Chimney passage through a wooden wall. Why is the chimney brought out through the wall? Pros and cons of external smoke exhaust through the wall

One of the most important tasks when building a bathhouse is the correct exit and sealing of the chimney pipe. Moreover, two problems need to be solved at the same time: ensuring fire safety and insulating the pipe joint from the flow of precipitation and condensate.

First of all, before solving the problem of water passage, it is necessary to determine where the pipe exits on the roof. The height of the pipe must comply with certain standards. The height depends on where the pipe will exit on the pitched roof.

When installing a pipe, the following rule applies: “The closer to the ridge, the higher the pipe should be raised.”

Elevation chimney above the roof plane

If the distance from the center of the chimney to the ridge of the roof does not exceed 1500 mm, the pipe must be raised above the ridge not less than 500 mm;
With a distance from the center of the pipe to the ridge from 1500 to 3000 mm, the top of the pipe can be at the same level as the roof ridge;
At a distance of more than 3 meters, the top of the pipe must be no lower than a line drawn down from the ridge at an angle of 10 degrees to the horizontal.

Where is it better to route the pipe through the roof of the bathhouse?

The most convenient option for bringing the pipe through the roof is to pass it through the ridge. In this case, installation is easiest; there are rarely snow pockets on the ridge, and thanks to this arrangement, it is easy to carry out insulation work. But this method has a drawback: rafter system should not have a ridge beam. An option with two beams that are attached in the area where the chimney passes through the roof is also suitable, but this is quite difficult to implement and is not always possible.

The most unfortunate option for the location of the chimney is in the valley (the valley is a roof element made of a kind of tray, forming an internal angle between the joints of the pitched roof elements). Large masses of snow usually accumulate here; during rain, water flows down from two slopes, so even with the most careful insulation, a leak will only appear a matter of time.

The most convenient option for venting the pipe through the roof is near the ridge

Based on this, the most acceptable option for pitched roofs– not far from the ridge, but below it:

installation is quite simple,
There is usually little snow accumulation, which means there is no need to install snow retention,
installation is not the most difficult,
Due to the not very high height of the pipe, it does not need to be reinforced with braces.

If it turns out that the chimney runs close to the floor beams, or close to them (the minimum distance should be 13-25 cm depending on the type of pipe), exits in the valley or close to the slope, an additional elbow, with which you can lead the pipe to the right place.

In any case, to drain condensate in the waterproofing layer, you will need to attach a drainage groove. You can buy it (usually it is made from stainless steel), or you can make it yourself from a film of sufficient thickness. The groove is secured around the pipe and its end is pulled out to the side. Thus, the condensate flows into this groove and is discharged onto the roof slope.

Passage through the roof depending on the roofing material and type of chimney

When passing through the roof, the most important thing is to remove the water flowing down the roof and the pipe itself. To protect against precipitation, protective aprons are used, the upper edge of which is placed either under the sheet of roofing material located above, or under the ridge.

When venting the chimney through the roof, it must be fixed, but so that it remains movable relative to the roof. Otherwise, due to thermal expansion/contraction, the integrity will be compromised and leaks will certainly appear. For example, a round pipe can be given direction by metal strips or corners.

When installing, check the verticality using a plumb line - this is important so that soot does not accumulate and there is good traction.

Brick pipe passage through the roof

If the chimney is brick, rectangular or square in shape, you can use the materials included with the roofing material.

You can make an apron for a square or rectangular pipe yourself. Roofers usually use sheet metal for this, but sheet aluminum works well. Four separate parts are made of metal - two side, front and back.

The metal strips are bent so that one part fits onto the pipe, and the second is attached to the sheathing. In a brick chimney, in the upper part of the apron, an edge is made, which is inserted into a special groove and coated with sealant. To prevent water flowing down the apron from getting onto the sheathing and insulation pie, a sheet of metal of large width is placed under the front part of the apron, with curved sides along the edges. It goes under the roofing material and is called a “tie.”

