Chimney pipe: choice of material and general installation rules

The safety and effectiveness of your home’s heating system depend on the material you choose for your chimney pipe. Varying degrees of heat resistance, durability, and affordability are provided by different materials. Stainless steel, copper, aluminum, and galvanized steel are typical choices. Because of its durability and corrosion resistance, stainless steel is frequently chosen for both indoor and outdoor applications.

To guarantee appropriate operation and safety, there are a few general guidelines that must be adhered to when installing a chimney pipe. First and foremost, it’s critical to ascertain the appropriate chimney pipe size based on the kind of heating appliance and the size of the flue. This guarantees an effective draft and keeps gases or smoke from seeping back into your house. In accordance with local building codes, the pipe must also be installed with adequate clearances to combustible materials.

Making sure the chimney pipe installation is stable and properly supported is another crucial component. To stop the pipe from sagging or moving over time, the proper brackets and supports must be used to securely fasten it. This prolongs the lifespan of the chimney system and improves safety.

Finally, weatherproofing and sealing are crucial phases in the installation of chimney pipes, particularly for outside systems. Sealing joints and connections properly stops leaks that can cause reduced efficiency or water damage. By protecting it from the elements, weatherproofing helps the chimney last a long time while retaining its structural integrity.

Choosing Materials Consider factors like durability, weather resistance, and cost when selecting materials for chimney pipes.
Installation Rules Ensure proper ventilation, secure anchoring, and compliance with local codes during chimney pipe installation.

Choosing material for chimney

Prior to delving into a comparative study of chimneys made of different materials, you ought to discuss the most desired parameters and attributes.

  1. Round section of the smoke -sobbing canal. The fact is that due to uneven heating of the walls of the chimney, the gas flow in it is twisted around the vertical axis. The round channel does not provide any counteraction to such a stream, while the appearance of vortices in the corners of the vortex is characteristic of a rectangular.
  2. Waterproof walls. There is always water vapor in smoke gases. The humidity of the fuel has nothing to do with it – the water is formed as a result of oxidation (that is, combustion) of hydrocarbons. Some of its amounts condenses on the walls of the chimney, so it is extremely desirable that they are waterproof. The porous structure will absorb water, and that during a break in the work of the heat generator will freeze and will cause destruction in the material.
  3. Smooth inner surface. The smaller the chimney meets this requirement, the faster it is overgrown with soot. In addition, condensate flows along the smooth wall better.
  4. Chemical stability. The biggest danger of condensate is that, entering into reaction with oxides contained in smoke gases, forms various acids. Including sulfur. Moreover, sulfur is present not only in solid fuel, but also in a gaseous – in the composition of the fragrance, which gives natural gas a characteristic unpleasant odor. That is why resistance to acids is very desirable for the material of the chimney.
  5. Resistance to high temperatures.
  6. Small heat capacity of the wall, that is, the ability to quickly warm up. If the wall will dial the temperature for a long time during kindling, then a large amount of condensate will form on it. But at the same time, it must be remembered that the chimney should be well insulated, because good craving is due to the high temperature of the smoke gases.

We now compare the different chimney options that are currently on the market.


The brick pipe has the following advantages:

  • high strength;
  • Absolute fire safety (even when the soot fires inside the chimney, its thick brick walls reliably protect the room from fire);
  • Significant heat capacity: after burning the fuel, the chimney gives the heat for a long time.

But given the current circumstances, not everyone will find this decision acceptable because of its many drawbacks:

  1. Rectangular section.
  2. Uneven and rough walls (the situation can be slightly improved by plastering from the inside).
  3. The porous structure (brick, like plaster, absorbs moisture).
  4. Lack of resistance to acids. In the most difficult conditions, brick chimneys are connected to heat generators with a low exhaust temperature – modern super -economic gas boilers and stoves such as “Bulerian” or “Professor Butakov”, working in smoldering mode (they are also called prolonged burning furnaces). Condensate, which immediately turns into an acid cocktail, is formed from such an exhaust in especially large quantities, which leads to the rapid destruction of brickwork. Therefore, brick pipes connected to such devices must be guilled (a pipe made of chemically stable material is placed inside).
  5. Significant weight (the foundation device is required).
  6. Construction takes a lot of time.
  7. High price. The simplest and most short chimney will cost at least 40 thousand. rub. This amount also includes the payment of the master’s work, but it is better not to give up his services in order to save and do everything yourself: an attempt without having enough experience with your own hands to build a narrow, high and massive structure that has to work in the conditions of temperature loads and changes, can end very badly.

Even so, brick chimneys are still in demand today—just not as standalone structures, but rather as internal walls with flower-shaped canals built inside. If the house is two stories, the heating system on this wall will also provide a comfortable temperature on the second floor. It is located next to the boiler room.

