Sandwich pipes for chimneys: how to properly mount the structure

Chimney sandwich pipes are a ready-made design solution suitable for both indoor and outdoor use. Such structures are assembled from ready-made shaped parts, regardless of the stage of construction of the house. They are lightweight, have a smooth inner surface and do not require insulation, as they have a fire-resistant heat-insulating layer. Their installation must meet all the requirements for chimneys.

Chimney pipes made of stainless steel

Stainless steel is a relevant material that has found application in various structures, including the production of chimney ducts. The use of stainless steel pipes for chimneys in almost all types of heating equipment is due to the material's resistance to corrosion and aggressive environments resulting from the condensation of water vapor from the discharged products.

However, not all types of steel can be used for chimney structures. The choice of a steel grade suitable for chimneys depends on the temperature of the outlet of the products: up to 400 ° C use chrome-nickel steel AISI 304, 321, up to 800 ° C - heat-resistant chrome-nickel-molybdenum steel AISI 316. As for galvanized or black steel, they do not have anti-corrosion properties and quickly burn out as chimneys.

The indisputable advantages of stainless steel pipes for the chimney are:

• light weight - facilitates ease of assembly and does not require the construction of a foundation;
• modularity of systems - a huge number of pipes and fittings of various diameters allows you to assemble a structure not only in a new building, but also in an inhabited room;
• ease of installation - the quality of the connecting elements guarantees a gas-tight assembly of an error-free design. In addition, such chimneys can be deflected from the vertical state to bypass all kinds of obstacles;
• smoothness of the inner surface;
• resistance to burning - contributes to the long-term operation of the chimney;
• tube thinness - allows the system to heat up quickly at start-up, reducing condensation and providing good draft.

Steel chimneys are produced in two versions:

• single-walled (single-layer, single-circuit) - such chimney systems are intended for use in heated buildings, connecting the boiler to an existing chimney system or for repairing and restoring an old chimney by means of sanitation;
• double-walled (three-layer, double-circuit, sandwich pipes) - in the construction of sandwich pipes for the chimney there is an insulating layer located between two pipes of different cross-sections. Such a pipe arrangement makes it possible to mount them both inside and outside the building without a thermal insulation device. Insulation is carried out only in the places where the chimney passes through the ceiling, wall or ceiling.

DIY chimney device from a steel pipe: basic rules

The modularity of the design and a wide selection of all component parts makes the independent installation of a stainless steel chimney as simple as possible. But, despite the simplicity of installation, such chimneys are part of the general cycle of operation of gas equipment and must comply with the requirements regulated by SNiP and safety rules of the gas industry.

How to install the chimney correctly? It will be useful to familiarize yourself with the thematic video instructions before assembling a stainless steel chimney. On the Internet, you can easily find a whole series of videos of installing a stainless steel chimney with your own hands. The videos contain a lot of useful information about the nuances of installation and the most common mistakes when installing a chimney with your own hands.

Despite the ease of assembly, it is better to entrust the chimney device to a specialist than to carry out the installation yourself. A stainless steel chimney must meet the following requirements:

• if single-circuit steel pipes are used to remove exhaust gases, it will be most acceptable to use an internal chimney installation scheme, in which case the system is placed along the main internal walls;
• the diameter of the pipe must be suitable in size to the inlet flue gas boiler, which will ensure reliable tightness of the structure;
• the location of the chimney pipe at the junction with the boiler must be vertical and have a length of 50 cm or more;

• if the finish of the wall next to which the steel chimney is installed is made of combustible materials, the distance from the pipe to the wall should be at least 25 cm, if the installation involves closer placement, it is necessary to upholster the wall with protective screens so that the upholstery on the wall protrudes beyond the dimensions pipes 15 cm on each side;
• it is forbidden to use more than three swivel elbows in the structure;
• chimney length must be at least 5 m;
• the value of the chimney height above the roof must exceed 0.5 m;
• the presence of revisions, tees and condensate traps in the design is mandatory.

Helpful advice! When installing the chimney system yourself, remember that an improperly installed structure can cause a gas explosion, fire and carbon monoxide poisoning.

Using stainless steel chimney sealant

Answering the question of how to make a chimney correctly, we can say with confidence that to ensure its safe operation, the structure must be absolutely sealed. To achieve complete tightness and protection of the structure from moisture, you can treat the joints of the system elements with a special stainless steel chimney sealant.