If metal tiles are used on the roof, then an apron is made from a smooth sheet of the same color, the upper edge of which is tucked under the row of roofing material located above so that water flows onto the apron and does not flow under it. If the pipe comes out close to the ridge, you can either tuck it under the ridge itself, or bend it to the other side.

There is one important nuance: if the width of the brick chimney is more than 80 cm (its size is perpendicular to the rafters), you need to make a slope - a small gable roof located higher. It removes sediment, reducing the likelihood of leakage. But such a width of chimneys in a bathhouse is the exception rather than the rule.

Passage of a round pipe through the roof

Modern round chimneys in bathhouses are common. Occasionally you can still see on the roofs of the bathhouses asbestos pipes, even less often - a monopipe without thermal insulation.

A simple single wall, which is exposed through the roof, carries a very high probability of a fire. Therefore, using this option is extremely undesirable.

Modern round pipes are usually sandwich pipes

The video below shows an option for sealing a pipe when installed on a metal tile roof.

If metal tiles are used as a roofing material, then manufacturers often offer roofing passages. They are made from a sheet of the same color and connected to a special cap through which the pipe passes.

It is easy and simple to seal a round pipe on the roof if you use a factory penetration. It consists of an aluminum flange to which an elastic part made of rubber or silicone is attached.

Factory-made penetrations are the easiest option for sealing the junction of the pipe and the roof

They come in different sizes and have different slope angles. You can choose it for any diameter, roof type and installation location. The penetration flange is coated with a composition similar to the composition of the corrugated part; there are grooves along the edges into which they are filled with sealant. One of the penetrations, “Master Flash,” has 11 sizes that cover diameters from 3 to 660 millimeters.

Walkthrough "Master Flash" MASTER FLASH

When installing such a penetration, part of the corrugation is cut off in accordance with the required diameter. Then it is put on the pipe. The rubber must move with force to ensure a tight fit. Since the hole is about 20% smaller than the diameter of the pipe, you have to pull hard. To make less effort, you can lubricate both with soapy water.

After the corrugation is pulled to the desired location, the flange is given the required shape - the material is plastic and you can use a hammer, but you need to work carefully.

Then the grooves located on the inside are filled with sealant, the edges are pressed against the roofing material and secured (self-tapping screws are included in the kit). If roofing material not made of iron, self-tapping screws do not fit. You need to use either long screws that will reach the sheathing, or dowels for the floor slabs.

There are quite a few options for factory-made penetrations, and there are detachable models. They are used when there are thickenings on the pipe or when they have to be mounted on an already assembled chimney of great height. In this version, the kit includes clamps that connect the parts of the passage to each other. The rest of the installation is similar.

The video shows how to seal a penetration through a regular slate roof using a MASTER FLASH corner penetration.

Roof sealants

In order to seal the joints of different parts of the bathhouse pipe passage through the roof, you need to use not just a roofing sealant, but always a heat-resistant sealant. It is advisable to use a neutral silicone heat-resistant sealant.

If Master Flash is installed on a metal roof (metal tiles or metal profiles), then it is necessary to use silicone sealant that does not contain vinegar (non-acetic sealant). This is necessary so that it does not enter into a chemical reaction with the metal and does not destroy it.

Roofing silicone sealant retains its properties in the range from -50 ° C to +300 ° C, which is sufficient for all weather conditions and is quite suitable for sealing a chimney pipe.

But you need to remember that the surface to be treated must be clean and dry. The time for complete hardening is indicated on the packaging, usually 24 hours.

Fire safety precautions when using MASTER FLASH

MASTER FLASH made of silicone can withstand temperatures up to +300 degrees Celsius. This is quite enough to seal a sandwich pipe and, in many cases, a chimney made of asbestos-cement pipe.

As for the metal mono-pipe, in these cases it is possible to use MASTER FLASH in cases where the length of the chimney from the stove to the passage through the roof is at least 3 meters. As a rule, in this situation the temperatures will not be critical, but if not, then thermal insulation of the area that passes through the roofing pie is necessary.

Before reaching the roof, the pipe also passes through the ceiling. It’s not difficult to do the ceiling cutting correctly: there are factory-made feed-through units, but you can do without them.

