Installing a chimney is a crucial step in building or remodeling a private home that needs to be carefully planned and carried out. Safe indoor air quality and effective heating are guaranteed by a well-installed chimney. This guide, which covers everything from choosing the appropriate materials to the last stages of installation, is intended to assist homeowners in navigating the complexities of chimney installation.
First, it’s crucial to comprehend the various kinds of chimneys and materials that are out there. Selecting the appropriate chimney type is essential for a successful installation because different types cater to different heating appliances and house designs. This post will go over your options and assist you in choosing the best chimney for the heating requirements of your house.
There are a few essential steps in the installation process of a chimney that need to be carefully followed in order to avoid common pitfalls that could result in subpar performance or safety hazards. Whether you’re working with experts or doing some of the work yourself, we’ll guide you through a step-by-step algorithm with photos to help you through each phase. This will make it easy for you to follow along.
By the time you finish reading this guide, you’ll know exactly how to make sure your chimney is installed properly, giving your house the best possible functionality and safety. You can increase the heating efficiency of your house and take pleasure in the comfortable warmth without having to worry.
- Types of chimneys
- Features of chimneys made of different materials
- Scope of brick chimney ↑
- Advantages of using ceramic chimneys ↑
- Characteristics and varieties of steel chimneys ↑
- Installation of an external chimney for a boiler
- Installation of a chimney of sandwich panels
- Features of sandwich pipes for baths
- Preliminary calculations
- Length calculation
- Location
- Installation sequence
- For a solid fuel boiler chimney made of bricks
- How to install stainless steel or cast iron chimneys
- Stages of chimney installation
- Correct installation of sandwich chimney with your own hands
- Installation of an external chimney
- Design features of a sandwich chimney
- Varieties of chimney pipes
- Technical characteristics of sandwich pipe
- Mounting of the structure
- Rules of work execution
- Installation
- Chimney in the sauna
- Material from which the chimney is made
- Why to finish the pipe
- What to rely on when designing a project
- Pros and cons of using a sandwich chimney
- Three options for self-construction of the chimney from the outside
- Variant #1: arrange a brick chimney
- Option № 2: installation of the frame
- Option #3: ready-made solutions
- Design features
- What should be the height of the chimney
- Structural elements and their features
Types of chimneys
Not only do standard stoves need drainage shafts for the output of harmful gases saturated with combustion products, but gas boilers and fireplaces also need them. There are currently several known types of chimneys. Among them are:
Flowing straight ahead. This type is regarded as a well-liked construction that is most frequently utilized for living space arrangement. Such a chimney’s only drawback is its quick heat loss. Here, the majority of the thermal energy is volatilized in addition to hazardous materials.
Chimneys with a straight flow and jumpers. When materials burn, they retain the majority of the heat. Bathhouses frequently use this design. Cleaning is necessary on a stove with a chimney that burns for so long. Ash easily accumulates on the lintels’ surface, delaying the removal of hazardous materials.
Labyrinthine chimney with direct flow. High heat dissipation is a defining characteristic of this variety. Gases containing carbon monoxide flow through multiple lintels. They contribute to the room’s maximum heating by swiftly heating the chimney’s walls.
With a hood. For the Russian stove, it is utilized. The smoke turns red-hot and shoots upward, where it cools off gradually. After that, it is lowered via the masonry vault in the chimney. Such a structure’s uneven heating is its lone drawback.
Adaptable. An alloy of metal makes them. They are intended for use with gas-fired heating units. Stove metal chimneys are capable of handling the acidic byproducts of methane combustion. In this instance, the brickwork will crumble rapidly.
Features of chimneys made of different materials
The following materials can be used to build a chimney in a private home:
It is not possible to choose one over the other and declare one to be the clear favorite. Only by considering a wide range of intricate influencing factors can the right material for the chimney’s construction be selected. Prior to any other analysis, the particulars of the operating environment, the characteristics of each material, and the costs at the time of comparison must be examined.
Ceramic chimney stove
Scope of brick chimney ↑
In general, a brick chimney costs less than other chimney systems. It is resistant to soot fire and high temperatures. Its large size and intricate construction are its main drawbacks. It is constructed on a reinforced concrete slab or foundation. Working with wood-fired boilers, fireplaces, and stoves is particularly dependable and long-lasting because the high temperature of the escaping gases prevents condensation from forming. In other situations, it deteriorates rapidly.
The fireplace’s brick chimney
You need to be skilled in both masonry and stovemanship to build a brick chimney in your home by hand. The trunks must be free of any fissures or abnormalities. This is a significant construction project that calls for qualified labor.
You can do brick chimney restoration fairly well on your own. All you have to do is slide an appropriate length of special flexible corrugation into the channel from above.
Stainless steel chimneywithin a brick chimney
Advantages of using ceramic chimneys ↑
Additionally, ceramic chimneys are reasonably priced. Its enhanced resilience and capacity to retain heat are its distinguishing features. Its high fire resistance makes it suitable for use in solid fuel heat source systems operating at high temperatures. When burning soot, a ceramic chimney can withstand temperatures of up to 1200°C. The building’s service life is equal to its service life with proper maintenance.
Using unique grooves, ceramic components of various sizes are joined and sealed with an adhesive sealant that is fireproof. Ceramic pipes can be installed both inside and outside of the home, both openly and in shafts composed of bricks or unique hollow blocks.
Chimney pipes made of ceramic
It is highly advantageous and practical to use system chimneys, which are composed of ceramic pipes installed in special shafts, in new construction. They work well with all kinds of combustion machinery.
Characteristics and varieties of steel chimneys ↑
In theory, a builder can easily assemble a steel chimney. You can install and configure a chimney in a private home in nearly any way you want, both during construction and during use, thanks to a large selection of fittings and fasteners.
Rather than using regular steel for the pipes, galvanized or stainless steel is used, as this material is more resistant to corrosion and acid. Although stainless steel costs a lot more, its lifespan is extended.
Specifications of the stainless steel chimney
Because SNiP 41-01-2003 states that steel products have a maximum temperature of 500 °C, their range of application is restricted to systems with relatively low flue gas temperatures. As such, using solid fuel boilers is not recommended.