Block chimney

In this instance, the block is a brief, thick-walled pipe that can be constructed from reinforced concrete or burned clay, just like regular brick. These chimneys will resemble brick chimneys in every way, save for the fact that they are constructed much more quickly and have a circular section rather than a rectangular one.

Potter from asbestos -cement (a/c) pipes

Any pipe that serves as a chimney is beneficial because its section is rounded. However, the pipe’s greatest benefit is its incredibly low cost. On the other hand, there are several drawbacks to this material:

  1. Low heat resistance. A/c pipe withstands a temperature of not more than 300 o C. Because of this, the scope of its application is greatly limited: either with low-power gas equipment, for example, in columns, or in areas removed from the heat generator over a sufficient distance. Most often they do this: the inner part of the chimney is mounted from steel, and outside the house it increases to the desired height asbestos -cement pipe. Such chimneys have to be cleaned more often, since the fire of soot in them leads to extremely dangerous consequences: a/c chimney in conditions of strong overheating may even explode.
  2. Fragility. Because of it, it is impossible to make a revision hatch in a pipe a/c, it is also impossible to make a discharge to change the direction of the pipe.
  3. Porous structure.
  4. The lack of the possibility of a reliable connection of individual pipes: for this, rubber couplings are used, which with a high probability can pass smoke.

Additionally, it should be remembered that during the post-Soviet era, asbestos-cement pipes were frequently released in violation of GOST, which had a detrimental effect on the material’s dependability and quality.

Ceramic chimney

A very useful contemporary fix. The three layers that make up pipes and other components are reinforced concrete on the outside, thermal insulation in the middle, and heat-resistant ceramics on the inside. There are no hidden signs of a well-built chimney:

  • round section;
  • smooth waterproof wall;
  • resistance to acids and high temperatures;
  • lack of the need to perform insulation;
  • durability.

However, the price of all of this is high: 31 thousand rubles will buy you a chimney that is 5 meters high and 140 millimeters in diameter.

Video: Installation of a ceramic chimney

Chimney from metal pipes

All metal pipes have the following common benefits:

  • round section;
  • small weight;
  • smooth and waterproof wall;
  • simplicity and high installation speed (you can assemble it with your own hands);
  • Fast warming up (during kindling condensate is formed in a minimum volume).

The drawback is that the pipe requires a thick layer of insulation because of its high heat conductivity.

These are the pipes that are currently manufactured for chimney installation:

  1. Cast iron: very rare and very expensive variety. An element like a divert or revision costs about 5 thousand. rub., A pipe about 1 m long – 11.2 thousand. rub. But the cast iron is much better than ordinary steel confronts corrosion, which allows some manufacturers to give a guarantee for their cast -iron chimneys for up to 30 years.
  2. Steel corrugated: flexible pipes with a thin wall. Designed for removing smoke with low temperature, for example, from a gas column. Layed indoors or are used for boiling chimneys.
  3. Steel without alloying additives: such pipes are inexpensive, but with the constant operation of the heat generator they will not be enough for a long time. However, with sufficient wall thickness, they are still used – paired with a reserve boiler, which is launched only in case of breakdown of the main heater.
  4. From galvanized steel: such a pipe is a little superior to the previous one-the zinc coating is quickly burned out, after which steel in a short period becomes unusable due to corrosion and exposure to acids. It is allowed to use with installation that works episodically and produces smoke gases with low temperature.
  5. Steel stainless: for constant operation with powerful installations, only stainless steel is suitable, that is, such that contains alloy additives – molybdenum, chrome, nickel, titanium, etc. Different brands are used for various conditions. Some of them are intended for high temperatures, others are acid -resistant.
  6. Sandwich Dymage: It is most advisable to purchase a stainless pipe and other elements as part of the so-called sandwich dummage-a set in which each element is wrapped in a heat insulator (basalt wool) and is enclosed in a covered steel or cheap stainless steel casing or cheap stainless steel. All modules are equipped with constructive elements that provide their reliable connection (in the bell, baguette or flange). Each manufacturer produces a full list of parts that can be needed when the chimney is made of any configuration, including the elements of fasteners and sealing the passage through the roof. Cost: For a pipe with a diameter of 150 mm and 1 m long, you will have to pay about 2 thousand. rub., other elements (bounces, tees, revisions, etc.) cost 2.7 – 3 thousand. rub. Thus, a 5-meter sandwich diterack will cost about 15 thousand. rub.
  7. Heat -resistant seamless: such pipes are also made of stainless steel, but special brands that can work at ultra -high temperatures (1200 o C and above) while the effects of aggressive substances. They can be used as chimneys of industrial furnaces or chemical enterprises, the exhaust of which is especially caustic. In domestic conditions, such a chimney will serve decades.

