Installing a sandwich chimney with your own hands: how to install it correctly in a house or bathhouse

The chimney is an important part of any heating system, which is responsible for removing combustion residues in the form of smoke and soot.

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Chimney installation is carried out in private homes, bathhouses, and industrial enterprises where there is a gas or wood boiler, stove, or fireplace.

The life and safety of operation depends on the correctness and quality of installation.

In private households, a smoke duct made of sandwich pipes has become popular. Assembling it is simple and quick, so many owners do it without the help of specialists.

Design Features

The reliability of the design of lightweight systems is ensured through the use of several layers of modern building materials. The design is called “Chimney Sandwich” in honor of the English sandwich, in which several ingredients are combined in layers. It consists of two pipes made of high-quality steel alloy.

The diameter of the outer pipe is significantly larger than the diameter of the inner one. A layer of thermal insulation material is laid between them, usually non-flammable stone wool. The outer pipe provides protection against damage and mechanical stress. The inner tube can withstand high temperatures. A cushioning layer of mineral wool compensates for the difference in temperature conditions. The thickness of the thermal insulation layer depends on:

differences in diameters of the inner and outer pipes;
temperatures during operation;
the diameter of the stove opening to which the chimney is connected.

Important! Stone wool is a non-flammable material. Therefore, in the event of deformation of the internal steel contour, it will be able to protect against combustion products from entering the chimney.

Sandwich chimney pipes Source i1.wp.com
The principle of assembling a chimney is identical to that of a constructor. You can invite a specialist, but after learning how to make a sandwich pipe for a chimney with your own hands, you can carry out a complex of work yourself. The system consists of parts that are equipped with fasteners for a strong connection with each other. The elements have two types of connections that allow installation using:

corrugated end elements, which allow easy assembly, but require the use of expensive sealant;
socket connection, complex due to the need for careful adjustment of parts, but more airtight if installed correctly.

A properly installed sandwich chimney will last 15 years or more. But you need to remember that to prevent soot outbreaks, the system must be cleaned regularly.

Assembling a sandwich chimney with your own hands Source klimatlab.com

External and internal chimney: do it yourself or with the help of professionals?

On the Internet you can find numerous diagrams for connecting external and internal pipes, their designs and fastening methods. But installing a chimney with your own hands is always a big risk. Since it concerns fire safety, property safety, life and health of the residents of the house, it is recommended to use the services of trusted specialists.

Carrying out installation work by professionals has the following advantages:

preparation of a work plan taking into account all technical features of the structure
guarantee for work performed
guarantee of high quality assembly and installation
guarantee of compliance with all required standards, including those established by law
taking into account all the nuances and features of the smoke exhaust system
high efficiency of work
fire safety guarantee

Advantages and disadvantages

Technological progress has made it possible to move away from the use of heavy foundations when building a house and to build on prefabricated pile-screw and drill-fill foundations. And if previously heating a house could only be done using a heavy Russian stove or fireplace made of brick, now they have been replaced by modular structures made from a portal with a firebox weighing about 500 kg.

Sandwich chimney in a bathhouse Source spskamin.ru

When wondering how to assemble a chimney for such systems, you need to know the advantages and you need to know their advantages and disadvantages:

When used, only the internal part of the system becomes very hot. Thanks to the compensation layer of mineral wool, the outer pipe has an acceptable temperature, which significantly reduces the risk of burns;
after heating the chimney, the draft increases significantly;
the steel surface of the chimney is not susceptible to soot settling as in systems made of brick or ceramics;
due to the rapid removal, combustion products do not accumulate in the chimney, which does not lead to the accumulation of condensate on the walls;
the design of the chimney provides maximum protection: on the outside it is protected by the outer diameter of the pipe from deformation under direct influence, the inner pipe does not allow heat and combustion products to pass through, and mineral wool is a protective layer from fire since it is not hot;

Installed sandwich chimney Source petropech.ru
Since the sandwich chimney system is relatively light in weight, its installation does not require the installation of a special foundation. It is advisable to strengthen the structure of the subfloor with additional lags, but if this is not possible, this may not be done. With proper care, the system will last a long time, but after about ten years, areas with partial depressurization may appear in the seam area.