When designing wooden house It is important to consider how it will be heated. There are no problems when connecting to a centralized heating system. But if you decide to design a more economical autonomous method of heating rooms (boiler, stove), then you need to think about how to remove combustion products from the room. The main problem here is how to install a chimney through a wall in a private wooden house. To prevent unpleasant consequences, you must follow the recommendations for fire safety when designing and installing with your own hands.

Methods for making chimneys

Installation of the system through which combustion products are removed can be made from the following materials:

brick;
ceramics;
metal.

Types of external chimneys

A chimney in a wooden house made of brick is a solution that is now practically not used. The use is justified, for example, in the restoration process, when it is necessary to recreate the original appearance of a house that is of historical value.

Ceramic products are a more modern solution. It is a structure made of special chimney bricks, insulation and an internal ceramic pipe. Their installation ensures the smoothness of the inner walls and reduces the deposition of soot on the inner surface of the pipe.

A metal chimney is a composite pipe consisting of two shells with insulation laid between them. Each type of structure has its own installation and design requirements. Therefore, without a detailed consideration of each individually, it is difficult to understand the technology of the device through the wall.

Ceramic chimneys

When manufacturing an internal chimney, the following requirements are imposed on it:

Ceramic pipe installation

the minimum distance from the chimney to the load-bearing beams, if laying asbestos sheets in two layers between the pipe and the ceiling is provided - 250 mm, without laying asbestos - 380 mm.
if there is asbestos insulation, the distance from the pipe to the wooden wall is taken to be 250 mm or more; if insulation is not provided, the distance is taken to be at least 380 mm.
when using mineral wool for insulation, the distance from the pipe to the rafters is taken to be at least 130 mm;
when using flammable materials - 260 mm;
For roofing in places of contact with the pipe, materials resistant to high temperatures should be used (steel, ceramic tiles, slate). If materials such as flexible bitumen shingles are used, it is necessary to prevent their contact with the pipe. The distance from the bitumen coating to the chimney in plan should be at least 50 cm.

All the requirements described above are relevant for the manufacture of an internal chimney, but sometimes it is better to choose an external outlet. It avoids complications and increases the safety of the structure, since combustion products cannot enter the room.

Combustion products are immediately removed to the outside

This installation is only suitable if the boiler is located directly on an external wall. The design will not allow for an extended horizontal section. The advantages of using include attractive appearance building. This option is best suited for boilers running on liquid and gaseous fuels. The disadvantage of the design will be the increased formation of condensation, which leads to the deposition of substances on the walls that destroy the pipe.

The external chimney is made in the same way as the internal one, but insulation of its walls in contact with cold air should be provided. The thickness of the thermal insulation is up to 10 cm and is assigned depending on the climatic characteristics of the area. It is important that in most cases the pipe will still pass through the roofing, so it is worth following the recommendations for internal connections. A hole is provided in the lower part for inspection and cleaning, and a drip is installed. Under the brick pipe you will have to make a separate foundation or a support ledge for the house.

It is worth considering the following masonry requirements:

providing dressing;
production of ceramic solid bricks using lime (cement-lime) mortar inside the house;
after exiting through the roof, the masonry is carried out using cement mortar;
the thickness of the seams should not exceed 10 mm;
Plastering the inner surface of the pipe is prohibited.

Metal chimneys

Here, during installation, in addition to taking into account the distance to protect the wall or ceiling, different thicknesses of the inner wall are adopted for heating devices from which combustion products are removed:

Smoke removal system through a sandwich pipe

boilers using gas, diesel fuel, pellets – 0.5 mm;
fireplaces and stoves – 0.8 mm;
coal boilers -1.0 mm.

The wall is made of stainless steel. An additional advantage of such a chimney is that it comes complete with elements in order to allow the chimney to pass through wooden floor, roof or wall.

Installation through a wall fence eliminates the need to go through the ceiling and roof. This method increases the safety of the system, since the pipe is located outside and combustion products cannot enter the room. Ready-made parts are used to pass the metal pipe through the wall. At the same time, it is important to remember that a horizontal section appears and it is necessary to provide a sliding seal that will not damage the chimney during shrinkage of wooden structures.

