The chimney is one of the main parts of the heating system of a residential building, which allows you to remove carbon monoxide and combustion products. Smoke components settle on its inner walls. During the formation of condensate, a chemical reaction takes place, during which acids are created, destroying the internal structure of the brick material or provoking the development of corrosive processes in the smoke channel from metal elements.
Additionally, the pipe is affected by external factors — gusts of wind, seasonal temperature changes, various precipitation, a chimney is flowing. The resulting damage causes a decrease in traction force, leads to an increase in fuel consumption, there is a risk of poisoning people with combustion products, and as a result, repair of a house or industrial chimney is necessary.
Breakdowns can occur for many reasons, the main ones are:
- Incorrectly executed laying of smoke channels, which causes the formation of condensate.
- The masonry is made of poor quality bricks that break down in a short time.
- Mechanical damage to the pipe.
- Wear out of masonry in a natural way.
It is necessary to check the condition of the chimney once a year, this is especially important before the heating season, it is unacceptable not to inspect the smoke channels for more than 5 years. During these examinations, the causes and extent of damage are found. Detected defects must be immediately eliminated so that the thrust is normal.
With a decrease in traction, you should immediately check the pipe for possible blockages, the cause may be bird nests, fallen pieces of concrete or brick. The passage may be clogged with soot.
The easiest way to check is by lowering a weight into the smoke channel (it will stop at the blockage). The defect is easier to eliminate with a falling weight. If this does not work out, to repair the chimney, you will have to disassemble it at the site of the blockage and remove it, after which the wall is folded again.
The flow of vapors into the smoke channel from the furnace is a reason that can cause several troubles:
- The traction force will sharply decrease and the smell of burning will appear in the room.
- The masonry is saturated with moisture, which leads to its further destruction.
- Resinous black spots appear on the stove and on the surface of the chimney.
- Increases corrosion and provokes the main malfunctions of metal pipes.
Condensation appears for several reasons:
- Under the surface of the roof there are through cracks, this quickly cools the air. Condensation will definitely appear under these conditions;
- The chimney does not have thermal insulation — the pipe is plastered or enclosed in a metal casing. Internal smoke channels are protected with glass wool or basalt fiber.
Trouble can occur for 2 reasons:
- The deflector above the chimney is not installed or broken. The deficiency must be corrected immediately.
- Nearby buildings or tall trees create an obstruction that prevents the chimney from working properly. It is necessary to increase it by 0.5-1 m, which will allow it to be removed from the area of wind backwater.
The smooth inner walls of the smoke channel are very important — the surface without unnecessary protrusions improves the flow of gases. With a large diameter of smoke channels in a private house, if they are larger than necessary for the stove, the gases will slowly rise up, they gradually cool down and the air moves even worse.
The head of the chimney is the most vulnerable place, which is affected by weather phenomena. Its integrity is very important for the quality of traction, for this reason it is important to immediately eliminate any malfunctions. It is possible that even a new chimney will begin to work inefficiently — smoke occurs, the smoke does not go away well, or even reverse draft appears. These troubles indicate errors in the design or when laying the chimney.
It should be examined by a specialist in order to find the cause of the trouble, and give an opinion on how best to repair brick chimneys. The entire structure may need to be redesigned.
Masonry inspection and minor restoration
During an external examination of the pipe, the level of destruction of the brick is determined or all defects that can cause a decrease in traction force are detected. If cracks are found, a mortar that has crumbled from the seams, the pipe is smeared again.
Remove the old solution with your own hands using a chisel. You need to cut into the masonry by at least 2 cm, so you can free up space that will be filled with fresh mortar.
The solution is prepared from 1 share of Portland cement, 2 shares of lime and 7 shares of sand. The seam is moistened in advance, this will enhance the adhesion of the solution. A trowel is used to coat the damaged section of the pipe, filling the voids. It will be possible to seal the seams well with the help of an aluminum tube bent at an angle, its thickness should be the same as the width of the seam.
Cracks found on the pipe are cleaned with a metal brush, and dust is removed from them. Seal all cracks with a heat-resistant sealant or a simple clay mortar.
If serious damage is found during the inspection, the pipe will have to be restored until it is completely disassembled. The brick is removed in layers with a hammer and chisel, there is no need to rush. The material is removed to the area where the row will be without damage. The disassembled brick is lowered to the ground, the pipe is folded into one brick, the masonry must be constantly monitored by the level.
Masonry should be done so that the inner surface remains completely smooth, this will improve the passage of smoke. The upper part of the pipe must have a head, which is made of cement mortar, it protects the masonry from the effects of negative weather conditions.
