The sandwich chimney is a two-circuit structure made of stainless steel, in which there is a heater between the two pipes, external and internal. Non-combustible, environmentally friendly material is used as a heater.
In another way, a sandwich chimney is an insulated chimney. This design is used widely and everywhere: for fireplaces, stoves, ventilation systems and where the device of the internal structure cannot be used. Consider how to properly install a sandwich chimney with your own hands.
Features of sandwich chimneys
A three-layer chimney, like any other device, has a number of features that distinguish it from other similar designs. First, consider the advantages and disadvantages of the design.
Advantages and disadvantages
|Ease and availability of installation
|Installation of a sandwich chimney is simple and affordable, unlike the same devices that require control by a specialist
|Short service life
|The service life of sandwich devices is about 10 — 15 years, while conventional pipes can last much longer, several decades.
|The chimney sandwich pipe can be pulled up and to the sides, that is, into the walls, which makes it possible to choose when configuring
|Rapid loss of tightness
|Due to temperature changes, the sections are constantly narrowing and expanding, as a result of which its tightness is reduced.
|Has high quality insulation
|Due to which the device has low heat loss and high performance
|Quality items and parts have a high price
|It is safe for humans to use such a design, since the external circuit heats up to certain values and is not capable of harming and causing burns.
|Does not allow condensation, a large amount of soot to appear
As we can see, the disadvantages of such a design are much less than the advantages, which greatly distinguishes it from its counterparts. Thus, the insulated sandwich structure on the outside allows for rapid heating of the inner pipe, resulting in a constant natural draft, and combustion products are immediately removed to the outside. In addition, they have a high standard of safety and reliability, are resistant even to sudden changes in temperature and have a low level of condensation.
SNiP 21–01-97 and technical characteristics of the basalt thermal insulator
When installing a sandwich chimney, it is important to study the technical characteristics of the basalt thermal insulation layer, that is, the thickness of the contents. Its meaning can vary from 2.5 to 6 cm.
The cross section of the device can also be different and it depends on the power, another indicator that should be taken into account when installing in accordance with building codes and regulations.
|Power rating N (kW)
|Section value (mm)
|Less than N 3.5
|3.5 N 5.2
Table — The ratio of power and cross section
During installation on their own, products of round section are mainly used. In such situations, first of all, the cross-sectional area is calculated according to the rules of SNiP 21–01-97, and only then the necessary products are selected that have certain indicators.
What should you pay attention to when choosing a design?
When choosing a chimney pipe already from finished products, you should pay attention to several main factors:
- it is important that it provides normal traction;
- the chimney must not be clogged;
- the device must be correctly installed;
- the design must meet the requirements of safety, comfort.
At the same time, the price when buying parts and elements should not be a determining factor.
Preliminary calculation of the chimney and installation diagram
Installation of a sandwich structure should take place after preliminary calculations, among which it is important to determine not only the cross-sectional indicators, but also the length and its location.
Chimney height and location on the roof
When determining the location in which it should be located, it is important to take into account the following:
- In a situation where the house has a flat roof, the sandwich structure should be placed at least half a meter (0.5 m) above the roof.
- When the distance between the outlet and the roof ridge is less than half a meter (1.5 m), then the chimney should be installed half a meter above the ridge.
- If the distance between the chimney and the ridge falls in the range from one and a half to three meters, then the height should be made equal to the height of the ridge.
- When the above distance is more than three meters, then the height of the chimney is based on the principle of an imaginary line, which it should be equal to. An imaginary line, in turn, is drawn from the ridge to the horizon at an angle of 10 degrees.
When calculating the length, it is important to consider a few basic rules:
- According to building codes sandwich the system must have height not less than 5 m.
- When using a material with a high degree of combustion as a roof covering, chimney sandwich over ridge roof worth an extra boost about 1 — 1.5 m.
- When using non-combustible material on the roof, the same height must be at least half a meter.