Installation through an external wall metal pipes- the simplest option for making a chimney with your own hands. This method allows you to change the direction of the pipes without difficulty. The work is carried out in the following order:

Marking the laying route, determining the exit point through the wall fence. Making a hole according to the dimensions of the chimney.
Fixing the inside of the pipe, passing through a hole in the wall, insulation.
Changing the direction of the chimney at an angle of 90 degrees using a special tee with a cleaning valve, which provides the possibility of inspection and cleaning. The device is installed at some distance from the wall.
Increase the height of the pipe. If direction changes are required, additional tees are required. The chimney is fixed to the wall using special fasteners located every 2 meters.

Pipe thermal insulation

To bring the pipe outside with your own hands, it is necessary to provide for its insulation. The situation here is similar to the insulation of a chimney when passing through a cold attic and after exiting to the roof. Installation of thermal insulation can be carried out using various materials.

Thermal insulation using mineral wool

Mineral wool is easy to install and does not burn. There are special elements on the market for pipe insulation that will greatly facilitate the work. If you want to save money, it is better to choose glass wool in mats (rolls). Characterized by high efficiency. You can choose a material that is suitable in thickness and density.

Basalt pressed cardboard is a durable material that can withstand up to 2000 heating and cooling cycles. Basalt fiber does not burn. Positive aspects will also be low cost and the ability to withstand high temperatures.

Asbestos fabric is common in our country to meet fire regulations, but is not used in Western countries due to its carcinogen content. When used in external chimneys, human contact with asbestos is minimal, so the material does not pose a danger.

Installation of insulation for brick pipes is carried out in the same way as thermal insulation of external walls. For metal chimneys there are two options. The first is the simplest - buying sandwich type pipes. The design already includes insulation and consists of an outer and inner pipe. The second option is to make an outer casing from stainless steel and lay effective insulation between it and the chimney. The easiest way in this case is to use mineral wool. The thickness of the thermal insulation is taken to be no more than 10 cm.

Installation of an external chimney is especially important when installing a boiler in an already used house, since it allows you not to affect the ceilings and roof.

One of the most important issues here is sufficient insulation of the pipe.

There are times when it is not possible to remove the chimney pipe in the usual way - through the roof, and then you have to install a chimney through the wall. In order for the functioning of the chimney to be as efficient as possible, it is necessary to select the most suitable pipes for the boiler, carry out high-quality installation of the chimney, and, if necessary, insulate it.

Brick chimneys, which were once very popular, are losing their relevance and are being used more and more today. These products are easy to install and inexpensive. Their surface is smooth; these pipes do not need to be insulated.

You can find out the price and buy heating equipment and related products from us. Write, call and come to one of the stores in your city. Delivery throughout the Russian Federation and CIS countries.

Advantages and disadvantages of a chimney through the wall

By venting the chimney through the wall you will get the following advantages:

the chimney pipe almost completely protrudes onto the street, rather than passing through the entire house;
You can install the product both at the construction stage and after the house has been built, for example, during the installation of a heating system;
there is no need to make holes in the ceilings when the boiler is located on the ground floor of a building several floors high;
the integrity of the roof is maintained;
When assembling and installing a chimney through a wall, there will not be any particular difficulties.

Chimney through a wall in a wooden house

Despite the large number of advantages, the design also has disadvantages and they must be taken into account:

A prerequisite for installing a chimney through a wall is.
Inside or outside the house, you will need to allocate a fairly large horizontal area for such a chimney.
According to experts, the external gas exhaust pipe has low productivity.
It is unlikely that the product will fit the design of the room, so you will have to get confused here.

Installation of a chimney through the wall

Installation

Before proceeding directly to installation, it is necessary to carry out a number of preparatory measures, including calculating the boiler power, determining the optimal diameter of the pipes, as well as the thickness of the heat-insulating layer.