If it is impossible to completely sort out the chimney, a sleeve is installed in it to eliminate defects — a ceramic or steel pipe of the desired diameter. A smooth ceramic or metal surface will not trap soot and improve traction. Before installing the sleeve, you must first make sure that there are no foreign objects in the chimney. The sleeve is lowered into place as a whole or with a long chimney in separate parts, but in order to connect the individual elements of the sleeve, it will be necessary to disassemble the masonry.
The void between the masonry and the pipe is filled with asbestos cord or other non-combustible heat-insulating material. Upon completion of work, a protective visor made of painted metal is installed on top of the smoke channel. The installation of a round sleeve improves smoke removal, increases the tightness of the smoke channel, and significantly reduces heat loss. This method can only be used for straight chimneys, the diameter of which does not change along the entire length.
Repair of industrial chimneys
Industrial chimneys are serviced by specialists who have a special permit to work at height. This, perhaps, is the replacement or strengthening of worn elements or individual parts of the structure.
The restoration of the pipe head requires a temporary shutdown of the process equipment. Part of the repair work can be carried out without stopping the operating mode.
Examination of chimneys
Assessment of the condition of smoke exhaust devices at industrial facilities is carried out regularly. Taking into account the nature and extent of defects, the chimney repair is divided into current and capital. Overhaul of boiler room chimneys is carried out by organizations that include workers with the necessary certification.
Work at these facilities consists of several operations:
- Restoration of the protective coating, protection of the chimney shaft against corrosion.
- Elimination of the roll of the pipe, if it is above the permissible values.
- Replacement or complete repair of tension devices for metal pipes.
- Restoration of brickwork.
- Repair and strengthening of heads.
- Restoration or new laying of lining of brick channels.
- Restoration of blind areas.
- Restoration and arrangement of concrete sills.
After completing the examination of the chimney, a repair project is created. The most common defects:
- Mounting and tensioning the clamping rings, this will remove cracks on the surface of the pipe.
- Cracks no more than 3 cm are cleaned from dust and dirt, after which they are sealed with concrete mortar.
- Cracks larger than 3 cm are preliminarily cleaned, destroyed bricks are replaced.
- After eliminating the shortcomings, tighten the compression rings.
If there has been a deformation of the base of an industrial pipe, which causes the entire structure to roll, recovery methods include:
- Reinforcement of the soil around the structure by resinizing or grouting.
- Additional load on the base from the side against the tilted wall.
- Partial removal of soil opposite the roll.
For an industrial chimney made of bricks, it happens that it is necessary to eliminate small cracks, and sometimes — the restoration of the masonry. If horizontal or vertical cracks have formed on the surface, then during the repair they are sealed with cement mortar and the foundation surface is plastered. Metal chimney parts require repair after a short period of time. Bandage rings are tightened over time, as they weaken over time and do not fulfill their purpose well.
It is important to pay attention to the condition of the masonry mortar. Over time, it loses its characteristics and is washed away by precipitation. To prevent the destruction of the masonry, it is necessary to cover the empty seams with a high-strength plaster mortar.
Restoration of reinforced concrete structures
Industrial pipes made of reinforced concrete products in some cases at thermal power plants reach 350 meters. It is possible to work on such structures only with the help of a winch. Metal reinforcement is laid in the frame of reinforced concrete products, it corrodes over time, at the same time concrete is destroyed. If a pipe section is damaged to a depth of up to 3 cm, it is covered in 2-3 layers along a metal mesh.
Industrial pipes made of reinforced concrete products are restored inside, embroidering and covering up the detected cracks after that. Large damage to the pipe surface requires complete surface plastering. After repair, industrial pipes are painted using organosilicate paint. This material does not tarnish over time, and can be used to protect metal surfaces.
Restoration of industrial metal pipes
The main works in the repair of damaged industrial chimneys are surface preparation and painting. Sometimes it is necessary to replace the bracket or other component of the smoke channel. At the preparation stage, a layer of old paint is peeled off.
With the help of spatulas and metal brushes, from 10 to 30% of the old coating is removed. There are requirements to clean all 100% of the surface. This can be achieved by using a special acid solution. It is applied to the pipe and after three minutes the old layer of paint is carefully removed. Areas where corrosion is detected are treated with drugs that stop these processes. It is necessary to paint the surface after a previously applied primer, after waiting 2 hours before painting.
No matter how high-quality the chimney is, over time it collapses. If the first signs of problems were found, such as cracking of the masonry or shedding of the mortar, it will be necessary to immediately repair the industrial or chimney pipe. Without timely repair, the pipe will eventually fail and will need to be repaired.