The most important installation rules

If you are planning to install a chimney through a wooden wall with your own hands, take the trouble to accurately calculate the diameter of the pipe from the beginning. This value is determined by the boiler power and other characteristics. Incorrect calculation leads to poor traction or large excess fuel consumption;
Remember that the sleeve has a hole only for the chimney pipe! There should be no communications nearby;
Any chimney outlet into the wall must strictly observe an angle of 90 degrees, that is, it is advisable to make the chimney outlet through the wall strictly horizontal, and it should not be longer than 1 m. Optimally, a 60-centimeter horizontal transition;
All vertical structures must be strictly perpendicular, and this is the most important answer to the question “how to bring a chimney through a wall”;
No matter what the wall is made of, and even more so, installing a chimney through a wall in a wooden house with your own hands requires strict adherence to fire safety rules! The wall must be reliably protected with fireproof and heat-insulating material.

Calculation of sandwich chimney pipe sizes

Diameter

To determine the optimal pipe diameter size for a sandwich chimney, you need to know the conditions under which the operation will take place. The heating power of the furnace depends on how large the area is, as well as what the planned temperature range is.

As a rule, in order to heat 10 square meters they take 1 kW. Accordingly, in order to heat an area of 100 square meters, you need to purchase a 10 kW stove. Having decided on the power, you can choose a model for individual parameters.

Chimney facing the street Source santehnika-otoplenie.ru

If a system is needed to remove combustion products from a heating boiler, then you need to know the type of fuel and the power of the boiler itself. The higher the temperature of the gases passing through the chimney, the stronger its heating will be. The lowest temperature is for gas boilers, which heat up from 120C to 200C, and the highest for coal boilers, where the temperature of combustion products reaches 700C.

The choice of sandwich should begin with the diameter of the inner pipe. The more powerful the stove is planned to be installed, the wider the diameter should be. For example, if a 3.5 kW oven is installed in a room of 4 square meters, then the width of the outlet from it will be 158 mm. And for an area of 90 square meters with a 9 kW oven, a hole of 220 mm is suitable.

Despite the fact that open fireboxes are not currently recommended for installation, they also have their own standards. The outlet channel in this case should be no more than one hundredth of the total volume of the boiler. If this rule is not observed, the draft in the system will be weak with potential turbulence of air masses with combustion products.

Sandwich chimney inside the house Source pechivrn.ru

Height

To ensure safe removal of smoke away from people, it is necessary to maintain height standards. The total length of the structure should not be less than 5 meters. If the condition is not met, reverse draft may occur, as a result of which the residential area will be subject to smoke. In addition to the overall length, you must also follow the rules for venting the chimney through the roof.

If the roof is pitched, then the upper edge of the chimney should be at least 0.5 meters above the ridge if the middle of the pipe is at a distance of 1.5 meters or less from it. At a distance from the chimney of 1.5 to 3 meters, the chimney should end at the same level as the ridge in a horizontal plane. When removed by more than 3 meters, the top edge should be 10 degrees below the ridge.

Rules for installing a sandwich chimney on the roof Source stroy-good.ru

If the sandwich system is installed on a flat roof, then the height of the upper edge should be located at a distance of 0.5 to 1.5 m. Since the total size of the chimney should not be less than 5 meters, if the dimensions are insufficient, you can increase the length of the outlet through the roof to 30 cm, making sure to use special reinforcement braces.

What to look for when installing steel chimney systems

Holes in ceilings, walls and roofs

When the installation parameters of the DS are determined (height, location, type of connection), you need to make holes in the ceiling, wall and roof. When making holes, it is necessary to take into account that the chimney will heat up during operation and this can lead to burns or fire. In this regard, it is necessary to strictly observe the clearances from combustible structures.

Ilya Manaev

It is important to know! Even if the chimney pipe passes through non-combustible structures, small gaps must be left, since the chimney system is a self-supporting independent structure. Its rigid fastening (clamping) to building structures is strictly prohibited!

Before installing the DS and making holes in the building structure, check the fire safety distances specified in the manufacturer's instructions. Russian standards state that the manufacturer of chimney systems must indicate safe distances to combustible structures.

SP 7.13130.2013 Heating, ventilation and air conditioning clause 5.27 The dimensions of grooves and offsets for heat-generating devices and factory-made smoke ducts should be taken in accordance with the technical documentation of the manufacturer.