It should be noted that special heat-resistant silicate sealants are used for chimneys. Before installing the chimney pipe on the previous link, their joints are processed with this composition. Sealants they bond well with most materials: stone, metal, concrete, ceramics.Given that the surface of the stainless steel chimney elements is smooth, it is recommended to abrade before using the sealant.

Sealing works are carried out at a positive temperature of 20 to 40 ° C: this will ensure rapid drying of the composition. If you coat the entire contacting surface with sealant, you will get a monolithic structure, which will be difficult to disassemble without damage. This should be taken into account if in the future you need to disassemble some of the chimney links for maintenance.

The sealant is treated with a pistol, applying a layer of paste no more than 1 cm thick.Do not apply the composition in a large layer: they may not dry out enough, and if they dry out, they will crack in the future. Some chimney sealants dry for several hours at different temperatures, which will be indicated on the package. Chimney sealants are available in gray and black only.

Helpful advice! It is necessary to work with the sealant with protective gloves, as if they come into contact with the skin, they can cause chemical burns.

How to insulate a chimney pipe with your own hands

Thermal insulation of chimney pipes solves several problems at once, the main ones of which are preventing the destruction of the roof structure adjacent to the channel, and protecting the chimney itself from the effects of negative natural factors. In addition, with thermal insulation, heat losses are significantly reduced, which also has a positive effect on the processes taking place inside the system.

By insulating the pipe, you can significantly extend the life of the chimney due to the following factors:

• the ingress of chemically active condensate on the inner surface of the pipe is minimized;
• the effect of temperature differences between the outgoing hot substances and the cold air of the atmosphere is reduced;
• heat losses contribute to energy saving, which in general allows economical fuel consumption;
• the mechanical strength of the entire structure increases, since the insulation casing acts as a frame,

How to insulate metal pipe chimney? The main requirements for the insulation material are incombustibility, and the weight of the insulation material should be weighed against the roof's ability to withstand it, otherwise it will simply push it through. The most suitable chimney insulators are glass wool or rock wool. You can purchase a ready-made cylindrical structure with a protective foil layer. They come in different diameters, so you can choose the option that suits the design.

Before doing the work yourself, you can see the video on how to insulate chimney pipes with your own hands. A visual description of the installation will help to correctly fix the joints of the insulation using the most suitable materials.

Helpful advice! It is advisable to provide for thermal insulation of chimneys at the design stage of the house building itself.

Recommendations for installing sandwich pipes for chimneys

When installing a stainless steel sandwich chimney, the following recommendations should be followed:

• when installing a sandwich chimney, it must be remembered that the structure should not have horizontal pipe sections longer than 1 m;
• it is necessary to exclude the contact of the flue duct with electrical wiring, pipeline, gas appliances;
• the installation of the chimney through the wall is accompanied by the device of insulated pipes in these places;
• when assembling a sandwich pipes for a chimney with your own hands, it is necessary to provide an inspection window for maintenance and cleaning from soot.

How to properly install a chimney from a sandwich pipe? Before installing the structure, you need to know how to calculate the diameter of the chimney and its total length. The cross-section of the pipe is selected depending on which gas equipment it will be used with: the more powerful the device, the larger the diameter you need to choose. The diameter value is indicated in the technical documentation for the device.

Another important size of a chimney sandwich pipe is its overall length. The length of the structure should not be less than 5 m. If the chimney involves a slope, elbows from 20 to 90 degrees are used for its device. The length of the outer part of the pipe must be such that it exceeds the level of the roof ridge by at least 0.5 m, if it is 1.5 m from it to the ridge.In the case when the chimney is 3 m away from the ridge, the length of the pipe may be even with him.

Related article:

Stainless steel sandwich chimneys: prices for pipes and accessories

Prices in stores. Chimney production. Chimney sizes. Recommendations for selection and installation. Where to buy chimney pipes.

Before assembling a chimney from a sandwich pipe, you should familiarize yourself with the key assembly steps. You can get a visual idea of ​​the installation by watching a video of the assembly of a chimney sandwich on the Internet. Basic installation rules:

• the inner pipes of the sandwich structure are joined by the upper contour of the pipe to the lower one, and the outer ones are vice versa. On the one hand, this ensures unobstructed smoke removal, on the other hand, it protects the system from moisture;

• docking places, areas where the pipe joins the equipment, as well as the places where the chimney passes through the roof are fixed with clamps;
• to improve the strength of the connection, the joint seams are treated with a heat-resistant sealant;
• to service the chimney, a tee is built into the structure for revision, to drain moisture - a condensate collector;
• the outer section of the pipe is equipped with a cap to prevent foreign objects from entering the channel.