Installing steel chimney systems in existing homes is very convenient because they can be done quickly and don’t require cladding, plaster, or a foundation. They cost significantly more than the brick and ceramic ones at the same time.
Chimneys with two walls can also be made of steel using the "pipe-in-pipe" principle. We refer to them as coaxial. They are employed in closed combustion chamber condensing and turbine gas boilers. Instead of coming from the room, the air needed for combustion comes from the street.
Coaxial chimneys supply air for combustion on the outside while expelling combustion products on the inner pipe. They are put together in the same manner as steel ones with a single wall. The least expensive type of chimney installation is coaxial.
Installation kit for coaxial chimney
Installation of an external chimney for a boiler
We now have a better understanding of the material peculiarities for the external chimney device. Depending on the kind of fuel the boiler runs on, the best setup is a stainless steel pipe with the right steel grade and wall thickness. It should be immediately noted that in the event that the boiler is multi-fuel, the steel grade and wall thickness are determined by the fuel that has the highest combustion temperature.
The lack of horizontal transitions is a prerequisite for installing an external chimney. Typically, the most soot and condensate build up occurs there, preventing regular draughts.
The distance that separates the chimney from the roof’s ridge, which influences the chimney’s height, is also crucial. The chimney’s height increases with proximity to the ridge’s summit.
The following are the prerequisites for building an outdoor chimney:
- Installation work should be carried out "from bottom to top", inserting each subsequent section inside the previous one. The depth of the joint should be not less than half of the outer diameter of the pipe.
- When installing an outdoor chimney with your own hands for sealing, each joint is treated with a special sealant and clamped with a clamp.
- The walls along which the chimney is laid must be made of non-combustible materials. Otherwise, a technological gap or a gasket made of non-flammable material is required.
- At a distance of 1-1.5 meters the pipe section is fixed to the wall of the house with a special bracket. Transitions or other structural elements are attached separately.
- It is necessary to exclude contact of external chimney sections with electric wiring or gas mains.
- When installing an external chimney on the exterior wall, it is necessary to provide a revision window or removable part for maintenance of the system.
Step-by-step instructions for installing the chimney:
- Make a hole in the wall. It should be located at a distance of at least 50 cm from the boiler itself.
- Fix the fixing elements, which will serve as a support for the installation of the chimney. Fasteners for the pipe are installed with a spacing of no more than 90 cm.
- Connect the lower part of the chimney to the boiler.
- Bring the upper part of the chimney to the street.
- Mount the condenser.
- Fix the chimney.
Installation of a chimney of sandwich panels
It does not take special skills to learn how to build this kind of chimney. It is sufficient to comprehend the components of such a chimney and then put each one together correctly. It’s interesting to note that some retail locations provide nearly prefabricated sandwich panel chimney designs that are easily purchased and installed on their own. It is possible to pick up each component separately, as suggested by a knowledgeable salesperson. The following items are part of the technology used to install such a chimney:
- all components are installed from bottom to top;
- in roof and attic ceilings, remember to use a non-combustible insulator (rock wool) to prevent fire;
- a steel platform is installed to the ceiling, through the center of which the chimney passes;
- T-pieces with condesato outlet are used for the external sandwich pipe;
- the components going up in level are inserted inside the lower ones;
- if it is an internal chimney, the output to the roof is carried out using a platform-roof, which has a different angle of inclination, which can be picked up at different points of sale depending on the individual characteristics of the roof;
- After installation, do not forget about protective elements: weather vane, deflector, thermo fungus or spark arrestor.
It is essential to understand that the cross-section’ssizeand height are crucial when constructing a sandwich panel chimney. A higher pipe will result in a better draft, but it shouldn’t be too high because there will be significant aerodynamic resistance.
The rule states that the internal diameter to the maximum dimensions of the firebox opening should be 10:1, which determines the cross-section of the chimney made of sandwich panels.
Features of sandwich pipes for baths
Since the bathhouse is typically constructed of wood, thermal insulation is especially important (especially if it is made of foam blocks, in which case the interior is lined with combustible material). For a bathhouse, only brick and sandwich chimneys are permitted—single-layer chimneys are not. As per SNiP, every distance between the chimney and combustible objects needs to be closely examined and followed. It is required to insulate all pyrohazardous surfaces using asbestos or vermiculite. Because of its strong sailing, installing a deflector on the sauna chimney is prohibited. At least 25 centimeters separate the wall from the chimney!
Be careful: the chimney and sauna ventilation system should never be combined.
Preliminary calculations
You should ascertain the chimney’s length and proper location in addition to the cross-section.
Length calculation
These are the prerequisites; let’s get acquainted with them.
- According to the same SNiP, the minimum height of the chimney should be 5 meters.
- If the roof covering in your case is a combustible material, the chimney should rise above the ridge by another 1-1.5 meters.
- If the coating is incombustible, then this height will be at least 0.5 meters.
Kindly take note! Should the house have any additions that rise higher than the original structure, the chimney will need to be removed above the corresponding extension. Whereabouts
Location
- If the roof is flat, the chimney must rise above it by at least 0.5 meters.
- If the chimney is less than 1.5 meters from the ridge, it must rise at least 0.5 meters above the ridge.
- If this distance varies within 1.5-3 meters, then the height of the pipe should be equal to the height of the ridge.
- Finally, if the chimney is located further than 3 meters, then this height should be equal to the line drawn in the imagination from the ridge at an angle of 10 degrees relative to the horizon.
If every one of these specifications is met, the chimney pipe installation will be done correctly.
Chimney requirements for gas boilers
The proper placement of a chimney, its design elements, and how to install one for a gas boiler. Find out the responses to these queries you
Other considerations to make?
- The installation of the structure should start from the heater and gradually rise upwards.
- Various engineering communications (such as electrical wiring, gas piping, etc.) should be taken into account.) must not touch the chimney.
- It is not allowed that there are ledges in the construction.
- The structure should be protected from the effects of precipitation. For this purpose, you will need a deflector or any other device. It is important that such protection does not prevent the free release of flue gases.
- The temperature of flue gases moving through the channel should not exceed 50 degrees Celsius.
