Variants of the device of ventilation of a warm roof. Roof ventilation. Roof ventilation options. Ventilation roofing tape

Structures of almost all types of roofs, consisting of several layers that form a roofing pie, need ventilation. The passage of air flows through the gaps between the individual layers protects the insulation material from the accumulation of condensed moisture on its surface.

Some developers believe that the protection of the insulation with waterproofing on the one hand and vapor barrier on the other is enough to prevent water from falling on it, and do not care about arranging ventilation ducts, moreover, building codes do not standardize methods for arranging roof ventilation systems. This fairly common mistake leads to a significant deterioration thermal insulation properties insulation, rotting of wooden structures and a reduction in the life of the roof as a whole.

Where does the moisture in the roof come from?

Where can moisture come from in a practically hermetic space? First of all, a certain percentage of moisture is always present in the air, and at high humidity during fogs or rains, as well as in the heated indoor air, it increases significantly. Some amount of moist air passes through the vapor barrier, some through foam concrete or brickwork etc. It is almost impossible to create a vacuum between the layers where air does not penetrate. Water vapor under the influence of temperature difference condenses on cooled surfaces, penetrates into the insulation material, destroys wooden structures. Thus, ventilation of the roof and under-roof space, with rare exceptions, must be organized.

Roof ventilation device

The most common and effective type of roof ventilation is the installation of special ventilation holes in the ridge and under the overhangs of the roof structure. Under the influence of wind and temperature difference, air enters the holes under the overhangs, passes through the ventilation gaps between the insulation and waterproofing and exits through the holes in the ridge. The value of the ventilation gap depends on the parameters of the roof and averages 5 cm, for roofs with a slight slope slope - 8 cm. Such ventilation is natural, that is, it does not require additional equipment for air injection. If the system is done correctly, the airflow will be able to completely pass along the entire roof twice in 1 hour.

There are other ways to arrange ventilation, for example, exhaust holes are made not on the ridge, but on the slopes using special elements. For tiles or other piece roofing materials, special tiles with ventilation holes are produced.

Roof ventilation through skylights

Another option - dormer windows on the slopes. This is one of the oldest methods of ventilation, which in recent times rarely used on its own - only as an addition to ventilation gaps. The fact is that when using such windows, unventilated zones are formed around the windows themselves. For ventilation to be as efficient as possible, you need to make two windows - one opposite the other. Their size is usually 0.8x0.6 m. Windows are made during installation truss system, their frame is attached to the rafters with the help of racks. The canopy above them and the "walls" are most often covered with roofing material, the same as the entire roof. "Walls" can also be sheathed with plastic clapboard. After manufacturing is completed, the opening is filled with a window box or ventilation grill. When choosing the size and location of the dormer windows, you need to take into account the design features of the roof and its appearance, you do not need to install them too close to the cornices or ridges. The distance between the dormer windows on one slope should not be less than 1 m, the total number of windows should be reduced to an optimal minimum, because they greatly complicate the process of installing the truss system.

Other ventilation options

As an option, the organization of a forced ventilation system using turbines or deflectors can also be considered. They are mounted in such a way that it is possible to draw air directly from the under-roof space.

If the roof design provides for a small angle of inclination of the slopes, care must be taken to protect the ventilation openings from snow drifts. Usually in these cases, instead of exhaust holes, pipes are used, the length of which is chosen above the snow layer.

The method of ventilation also depends on the purpose of the under-roof space. For non-residential attics there are quite enough holes along the overhangs and the ridge, as well as gable windows. For attic ventilation, aerators are often additionally used - elements that increase air exchange.

roof insulation ventilation

How does the ventilation of the insulation layer take place and is it really important to keep the insulation dry?

First, a few words about the thermal insulation of the roof. The heat-insulating layer is the thickest in the roofing pie; the total thickness of the roof, as well as its energy-saving properties, largely depends on it. High-quality insulation allows you to create and maintain the most comfortable microclimate inside the house, regardless of weather conditions. Depending on the climatic area of building, the thickness of the insulation can vary significantly. On average, it can vary between 10-15 cm.

Almost all heaters absorb moisture, which significantly impairs their thermal insulation capabilities, since water, which conducts heat well, pushes air out. Even with 5% moisture, the insulation loses 50% of its properties. Ideally, the heat-insulating layer is protected on both sides by hydro- and vapor barriers, as mentioned above, but even they are not able to completely isolate the insulation from steam and its condensation. That is why the surface of the insulation must be constantly dried by a stream of air, preventing drops of moisture from settling on its surface. To do this, there must be a gap between the insulation and the waterproofing layer, which is formed due to the boards of the counter-lattice. Air enters the gap through holes in the overhangs of the cornices and exits through holes in the ridge. If the slopes have large area or a slight slope, for more effective ventilation, you can use deflectors to create forced draft.

