Proper installation of a passage through the roof for a stove or ventilation pipe ensures not only the safety of the stove, pipe and building, but is also the key to the safety of residents. At first glance, designing a roof penetration for a chimney seems to be a simple matter. However, here it will be necessary to ensure impeccable hydro- and thermal insulation of the passage unit, choose the best place to bring the pipe to the roof, and not destroy the aesthetic design of the building.
There is an opinion that the efficiency and safety of an individual heating system depends on the design of the stove and the skill of the stove maker. Few people think that complete combustion of fuel depends more on the chimney and traction force. And only specialists know how important it is to install a high-quality passage through the roof.
When building a furnace, the main attention is paid to the temperature stability of the materials. But the fire-resistant brick of the chimney and the mineral insulation of the sandwich pipe are defenseless against systematic moisture.
Poor design of the pipe outlet to the roof entails serious consequences affecting the operation of the chimney. Violation of the standards for thermal insulation of pipes from flammable roofing materials and attic floors can lead to:
- to fire in places where the pipe and combustible materials of the house structure come into contact;
- to the formation of a large amount of condensate in the pipe, which will lead to its rapid destruction;
- to the formation of a thick soot deposit on the inner wall of the chimney and a decrease in its working clearance;
- to a decrease in stove draft and the formation of carbon monoxide, which is dangerous to human life.
Poor quality waterproofing of a roof penetration assembly threatens:
- penetration of atmospheric moisture into the attic, which provokes the formation of fungus and mold;
- getting the rafters wet leads to the initiation of wood rotting processes, no matter how well it is treated with an antiseptic;
- destruction of the brickwork of the chimney;
- increased corrosion of the metal pipe;
- by getting the thermal insulation (mineral wool) wet, after which this material becomes completely unusable and loses its thermal insulation properties.
Roofing penetrations are special devices that provide ventilation shafts, pipes, antennas, flagpoles and other similar things to the roof surface. The main task of these devices is to prevent precipitation from penetrating into the under-roof space. In this case, the devices must not only be sufficiently sealed, but also prevent condensation from accumulating on the inner surface of the roof. In general, to pass through the roof, a special pipe is inserted into the hole made in it, which, in turn, is placed in a glass. Types and shapes, as well as materials of manufacture, vary.
The types of roofing penetrations depend primarily on the purpose of the devices that are brought to the surface of the roofing covering. These could be antennas, flagpoles or pipes. Another type is intended for ventilation openings, and for interior spaces, sewerage or under-roof ventilation they are made of their own type.
A separate type of penetration for access hatches to the roof, and even more special arrangement, requires passages through the roof for stove and fireplace pipes. The cross-section of the penetration units can also be very different, this depends primarily on the type of roof and the design features of the roof.
In addition to the cross-sectional dimensions, the roof penetration can have different shapes: round, oval, rectangular or square. The choice of type of penetration depends on the following parameters of the roofing covering:
- The material from which the roof is made.
- The angle of inclination of the roof relative to the ridge, as well as the distance from the hole to the ridge and slope.
- The size and area of the roof covering.
- Availability and area of attic space.
- Parameters of the communication to which the penetration will be connected.
If at least one of these parameters is not taken into account, inevitable problems will arise either during operation or during the installation process.
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Design features of penetrations
To create penetrations, a metal tube with a thickness of 1 to 3 mm, coated with a special heat-resistant enamel, is inserted into the hole made in the roof. It is placed in a special glass, which can be either metal or reinforced concrete. In the latter case, the penetration is attached to it using pre-concrete anchors.
If the basis of the penetration is a reinforced concrete floor, a hole for it should be provided at the stage of creating the project. Then it is done at the stage of casting the floor, which helps to avoid such a costly and time-consuming process as drilling a finished concrete slab. If a hole violates the strength of a hollow concrete slab, it is customary to make the area with the hole monolithic.
Penetrations through the roof are divided according to their design features into several options according to the method of adjusting the air flows passing through them. Valveless penetrations are the simplest of them. They cannot limit the flow in any way and always operate in a constant mode. Other penetrations are equipped with a simple mechanical valve that is manually adjusted.