- All nuances concerning the installation of the sandwich chimney must be taken into account during installation. So, if the roof is made of flammable material, and peat or wood is used as fuel, then it is obligatory to put spark catchers, which are usually made of metal mesh with mesh sizes of 0.5×0.5 centimeters.
- The pipe sections that are under the slope should not be rough. In addition, the area of their cross-section must at least correspond to the vertical one.
Such chimneys can be connected in a number of ways:
- flanged;
- by condensate;
- bayonet;
- by smoke;
- and finally, by cold.
Kindly take note! The building is put together by smoke, which totally prevents carbon monoxide from entering the space. However, on the condensate, in order to allow condensed moisture to freely flow along the walls as a result of temperature variations.
If the installation of a sandwich chimney with their own hands was made in the first way, then the smoke gases will not meet any obstacles and thanks to the draught will be quickly taken out to the street. But if the joints in this case are sealed poorly, then the condensate can penetrate inside the structure, which will have a very bad effect on basalt insulation. In the second case, however, the inner tube is installed in the socket, so moisture can in no way penetrate into it. But if there is even a small gap, the smoke can get into the room. So which one to choose? Condensed moisture is harmful to insulation, and flue gases are harmful to human health. The way out is obvious: regardless of the chosen method, all joints and gaps should be thoroughly caulked.
Be mindful! The inner tubes of the structure should be positioned along the condensate to prevent it from flowing in and getting on the joints.
Remember that these chimneys, even with two layers, still need to have well-insulated parts, specifically the roof, beams, and ceiling, as these are the areas that are most fire-safe. Furthermore, you shouldn’t connect the sandwich straight to the heater.
You’re already acquainted with the technology, then. All that’s left to do is buy the required supplies (which must be certified and of the highest caliber) and start working!
Installation sequence
The process of installing an internal chimney starts with designing a plan and figuring out how many pipe segments are needed. The device is assembled correctly if the following steps are followed:
Diagram showing the chimney output through the corrugated steel sheet roof
- The surface of walls and floor behind the heater and chimney is protected from heat with fire-resistant material, for example, asbestos sheets.
- The first pipe segment is connected to the spigot of the heat generating appliance or furnace. If there are gaps at the joints, use an adapter or a sealant. To seal the joint, use fire-resistant sealant and metal clamps.
- Each subsequent segment of the single-circuit pipe is put on the one below, so as not to impede the passage of smoke. Sandwich pipes are connected in a different way – the elements of the inner contour are inserted into the underlying module, in the outer one vice versa.
- It is recommended to observe the overlap between the pipes, equal to a quarter of the radius. To make it more convenient to treat with sealant and tighten the joints with clamps, do not place them in the places of passage of interfloor ceilings and the roof.
- If it is necessary to turn the pipe, the modules are connected by means of a swivel elbow with an angle of 45 or 90 degrees.
- To conduct the chimney through the ceiling and roof, you need to make a hole in them and install a passage box or spigot, in which you pour fireproof insulation.
- After the pipe is brought to the roof, it is protected with an elastic seal in the form of a funnel, which reliably protects against water penetration. Installation of silicone sealant for waterproofing the connection between corrugated board and the chimney
- The chimney is built up to the calculated height and a protective umbrella is put on top to prevent debris, branches and birds from getting into the chimney.
- The place of the pipe outlet is decorated with a decorative apron, matching the color of the roofing material.
Once the installation is finished, the heating system must be turned on and the tightness of the connections checked. Even a small amount of smoke can indicate serious issues that should not be put off.
Installing a chimney in a home is a responsible task; its success depends on how safe and comfortable the heating system is to operate. Therefore, pay attention to manufacturer recommendations and installation work technology.
When installing a chimney in a private house, it is crucial to prioritize safety and efficiency to ensure that the structure not only effectively removes smoke and harmful gases but also minimizes heat loss. The installation process involves selecting the right materials, such as heat-resistant bricks or stainless steel, and adhering to a step-by-step algorithm that includes planning the route of the chimney to avoid obstructions, securing structural supports, and ensuring proper insulation to prevent fire hazards. Additionally, integrating a well-designed cap and maintaining adequate clearance from combustible materials are essential for maintaining the chimney"s functionality and safety. Photographs of each step can serve as a valuable guide to ensure that the installation adheres to building codes and best practices.
For a solid fuel boiler chimney made of bricks
Generally speaking, brick chimneys are less expensive than contemporary chimney systems. High temperatures from exhaust gases are easily withstood by a traditional chimney pipe composed of ceramic brick. The chimney is capable of withstanding the ignition of soot buildup.
A brick boiler chimney in a private home is a substantial structure. The foundation or a sturdy reinforced concrete floor is where the chimney is situated. A skilled mason-stoveman is the best person to handle the masonry of a tight and long-lasting chimney, as it requires specific skills to construct.
A brick chimney is frequently used to house chimneys, ventilation ducts, and chimneys.
Superior full-body ceramic bricks with a minimum grade of M125 are used to construct chimney masonry, set in regular masonry mortar. Bricks with a face or clinker finish can be used for the pipe’s upper section, which is located above the roof. The minimum thickness for a chimney wall is 120 mm, or half a brick.
Brickwork around the chimney. Ventilation ducts are typically arranged in a single vertical block next to the chimney. Laying even channels with smooth walls is made easier with the use of templates.
Considering the thickness of the vertical joints, the chimney and ventilation channels are selected to be a multiple of the brick size. A duct’s cross-section, for instance, can measure 140 by 140 mm (1/2 by 1/2 brick), 140 by 200 mm (1/2 by 3/4 brick), or 140 by 270 mm (1/2 by 1 brick). In actuality, a 20 x 20 flue duct is frequently constructed using 3/4 x 3/4 bricks. If required, it is simple to choose and fit a round steel or ceramic insert into such a chimney that has the proper diameter.
It is important that the flue gases in the chimney channel not get too cold. As a result, the chimney attempts to be fixed to the wall or built into the masonry of the house’s inner wall. sections of chimneys insulated with mineral wool that travel through unheated spaces (like attics) or outside the home.
Brick Only at high temperatures of exhaust gases, which inhibit condensation in the chimney, will the chimney function dependably and long. This requirement is typically met when the chimney functions with a conventional one.