What are vents and why are they needed?

Ventilation openings through which air enters the ventilation gaps and exits are called vents. As you might guess, the vents are cornice and ridge, depending on their location. Eaves are best done along all eaves. At their core, these are gaps between the roof and the wall, the width of which is about 2-2.5 cm. There are also point vents, which are not a continuous gap along the eaves, but separate holes. The diameter of such holes depends on the slope of the slope: at an inclination of more than 15 degrees, it is 10 mm, less than 15 degrees - 25 mm. All vents must be closed: point ones with gratings, and slotted ones with nets or slats (soffits).

Ridge vents are also slotted (gap width 5 cm) and point. Spot blows are made at a distance of 6-8 m from each other. Piece roofing materials have special additional elements with ready-made ventilation holes. For example, when laying natural tiles the second row from the ridge is laid out with special ridge tiles.

Elements of the ventilation system of the roof can usually be purchased together with the roofing material. Many large manufacturers produce such additional elements for all types of coatings. They are combined with the color, texture, material of the roof and, during installation, fit perfectly into general form. Ventilation elements include ridge and cornice air vents, exhaust openings, through channels.

Exhaust openings located closer to the ridge are of several types: in the form of a gable lattice on the gables, a roof outlet on the slopes. Also, the hood can be placed on the ridge itself in the form of an aerator. For effective ventilation, the area of the exhaust openings should exceed the area of the supply openings by 10-15%, which will increase the draft. The total area of the vents is selected at the rate of 1/300-1/500 of the area of the under-roof space. In other words, for 200 m2 of attic area, you need to provide the amount of air with total area not less than 40 cm2.

Roof aerators

One of the types of exhaust products is an aerator. In principle, this is the same hole for removing air and moisture, only slightly “cultivated”. In appearance, aerators are pipes covered with umbrellas installed near the ridge. The principle of their operation does not differ from conventional air vents: air also enters the under-roof space through the cornice air vents and rises up under the influence of pressure and temperature differences. Aerators are continuous and point, and the latter - pitched and ridge. Point aerators are used for local ventilation of individual sections of the attic. More modern models are mushroom-shaped and have built-in fans to create additional traction in the system.

Continuous aerators provide ventilation for the entire under-roof space and are placed along the entire ridge. Usually these are plates with exhaust holes hidden by roofing material. Such aerators are almost invisible from the outside.

The choice of type of aerator depends on the type of roof, roofing material, the purpose of the under-roof space. There are aerators for flat roofs, natural, bituminous tiles, metal tiles, as well as universal models. They, like other ventilation elements, are often sold together with roofing materials.

Why do you need roof penetrations?

Pass-through elements or simply penetrations allow you to install fans and ventilation ducts on any roof, while ensuring the tightness of the unit due to seals. Pass-through elements are selected depending on the roofing material, the roof structure and the diameter of the ventilation passage. Manufacturers of roofing materials produce penetrations for tiles, soft roof, metal tiles, seam roofing. Penetrations may differ among themselves in elements of adjoining to the roof, and in the method of installation. They are usually installed in parallel with the laying of roofing material, but some models can be mounted on a finished roof.

Ventilation of the under-roof space

Moisture can enter the house from the outside in the form of precipitation and from the inside as condensate. Its presence in the premises leads to the spread of harmful microorganisms and mold, which will be difficult to cope with. To prevent this and increase the life of a home with a warm attic, a roof ventilation system will help.

Appointment of forced ventilation of the roof of the house

When arranging roofing cake households with a residential attic, specialists observe the principle of complete tightness, placing the materials in layers, overlapping each other. Thanks to the design of such a system, reliable protection from moisture and heat remains indoors.

At the same time, the "pie" is an obstacle to exhaust through the roof. Therefore, they make a system in a residential building forced ventilation, which is mounted in accordance with the requirements prescribed in SNiP.

