Repair and construction

Chimney repair: causes of destruction and methods of reconstruction of chimneys

January 12, 2020

The chimney is a channel, which is made of different materials and carries out the removal of combustion products outside the residential building. From the integrity and purity of this channel, depends on the quality of heating, and sometimes the lives of the inhabitants. In case of various defects in the chimney design, the only correct solution will be their immediate elimination.

The operation of the heating system depends on the condition of the chimney, therefore repair of a flue needs to be carried out in time

What are the functions of the chimney?

The chimney is located in the vertical plane and is a channel, the shape of which may be different. Consider the two main variants of the cross-sectional shape of these structures:

  • rectangular;
  • round.

The most common materials for chimneys, usually, is:

  • brick;
  • steel (stainless or galvanized).

Each design of this type must comply with certain building and fire regulations, which are described in detail in the relevant documentation. Consider the main functions, who perform these channels:

  • elimination of combustion products, processed in heating devices, outside housing;
  • providing the necessary traction indicators. Thrust in the chimney communication is a very important indicator, on which the efficiency of the heating system as a whole depends;
  • some chimneys are rightly considered an indispensable element of the decor of the building.

Importantly! Any problems, which occur during the operation of this heating communication, can lead to deplorable consequences. In a faulty design, the thrust is broken, which leads to a decrease in the quality of heating. Such a phenomenon can occur, how back draft and combustion products can enter living quarters, what, undoubtedly, endangers the lives of residents.

In addition to the main function, the chimney can play the role of a decorative element in the exterior of the house

There are many factors, which affect the chimney and contribute to its destruction. These factors are especially dangerous for brick buildings, since they are less resistant to them.

Reasons for the destruction of brick chimneys

There are natural and artificial factors, which contribute to the destruction of flues. Natural factors include:

  • temperature differences;
  • aggressive chemicals, which are part of the smoke;
  • condensate, which occurs due to the temperature difference inside and outside the channel.

Natural factors have a detrimental effect on brick structures, as the brick has no anticorrosive effect and wears out quickly at temperature fluctuations. Metal pipes cope with these factors much better, however, they also have their vulnerabilities.

In turn, artificial factors are no less, and sometimes more detrimental to brick canals. Consider them:

  • incorrect technology of execution of a bricklaying, relating to installation errors, may cause poor traction in the flue structure;
  • low quality materials, from which the channel for smoke removal gathers;
  • operational errors;
  • other errors when installing the system.

Chimneys break down the fastest, made of brick

Errors when installing this communication, apparently, is one of the most common problems. During operation, incorrect system design affects its operation, the amount of condensate in the channel increases, which in the cold period of the year leads to icing of the inner walls. Freezing of condensate destroys the solution and, so, spoils the masonry. In addition, incorrect design affects the thrust in the system.

Application during installation of a chimney of a low-quality brick, did not pass the hardening procedure properly, leads to its rapid wear. Using low quality materials can cause a fire in the future. The destruction of the chimney structure can also occur due to mechanical influences. In any case (regardless of the cause of the destruction) experts recommend to react immediately and perform the necessary repairs.

In what cases it is impossible to do without repair?

Chimney repair is a serious procedure, which often takes a lot of effort and time. Many owners of private homes, which are equipped with an autonomous heating system, which includes a flue, are asked questions: how to determine the need for chimney repair? Consider the signs, indicating that, that it's time to repair the chimney:

  • repairs are needed in that case, if the chimney on the roof began to collapse;
  • cracks, visible in the area of ​​brickwork, which is located inside a residential building is also said to be, that it is necessary to perform the reconstruction of the chimney;
  • reduction of traction. This may indicate a number of reasons, including: clogging of the flue with soot, chipped fragments of mortar and bricks, as well as installation errors;

Decreased draft in the chimney may indicate this, that the pipe has cracked or is clogged

  • slotted holes in the foundation of the furnace, which arose as a result of system operation. Such gaps indicate that, that the fireplace or stove does not heat up enough during system operation;
  • problems with the seams of the chimney structure, arising as a result of their poor quality.

pay attention! Usually, the cause of the destruction of the flue is the impact of the environment, namely: rain, snow, wind and temperature changes. However, other options are possible (example, the pipe on the roof can be damaged by mechanical impact).

It should be remembered once and for all, that the repair of deformation manifestations of the chimney must be performed immediately after their detection. There are several ways to repair chimney structures. The selection of the method of repair depends on it, what material was used in the construction of the chimney structure.

Features of repair of steel chimneys

Steel flues are a more modern solution and have some advantages, in front of brickwork. Consider the main advantages of using steel pipes for installation of flues:

  • accessibility;
  • resistance to corrosion;
  • resistance to aggressive chemicals;
  • resistance to temperature changes;
  • ease of installation.