Brick chimneys are quickly destroyed when operating modern gas or liquid fuel boilers, solid fuel pyrolysis boilers, pellet boilers, and other boilers for extended periods of time in the low-intensity, slow-burning mode.
The exhaust gases from modern boilers are made to have a relatively low temperature. Water vapors from the flue gases condense in the chimney as a result. The chimney’s walls are continuously wet. Additionally, water creates aggressive chemical compounds on the inside surface of the pipe when it combines with other combustion products.
Boiler exhaust fumes, in particular, contain sulfur, which reacts with water in the chimney to form sulfuric acid, which corrodes the walls. Signs of external damage include dark, wet patches on the brick chimney’s exterior.
Brick chimneys are rapidly destroyed by aggressive condensate that forms in the chimney as a result of the solid fuel pyrolysis boiler’s mode of operation.
The accumulation of solid soot particles on the chimney walls is partly caused by their rough exterior. It is challenging to remove deposits from the chimney because of the irregular shape of the chimney and the roughness of the walls.
A liner, such as a steel or ceramic chimney pipe, must be installed in the brick channel in order to connect to the brick chimney of gas and other boilers with low flue gas temperature.
How to install stainless steel or cast iron chimneys
The installation of a metal pipe is the most affordable and straightforward method of setting up a chimney. There are multiple stages that make up the entire installation:
- First you prepare the channel for the chimney.
- Then you actually install the chimney.
- And at the final stage you install insulation around the pipe.
For the metal chimney, the channel should be about 1.5 times the diameter. You will still have room for insulation in this situation.
The fitting of a chimney made of stainless steel
A metal pipe, adapters for mounting the coil, head, and condenser are the actual parts of a metal chimney. A chimney swivel, a device that raises the system’s draught, is installed in a number of chimney designs.
Stages of chimney installation
During the first phase of chimney installation, the pipe lengths must be adjusted. After that, the finished structure is inserted into a channel that has already been prepared. The heater (stove or boiler) and the condenser are then linked to the system. Installing the headband is the last step.
The pipe needs to be fixed to the wall at least every 1.5 meters in order to be fixed firmly.
High-quality thermal insulation for the chimney should be provided when installing steel and cast iron pipes. You won’t be able to prevent the ceilings and nearby structures from burning down because of an unexpected chimney burst except in this scenario. The best way to insulate a metal chimney is with fireproof clay, the traditional method. However, special fireproof foam can also be used in dire situations.
Additionally, the joints of a metal pipe chimney with the floor and roof can be made and decorated with clay.
Connection between the slab and the metal chimney
If you use a metal pipe, you have to fasten it every half meter to the walls and floor. This is because these chimney pipes weigh a lot. The landing holes are also more expansive, measuring about two pipe diameters.
Longer chimney life is guaranteed by cast iron pipe, but installation can be challenging. Therefore, a bolgarka is the only tool necessary to cut such a pipe.
Correct installation of sandwich chimney with your own hands
Conventional metal pipes are being replaced by sandwich chimneys composed of multiple materials. Superior floor insulation against stove combustion products is made possible by the multilayer construction. Since installing a chimney of this type doesn’t need extra insulation, the landing holes can be made nearly identical to the pipe’s diameter.
Metal pipes nestle into one another like matryoshka dolls when installed, and connecting the pipe elbows doesn’t require any extra fasteners. A specific construction adhesive is required to join the pipe elbows in sandwich chimneys. The construction adhesive not only seals the elbows but also keeps smoke from entering the building.
Sandwich pipes should not be used for installing outdoor chimneys because they are highly susceptible to condensation forming from ambient moisture. A pipe of this kind can last up to 70 years inside the structure.
Installation of an external chimney
Stainless steel pipes will be the best material to use when building an external chimney. It’s not too heavy and works well even with the most basic tools.
Installation of an outdoor chimney
To install an external stainless steel chimney, complete the following tasks:
- Make a hole in the pipe adjacent to the boiler. It should be located at least half a meter from the top of the boiler.
- Place the fixing elements one meter apart on the outer wall.
- Connect the chimney inlet to the heater.
- Lead the curved pipe elbow out of the room.
- Install a condenser.
- Fix the chimney to the wall.
- Install the chimney cap and protection.
Design features of a sandwich chimney
All structures with more than three layers are called "sandwiches" because of the British. Naturally, there is also a chimney with the same name, in which a layer of thermal insulation (composed primarily of materials based on basalt) is positioned between the two circuits.
This allows for the most effective removal of combustion products from the combustion chamber, including:
- The internal surfaces are perfectly resistant to condensation moisture and high temperatures;
- The thermal insulation layer prevents overheating of the external circuit;
- an excellent draft is achieved;
- The design features prevent moisture from reaching the thermal insulator.
Stainless steel, which makes up the chimney’s inner section, is renowned for its ability to withstand rust. Regarding the outside, galvanized steel is frequently used; this material is less expensive but also less long-lasting. As such, you will have to decide between economy (galvanized) and quality (read: stainless steel). Furthermore, the external pipes need to be precisely durable in order to prevent the structure’s overall shape from changing, especially if the internal pipes are primarily required to withstand critical temperatures.
Apart from the chimney itself, the following items are required for installation:
- special "adapter" to pass through the roof;
- brackets for fixing pipes;
- platform for unloading – it will allow to evenly distribute the weight and relieve the base from the load;
- revision with a window for cleaning;
- clamps for fixing structural elements;
- adapters;
- 90 or 45 degree elbow (in order to change the direction of the chimney);
- adapters.
Note: You can add other decorations to the top of the pipe, such as a mushroom, spark arrestor, whopper, vane, etc., in addition to the cone. Sandwich chimneys can be installed both inside and outside of homes since they offer superior thermal insulation.
However, it will work much better if you install it inside the home, as close to the heat source as possible (this minimizes heat loss).
Sandwich chimneys can be installed both inside and outside of homes because they offer superior thermal insulation. However, it will work much better if you install it inside the home, as close to the heat source as possible (this will minimize heat loss).
Learn more about building a solid fuel boiler chimney.
We have previously discussed the fundamentals of installing this kind of chimney; read on for more information.
