregnated asbestos cord is used.
- Laying a chimney through a wall or ceiling.
- Fixing the communication to the walls and roof.
- Installation of the head.
Having built a chimney with your own hands from an iron pipe with insulation, you can not worry about its additional finishing. The product does not actually heat up; it can be laid through a wooden ceiling without installing an apron.
Chimney operation and cleaning
With proper operation, chimneys can serve for decades without accidents and repairs. The maintenance rules for the device are quite simple. They should be regularly inspected for damage and cleaned regularly. In winter, it is necessary to drain the condensate more frequently to prevent it from freezing.
To avoid the rapid formation of soot, it is recommended to use a quality, dry fuel. In this case, you should not raise the temperature in the furnace to a critical one, as this negatively affects the pipe.
The chimney is cleaned from the wood-burning boiler as soon as it gets dirty, but at least once a year. The following methods are used:
- Mechanical. A ruff is used with a load, on a cable or a rigid handle.
- Thermal. Carbon deposits are destroyed by burning aspen wood, which emit a strong heat during combustion.
- Chemical. Synthetic or organic ingredients are added to the fuel, which turn the soot into dust or a liquid substance.
For best results, it is advisable to carry out preventive cleaning every month with regular use of the oven.