The most practical are steel chimneys, this design is easy to install and lasts a long time

From a constructive point of view, such channels are modular and consist of pipes, which are interconnected. Joining of pipes in such constructions is carried out by means of special connecting clamps.

Consider the gradual repair of steel structures:

  1. First you need to clean the chimney.
  2. After cleaning, you need to conduct a preliminary inspection of the chimney. This measure will identify the cause, which prevents the flue from performing its functions properly. Usually, the main reason for the reduction of draft in the steel chimney - the occurrence of cracks.
  3. If a crack is found, the repair is quite simple: the damaged segment is replaced by another.

Repairing a steel chimney is considered very simple, as does not demand carrying out full dismantle of a design (damaged modules can be easily replaced with new ones).

How to repair a brick chimney?

To date, several methods are used to repair brick chimney structures. In most cases, brick chimneys are built to remove the products of solid fuel combustion (coal, firewood). Old brick structures are not only covered with cracks, but also crumble. In particularly advanced cases, the old smoke communication may collapse completely.

In most cases, the repair of the chimney requires disassembly. And dismantling is carried out from the top point of a pipe, located on the roof, to the damaged area. This is quite hard work, which takes a lot of effort and time. In some cases, it is easier to make a new chimney, than to dismantle and reassemble the old structure.

If the brick chimney is badly damaged, then it is dismantled and a new pipe is built

pay attention! To repair the flue, made of brick, it is recommended to use only quality materials. Such materials must withstand high heat, which is formed as a result of processing of solid fuel.

In addition to the basic method, described above, there are other options for restoring a brick chimney. Consider them:

  • sleeve;
  • masonry or lining;
  • reconstruction of a pipe by means of polymeric inserts.

Chimney liner

Chimney lining is the introduction of a steel or ceramic pipe into an old brick channel, collected from individual segments. Consider the main advantages of such reconstruction:

  • increase in traction due to that, that sleeve, usually, has a round shape. This form is best suited for high-quality removal of combustion products;
  • smooth inner walls of pipes, installed as sleeves, exclude the possibility of rapid clogging of the channel with soot;
  • heat losses in this design are minimized.

For brick chimneys use a sleeve - the installation of a steel channel inside the structure

Before the reconstruction of the flue with a sleeve, it is recommended to carry out preparatory work. Preparation for the reconstruction of the brick chimney is performed in the following order: first the reliability of a bricklaying and passability of the internal channel is checked. Next according to the size of the inner channel, the section of pipes is selected, which will act as a sleeve.

After the completion of preparatory work, the chimney is lined directly. Consider this process in stages:

  1. First of all it is necessary to rise on a roof and to execute dismantle of a bricklaying. This is a necessary measure, which allows you to free the channel for mounting the sleeve.
  2. In the second stage, the sleeve is installed. In most cases, this process is performed from the top of the old chimney to the bottom. First, the lower part of the sleeve is fixed to the ropes and immersed to the required level in the brick channel. Then the next module is inserted into the first segment, and so on. d. At the joints of individual segments of the sleeve must be dismantled brickwork, to securely connect the pipes.
  3. Further, the free space between the inner wall of the brick channel and the outer wall of the sleeve is filled with a suitable insulating material.
  4. After placing the insulation on the end of the sleeve put on a protective cap. It is necessary for that, to protect the new flue from precipitation and debris.

Council! During the installation of the sleeve, experts recommend to take care of the organization of a special inspection door. Така дверцята необхідна для проведення очищення ділянки дымоотводного каналу.

  1. At the end of the laying of brickwork, which was disassembled to join the structural elements of the sleeve.

There should be free space between the sleeve and the brick walls, which is filled with insulating material

Flue construction

Chimney lining or lining is a universal method of reconstruction of flues and ventilation ducts, which involves the use of special refractory compounds. The most popular means, used for the reconstruction of chimneys, is:

  • Mordax;
  • Mosan.

The main element, which is part of the first means, there is a granite crumb. Such a tool is produced in Finland, therefore has good quality characteristics. To obtain the required solution, which will allow to repair the chimney, made of brick, this tool is mixed with lime, as well as cement mortar and water. Mosan is a domestic analogue of Mordax, which is made on the basis of perlite.

Both of the above tools differ, easily gripped with brick and concrete material. The main advantage of this reconstruction method is, that it is carried out without dismantling of a bricklaying. After reconstruction, the walls of the inner channel of the chimney become smooth. So, increases the thrust in the system and simplifies its cleaning.

Usually, bricklaying is carried out very quickly. The whole reconstruction process takes no more 3-4 hours. Consider the order of work during the execution of the masonry:

  1. First of all it is necessary to clear the internal channel of an old brick chimney, removing all soot and other foreign elements.
  2. Further, the channel is humidified.
  3. In the third stage, the blowing tool is immersed in the channel (brush), which sprays the composition on the inner walls of the channel.
  4. Spraying the mixture is repeated 3 times. Each of the previous layers must dry before applying the next.