Varieties of chimney pipes
The purpose of the chimney pipe is to release combustion products and smoke into the atmosphere. It originates at the house heater’s inlet and terminates above the roof ridge with a protective umbrella. In private construction, the following kinds are typically used:
- Brick. Brick chimney has been used since the time when people began to build fireplaces and stoves. The difference of the modern – the use of special kiln, fire-resistant brick. Due to its heat-accumulating properties, this material keeps the heat inside the chimney, preventing overheating of the house finish in contact with its walls. Complicated device of the pipe from brick, a significant mass make homeowners refuse this option. Properly do the installation of chimneys of this type can only be done by experienced stove masters, which increases the cost due to the payment of the master"s labor.
- From metal. Sale of chimneys from metal made it easier to create a chimney system in a private house. Alloy steel chimneys with thickness of 1 mm and more, lighter and cheaper than analogs made of brick. The device of such a chimney consists of separate modules. Straight modules are used for laying vertical and horizontal sections, and bends and tees for rotary ones. Installation of a chimney made of galvanized steel has one disadvantage, which is that its material has a better thermal conductivity than pipes made of brick, so it needs additional insulation. However, self-installation of this type of chimney is much easier, to do everything correctly, it is enough just to follow the instructions. Metal chimney of the internal type
- Ceramic. The arrangement of ceramic chimney combines the strengths of brick and metal stove pipes. It has a modular design and has low thermal conductivity. The price for such products is higher than for metal pipes, but significantly lower than the cost of brick pipes. Ceramic chimney is problematic to make curved, it is better suited for vertical system configuration.
Chimney pipe made of ceramic
Three criteria can be used to accurately select the material used to make the chimney: compatibility with the heater’s material, low heat conductivity, and tight connections.
Technical characteristics of sandwich pipe
- Material. Basalt fiber (mineral wool) is mainly used as thermal insulation material. This type of insulation is characterized by resistance to high temperatures and to the effects of chemicals. Mineral wool has excellent thermal/sound insulation properties and is laid with a thickness of 30-60 mm. Due to their fire-safe properties, sandwich pipes can be used in houses built of any material. More expensive alloys with a high degree of heat resistance are used for the inner casing.
Sandwich pipes can have an outer layer made of copper, brass, stainless steel, or another material, while the inner layer is typically made of galvanized steel. The price and range of applications for the pipe are determined by the composition of alloying materials, different alloys, and the thickness of the thermal insulation layer.
Sandwich pipes made of stainless and galvanized steel
- Connection type. Elements of sandwich pipes are connected by two methods: corrugated edges and sockets. The advantage of the corrugated connection is the ease of installation, but to ensure tightness, a large amount of sealant is required, and this increases the cost of the chimney. At the socket connection, a high degree of tightness is achieved due to the presence of a wider chamfer on one side of the pipe. The plus is a high degree of tightness, so that the design can be used for gas boilers. But the disadvantage is the complexity of installation and the need for a very accurate fitting of all parts.
Sandwich pipe connections types
Mounting of the structure
Its primary component, the external chimney, is mounted outside the building and is connected to the heating unit via a horizontal pipe that passes through the building’s wall. The heating boiler needs to be installed and then connected to the chimney pipe, which is situated outside the structure. At first glance, it appears more difficult than it actually is. Nonetheless, there are a few guidelines for the chimney output through the wall that must be followed.
Rules of work execution
The chimney is always installed starting at the heating boiler, or more accurately, starting at the hog. The gas exhaust chimney is always positioned above the other one to prevent moisture from penetrating the insulation.
- Heat-resistant sealant is used to make the construction airtight, at least 1000*C.
- Clamps should be used in waste connections, tees and pipes.
- At the interval of two meters the external chimney must be rigidly fixed to the wall with special brackets. They should also be used when fixing tees.
- Horizontal sections of the chimney pipe are not allowed to exceed one meter.
- Avoid contact of gas pipes with chimney ducts and electrical wiring.
- If the chimney passes through a combustible structure, use special fire protection spigots.
- Install a removable door for cleaning (it should be done twice a season) of the structure, at the base of the chimney.
Installation
You can begin the primary work once all construction-related information is available and the material is prepared.
- Connect the chimney to the heating boiler socket using an elbow, pipe or tee (depends on the design).
- Connecting the pipe to the chimney with the necessary transition piece.
- The joints are treated with sealant and clamps are installed.
- Passage through the wall is carried out with the use of a special passage spigot (in the place of wall passage, jointing is prohibited).
A minimum of 0.5 of the pipe’s cross-section (depth of landing) should separate the points of insertion when inserting the chimney pipe, and all of the links should fit snugly together without any spaces between them.
The wall-mounted chimney outlet
- Prepare the installation of the vertical part of the structure. At the end of the horizontal pipe, led through the wall, fix a tee with fasteners for the vertical pipe. If we use an elbow, it is necessary to create conditions for cleaning the horizontal gap of the connection. When using a tee, the bottom outlet is blocked with a plug, which is removed or we use a tee with revision. How and where to attach the chimney depends on where it is located. The pipe is fixed to the wall with wall brackets every 2 meters. If the main pipe has a heavy weight, install the elbow on a support. Often it happens that it is impossible to fix to the wall along the entire length of the structure, in this case we use stretching bars.
- We install a clamp with lugs, attach clamps to the lugs and attach the stretching cables of the required length to them. In this case, the cable for stretching should be at least 3 mm in diameter.
- In the places where the stretches are fastened, we install eyebolts or anchors (we choose based on the fastening surface).
Putting the outer pipe together
The vertical pipe’s entire structure needs to be lifted and secured in place. Partially erected structures are feasible, but working at heights is dangerous, and occasionally complete construction is not feasible. Typically, the pipe is put together on the ground. Use clamps to secure every component, and get ready to install brackets and stretch fasteners.
- To facilitate this process we use a hinge.
- Select the required elbow for the joint and fix the joint to the edge of the outer pipe, weld it.
- Raise the finished end of the pipe to the level of the joint and also attach the joint to the end of the elbow.
- We lift the whole structure with the help of attached ropes and a slingshot. This should be done in good weather, it is inadmissible to do it in gusty winds.