Features of installing a chimney from a sandwich pipes through the wall

When installing a chimney through a wall, you must follow the basic rules and requirements for the installation of chimney ducts. However, there are some nuances that must be considered when removing the chimney through the wall. If the first link of the chimney is planned to be displayed horizontally into the wall, it is necessary to make a slight slope from the device. This will prevent condensate from getting inside the boiler.

How to install a chimney through a wall? There are two ways: you can raise the duct to the ceiling and bring it outside at this level, or make a place for the chimney to exit through the wall at the level of the inlet pipe of the gas appliance. From the point of view of ease of installation and use of fittings, the second method is more preferable, since it has one swivel elbow.

The procedure for performing work on the installation of a chimney through the wall:

• We punch a hole in the wall where the pipe will pass. Its dimensions must be such that the SNiP requirement is met: the distance from the outer surface of the pipe to the wall is from 0.5 m. To reduce the distance to 0.38 m, the hole is sheathed with sheet metal or a finished metal box is inserted into it;
• a sandwich chimney pipe made of stainless steel is inserted into the finished hole so that the joints do not fall into the passage unit. The pipe is fixed, and the space between the box and the channel is filled with heat-resistant insulation;
• the length of the horizontal section should not exceed 1 m;
• the hole in the wall is covered with decorative overlays, which are sold complete with pipes;
• from the outside of the wall, we fix the holding bracket and the swivel unit for the withdrawn channel;
• we fasten the vertical section of the pipe to the wall in such a way that the step between the fasteners is at least 2 m.

Helpful advice! It is strictly forbidden to insert ordinary single-circuit pipes between the sandwich pipes. The entire system must be made up of identical pipes.

Installation of a chimney from a sandwich pipe through the roof

Before installing the chimney from the sandwich pipes through the roof, it is necessary to properly plan the outlet. The fact is that given the configuration of the roof structure, it is not possible to draw the chimney through the roof in all places. These include:

1. Endowy, where a lot of precipitation accumulates and it is difficult to provide waterproofing.
2. Places in the immediate vicinity of roof windows.
3. Opposite the windows of neighboring buildings.

Before installing the chimney through the roof, you should also consider the location of the floor beams and rafters. The channel must be located between these elements. To move the chimney line, you can use two swivel elbows at 45 degrees. The sequence of work on the passage through the roof of the chimney sandwich:

• a hole is made in the ceiling, according to existing standards;
• the ends of the hole are protected with a non-combustible material;

• a pipe is inserted vertically into the formed box. It is worth noting that the chimney cannot be rigidly fixed, it must move freely up and down, since its length will change when heated;
• the space between the pipe and the box is filled with basalt-based cotton wool, after having sewn up the entry point with a metal sheet. Mineral wool cardboard is placed in the space between the screen and the ceiling. You can simplify the organization of the passage for the chimney through the roof and ceiling if you purchase a ready-made ceiling passage unit consisting of a factory box and a decorative stainless steel screen;
• for the passage of the chimney through the ceiling, arrange a hole in the roofing cake. The layers of the cake are cut crosswise so that they can be folded over and secured with staples. A hole in the crate is made so that the distance from the edge of the passage to the surface of the pipe on all sides is at least 13 cm;
• all the resulting ends of the hole are closed fiber cement slabs - minerite.

When arranging the passage of a chimney through a roof made of metal or other roofing, a special universal master-flash seal is used. Its purpose is high-quality sealing of the site when the chimney passes through the metal tile. The skirt of the roof seal is shaped into a roofing material, after which it is fixed to the surface. The joint lines of the sealant with the pipe and the roof surface are treated with a heat-resistant sealant.