This design solves a number of problems:

It releases warm air saturated with water vapor into the atmosphere, which is collected in rooms located on the lower floors. If there is no effective exhaust, steam begins to settle on the elements of the rafter system in the form of condensate.
Prevents excessive dampness and unpleasant odor from appearing inside attic room. The roof ventilation system creates an influx of air from the surrounding atmosphere, which contributes to the creation of a favorable microclimate in the house.
In hot weather, it lowers the heating temperature of the roof surface. Properly equipped ventilation can minimize it.
Provides protection of the roof surface from ice build-up. Due to the difference between the temperature outside and inside a warm house snow mass starts to melt. As a result, ice is constantly formed, which is not easy to deal with.
The original qualities of the heat-insulating material are preserved. An increase in the humidity level of the insulation by 5-10% due to the formation of condensate leads to an increase in its thermal conductivity by 35-50%. Even in the case of complete drying, this indicator does not return to its original value.
In accordance with the provisions of SNiP, an attic can be called habitable if it has a forced ventilation system. In this case, the total area of the ventilation outlets must be at least 1/300 of the roof surface.

Roof ventilation elements

Forced ventilation operates according to the principle of convection: since warm air is lighter, its flows move upwards, while freeing up space for cool air masses with a large weight. Often also installed, facilitating air circulation.

According to the provisions of SNiP, to ensure the hood, the following elements will be required roof ventilation:

Cornice products. Through them, atmospheric air penetrates under the roof with an attic. For the manufacture of products, inexpensive lumber is used, which is attached with a small gap, or special designs - spotlights, which are metal or plastic panels with partially applied perforation. Through these openings, air can freely enter the room.
Dormer windows. They serve to extract and provide air access. Such windows are equipped if the attic room in the house is not heated, and it is not used for living.
Ridge aerators. This perforated ventilation element is mounted along the ridge of the mansard pitched roof. It serves to bring the heated air out of the room.
Pitched deflectors. These devices are nothing more than pipes for ventilation. Install these air ducts on the roof, on the slopes. They consist of a tube with a cross section of 20-50 millimeters, which is laid through the layers of an insulating cake. From above, the deflectors are equipped with a protective mesh and a cap.
Roofing material of modular type. Lay a coating of individual tiles, leaving gaps for the circulation of air masses. From a ventilation point of view given material is more good decision for roofs with a warm attic than sheet steel or soft shingles.

Roof ventilation elements for a heated attic and a cold attic differ significantly. For non-residential premises two dormer windows and eaves will be enough.

If designed residential attic, then you will need to install a more complex system consisting of:

pitched deflectors;
cornice products;
ridge aerator.

According to SNiP, the number of ventilation holes is determined taking into account the area of the roofing surface at the rate of 1 - 2 pieces per 25 "squares".

Pitched deflectors and air ducts for the roof

These devices are placed on the slopes of roofs in order to remove heated air from the attic room, and moisture from the layers of the roofing pie.

Deflectors consist of the following elements:

Frame. In appearance, it resembles a bottle, which has two parts. Its lower part is placed in an insulating cake at the stage of arrangement, and the upper one is installed at the end of work. The case diameter can be 30-50 mm.
Protective filter. It is installed inside the deflector housing. A mesh or sponge filter is required to protect the ventilation structure from debris.
Umbrella or mushroom. This part is placed on the head of the housing pipe so that moisture does not penetrate into it during rain or snow.
Flange. To ensure the tightness of the junction of the deflector to the roof cake, an apron made of silicone or rubber is used.

Air ducts are mounted on the roof at a distance of 50 centimeters from the ridge - so it will be easier for warm air to go outside. Even on roofs whose area does not exceed 25 square meters, you will need to install 2 deflectors.

Rules for installing elements of the ventilation system

In order for the ventilation installed on the roof of the house to function efficiently, ensuring the circulation of air masses inside the attic, you must follow a few simple rules:

The height of the ventilation pipes above the roof of the building should be 50 centimeters.
When the pipe is brought out at a distance of 50-150 centimeters from the ridge, it is necessary that it rises 50 centimeters or more above it.
If such a pipe is installed at a distance from the ridge exceeding 3 meters, and is close to the eaves, then its height must correspond to the level of the ridge.
A pipe brought to a flat roof should rise above its surface by at least 50 centimeters.
The ventilation pipe located near the chimney is made of the same length.
The configuration of the roof is the more complex, the more ribs, slopes and valleys it has, which means that it needs more exits to provide efficient exhaust.
In regions with severe winters, ventilation ducts must be insulated to prevent the structure from freezing at sub-zero daily temperatures.
When installing pitched aerators should be given Special attention tightness of the joints, since moisture can penetrate through them, which over time can destroy the roof pie and its truss system.
It is necessary to select the elements of the ventilation system so that they are made by one manufacturer, and then the products will complement each other optimally.

Natural roof ventilation

The creation of such ventilation does not require energy costs, so its arrangement is preferable. Recently, however, roofs of complex architecture have been increasingly erected. They lack the natural ventilation of the roof and then there is a need to create a forced system.