- Fixing in accessible places.
- For stability we fasten the stretches not firmly.
- Unscrew the nuts that were used to fix the joint. We cut the bolts themselves with a bolt cutter and knock out the endings.
- Knock out the hinge and fasten the remaining bolts on the joint.
- Make a full tensioning of the stretching rope. Adjust the tension with the turnbuckle screws.
We’ve reached the end of the assembly. Seal the joint and tighten it. Install insulation (which will prevent condensation) after we have insulated the vertical pipe. You can finally feel comfortable about heating your home.
Chimney in the sauna
A metal chimney is the best choice for a bathhouse. Extremely high temperatures are rarely reached by bath furnaces, and adequate room insulation is the only way to maintain the bathhouse’s atmosphere. However, since the building will have a high relative humidity, which will negatively impact the metal’s durability, it is preferable to use stainless steel in this situation.
The available outputs of the bath chimney are displayed in the options that are given. It is important to remember that the outside of each of them is thermally insulated. In order to minimize heat loss and metal damage, this is required.
The design of the chimney for a sauna stove is not very complex; condensation is the only significant consideration in this case. It will continually build up because of the high humidity and temperatures. This will shorten the time that the chimney operates, which is undesirable.
After that, the assembly starts. Despite the slight differences in design, the assembly is done pretty much the same way. It is made up of multiple parts:
- Single-circuit pipe connecting the stove and the chimney outlet.
- Adapter.
- Double-circuit pipe.
- Condensate drain.
- Umbrella.
Before anything else, these parts need to be assembled. The different parts of the chimney can be connected using clamps and adapters to complete the task. In order to lead the pipe out to the side, you will also require an outlet that is 45 degrees. To prevent condensation on the structure, it is advised to lead it out through the wall rather than the roof.
A helpful hint is that the assembly can be done before or after the building’s component installations.
After that, every passageway needs to be completely insulated. If the pipe is double-circuit, insulation of the pipe itself is not necessary.
Material from which the chimney is made
For various heating appliances and fuels, different kinds of steel are chosen. It should be a highly alloyed stainless steel that is appropriate for making chimneys that are fireproof and resistant to chemicals.
One of the primary features of the chimney device is the steel grade, which serves as a standard for durability and resilience against outside influences.
Chemically active substances such as sulfuric acid, sulfur, and hydrochloric acid may build up in the chimney during the combustion of different substances. Furthermore, there can be significant variations in temperature when various fuels burn.
It does not get hotter than 450°C when heated with wood or gas, but it can get as high as 700°C when burning coal. Metals respond to these parameters in different ways. Thus, the quality and property of steel should be your primary consideration when selecting a smoke extraction system.
Option No. 1 is alloying additive-treated stainless steel.
The following are the primary steel alloy grades used in sandwich chimney production:
- Stainless steel stabilized with titanium (AISI 321). Used for wood-fired equipment. Not resistant to corrosion in sulfur-containing environments. Permissible operating temperature – 600-800°C.
- Stainless steel stabilized with molybdenum (AISI 316). Installation of a sandwich chimney from this grade of steel is carried out for heating installations that operate on wood, gas, diesel fuel. Metal is acid-resistant, characterized by increased resistance to corrosion, aggressive media of various nature.
- Heat-resistant steel (AISI 304). The inclusion of chromium and nickel makes the steel insensitive to elevated temperatures and acidic environments. It is used for production of chimneys with high temperature of exhaust gases – about 1000 °C. At temperatures of 600-800 °C it tends to lose its toughness and ductility, which leads to embrittlement.
- Widespread grades AISI 409 and 430 are weakly resistant to high temperatures and acids. Most Chinese products and some domestic products are made of these grades of steel.
Visual verification of the steel grade is not feasible. You can use a magnet to approximate the quality or look for markings on the product itself before making a purchase. A magnet will be drawn to low-quality material, but not to metal that has alloying additives added.
When selecting chimney pipes, find out about their primary features. Bring a magnet with you if you have any concerns about the seller’s integrity; it will be drawn to steel products that have too little ligating additive.
Option #2: Chimney pipe made of black metal
The ferrous metal itself oxidizes and burns quickly. For that reason, a unique enamel is applied to protect it. Resistance to acidic environments is increased as a result. The enamel can tolerate brief temperature increases of up to 750 °C and can endure for an extended period of time at a maximum temperature of 400 °C.
Because enameled pipes come in so many colors, they’re very popular.
The combustion byproducts from heating columns, stoves, heating boilers, and fireplaces are removed using enameled pipes. They can be painted a variety of colors, unlike steel. This enables you to choose the appropriate shades to complement the house’s exterior or interior.
Combination sandwich chimneys, variant № 3.
Companies try to use less expensive materials to reduce the cost of production. The product’s service life is not significantly affected if the outer pipe is made of enameled or galvanized metal and the inner pipe is made of pricey stainless steel.
Even worse would be the opposite situation, where inexpensive, low-quality material is concealed inside and stainless steel is utilized on the exterior. If used extensively, such a pipe can last up to a year before failing, resulting in additional expenses for installation and materials.
Layer of internal insulation
An insulating layer sits between the sandwich chimney’s two pipes, keeping heat inside and ensuring a decent draught. The best fire resistance class fibers are used as insulation, such as ceramic wool or basalt.
Ceramic wool can tolerate temperatures of up to 1000°C, while basalt wool can only tolerate 600°C. Both materials are effective at insulating against heat. Apply a 25–50 mm layer of insulation. The larger the chimney, the better, especially if it is installed outside.
Why to finish the pipe
Finishing stove pipes on the roof is required for the following at least three reasons:
- High temperatures, on the one hand, and cold air on the other – lead to the fact that on the inner surface of the pipe settles condensate. But this is not just water, condensate is an aggressive acid cocktail that gradually corrodes the pipe. External insulation shifts the dew point inside the insulation and eliminates the appearance of condensation;
Finishing is not necessary for clinker brick.