It is very important that the diameter of the inner pipe is not less than the diameter of the pipe on the boiler. The boiler is selected based on the criterion of the heated volume, and only after that the components for the chimney are selected for it.

If the diameter of the pipe is larger than the diameter of the pipe, then an adapter must be placed in the middle of them.

When installing pipes of a certain diameter, it is necessary to take into account the power indicators of the heating device. So, for boilers with a power of up to 3.5 kW, the diameter of the pipes should be 8 cm, for equipment with a power of 3.5 to 5.2 kW, pipes with a diameter of 9-11 cm are needed, for products with a power of 5.2 kW - The diameter of the pipes must be greater than 11 cm.

It is also necessary to take into account the thickness thermal insulation layer. When working temperature conditions 250°C, like a gas boiler, the basalt layer should be at least 3 cm.

For wood and liquid fuel boilers with an operating temperature of 400°C - already 5 cm.

Installation of a chimney

There are two ways to exit the chimney through the wall:

The pipes inside the room must be raised a short distance from the ceiling, where they are brought outside.
From the boiler nozzle, pipes lead immediately through the wall in a horizontal position. The advantage of this method is that fewer bends are formed, and this has a positive effect on the performance of the chimney.

Assembling a sandwich pipe when installing the vertical part of a chimney can be done in two variations - “smoke” or “condensate”.

Assembling a chimney “for smoke” and “for condensate”

When installing a pipe along the smoke, gas and combustion products move upward, but here you will have to deal with such a negative aspect as the formation of condensation that accumulates in the pipe. This method has gained popularity in cases where the chimney is assembled through the roof. Here, almost the entire pipe is located in the house, and not much condensate is formed.

Condensate installation is an installation method in which the pipe with its expanded end is directed upward.

With this assembly, the condensate simply flows through the pipe into the glass. The disadvantage of this method is that smoke can leak out if the areas at the joints are not properly sealed.

Condensate collection is used when a chimney passes through a wall: in this case, the condensate is directed into a glass, and the smoke comes out of the joints on the street. This will not affect the well-being and health of the residents of the house.

Basic installation rules

In order for the functioning of the chimney to be as efficient as possible, during the installation process it is necessary to follow a number of rules and recommendations on which not only the performance of the installation will depend, but also safety.

Basic requirements for installing a chimney through a wall:

It is important that the pipe rises above the ridge by at least 50 cm, and preferably 100 cm. The traction force depends on this. The traction force directly depends on this.
The total length of the vertical part of the pipe should ideally be 5-10 meters; if the pipe is located at a greater distance, the draft will be too strong and the fuel will burn out very quickly. If the pipe length is not enough, then the draft, on the contrary, will be weak, and, accordingly, the operation of the heating device will not be very efficient.
To prevent the heat insulator from melting, the first segment of the chimney must consist of a single-circuit pipe. It is necessary to make a joint with a sandwich pipe, while maintaining a distance sufficient to ensure that the fastener does not overheat during operation.
The boiler must be placed on a metal sheet. Insulating the wall from the boiler is done in the same way. For wooden houses, according to SNiP, it is necessary that the boiler and chimney be located at a distance of at least 45 cm from building elements that can catch fire, and 25 cm from parts made of low-flammable materials. To ensure that the outlet hole for the pipe is not too large, the wood must be sheathed with metal, in which case the outlet hole may be 25 cm rather than 45 cm.
A metal box must be placed in the finished hole through which the pipe is passed, without any connections, because if necessary, access to them will be very difficult. The cavities in the wall must be filled with heat-insulating material that is not afraid of burning.
Next, you need to sew up the pipe hole from the outside and inside. A metal sheet is used for this.
Then, using brackets, you need to fix the support platform for the chimney outside the building, and a tee should be placed on the outlet section of the pipe. The bottom of the pipe is removable, it has the shape of a glass and condensate, which is formed during the combustion of fuel, gets into it. Often the glass is equipped with a tap and a drainage hose. Condensation is a toxic substance, so it is better to drain it away from home.
The chimney at the top is also secured using brackets, which are located one from the other at a distance of no more than a meter. To protect against precipitation, a cap is placed on top of the pipe.
To properly seal the joints, they must be coated with heat-resistant sealant, after which the joint area must be tightened with a clamp.