Modern roof structures are a complex system in which elements work effectively only by closely interacting and complementing each other. When creating a roofing project from soft tiles, you need to take into account a lot: protect the insulation from getting wet, prevent rotting of the rafter frame and premature wear of the coating. Particularly noteworthy are "warm" roofs, devoid of insulating air gap. In order for the microclimate in such houses to be suitable for life, it is necessary to establish air circulation between the under-roof space and the atmosphere. For this on pitched roofs ah, a ventilated ridge is installed, the installation of which is a prerequisite for the organization of forced.

Ventilated ridge - a device installed on pitched roofs to organize forced ventilation of the roof. It is a simple plastic device installed along the ridge of a roof made of soft tiles, corrugated board or metal tiles. The ventilated ridge profile has the following features:

Reliably seals the ridge connection of pitched roofs so that no leakage occurs through it. The triangular shape of the ridge complicates the sealing of this weak point of the corrugated board and corrugated sheet roof, through which melt and rain water can seep.
Opens air access. The ventilation gap that is formed when installing a ridge of this design opens the way for the heated air inside the room to the street, which creates a kind of draft and forces the air to circulate inside the house.
Closes the ventilation gap from the penetration of insects and snow. The device of the ridge is conceived in such a way that water, snow or insects cannot flow into it.
Lets evaporate excess moisture. Vapors saturated with moisture are a product of human activity. Together with the air, they rise up, cool and condense on the elements of the truss frame. The thermal insulation layer of a roof made of corrugated board, soft tiles or metal tiles, due to wetting, loses most of its heat-saving properties, and the wood of the frame rots and becomes moldy. Mounting a ventilated ridge solves this problem by opening the air to oxygen and allowing excess vaga to evaporate.

Note! Installation of a ridge with ventilation holes is part of the arrangement of a forced ventilation system for a roof made of soft tiles, corrugated board or metal tiles. In order for ventilation to work, air vents are installed in the cornices, fence places fresh air from the atmosphere.

Installation of a ventilated ridge does not spoil the appearance of the roof, while quality installation this element of the ventilation system cannot be seen. To make the installation site look more aesthetic, a strip of soft tiles or metallic profile which protects the aerator from impact sun rays and penetration of atmospheric moisture.

Operating principle

In the old days, builders did not even think about installing a ventilated ridge, since air naturally circulated through cracks or gaps in building materials and structures. or corrugated board requires almost complete tightness, installation is carried out in the form of a kind of "pie", in which there is a layer of insulation, waterproofing and vapor barrier. This design does not leave a single slit to the air, which is why a stuffy, humid microclimate is established inside the house. To solve this problem, it is necessary to develop high-quality ventilation at the project approval stage. Depending on the type of roof, there are 2 options for ventilation systems:

Natural. Ventilation natural type It is equipped for houses with "cold" roofs, in which the attic is not heated. With this design, dormer windows are made in the roof slope, which are necessary for air circulation. In this case, an unheated attic performs the functions of " air cushion”, which isolates heated rooms from a cold roof. Mounting a ridge with ventilation holes is extremely rare under such circumstances.
Forced. Forced ventilation works on the principle of convection, which means that heated air always rises. Roofs with a heated attic made of metal tiles, corrugated board and roll materials equipped with a ridge aerator, as well as eaves, to force air masses to circulate between the room and the atmosphere. The air flow enters the roof structure through the vents, heats up and rises under the ceiling, exiting through the ventilated ridge and making room for fresh air.

Important! Forced ventilation was developed on the basis of physical properties gas. For its operation, no power sources are needed, since thrust is created according to the law of convection: warm air rises, and cold air sinks down. To achieve maximum efficiency of the ventilation system, its elements are placed evenly over the entire roof area from corrugated board, metal tiles or rolled materials.

Types of aerators

The design of the ventilation system depends on the area of the slopes, the nature of the use of the under-roof space and the roofing material used. Installation of ventilation for "warm" mansard roofs is more complicated and more expensive than for cold ones. To determine the optimal composition and mutual arrangement elements, perform installation based on determining the volume of air in the attic. The following types of aerators are used for ventilated ridge equipment:

Note! The simplest and inexpensive way ventilated ridge equipment - the use of corrugated ventilation tape. It is sold in rolls, and on the underside of the tape is a self-adhesive layer with a protective film. To perform the installation, you need to remove the protective film, stick the tape on both sides of the ridge, and then install the metal ridge bar.