But today, not every manufacturer can provide such information, and there are even fewer who can confirm it with certificates and test reports. By the presence of these documents, you can distinguish a bona fide chimney manufacturer from those who produce low-quality products.

Fireproof indentations

How to choose

Since different boilers produce different combustion temperatures, in each case the composition of the steel from which the inner and outer pipes are made can play a role. After burning, sulfur, sulfuric and hydrochloric acid may remain on the walls of the chimney. Temperatures also differ depending on the type of fuel used.

Sandwich chimney details Source www.stroimdom.com.ua

When learning how to properly assemble a chimney from sandwich pipes for a home or bathhouse, you need to know that different grades of steel react differently to aggressive influences. The most common:

AISI 304. High temperature resistant steel alloy. It has a high content of nickel and chromium. It is used at elevated temperatures up to 1000C, since at low temperatures around 600C it becomes brittle;
AISI 316. High alloy molybdenum stabilized alloy that is acid resistant. Characterized by the absence of corrosion;
AISI 321. High alloy steel alloy stabilized with titanium. Suitable for use in the average temperature range, up to 800C. Corrodes when interacting with sulfur;
AISI 430 . It is used at low temperatures, as it has a low level of resistance to aggressive influences. May be corroded. It is used in the use of inexpensive budget models.

Sandwich chimney components Source www.rus-dimohod.ru
Since it is most often impossible to determine the type and grade of steel with the naked eye, a magnet can be used to determine the type. When learning how to properly assemble a chimney from sandwich pipes for a stove or boiler, it is necessary to take into account the characteristics of steel. If the steel is of high quality, then it will not be attracted, but if the alloy is of low quality, then attraction will arise.

Type of chimney placement

If you are interested in how to assemble a chimney from sandwich pipes, you need to carefully analyze the place where you plan to install it. Depending on the area of the room, the location of the furniture, the level of humidity and other factors, it is necessary to choose the type of placement of the sandwich chimney. Installation is possible indoors or outdoors.

Outdoor installation

A chimney that is assembled from the street side significantly saves space inside the house or bathhouse. Having studied how to install a chimney in a bathhouse from sandwich pipes, you can assemble such a structure with your own hands. There is no need to make a decorative box for it, which significantly saves money.

Main types of chimney assembly Source otopleniehouse.ru

The system consists of assembled elements of the required length, which are connected to a structure located indoors with a special through pipe. To ensure good traction, it is necessary to follow the rules when the length of the passage section should not be more than 100 cm.

During installation, a technological slope of 3 degrees must be observed so that condensate does not accumulate in the boiler or furnace. In this placement, the roof must be more than 50 cm from the edge of the steel outer pipe. The best answer to the question of how to properly install a sandwich pipe in a bathhouse, outside or inside, would be installation from the street side.

Important! If continuous use is not planned in winter, it is advisable to insulate the chimney to avoid freezing and deformation from temperature changes.

External installation of a sandwich chimney Source fluesystems.ru
See also: Catalog of companies that specialize in the installation of stoves, fireplaces, grills and barbecues.

Indoor installation

The chimney, which is installed in the room, consists of an internal part of the system, located perpendicular to the floor, and an external part, discharged through the roof. The structural parts must be joined together in open areas so that inspection can be carried out. A joint located in the interfloor ceiling does not provide such an opportunity and is considered a potential fire hazard, since if the seal is broken, the wooden floors, floor materials of the second floor and ceiling of the first will overheat.

The placement in a completely vertical position gives a good level of draft, and in addition, such a chimney is easy to maintain. If during installation it turns out that when installed vertically, the chimney rests on the ceiling or rafter, then in order not to interfere with the structural part of the house, it is better to bend the pipe using special connecting elbows.

Installation of a chimney through a wall - instructions

To properly install a chimney through a wall, you must adhere to certain rules:

in the place where the pipe passes through the wall, there should be no pipe joints with the internal communications of the house;
installation begins with hanging the chimney from the heating boiler. The chimney exits through the wall at an angle of 90 degrees;
the next part of the chimney will be installed perpendicular to the first section. In this case, a condenser tank is placed in the lower part, the main mass of the chimney will be connected to the upper part;
The passage of the chimney pipe through the wall must be insulated. Various thermal insulation materials are excellent for these purposes; they must be selected correctly before insulating the chimney pipe. It is advisable to cover the entry and exit points of the pipe with a protective casing or plaster;
each joint is fixed with a clamp;
pipe fastenings to the wall are installed at an equal distance from each other. In this case, you should not exceed an interval of 100 cm. A distance of 60 cm is considered optimal;
after completing the installation work, install the cap on the chimney pipe;
To prevent contact between the chimney pipe and the wall, a layer of mineral wool is laid between them.