- If the house has extensions on the roof and they are higher than the house itself, then the structure must be installed so that it is higher than such a building.
Scheme of installation of a sandwich chimney
In order to make it easier to imagine how it is worth doing the installation correctly, we present a diagram.
Figure — Mounting scheme
Thus, if all the requirements and rules are taken into account when calculating the location of the sandwich chimney, its height and length, then the installation will be performed correctly.
DIY installation instructions
Required parts, fasteners and tools
Before starting the installation of a chimney sandwich structure on your own, it is worth preparing some fixtures and parts. These include:
- a special adapter that will allow you to bring the device to the roof;
- console (bracket) for fixing the sandwich structure;
- platform for unloading, thanks to which it will be possible to evenly distribute the weight and thereby remove the load from the base;
- a kind of hole (window), through which the chimney will subsequently be cleaned;
- clamps for fixing structural elements;
- several adapters;
- a knee at an angle of 90 or 45 degrees, it will allow you to change the direction of the chimney sandwich;
- device for the upper part — cone, fungus, wobbler, etc.
Before proceeding with the installation, you should find out how and in what way the elements can be connected. There are several such methods:
- flanged. Such a connection allows smoke to escape through the pipe without obstacles due to excellent traction, but with poorly closed joints, moisture can seep into the structure and damage the basalt insulation.
- condensate. This method is used when it is necessary that condensed moisture, which occurs due to temperature differences, flow freely along the walls. With this installation, the inner tube is placed in a socket so that moisture does not penetrate inside, but at the slightest gap, smoke will enter the room.
- bayonet or bayonet. Such a connection of parts is obtained as a result of movement along the axis and rotation, and sometimes lateral displacement, of one part relative to the other.
- smoke. Sandwich construction is assembled according to this method in the case when it is necessary that carbon monoxide does not penetrate into the house.
When choosing any of the options for connecting the chimney pipe, it is important that all the cracks are carefully closed, then moisture cannot damage the insulation, and flue gases will not damage the health of the household. In addition, it is recommended to install the internal pipes of the structure along the condensate so that moisture does not enter the joints and does not leak.
After preparing the necessary parts and choosing a connection method, you can proceed directly to the assembly. Installation of the structure does not require special or additional skills and abilities. It can be performed even by a person who is far from construction.
The main rule to remember before starting the assembly is that the installation should start from the bottom, i.e. from the boiler, and continue towards the roof. The installation can be divided into four main stages.
Assembly of stainless steel chimney elements
Stage 1 — assembly of parts.
Connecting the parts together is quite simple, the main thing is to be careful. First of all, what you need to pay attention to is that one end of the pipe has a small radius, and the other is slightly larger. In order to properly connect the parts, you need to push the end with a smaller radius into a larger one.
This assembly has many advantages:
- soot will not accumulate;
- moisture will be easily removed.
However, to ensure that condensate and moisture actually come out, and do not settle inside the device, it is necessary to insert tees.
Stage 2 — the withdrawal of the chimney.
Sandwich pipe on the street can be removed in two ways:
- Through the wall
- Through the roof
We will consider each of the options a little later.
Stage 3 — fixing the chimney.
Stage 4 — completion of work.
Mounting through the wall
Let’s return to the second stage and consider ways to remove the chimney structure. When installing an insulated chimney through a wall, the following steps should be taken:
- When removing a sandwich pipe through a wall, the first step will be to disassemble the entire structure and fix the landing brackets (props).
- Install the outer console and attach a couple of corners to them in such a way that the shape of the “runners” is obtained. They will allow you to move the tee in the process of work without obstacles.
- Close the wall with a 1 cm sheet of plywood and fix fine-fiber asbestos material on top of it with screws.
- On top of the asbestos, one galvanized sheet with parameters 12 * 20 cm should be installed.
- Next, a square hole must be made in the sheet through which the pipe will go out, the sheet itself should be well fixed with screws.
- After installation, the support must be varnished with an anti-corrosion effect.