This allows you to regulate the ventilation flow until it is completely blocked. The third option is equipped with an electronic valve that can be controlled remotely. These valves are installed on complex controlled ventilation systems. However, it is worth remembering that the valve cannot be placed below the ring coupling, as this will inevitably lead to the accumulation of condensate in it.
Nowadays, along with specialized roof penetration units, a device called a universal penetration has appeared. It is made in the form of a stepped pyramid made of silicone, the expanded part of which is attached to a rigid flange made of polymer material or aluminum. Such systems are sealed, resistant to gusts of wind and easy to install. Most often they are used to connect lighting fixtures and antennas to the roof. The advantages of such a system are that it can be installed on a roof made of any material and with any slope angle. The silicone used to make the pyramid can withstand temperature changes from 74° below zero to 260° above zero.
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Installation and its methods
First you need to select a seal. If the penetration is round, the diameter of the seal should be approximately 20% smaller than the diameter of the pipe passing through it. This will guarantee the tightness of the connection. Excess sealant is simply cut off with a knife or scissors. After this, the sealant is pulled onto the pipe; to facilitate the process, its surface must be lubricated with liquid soap, then the sealant is pressed tightly against the surface of the roofing. A sealant is applied under the surface of the flange, and the flange itself is screwed with self-tapping screws, the distance between which should be no more than 3.5 cm.
The types of penetrations for chimneys are particularly distinguished. The distinctive features of their installation are determined, first of all, by fire safety requirements. The gases released through such ventilation devices, formed during the combustion of fuel, have a fairly high temperature. It is transferred to the surface of the pipe, which can lead to fire in roofing materials. This is especially dangerous for roofs with wooden supporting structures.
In order to avoid such a danger, the chimney placed in the penetration is covered with thermal insulation, in which asbestos is most often used.
In addition, a specially regulated gap is left between the surface of the pipe and the under-roofing materials, which are especially flammable. It is recommended that the structural element of the penetration itself, at the point of passage through the layers of insulation and waterproofing, be mounted inside a special casing, which is easy to assemble from galvanized sheet. The space between it and the penetration is filled with mineral wool or other non-combustible material.
If the roofing penetration is correctly selected and installed correctly, the penetration of moisture under the roofing will be reliably blocked.
And this is the main condition for both the reliability of the roof and its long-term operation. It is roofing penetrations that allow a variety of devices to be brought to the roof surface without causing damage to the protective properties of the roof. Some of their varieties can be installed with your own hands, especially if the angle of the roof slope is small. But most often, it is advisable to entrust the methods of their installation to specialists with sufficient qualifications and knowledge.
The house requires appropriate infrastructure support. In particular, the chimney and ventilation system provide for the organization of exit through the roof. Previously, this possibility was provided with the help of special openings, which, after installation, were properly sealed with sealing means. Nowadays, manufacturers of engineering equipment offer more reliable solutions, including roof penetrations, which are installed directly in the roof structure.
What problems does roof penetration solve?
To determine the purpose of such additions, it is worth turning to the function of the roof itself. It must protect the house from precipitation and other external influences, while maintaining optimal heat, noise and waterproofing performance. The presence of holes and cracks in the roof is not allowed, therefore communications passing through the roof must be carefully sealed at points of contact with the finishing material and the load-bearing structure. In turn, roof penetration initially creates a minimum of free space, which is not used for engineering purposes. At the same time, it promotes the effective removal of smoke and air, protecting the roof materials from thermal effects. Ventilation systems, by the way, often lead to the formation of condensation in places where air flows are discharged. Special units for such channels prevent the processes of drip formation, removing moisture outside.
Types of penetrations
There are several classifications of roof penetrations. First of all, you should focus on a specific purpose. Manufacturers produce special models for organizing the passage of antennas, pipes, and chimneys. Whether a unit belongs to a specific group is determined by both the design and the material of manufacture. So, not all types of penetrations can be adjacent to a stone chimney. Also, plastic devices are not compatible with some types of metal pipes. The nodes also differ in shape. The most widespread are round and square sections, but in some cases only an angular roof penetration can help, which has its own disadvantages, but also advantages. Structures with such a cross-section, for example, are advisable to use in cramped conditions or when laying non-standard coverings.
