Installing a sandwich chimney with your own hands: how to do it correctly and avoid installation mistakes

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

Safety Tips

If there is a possibility of a noticeable increase in pressure in the channel, the connection points are also closed with special couplings, just in case. Often, when installing steel pipes, heat-resistant sealants are used to cover the joints. The more insulated the chimney, the more correct the draft.

Despite the excellent insulating properties of “sandwiches”, when pipes cross floors, there is some likelihood of overheating and ignition of materials adjacent to the pipe. To guarantee a certain level of fire safety, it is recommended to increase the thickness of the thermal insulation layer at the joints.

Fixing a chimney with your own hands is not at all difficult; all you need to do is understand the device and know the basic safety rules. After installation, it is necessary to properly maintain and clean the chimney to reduce the risk of accidents when operating stoves.

There are effective folk remedies for cleaning chimneys. So, recently it is often recommended to occasionally heat the stove with aspen wood: the result is a powerful flame that burns sediments on the surface of the pipe walls

You should not do this often, you should be careful, because it often provokes fires

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.

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.

Principle of operation

The basic principle of operation of the chimney is based on the difference in air temperatures inside the pipe and outside. This difference creates cravings. The higher the pipe and the temperature difference, the greater the draft. Because The density of cold air is greater than that of warm air, which creates a pressure difference at the base of the house and the top of the chimney. This difference ensures the flow of cold air into the house. Thus, the stove not only heats the house, but also creates natural ventilation.

The draft depends on the cross-sectional area of ​​the channel and the height of the pipe. For example, to create good draft in a fireplace, the cross-section of the chimney must be at least 1/10 of the area of ​​the inlet.

At the same time, a pipe that is too wide reduces traction. Therefore, it would be better to increase its height. For stoves and fireplaces, the optimal pipe height is 5 m from the level of the grate.

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.

How much will it cost

Over the course of three centuries, the brick chimney on the roof has become a visual constant. And a building with such a finish looks, according to subjective assessments, much more attractive.

All that remains is to determine how much compliance with the canons will cost you. If you involve third-party craftsmen, the cost of the work will also be added to the cost of the brick. And she's quite big. In St. Petersburg and the region, for example, laying one brick will cost from 50 to 90 rubles.

Solid single brick grade M 150, which is used for laying stoves, costs from 15 to 20 rubles per piece. The solution, if you prepare it yourself, is free.

Five kilograms of ready-made masonry mixture cost 60-70 rubles. One package is enough for 10-15 rows of pipes with a cross-section of 125 by 250 mm (sixes).

Let's compare the cost of a meter of a metal sandwich pipe with a diameter of 250 mm and a brick pipe with a cross-section of 250 by 250 mm. Just the kind that can be used for installing fireplace chimneys.

As you can see, the prices are almost the same. Of course, it’s worth adding the cost of laying the fluff, the otter and the head. But, given the better performance characteristics of brick pipes - lack of corrosion, greater heat resistance, it makes sense to spend money on such a purchase. And if you are planning to lay a brick chimney with your own hands, it will cost almost half the price of metal sandwich pipes.

Uninterrupted sewerage operation is easy. An infiltrator will help, what it is and why it is needed read here. How to choose sewer pipes in a private house - a detailed article.

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.

Range of modules

Installation of a stainless steel chimney is carried out using ready-made modules of various types, so it is not difficult to do it yourself. Manufacturers offer the following elements:

• Straight pipes. The part can have a length from 33 to 100 cm. The elements are firmly connected to each other through bell-shaped coupling; installation does not require the use of additional fasteners.
• Bends 45°. They are used when it is necessary to perform a deviation from the vertical.
• 90° bends. Used to transition between vertical and horizontal sections of the structure.
• Tee 45° or 87°. Designed for installation of a condensate assembly unit, it can also be used to connect two heating units to a common chimney.
• Condensate collector. It is mounted at the lower point of the main vertical channel; moisture condensed during cooling of the flue gases flows into it.
• Revision element. Installed in places where there is a higher risk of soot accumulation, to check and clean the chimney system.
• Penetrations. Special elements for arranging the nodes for passing pipes through floors and roofs help ensure fireproof insulation of structures, roof tightness, and an attractive appearance.
• Cap, spark arrester and other elements for installation on the top of the chimney. They protect the system from the penetration of precipitation, the occurrence of the reverse draft effect, and from sparks hitting the roofing.

Chimney elements

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

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.

Selecting materials

Only solid fire-resistant blocks are suitable for building a chimney. Recommended brands from M150 to M200. The material is available in three grades.

• 1st grade. With normal firing time. Even, smooth and dense. No crumbled areas. The color is bright red. When tapped, the sound is clear and clear.
• 2nd grade. Unburnt parts are pale orange. Porous, loose, with defects. They sound dull when tapped. They are characterized by weak frost resistance and heat capacity, low density.
• 3rd grade. Burnt bricks. They are distinguished by their dark red color. Pores, burrs and chips on the surface are visible. When tapped, the sound is excessively ringing. They are fragile, not frost-resistant, and do not retain heat well.

The chimney should be assembled only from first grade material. It is allowed to use the third, but only for arranging the foundation. The use of the second grade is excluded.

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For the construction of the chimney, only high-quality first-class bricks are used

• Decoration Materials

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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

Installing a chimney on the roof with your own hands or with the help of specialists?

Installation of a smoke exhaust route is a complex and responsible process that requires mandatory knowledge of many technical norms and regulations, standards and nuances. Failure to comply with even one rule or regulation can lead to unpleasant consequences - fire, failure of heating and smoke exhaust equipment. Due to these factors, it is highly recommended to carry out the installation and installation of the chimney, including fixing it to the roof, with the involvement of specialists.

Professional installation will guarantee both the safety of the entire heating system and its long service life. Self-installation cannot guarantee safety, health and property.

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.

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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