Sandwich pipe connection options

If you are interested in the question of how to assemble a sandwich chimney, another question will probably arise: how to join the system pipes together. There are two possible options, and each of them has its own name:

“By smoke”, when the lower pipe goes inside the upper one. In this case, combustion products have no way out and are freely discharged upward;
“Ppo condensate”, when the inner upper pipe is inserted into the lower one. External pipes are assembled with the top side facing out.

It is believed that in the second case the risk of moisture getting into the insulation is reduced, but if the tightness is broken, then some of the combustion products may enter the room.

Connection for smoke and condensate Source www.rusovent.rf

Calculations and installation rules

Installation rules imply careful consideration of all stages of future work:

You should make sure that the pipe itself will not come into contact with any flammable materials, which, under the influence of high temperatures, may begin to smolder and release toxic fumes.
When installing the system directly externally, it is necessary to remember the deflection angles, which will act as active guides for smoke removal. The chimney pipe should not be located parallel to the wall of the house, since in this case smoke stasis will occur - it simply will not be removed from the system.
Special tees must be installed in the lower and side parts of the pipe, which will be used as a place to install mechanisms for condensate drainage. If this step is not completed, then moisture when lighting a fireplace or stove will simply enter the firebox and extinguish the flame. All this will significantly complicate the kindling process!
The upper part of the pipe should rise above the edge of the roof to ensure that smoke and soot are blown away in an area of more rarefied air. Typically, such zones are formed at a distance of 15-25 cm from the roof sheet.

Sandwich system kit details

Once the location of the chimney has been chosen, whether outdoors or indoors, you need to understand what parts will be needed to understand how to properly assemble the chimney. To compile a list of the necessary parts, you can independently contact a specialized store or request a commercial offer via the Internet. But it’s better if you have an independent understanding of the process and what parts will be useful during assembly.

Manufacturers produce chimneys with all the necessary components so that a full assembly cycle can be carried out. If there are differences between manufacturers' models, they relate to decorative or connecting functions. The list of elements is usually the same. Therefore, having decided on the names, you can choose a manufacturer based on the criteria of reliability or availability.

Sandwich chimney parts Source pech-kamin.ru

Required Tools

After carrying out all the necessary calculations and deciding how to make a chimney pipe yourself, you need to prepare all the required elements. In addition to the list of parts of the sandwich system itself, you need to have on hand a list of the following items:

clamps for tightening;
support brackets;
necessary hardware fasteners;
heat-resistant sealant;
grinder, metal scissors;
spatula for sealant;
roulette;
square;
screwdriver;
drill and hammer;
building level.

You also need a marker or construction pencil for marking. When assembling, the joints of the parts must be secured with clamps. The entire resulting structure is fixed vertically along the wall using brackets in increments of 1.5 to 2 meters.

Chimney assembly

If you decide to implement the question of how to make a sandwich chimney correctly with your own hands, you need to once again make sure of the quality of the system and check the availability of the passport before starting the installation. This document must be handed over upon purchase and it indicates a possible assembly diagram, as well as some technical parameters of the composition of the chimney.

When the heating device is already installed, you need to insulate the wall with calcium silicate or mineralite. This must be done immediately, since after installing the chimney there will be no access to the wall. Also, you immediately need to mark and drill holes for the bracket for connecting the mono-pipe and pipe.

Elements of a sandwich chimney assembly Source pandia.ru

When starting assembly work, you need to coat the parts of the outlet of the heating device with sealant. After this, a tee is connected to the boiler or furnace pipe, which contains a plug and a device for collecting condensate.

On the opposite side, a mono pipe is connected to the tee. After the tee is firmly seated on the pipe, it is pushed in all the way and tightened tightly with a clamp. After screeding, you need to apply a building level and if everything is normal, then you can secure the first element with a support bracket to the wall.

Next, the pipes are connected to each other in the chosen way: “through smoke” or “through condensate.” All joints between parts are fixed with heat-resistant sealant. To apply it you need to use a spatula. After application, the composition is distributed in an even layer over the entire surface of the edge of the element.