Ways to control penetrations
All penetrations provide the ability to remove air through the roof. This creates a channel that can also facilitate the passage of cold air into the attic space. In the simplest models, this nuance is not taken into account in any way and the units constantly ensure uncontrolled passage of air. More advanced roof penetrations also provide the ability to control the flow using a valve. Inexpensive entry-level systems provide for manual control of gate valves, but you can also find many automated models that can be controlled remotely. Moreover, devices with intelligent control systems that control valves based on current weather conditions are becoming increasingly popular.
Universal penetration
Assemblies of this type are, in essence, insulating tubes that fit seamlessly into the opening thanks to the silicone shell. However, in such a configuration additional protection should be provided around the passage part. The main task performed by such penetrations is to mechanically protect the pipeline or chimney from damage. In addition to the external silicone coating, the unit has a metal layer and thermal insulation. These are the optimal roof penetrations for round pipes of ventilation systems, since they can be adjusted to any bend. What is also important is that, thanks to the stepped structure, such devices allow you to direct the channel in one direction or another as needed. Pipe orientation is also possible in traditional penetrations, but changing the direction in such cases requires a lot of effort.
Installation of penetration
The installation technique largely depends on the specific penetration option. But in most cases, installation involves three stages. First of all, a base is arranged on which the knot will stand. This can be a concrete or metal glass that will support the structure like a foundation. The second stage involves directly passing the communication pipe through the assembly, as well as performing crimping actions. The penetration ends with mechanical fixation on the roof surface. Self-tapping screws, screws and nails are used for this. The specific method of fastening depends on the finishing material of the roof.
Accessories for roof penetrations
Additional elements that increase the reliability, functionality and durability of the roofing assembly include crimping accessories, sealing and heat-insulating materials. For example, using a coating of silicone or polymer elastic fabrics, you can provide an isolated area around the installation site of the structure. Thanks to this reinforcement, the roof penetration will last longer and will not allow moisture and debris to pass into the opening. In some cases, it is advisable to use elements of mechanical reinforcement. Such solutions are used for the purpose of insurance in case of windy weather.
How to choose the right penetration?
Initially, you should focus on the dimensional parameters. The larger the ventilation opening or chimney, the thicker the walls of the unit should be. In addition, the insulating qualities of the penetration are taken into account. For example, if plastic can provide tightness, then in terms of thermal insulation it will only be effective if it is additionally reinforced. On the other hand, metal roofing penetrations for chimneys must necessarily have an anti-corrosion coating. In fact, due to the risk of developing negative rusting processes, experts do not recommend using such models at all.
Conclusion
Issues of additional roof equipment should be considered at the roof design stage. In the design itself, it is possible to provide technical conditions for both the passage of the communication channel and the installation of the unit. For example, a wide roof penetration for ventilation may require additional fastening in the rafter area. But this possibility is not always allowed in ready-made structures. Also, you should not save money and refuse modern offers from manufacturers of penetrations. The same automated models will eliminate a lot of hassle during the operation of the installation. For example, the latest versions of such units allow you to programmatically configure the valve control - so that it will automatically select operating modes depending on the season and temperature amplitudes. However, simple installations without valves should not be ruled out if operation is planned in a warm region.
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 of the 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: the 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 is 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 the 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 asbestos pipes on the roofs of bathhouses, and even more rarely - a single pipe without thermal insulation.
A simple single wall, which is discharged 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 the roofing material is not iron, self-tapping screws are not suitable. 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.
As you know, penetration through the roof looks like a passage unit, which is used to install steel ventilation shafts at their locations in roof coverings of structures of various designs and purposes.
Next we will talk about what types of roofing penetrations there are, as well as the features of their design and use. Thus, the roof penetration should be located on reinforced concrete glasses. It is fixed by screwing nuts onto the anchor bolts provided in the design. The thermal insulation material is a slab consisting of mineral wool and fiberglass.
A special mechanism that regulates valve control has two functional operating modes:
- "open";
- "closed".
Under no circumstances should the valve driving mechanism be positioned lower than the ring coupling, as this may cause condensation to accumulate in the system.
Typically, roof penetrations are installed in buildings that have one of two types of ventilation systems:
- natural ventilation;
- forced ventilation.