The most popular heat-resistant steel is that manufactured under the 20x23N18 brand. Nickel additives are highly desirable for a household chimney because they ensure resistance to sulfur compounds.

Composite ceramics based on tungsten carbide are used to create heat-resistant chimneys that can withstand the highest temperatures. However, their sole application is in industry—domain furnaces, for instance.

Plastic chimney

The least expensive method of boiling a brick chimney is to install a special plastic pipe, but this product is limited to the lowest exhaust temperatures.

DIY chimney installation

The following steps come before working on the chimney’s installation or construction.

Preparation of tools

  • plumb line: helps to ensure a strictly vertical installation of a chimney;
  • Level: helps to pave horizontal areas with a required slope of 3 degrees (for drainage of condensate);
  • screwdriver or screwdriver: it will be necessary to tighten the screws when sealing the passage through the roof;
  • roulette.

The type of chimney will determine what additional tools are needed.

To install chimneys made of brick, block, or ceramic, you’ll need the usual tools of the trade:

  • a container for the preparation of a solution or special glue;
  • Master OK;
  • putty knife;
  • grinding (used to smooth the plaster solution);
  • The template for the manufacture of seams of the same height (you can use the guidelines – the rail, on which the position of each row is marked with risks).

What they use when installing a steel chimney is:

  • a gun for feeding a tube of heat -resistant sealant;
  • Perforator for installing mounting elements of brackets, to which in turn the pipe will be attached;
  • Washing keys: with their help, a bolt connection is tightened, a tightening clamp (used to connect individual parts with each other and fastening the pipe to the brackets).

The calculation of the chimney

There are just two parameters you need to choose at the calculation stage.

The height of the chimney

The standards state that there should be a minimum 5-meter height difference between the pipe’s mouth and the burner or grate. The thrust will be insufficient at a lower value. All you have to do is follow this rule; the aerodynamic picture at the level of the chimney heading must still be considered. The latter should not be in the abstract zone created by an obstruction and air flow during windy conditions, as this will result in a push violation due to increased pressure. Taking these factors into account, the chimney mouth is raised to the following height on gable roofs:

  • 0.5 m above the skate bar (the upper side of the roof) if the pipe is located no further than 1.5 m from the ridge;
  • Matuas with the ridge bar, if the distance to the skate lies between 1.5 and 3 m;
  • below the ridge bar, at the level of a conditional plane drawn through it with an angle of inclination of 10 degrees to the horizon – if the distance to the ridge is more than 3 m.

Regardless of the distance between the pipe and the parapet, the height of the chimney’s mouth above the roof is assumed to be 0.5 m for flat roofs.

There is one exception: if the roof is coated in flammable materials (such as slate or bitumen), the heads must be protected from the coating by at least 1.2 meters.

The chimney has to be installed above a higher building if we are discussing the roof of an addition that is next to it, or if such a building is nearby. It will need to be expanded if such a structure developed after the pipe was installed. If the trees growing nearby are taller than the chimney, it will need to be done the same way.

The size of the internal section of the chimney

It is impossible to characterize the process of figuring out the ideal cross-section of the smoke excess channel as simple. You ought to carry out an intricate computation that connects several parameters:

  • fuel type;
  • exhaust temperature;
  • the length and configuration of the smoke channel;
  • the roughness of its walls;
  • The thickness and type of smoke pipe insulation.

It is not the first time, even with contemporary software complexes of automated design, to identify a set of parameters that would allow for an acceptable thrust in the pipe. However, the task is much simplified if we are discussing a standard chimney, which is not a bend in a permanent vertical pipe that is 5 meters high or slightly larger, since the section for such a case has already been calculated:

  • with a thermal installation power of up to 3.5 kW: rectangular pipe – 140×140 mm, round pipe – diameter 158 mm;
  • from 3.5 to 5.2 kW: 140×200 mm or 189 mm;
  • from 5.2 to 7.2 kW: 140×270 mm or 219 mm;
  • from 7.2 to 10.5 kW: 200×200 mm or 226 mm;
  • from 10.5 to 14 kW: 270×200 mm or 262 mm;
  • more than 14 kW: 270×270 mm or 300 mm.

The cross-section can be rounded to the closest standard range when using prefabricated pipes or concrete blocks with holes, but only in an upward direction.

To ensure efficiency and safety in your home, it is essential to select the appropriate material for your chimney pipe and to adhere to the recommended installation procedures. Your choice of material has an impact on its weather resistance, durability, and maintenance requirements. To avoid leaks and drafts, proper installation entails being aware of the clearance requirements, supporting structures, and making sure the fit is secure. This article examines and weighs the benefits and drawbacks of several chimney pipe materials, including stainless steel, aluminum, and galvanized steel. In order to maximize performance and safety, it also offers crucial installation guidelines, highlighting the significance of following building codes and manufacturer recommendations.