Options for heat exchangers for the chimney pipe

To use the heat generated as a result of the removal of combustion products, a special device is used - a heat exchanger for the chimney pipe. There are various options for such devices, among which there are the most relevant:

1. Air heat exchanger - the principle of operation of such a device is identical to that of a convector. Cold air enters the heat exchanger through the inlet pipe, after which the heated flow exits through the holes at the top of the device. As a result, additional heating of the room occurs. With a certain set of tools and skills, you can make an air heat exchanger yourself.
2. Coil-type design - flexible and corrosion-resistant copper or aluminum pipes are used for such a device. They are bent to obtain the required shape; at the end sections of the pipe, threads are made to connect to the expansion tank. For safety and improved heat transfer, it is recommended to protect the pipes with a special casing. The principle of operation of such a heat exchanger is the natural circulation of water.It is easy to mount it yourself, however, it is necessary to make weight calculations that take into account the properties of the liquid when heated to expand. The disadvantages of such a system include a decrease in the temperature of carbon monoxide output, which can negatively affect the traction and combustion of fuel.
3. A container with water - for the device of such a device, you will need copper pipes and a metal container with a capacity of about 20 liters. The container can be made independently from sheet steel. Holes are made at the bottom and top points of the tank. A tap is cut into the lower outlet of the tank to drain the water.
4. Corrugated device - for the manufacture of such a heat exchanger, three corrugated pipes are used, with which the flue duct is wrapped in the place of its passage through the attic floor. The surface of the chimney gives off heat to the corrugation, and the heated flow from it is directed to the room that needs to be heated. The operation of this heat exchanger reduces the chimney temperature, thus providing fire protection.

Where can you buy sandwich chimney pipes

Due to the fact that the operation of the gas boiler directly depends on the functioning of the chimney system, it is necessary to purchase high-quality and proven pipes to assemble a chimney sandwich. Only such products will be able to guarantee safe and efficient exhaust gas removal, preventing smoke from entering the room and the occurrence of backdraft.

It is very profitable to purchase the necessary product through the manufacturers' websites: you can study the assortment in a relaxed atmosphere, make a comparative analysis of prices from different manufacturers, and most importantly, get expert advice on choosing a model suitable for a particular equipment. Many online stores include delivery of goods in their services.

As a rule, many companies that sell chimney pipes offer professional chimney installation services. The price for the work depends on the thickness of the walls, the material from which the pipes are made, the presence of a passage through the wall for the chimney, the configuration and roof covering. The approximate cost of installing a chimney from a sandwich pipes is 1900 rubles. for 1 r.m. Departure of the measurer, connection of equipment, fire protection works are not included in the prices for the installation of chimneys from sandwich pipes.

Some online stores sell galvanized sandwich chimney pipes. Such material is cheaper, but it has good technical characteristics. Chimneys made of galvanized steel can be used to remove fumes at low temperatures. If the device of chimneys made of sandwich pipes involves only an external galvanized circuit, such a structure can be operated without the slightest harm to health. How profitable the purchase of a chimney from this or that material will be, you can find out by analyzing the price level.

Chimney sandwich pipe price

When buying products from manufacturers or their official representatives, you can be sure that you will purchase a certified and high-quality product. The assortment of online stores and specialized departments includes not only the pipes themselves, but also a number of factory bends, tees, fittings and other related products that can be easily found in catalogs. If the sandwich pipe chimney scheme provides for passage through the roof, you can also order a standard roof cut here.

Turning to the site, before assembling a sandwich chimney, you can get expert advice on any issue of interest. For those who are planning to install a chimney sandwich with their own hands, Internet sites offer information on various assembly examples and the most important installation points.

The prices indicated in the catalogs are indicative and are subject to mandatory clarification with the managers of companies and online stores.

Price of sandwich pipes for chimney installation:

Manufacturer	Stainless steel sandwich pipe, length 1 m
Diameter, mm	Metal thickness, mm	price, rub.
outer	interior
NEST company	220	120	0,5	1490
230	130	0,5	1600
240	140	0,5	1670
250	150	0,5	1760
260	160	0,5	1850
Smirnov company	200	120	0,5	1480
Ferrum PC	200	110	0,5	1970
200	115	0,5	1985
200	120	0,5	1990
200	130	0,5	2030

Helpful advice! Before purchasing a sandwich pipe, it is worth discussing with the manager the complete set of the chimney system and familiarize yourself with the rules for operating chimneys.

Some companies are engaged in the implementation of combustion products removal systems, which have already been collected as much as possible. By purchasing such a structure, you can reduce the labor intensity and reduce the time for installing a chimney sandwich with your own hands. In addition, the completeness of the modular design with various seals guarantees the tightness and reliability of the chimney system.

Thanks to a wide range of sandwich pipes of various diameters, as well as fittings and accessories for them, you can assemble chimneys yourself, adhering to the rules and regulations. Follow the recommendations of the professionals and use as an example the instructional video on how to install a chimney from a sandwich pipe.