- 222222If for the construction of the chimney was used full-body clinker brick or stainless steel pipe, then these materials are not afraid of weather troubles. While ordinary brick without external protection will start to crumble in a couple of years, steel will rust and concrete will crack;
- In addition to the strength of the chimney there is also such an important point as protection from rain of the roof itself. If the sealing of the sector of connection of the chimney with the roof was done poorly, then after a year the insulation will be in disrepair, and the wooden rafter system will begin to deteriorate.
Avoid waiting until the chimney has been completely destroyed.
What to rely on when designing a project
Of course, aesthetics and originality are crucial, but you should consider safety before completing the house’s chimney. I believe you can infer the serious repercussions for yourself.
So, it is not unnecessary to become familiar with the rules in order to avoid making mistakes and setting fire to the house. SNiP 41-01-2003, which governs the installation and use of heating, ventilation, and air conditioning systems, should be followed in this situation. Since the document is lengthy, I have summarized the key points for you.
SNiP 41-01-2003 norms.
- If combustible thermal insulation and finishing materials are chosen for the chimney, their spontaneous combustion temperature should be higher than the maximum possible temperature of the chimney by at least 20ºC. The same rule applies to all surrounding structures and objects within a radius of half a meter;
- Metal products that can corrode must have an appropriate coating to protect the surface from corrosion;
- The walls of heat-resistant brick chimneys should not be thinner than 120 mm. If we are talking about heat-resistant concrete, the wall thickness of such chimneys starts from 60 mm;
- The use of metal and asbestos-cement structures for the arrangement of the chimney is allowed only in the presence of a factory quality certificate, which authorizes the operation of products at high temperatures;
Finishing chimneys made of asbestos and cement.
It is strictly forbidden to use thin-walled stainless steel pipes and asbestos-cement in coal or coke-fired stoves. The temperature of the gases in such a chimney is too high for these materials to tolerate.
- The mouth of the chimney (top point on the roof) must be equipped with an umbrella, deflector or other protective structure to prevent debris and precipitation from getting inside the chimney. In this case, protective structures must not interfere with the exit of flue gases;
- The distance from brick and insulated chimneys to roof rafters and other wooden structures must not be less than 130 mm. If a heat-resistant ceramic pipe without thermal insulation is installed, the safe distance increases to 250 mm.
Deflector made of galvanized sheet metal.
The type of fuel your boiler or stove will run on should be considered when selecting the chimney itself as well as the exterior or interior surface finish. Flue gas temperatures are directly influenced by it.
Temperature of flue gases depending on fuel type | |
Type of fuel | Temperature of gases in the chimney in ºC |
Hard coal and coke | Up to 700 |
Dry firewood | Up to 500 |
Fuel oil | Up to 350 |
Pellets (pellets from pressed sawdust) | Up to 300 |
Natural and bottled gas | Up to 200 |
Fuel types for boilers using solid fuel.
Pros and cons of using a sandwich chimney
The following are drawbacks of chimneys made of sandwich pipes:
- Sealing failure after a certain number of heating and cooling cycles;
- compared to a brick construction, sandwich chimney has a higher cost;
- service life is about 15 years, while traditional chimneys made of refractory bricks last 10 years longer.
The primary reason for such a brief service is the use of inferior materials in the manufacturing process.
Selecting products from a reputable brand is the first step toward ensuring the chimney operates successfully and for a long time.
Picture Gallery Image from
Justification for sandwich systems
Suitability for heating systems
Features of the pipe’s design
The chimney assembly’s starting section
Information about the insulation of chimney passages
Characteristics of the passageway configuration
Setting up a unit for passage through the roof
A canopy is installed at the chimney mouth
Sandwich chimneys have the following benefits:
- Insulated walls. Thanks to thermal insulation, even a chimney placed outside does not lose its draught. Multilayer walls prevent the rapid cooling of combustion products, which are quickly removed through the chimney, and this prevents condensation and soot from actively forming.
- Simple installation. Having studied the principles of chimney construction, even a beginner can assemble them.
- Variety of variants. For the assembly of the structure are produced straight and angular modules. The chimney can be led upstairs or in the wall, it can envelope the rafter system, various architectural elements.
- Minimal settling of soot. Thanks to the smooth surface of the pipes, ash and soot are quickly discharged into the atmosphere and accumulate more slowly.
Furthermore, the sandwich system is relatively lightweight, making it simpler to build a support for it and eliminating the need for a unique foundation, unlike a brick chimney. It can be put straight on top of the heating apparatus and fastened to walls and floors. Sandwich chimneys are fire safe and nearly completely free of condensation when compared to single-wall systems.
Even the most intricate design can be assembled using the sandwich chimney’s basic components.
Three options for self-construction of the chimney from the outside
There are three options where an individual with no special training can complete everything by hand. The first option relates to brick pipes; they don’t require lining, but the joint with the roof needs to be sealed. The variant with ready-made factory solutions and the variant with a frame come next.
Variant #1: arrange a brick chimney
Prior to installing roofing material, the pipes on the roof should be waterproofed. Partially disassembling the roof will be required if it is already lying. You have to remove the lower portion of the roof from the pipe and to the edge of the slope in addition to removing the entire 50–70 cm perimeter.
Plan for caulking a pitched roof’s brick chimney’s perimeter.
We will require a wall metal profile made of the materials. You can either purchase one already made or bend one yourself out of galvanized steel. Four components make up the profile, and during installation, they overlap.
Purchasing the pipe’s outer apron in conjunction with the roofing material makes choosing the color easier and is definitely preferable.
A roofing iron sheet with bent sides on the sides is what is referred to as the "tie." It is wound beneath the bottom portion of the wall profile and laid from the pipe’s bottom to the slope’s edge.
A 20–30 mm deep groove must be cut in the pipe using a bolgar in order to securely join the brick pipe with the wall profile. This groove is filled with the profile’s bent edge.
For the wall profile, the pipe’s entire perimeter is cut.
After that, we fit the profile’s bent edge into the groove and add sealant to it. Next, we use press washers and self-tapping screws to secure the tie driven from below and all four profile components. This structure has roofing material applied to it.
The upper apron’s arrangement scheme for the stove pipe.
Self-tapping screws are used all the way around to secure the top apron to the pipe. It should be at least 100 mm on the chimney. Soft bituminous materials are commonly used to make the lower portion of the apron. It is secured to the corrugated roof by crimping it around it and using mastic or another type of adhesive.