Insulation of external chimney

As already noted, the most best option chimney is the use of a sandwich pipe, which is not only easy to install, it also does not require additional insulation.

If it is used for smoke removal, then you need to install it in a box, where the distance between the walls of the box and the pipe is filled with a basalt heat insulator. You can also use foil or other non-flammable material as insulation, but the top of the pipe must be covered with a dense layer of heat-insulating non-flammable material.

To summarize all of the above, it is worth saying that installing a chimney through a wall is quite simple. If you strictly follow the installation technology, this procedure will not take much time and effort, and the heating device will delight you with its operating efficiency and good traction.

A stove pipe with an exit through the wall is an essential element of any heating apparatus. But not many people think at the construction stage, where it will take place, and how to arrange it correctly. And after building a house, it is not always easy to build a structure for removing smoke. The article will tell you how the pipe should pass through the wall.

When placing a chimney inside a wall, you can hide unnecessary communications; this is a more correct structure, but external installation of the system has many positive aspects:

Higher fire safety. Sometimes the soot accumulated in the pipe ignites, usually at a temperature (+1200ºC). Only ceramics can withstand such heat. If a pipe embedded in a wall heats up to this temperature, a fire is most likely inevitable. Given the same situation with the external structure, the consequences will not be so catastrophic.
No smoke. Over time, the smoke and gas exhaust system becomes unusable and smoke begins to seep through the cracks and then enter the room, which can be avoided by placing the channel outside.
Useful space is saved. When the chimney is located inside, it will occupy some living space.
Installation can be carried out after completion of construction.
There is no need to interfere with the integrity of the roof covering.
To improve traction, it is possible to extend the pipe to a greater height.

There are also a number of disadvantages of such a structure.

These include:

Quite a high windage at a considerable height.
The need to use additional fastening material.
It is necessary to properly insulate the pipes.
High heat loss.
Sometimes the type of chimney does not match the style of the building.

Chimney installation rules

It is necessary to remove combustion products from the furnace for several reasons.

Chief among them:

Life and health of people.
Efficient operation of the furnace or boiler.

Advice: It is necessary to properly organize the removal of carbon monoxide; poisoning with it can even lead to death.

Any fuel does not burn without access to oxygen, which enters through the smoke channel.

There are several rules for installing chimneys:

There should be no communications where the channel passes.
The areas where the chimney passes through the wall are covered with a protective casing or plastered after first filling the space with heat-insulating material.
The chimney fixation is installed in increments of 60 millimeters.
This design usually uses dual-circuit systems that are better protected from mechanical stress. In this case, it is necessary to install a valve that allows you to adjust the draft.

What is needed to install an external chimney

To install a chimney you will need:

Bulgarian.
Electric drill with a set of drills of different diameters.
Riveter.
The sealant is heat-resistant.
Aluminum tape.
Clamps for fixing the outlet pipe.
Corners.

The main elements for installing an external chimney are shown in the photo.

An external smoke exhaust pipe is installed for:

The smoke exhaust structure is an element that is characterized by an increased fire hazard, so solving the problem of how to make a hole in the roof for a pipe should be approached responsibly. It is also important to protect the roof from moisture penetration, otherwise its service life will be significantly reduced.

Roofs made of corrugated sheets deservedly enjoy the trust of owners of private houses, since they have:

a light weight;
long operational period;
appearance reminiscent of the relief of ceramic tiles.

Corrugated sheets are thin, durable and corrosion-resistant sheets of metal that are coated with paint and pressed into the required shape. After installing stoves or heating boilers, it is necessary to make a passage for the chimney through the roof structure.

Every homeowner should understand how to route a pipe through a corrugated roof. Even if this work is done by professionals, it won’t hurt to check the result.

Types of chimney structures

The chimney pipe serves to remove smoke and combustion products into the atmosphere. It is a hollow cylinder.