- An adapter is inserted into the hole in the wall, in which a hole is also made, and then a pipe is put on.
When installing the chimney pipe through the wall, remember about the concession. A concession, or retreat, is a space that is necessarily left between the wall and the pipe. The value of the concession depends on the wall thickness of the chimney (furnace).
Table — Basic assignment parameters
|Wall thickness of the chimney (furnace) (cm)
|Distance from the surface of the chimney (furnace) to the wall (cm)
|flameproof (non-combustible material)
|not protected from fire (combustible material)
When mounting through a wall, it is important to correctly install the first element of the entire structure so that the first part is attached to the second above the level of cutting the ceiling. Such an installation will allow visual control of fire hazardous elements.
Installation through the roof
To bring the insulated chimney through the roof, do the following:
- A sheet of steel is applied to the exit hole from the inside.
- The chimney is led out through the roof.
- The sheet is fixed to the roof with screws.
- If necessary, it can be brought under the edge.
If the roof of the house is made of combustible material, then it should be additionally protected from possible ignition. To do this, the deflector itself should be equipped not with a cone or fungus, but with a spark arrester.
The conclusion of the structure on the roof is the most difficult and with this method of installation, one more detail will be required — roof cutting. This is a special metal structure that prevents the walls of the chimney from coming into contact with the roofing materials.
When fixing the structure and its constituent elements, some features should be taken into account:
- all parts and knees are connected and fastened together with clamps;
- the tee should be additionally fixed with brackets;
- if the top of the structure is not fixed, then for safety it should be fixed with stretch marks;
- docking elements must be additionally fixed and fixed to each other with clamps, and with other parts, for example, with an adapter, clamps on both sides.
How to insulate and seal the chimney from the outside
Features of the final stage:
- After all the installation and fastening work comes to an end, it is worth removing the protective film.
- It is important to check whether all slots and joints are well sealed. It is better to seal with a flame retardant sealant that can withstand very high temperatures, at least 1000 0FROM.
In this case, the sealant must be applied, taking into account some of the nuances:
- if it is applied to the inner pipes, then they cover the entire area of u200bu200bthe outer surface of the upper element;
- if on external ones, then it is applied according to the same principle (see above);
- if at the point of transition from a conventional pipe to a sandwich, then they should seal the entire area from the outside around the circumference;
- if at the junction of an ordinary pipe and other elements, then also on the entire area from the outside along the circumference.
- The most dangerous areas of the chimney should be checked for temperature.
- Do not forget to take a place for the inspection window so that there are no difficulties during inspection and cleaning.
- The correct length of the structure in the end should be approximately 6 m, counting from the grate.
Cleaning and maintenance of the chimney
It is a pleasure to use the results of your labors, especially if you installed the chimney correctly.
However, care is equally important. Usually, during the use of the device, soot accumulates in the pipe, which not only reduces the useful section, but can also cause a fire.
It is necessary to regularly clean the sandwich chimney, especially during the heating season, at least twice.
For this important matter, a special inspection window was provided during installation, which will allow you to clean the pipe without much hassle.
Prices and sizes of stainless steel components
The cost of sandwich pipes for chimneys is different and depends on several factors:
- diameter of the inner pipe;
- quality of thermal insulation material;
- thermal insulation thickness;
- pipe thickness;
- module length, etc.
When installing a sandwich chimney yourself, you should take into account many features and rules, the exact implementation of which will allow you to not only install the chimney correctly, but also safely.
- The average price for one sandwich pipe module is from 500 to 4000 thousand rubles.
- Short sandwich pipes 0.25 m and not large thickness can be bought within 500 — 6 dollars (we are talking about one element).
- Pipes about 1 m long will cost more 2000 — 3500 thousand rubles.
It is also important to choose the right chimney, for this you can read the characteristics, consult with experts, study the installation master classes. In general, if you have installation instructions and diagrams at hand, the necessary tools and parts, then you can do the installation of the chimney pipe with your own hands without much cost and hassle.