Also, in the process of designing a particular structure, the choice of a particular ventilation system is greatly influenced by a number of factors, which include, for example, humidity levels, the highest and lowest air temperatures, etc.
In this case, roof penetration is calculated by considering two main indicators:
- Roofing angle.
- Interval from penetration to roof ridge.
The passage unit includes a pipe connected to the support flange. This flange performs fastening functions and is used to fix the roof penetration to the reinforced concrete glass. The flange located at the bottom serves to secure valves and air ducts, while the top one is used when a shaft with a circular cross-section is used. To fix the braces located on the roof covering, it is necessary to use special brackets, and clamps should be used for this in the shaft.
Performance properties of roof penetrations
If the roof passage has a manual drive, then it should work stably so that there is no need to switch modes from time to time.
Typically, a manual drive consists of:
- tailor's cloth;
- control mechanism;
- cable;
- counterweight.
The installation of a system element such as a skirt will provide additional protection against water ingress to the roof covering. If necessary, roof penetrations can be equipped with a special element, the purpose of which is to collect condensate. This part can simply be welded to the pipe, and then it will prevent moisture coming from a mixture of gases and air from penetrating under the roof.
There is also a certain number of factors that directly affect whether both a conventional penetration and an angular roof penetration will work normally. According to this series of requirements, you first need to decide on the design of a certain unit in accordance with climatic conditions, and then take into account other options, for example, whether it will be possible to use a sealant for the roofing unit and in what quantity it can be used.
When making roof penetrations, it is customary to take black with a thickness of 1.5 to 2 millimeters as the main material.
Roof passage units can also be mounted using stainless steel, which comes in two categories:
- stainless steel having a thickness of 0.5 millimeters;
- stainless steel having a thickness of 0.8 millimeters.
Currently in production there are 11 options for the size of roof penetrations. However, sometimes manufacturers can create samples that differ from standard diameters and are intended for different systems.
The main purpose of roof penetration is to correctly install the ventilation system on the roof of a certain structure. This significantly improves air circulation and makes operating conditions more comfortable.
Also today there is a wide selection of supply systems, equipped with high-quality sound insulation during installation.
What are roof penetrations made of?
The design of standard units includes two main parts, and those, in turn, consist of external and internal circuits, each of which has a special insulating layer made using basalt fabric, resistant to fire and temperature changes.
Typically, roofing penetrations consist of black steel, which has a thickness of 1 to 3 millimeters and is coated with black enamel, resistant to high temperatures, so that the units can withstand exposure up to 600 degrees. According to some operational standards, as well as the technical characteristics and desires of the developer, stainless steel can also be used as material for penetrations. Its thickness can be from 1 to 2 millimeters.
The production of roof penetrations must be inextricably linked with the following three criteria:
- Roofing angle.
- The thickness of the space under the roof, as well as the roof rafters.
- Materials used as the basis for the construction of the rafter system, the ceiling of the building and the roof itself.
To prevent moisture that appears after precipitation from penetrating through the roof penetration, it is necessary to use special “layouts”, which look like a metal strip equipped with a hole intended for the chimney and a special side flange. The material for the “layout” is usually polyester, and it will be correct to use the color that matches the color of the roof covering. This element is located between the roof ridge and the passage unit, which should be covered by a “layout” on each side.
Installation of roof penetration, detailed video:
- The choice of seal ring is made on the basis of a calculation according to which the diameter of the resulting hole should be approximately 20% smaller than the diameter of the pipe going through the roof.
- The seal itself is pulled directly onto the pipe. If difficulties arise, you can use a soap solution.
- The seal is shaped into the base by pressing it against the roof. Tools can be used to secure the flange edges.
- A special sealant is applied to the space under the flange.
- The flange is fastened with screws, which should be at a distance of 35 millimeters from each other.
This completes the installation of the roof penetration.
This data should be used when bringing ventilation and chimneys to the surface of the roof. It is important to remember that when using roofing penetrations, this can be done not only simply, but also efficiently, moreover, it cannot cause any harm to the roof itself. If desired, any installation information with detailed photos and videos of the entire device process can be easily found on our website.