Installation features

The following guidelines must be followed when installing a chimney:

  1. The pipe must be built so that it has as few bends as possible. No more than three are allowed.
  2. The axis of a steel chimney, unlike a brick one, can be shifted to bypass the floor beam or rafter leg. To do this, you need to use bends with an angle of 45 degrees; 90-degree ones cannot be used.
  3. The length of the horizontal area in the chimney should not exceed 1 m. In this case, such a site is laid with a bias of 3 degrees, so that the hole where the smoke is located is located below the output. Such a slope, firstly, will provide convection necessary for natural traction, and secondly, it will contribute to the drainage of condensate.
  4. In the lower part of each vertical site, except for the fireplace directly above the firebox, it is necessary to install tees with condensation colleagues.
  5. If the place allows, the chimney is better to install indoors, since at the same time you can save on the insulation and use the heat of the dedicated gases for heating the house. Outside, the chimney is built in two cases: if there is little space in the house or a Bulerian -type furnace is connected to the chimney, which works in smoldering mode. Due to the incomplete combustion of fuel, its smoke is saturated with heavy hydrocarbon radicals, which, with a reaction with condensate (due to a low exhaust temperature, it forms quite abundantly) turns into a very toxic mixture. With the internal location of the chimney, the household would have to breathe it with evaporates, which is extremely harmful to health.
  6. The support for the brick chimney is the foundation. For steel – a special bracket with a supporting platform installed in the lower part of the vertical site. If the chimney is very high, somewhere closer to the roof you need to install another supporting bracket with an unloading platform, which will take part.
  7. The joints of individual parts of the steel chimney, as well as the joint between it and the boiler chimney pipe, should be sealed with a special heat -resistant sealant. Usually it has a black color, the maximum temperature that it withstands is 1000 – 1500 degrees. It must be remembered that it is difficult to disassemble the connection processed with such a composition, so it must be applied at the last moment when the position of the parts is finally determined.
  8. At the beginning of the chimney, it is necessary to install a gate damper, through which traction adjustment will be adjusted. For safety reasons, it is advisable to make the damper such that it does not even overlap the chimney tightly overlap (you can cut the sector in it).
  9. When crossing the ceiling or wall, it is necessary to exclude the contact of combustible materials with the hot surface of the chimney, for which the cutting is arranged – the framing of the heat insulator, covering the pipe at the intersection. In a brick chimney in such a place, a rush is made – a gradual thickening of the wall due to an increase in the number of bricks in each next row. The cross section of the inner channel does not change.

Video: Installation of a sandwich Dymage

Sealing the passage through the roof

Again, to avoid flammable materials coming into contact with the pipe’s surface, the opening in the roof must be quite large when crossing it. A conical part called a rat is used to block this opening; the upper part of the rat fits the pipe snugly, and the lower part is either glued to the roofing or fastened with self-tapping screws.

The completed cover can be bought separately or in conjunction with other roofing materials, such as metal or corrugated board, to complete a sandwich demolition device. The lower portion of the rat form that corresponds to the coating relief is provided by the manufacturers in the second instance.

The rat’s location to the coating and pipe is completely compacted with mastic or an external work sealant.

Video: installation of a chimney through the ceiling and roof

Selecting the appropriate material for your chimney pipe is essential to maintaining efficiency and safety in your house. Depending on your preferences, galvanized steel, aluminum, or stainless steel, each material has advantages over the others in terms of affordability, durability, and heat resistance. Despite being more expensive, stainless steel is a popular option because of its exceptional durability and resistance to corrosion. Contrarily, aluminum is less expensive and lighter but might not endure as long in inclement weather. Cost and durability are balanced by the use of galvanized steel, but rust prevention calls for regular maintenance.

To guarantee correct operation, it is imperative that you adhere to general guidelines when installing your chimney pipe. Always make sure the pipe is at least two feet above the roofline to enhance draft efficiency and stop downdrafts. For fire safety, it’s imperative to keep the appropriate distance between combustible materials like wood and insulation. Encircling the pipe with high-quality insulation reduces condensation and boosts overall performance. Furthermore, a tight, leak-free fit is guaranteed when joints are securely sealed using the right materials, such as high-temperature silicone.

Regular inspection and maintenance are essential to maintaining the best possible condition for your chimney pipe, regardless of the material or installation technique that is selected. Regularly check for any indications of wear, rust, or damage, particularly following severe weather. Every year, clean your chimney pipe to get rid of creosote buildup, which can cause a fire. Maintaining your chimney pipe in a proactive manner not only increases its lifespan but also guarantees the effectiveness and safety of your heating system.

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Alexandra Fedorova

Journalist, author of articles on construction and repair. I will help you understand the complex issues related to the choice and installation of the roof.

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