Support bracket Source topijar.ru

The sequence and list of necessary parts depends on how the chimney will be located. When the installation is carried out indoors and in a vertical position, it is advisable to install a tank for heating water or a specialized mesh heater.

If you place the sandwich elements at once, then exposure to high temperatures may cause the thermal insulating mineral wool layer to sinter, which will cease to perform its functions. The steel can subsequently burn out quickly.

If the question arises of how to assemble a chimney from sandwich pipes into a bathhouse and the system must be taken outside, then first a pipe is installed, and after it a section is immediately placed in a horizontal plane. The passage section must not be installed in a completely horizontal position or with a slope towards the premises, as accumulating condensate can get inside the heating device, which can lead to its deformation.

Chimney indoors Source dizajninterer.ru

Roof passage

When learning how to properly assemble a chimney from sandwich pipes for a bathhouse or home, special attention should be paid to the place where the sandwich chimney passes through the roof. It is extremely undesirable to crash into the rafter structure as this can negatively affect the roof structure as a whole. The holes should be:

with a pitched roof of oval or round shape;
on flat roofs or sheathing with frequent square or rectangular pitches.

The opening is cut with a jigsaw after applying the appropriate markings. The distance from the wooden roof elements should be 13 cm or more. If the chimney gets into the rafter, then you need to use your knees to take it to the right place.

Passage through the roof Source stroy-podskazka.ru

After the chimney is brought outside, there will be a gap between the roofing material and the sandwich pipe, which must be securely and hermetically closed. For this, the best option would be to use a master flush. Its design includes a flanged base reinforced with aluminum for a complete seal and a silicone cone-shaped cuff located at the top.

After installation, the master flush will reliably protect the roof and under-roof space from precipitation and dust. For maximum tightness, before installation, you need to trim the top part so that it is 20% smaller than the chimney pipe.

After this, the master flash is put on the pipe, lowered down to the roof and fixed with silicone glue. Then the upper edge is tightened with a clamp, and the lower edge is treated with sealant. To complete the installation, a head is placed on the upper edge of the pipe and secured with self-tapping screws.

How to vent a chimney through a wall?

The best option would be to exit the chimney from the gable side. If the heating equipment does not allow such an installation and the chimney pipe will exit from the side of the roof slope, then it is necessary to assemble a support post to which the chimney will be attached with sliding fasteners. If the roof overhang is more than 40 cm, then it is quite possible to do without such a rack.

In this case, the chimney can pass through the roof overhang, where additional fixation of the pipe can be arranged

It is also important to install snow guards above the chimney exit point. They will protect the chimney from damage due to snow.

How to remove a chimney through the roof, video instructions:

If a wooden house will be covered with siding, then it is worth keeping in mind that most manufacturers of this material indicate an operating temperature range from -50 to +50 degrees

Therefore, it is necessary to install the chimney so that the distance to the facing material is at least 15 cm. The place where the pipe exits through a wall covered with siding must be additionally protected with heat-insulating material.

Installation of a chimney is a fairly important stage in the construction of a private house (read: “How to properly build a chimney in a private house”). Therefore, before starting work, you should prepare and understand the most important aspects of installation. Not only the functionality of this element, but also the efficiency of the entire heating system depends on the correct installation of the chimney. Only full compliance with fire safety requirements and chimney installation rules can ensure its proper operation.

Briefly about the main thing

Installation of sandwich chimneys is carried out according to the assembly type of the designer.

The type of steel in the pipes must be selected depending on the fuel.

Installation can be done indoors or from the street.

The system can be assembled “by smoke” or “by condensate”.

You can do the installation yourself by preparing the necessary tools. During installation, special attention should be paid to the passage through the roof, walls and sealing the joints between parts.

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Final work and system check

After completing all stages of work, you should carefully test the chimney to ensure that the manipulations were performed correctly. Before starting a test fire, you should place your hand in the firebox and make sure that there is air draft. In order to increase skin sensitivity, you can pre-moisten them in water.

If you feel a breath of air, you can light the flame. With a properly installed chimney, there will be no clouds of smoke or unpleasant odor in the room. Modern smoke and fume exhaust systems are designed to eliminate minor installation errors, so the system is more likely to work properly.