A roof adhesive is required for the apron.
The plan operates as follows: the upper apron removes the majority of the moisture from the pipe; however, in the event that this barrier is unable to keep the moisture out of the pipe and it seeps through the roof, the wall profile will collect it and the water will flow from the roof down the tie.
Diagram showing the two layers of roof waterproofing in the area next to the stove pipe.
Option № 2: installation of the frame
This technique works great for insulating a chimney and covering it with siding, corrugated board, and other materials of a like kind. The base is initially covered in metal profile, to which corrugated board will subsequently be attached. Since the wall profile is wider than the ceiling profile, it is preferable to use it when creating the plasterboard frame.
More durability is found in the metal profile frame.
Although working with metal profile is not difficult, you can construct a frame out of wooden bars if you are unsure of your skills. A true wooden frame must be thoroughly impregnated with a composition that repels water, is antiseptic, and retards fire. Dense mineral wool slabs are placed between the frame’s laths to insulate the pipe.
The only insulation used in chimneys is thick mineral wool boards.
Using press washers and self-tapping screws, corrugated board or any other sheet material is fastened to the frame laths. This construction umbrella is crowned to provide rain protection.
Diagram of the section’s lined and insulated pipes.
Option #3: ready-made solutions
There are no issues at all with round pipes these days. For them, specific flexible aprons are made. Experience tells me that you can install such an apron in a few hours tops. Here are some photos showing how to install such an apron.
A detailed guide on how to install a flexible joint on a round pipe.
- Choose the pipe diameter you need and cut a hole in the soft polymer cone;
- Pull the cone over the pipe, the fit must be tight;
- Crimp the bottom soft metal ring to the shape of the roof;
- Thickly lubricate the perimeter under the ring sealant;
- Screw the ring to the roofing material with self-tapping screws with press washers.
Design features
Even though there is a vast array of materials available for building chimneys, two-circuit steel pipes, also known as "sandwich" pipes, are currently the most common.
The "sandwich" style chimney is built in two layers. A layer of thermal insulation material, acting as both an insulator and an insulator, is placed between two metal pipes of varying diameters.
Sandwich pipe chimney seen in a video
The double-circuit design has superior technical qualities and is more fire safe than single-circuit pipes, which are composed of steel with a 0.5 mm thickness. Installing a chimney outside of a building with a single-circuit chimney is not advised. They can’t hold on to heat during the cold season because they only have one layer. Condensate forms in such a chimney due to the extreme temperature difference, which lowers the draft and causes blockages in the pipe.
Design of a sandwich pipe with two circuits
Therefore, buying sandwich pipes will be the best option for installing a chimney through the wall. Such a two-circuit chimney is very popular because it is less expensive than a brick chimney, looks good, has great technical qualities, is fire safe, and has a long service life.
Furthermore, you can install a chimney made of this material with your own hands. Even a beginner will be able to complete the task if they carefully follow our comprehensive instructions, despite the nuances and subtleties.
What should be the height of the chimney
A decent draught is necessary for nearly all heat sources to operate steadily and dependably. It results from the temperature differential between the outside air and the flue gases. The draft rises in proportion to this difference. It is directly influenced by the chimney device’s height, features, and accuracy.
The wind’s movement has the potential to both exacerbate and disrupt the chimney’s natural draught. When the conditions are right, horizontal wind streams collide with the chimney and reverse course, moving from bottom to top. This causes a rarefaction at the outlet, which literally draws the combustion products out of the chimney. When there are other obstructions, the wind may be directed from top to bottom, which can cause a back draft—a reverse movement of gases—and produce smoke in the space.
Plan for calculating the chimney’s height
Anything tall that is close by that blocks normal wind movement, including a portion of the pitched roof, can cause problems. As a result, the regulatory scheme determines the chimney’s height by factoring in the distance to the ridge.
In addition, the overall height of the heat generator pipe should be at least 5 meters, and for a gas boiler, it should be at least 3 meters.
Structural elements and their features
You can complete difficult tasks for sandwich chimney construction thanks to the variety of products available.
Chimney manufacturers have created over twenty distinct components to help with installation implementation.
The following are the primary components of the chimney channel design:
- Straight pipe sections. Sections with a diameter of 80-600 mm, length up to 1 m. The ideal chimney design is straight, but in practice this is difficult to achieve.
- Knees and tees. They are used if it is necessary to lead the chimney through the wall, outside the building, or bypass the structural elements of the house – beams, rafters. Sometimes for turns (especially straight, 90 °) apply tees with revision – they allow you to clean the chimney in hard-to-reach places. They are installed and reinforced with brackets so that they do not bear the weight of the structure above them.
- Through spigot. Isolates the chimney from the interfloor partitions, serves as a fastener for the chimney.
- Roof sheathing. It is a metal cone, which is attached to the roof at a certain angle. Helps guide the pipe through the roof without compromising its tightness and increases fire safety. Instead, a special silicone sealant can be used, which serves as the best protection against leaks.
Apart from the aforementioned components, numerous devices are available for both the installation and ongoing use of sandwich pipe chimneys.
Every two meters, brackets are used to secure the chimney. The fasteners used to secure clamps to the wall are chosen based on the material that the clamp is folded from.
To ensure effective and safe operation, installing a chimney in a private residence requires careful planning and adherence to safety regulations. A thorough installation algorithm can help homeowners steer clear of common problems like poor draft and possible fire hazards. The procedure entails selecting the appropriate materials, taking precise measurements, and correctly fastening the chimney to the house’s framework.
When installing a chimney, photographic examples can be very useful as they offer a visual guide to go along with the technical instructions. They frequently draw attention to crucial procedures like installing insulation, positioning the chimney flue, and completing the chimney cap installation. Even individuals with limited construction experience can benefit from these images as they serve as useful references.
Lastly, it’s critical to review the chimney installation with a professional and possibly refer to local building codes. This guarantees that the system works well and complies with safety requirements. To keep the chimney operating efficiently and safely over time, routine maintenance and inspections are also essential. Homeowners can benefit from a functional chimney that raises the comfort and value of their property by following these steps.