To organize this process, stove makers build:

Brick chimneys. The smoke exhaust system is created from heat-resistant bricks, which are produced using a special technology specifically for the installation of stoves. The pipe has a rectangular or square cross-section. This method of getting rid of smoke is expensive, but it is more durable and safe. Its main disadvantage is the porous inner surface - for this reason, large amounts of soot and dust settle on it. If the pipe is not regularly cleaned, layers of soot can completely or partially clog it, reducing draft force and increasing the risk of fire. The process of how to remove a chimney through a roof from corrugated sheets is complex and therefore it is better not to do this work with your own hands - it should be done by experienced stove-makers.
Metal chimney systems. To assemble a structure of the required configuration, you need to purchase stainless steel pipes with the addition of zinc or molybdenum. Then insert the segments one into the other - you will need straight pipe products, clamps and bends. Thanks to the presence of a slippery inner surface, soot cannot accumulate, which means that smoke can freely move upward, outside the house. The disadvantage of this method is that metal does not retain heat well enough compared to brick, as a result of which condensation collects on it, since there is a temperature difference between the pipe and the air outside. The metal chimney structure can be easily brought to the roof, because it consists of separate elements.

Chimney outlet location - how to cut a hole

Before cutting a hole for a pipe in a profiled sheet, you should choose a convenient place for this. The decisive factor in this case is the location of the furnace unit.

According to professionals, the chimney should be placed strictly vertically, taking into account some nuances:

It is advisable to make a hole for the exit of the chimney pipe at the highest point of the roof, and therefore closer to the ridge. The optimal distance from it to the chimney is considered to be 50–80 centimeters.
Before you make a hole for the pipe in the corrugated sheet, you should make sure that it does not fall on the elements of the rafter system. To bypass them, bends are used, with the help of which a rotation of 45 or 90 degrees is set.
The length of the chimney segments is selected so that the joints between them are below or above the intersection of the roof and ceilings, otherwise a high-quality connection will not work.
It will be possible to achieve the required draft level if the height of the chimney structure exceeds this parameter at the ridge by 1–1.5 meters.
To ensure that the hatch location is correct, mark it on the roof with a marker and check the temperature at the end of the day. The pipe must remain in the cold zone at all times.

Preparatory measures for venting the chimney through the roof

There is the following technology for making a hole in a profiled sheet for a pipe:

First, use a permanent marker to mark the location where it will be placed on the roof.
The cross-sectional size of the chimney elements is selected taking into account the recommendations of the heating unit manufacturer. The thicker and higher the pipe, the easier the smoke comes out of the stove. The main thing is that there is no gap between the elements when connecting.
Cut a hole with a grinder with a thin blade for metal work, stepping back a few centimeters inward from the drawn line. The corrugated sheeting must be cut carefully and slowly so that the edge of the cut is without jagged edges.
Short cuts are made in the corners of the hole so that the edges of the corrugated sheet are bent upward.
A similar passage is made in the ceiling. Then a metal box is installed to connect the pipe to the rafters. The chimney is laid through a hole inside the box.
Hydro- and vapor barrier material, as well as insulation, are removed from the exit cut out in the roof.

For cold areas, where the thickness of the thermal insulation material is more than 15 centimeters, you need to use sandwich pipes that have two layers of metal and a layer of insulation between them.

How to remove a pipe on a roof from corrugated sheets

When preparation for how to remove the chimney pipe through the corrugated sheeting has been completed, it should be correctly connected and the chimney put into operation, for which:

You need to insert a pipe through the hole in the box and direct it towards the roof, and the edges waterproofing material Secure with adhesive tape to the surface of the chimney.
Expanded clay is densely poured into the box or mineral wool is used.
A rubber or silicone seal is placed on the pipe to protect the outlet from water seepage. To improve waterproofing, glue the seal to the corrugated sheet using a fire-resistant sealant.
The smoke exhaust structure is raised in segments to the required height, while the joints are tightened with galvanized steel clamps.
Install an outer apron, the color of the roofing, which will cover the box and rubber seal.

When installing a chimney pipe onto the roof, you must remember that negligence in such work can result in a fire and material losses.