When designing a heating system in a private house, such a need may arise as insulation of the chimney. It is necessary to prevent the formation of condensate, which leads to pipe damage and violation of the building’s operating mode.
Where to insulate
Insulation is required in places where the warm surface of the pipe is in contact with the outside air. This occurs in the space of a cold attic and after the conclusion to the roof. When doing the work yourself in your own home, you need to take care not only of the chimneys, but also of the ventilation ducts, which also need insulation.
Condensation always falls out from the side of the warm air. In the case of a chimney, this will happen inside the pipe, which will lead not only to its damage, but also rolling moisture down to the heating device, deterioration of draft. To prevent this, it is necessary to prevent the cooling of the pipeline.
Material selection
In order to carry out insulation with your own hands in compliance with fire safety techniques, it is necessary to correctly select the thermal insulation material.
Since chimneys are communications through which heated air passes, combustible and fusible materials for insulation are strictly prohibited.
The only material that meets these requirements is mineral wool. To insulate the pipes, you can use a heat insulator, available in the form of mats, rolled up in rolls, or special forms for pipes (not suitable for chimneys made of bricks). Do-it-yourself insulation of the chimney with mineral wool should be carried out in compliance with safety precautions. Each worker must have the following personal protective equipment:
- mask or respirator;
- glasses;
- gloves
- closed clothes.
This is necessary so that particles of material do not get on the skin, eyes and lungs. Mineral fiber can cause severe irritation and itching of the mucous membranes and skin.
The thickness of the insulation is selected based on the temperature of the gases formed and the outside air, as well as the location of the pipe:
- for external - within 70–100 mm;
- for those located inside the building - within 30-50 mm.
Mineral wool can be used in the following types: basalt, glass wool, slag. Before use, read the instructions of the manufacturer of the heat insulator. In addition to this effective material, brick bricks are sometimes used as an inexpensive alternative.
Brick chimney insulation
There are two ways to perform work to protect the pipe from freezing and condensation:
- grid plastering;
- mineral wool insulation.
To protect the pipes with your own hands in the first way, you will need to perform the steps in the following order:
- Fixing the reinforcing mesh to the wall surface. Before this, the structure is cleaned of dust and dirt.
- Preparation of plaster mortar. To do this, mix lime, cement and slag with the addition of water. Perhaps the use of modern "warm" plaster, which has good thermal insulation characteristics.
- Application of the solution to the surface. The thickness of one layer is 20-30 mm. If necessary, the composition is applied in several layers. Each subsequent stacks after drying the previous one. The very last layer of stucco is leveled and rubbed.
- After the plaster dries, the surface is checked for cracks and bumps. If necessary, they are eliminated. The work is completed by painting the pipe with lime or chalk paint to protect the plaster layer from the negative effects of the environment.
This method is ineffective.
Mineral wool will protect the pipe more reliably from cold. If you want to do it yourself, stick to the following scheme:
- The surface is cleaned from contaminants and deposits. Inspection for irregularities and removing them if necessary.
- Collection of the frame, on which the insulation will be mounted. The lath consists of metal guide profiles, which are fixed with dowels. The pitch between the rails is selected so that it is convenient to lay the insulation.
- Gaps and crevices should not be allowed. They will lead to heat loss and cold bridges.
- Fixing the vapor barrier with an overlap of 15–20 cm. The joints are glued with construction tape.
- The pipe lining has a decorative and protective function. When doing DIY in a cold attic, you can use sheets of drywall.
Thermal insulation of pipes made of stainless steel and asbestos
Elements protected by this technology consist of an internal pipeline enclosed in a casing of insulation, and an additional protective pipe. The outer casing is made of galvanized steel.
For insulation you can use mineral wool in rolls or special products for pipes.
When carrying out work, it is important to observe the following requirements:
- when insulating a chimney from a stainless steel located outside, the thickness of thermal insulation should be no more than 100 mm;
- for sections located inside the building, the maximum thickness of thermal insulation is 40 mm.
The work of insulating chimney pipes made of asbestos concrete can be performed in the simplest way, which does not require serious labor costs. This option is suitable as temporary measures to protect the chimney from the cold and condensation, as he is short-lived. The work is done as follows:
- prepare mineral wool in rolls;
- wrap the tube with this material (if necessary in several layers - depends on the required thickness of the insulation);
- tighten and fasten the material with brackets.
The method is only suitable for use in a cold attic. Material without a protective layer will not be able to work in outdoor conditions, since it is not resistant to moisture and the negative effects of the environment.
To perform a full insulation, you will need to carry out the following set of measures:
- A casing is made of galvanized steel. When selecting the sheet width for manufacturing, the necessary diameter of the inner pipe is taken into account (so that a heater of the desired thickness is placed between the two layers of galvanizing). With a large length of pipes, it is recommended that the outer pipe be made of components with a maximum length of 150 cm.
- The surface of the pipe and the place for work are cleaned of dirt, dust, debris.
- Fix the bottom of the galvanized casing. Fill the space between the pipes with insulation. Install the next element of steel and repeat the process. It is important to ensure a tight fit of the casing elements to each other.
- Having reached the top of the chimney, the structure is installed with a slight slope. All existing gaps are eliminated using cement mortar.
Proper insulation of the pipeline for the removal of combustion products will allow you not to worry about the lack of traction and violation of the operating mode of the structure.