Functions

To the unprofessional roofer, ridge ventilation may seem like an unnecessary overhead and an additional cost, but experienced roofers know that this simple measure increases the life of the truss frame and roof covering. Properly designed and installed ventilation system performs the following tasks:

Optimizes the microclimate in living quarters. Thanks to the constant flow of air saturated with oxygen, the house is always fresh, not stuffy, and a comfortable temperature regime is maintained.
Extends the life of the roofing. The ventilated ridge profile prevents bitumen-based roll materials from swelling due to solar radiation, allows excess moisture to evaporate, which has a positive effect on the service life of roofs made of metal tiles and corrugated board.
Maintains a healthy state of the rafter frame and battens. Thanks to the aerator, excess moisture evaporates, and the wood of the roof frame does not suffer from rot, mold and fungus.
Does not allow the insulation to get wet. Due to the constant air circulation, the insulation is ventilated and remains dry, which maintains the thermal insulation qualities of the material at a high level.
Makes the use of bitumen-based materials safer. Air circulation through aerators eliminates the possibility of penetration of bituminous vapors, which are considered harmful to human health, inside the premises.

Note! Dormer windows, installed during the organization of natural ventilation, are located at half the height of the slope, which is why stagnant zones are formed under the very ridge, where the air does not circulate at all. When installing forced ventilation, this problem does not arise, since aerators are installed directly on skating connection, which is the highest point of the roof.

Video instruction

Roofing materials reliably protect the building from snow and rain, providing dryness and comfort during indoor areas. But the trick is that moisture attacks not only from the outside, but also from the inside. In the second case, it is possible to neutralize its negative impact only with the help of roof ventilation.

Why do you need roof ventilation?

There are two reasons to take care of the roof ventilation device:

Living quarters always contain significant amount water vapor, which is formed as a result of breathing and sweating of residents and pets, cooking, hygiene procedures and other processes associated with the use of water (laundry, cleaning, washing dishes, etc.).
Roofing, by definition, is vapor-tight, so it is not capable of escaping steam.

Without special measures, water vapor rising with warm air would condense on the inner surface of the cold roofing with the subsequent occurrence of many negative processes:

To prevent all of the above phenomena, roof ventilation is arranged, which implies the presence of a blown gap and ventilation of the attic space.

The blown gap is called the ventilation gap. The movement of outside air in this gap will carry all the vapor penetrating the coating to the outside. Along the way, it performs two more functions:

The ventilation gap is arranged as follows:

a waterproofing film is spread over the rafters;
top along each rafter leg a board with a thickness of about 30 mm is stuffed - a counter-lattice (it will fix the waterproofing film);
a crate is stuffed on the counter-lattice across the rafters, and the roofing is laid on it.

Thus, the required gap is obtained between the waterproofing film and the roofing. Its height will be equal to the sum of the heights of the counter-lattice and the batten, which is approximately 50 mm.

To ensure the movement of outside air in the ventilation gap, as well as to remove moist air from the attic, various devices are used.

Roof ventilation elements

The main elements of the ventilation roofing system include:

Openings under the roof overhang, which are usually covered with so-called soffit gratings (protection from birds, insects and rodents), as well as along the ridge. These structural elements provide blowing through the under-roofing gap due to wind and convection (having heated up under the roof, the air rushes up).
Holes under the roof overhang are protected from rodents and birds with soffit gratings: they can be replaced with a filing with small gaps between the boards
Dormer windows. They are arranged in gables and serve to ventilate the attic space.
The dormer is one of important elements roof ventilation
ventilation outlets. As well as aerators, they are pipe sections, but not intended for ventilation of the under-roof gap, but for connecting exhaust ducts of general house ventilation to them or for ventilating the attic.
An exhaust fan can be connected to the ventilation outlet. house system or use it to ventilate the under-roof space
Aerators, also referred to as deflectors and weathervanes. They cut into the roofing at the ridge itself and serve to remove air from the under-roof space, that is, they perform the same function as the hole under the ridge. They are used in conditions where the thickness of the snow cover on the roof can exceed 2–3 cm (with small slopes), as a result of which the ventilation gap under the ridge would be muffled.
The roof aerator is used to remove air from the under-roof space in cases where there is snow on the roof

Design features of aerators

There are two types of aerators available:

point;
linear or continuous (installed over the entire length of the slope or ridge).

In addition, they also differ in the place of installation - they are ridge and pitched.

The design of the aerator can be made in the form:

fungus;
tiles.

The aerator can be made of stainless steel, but today in most cases the material for such products is polypropylene. It is cheaper, and besides, plastic can be given any color. At the same time, it has sufficient strength to withstand the weight of a person, so that installation or repair work on the roof can be carried out without difficulty.

The aerator has a replaceable element - a penetration, the design of which is selected taking into account the type of roofing.

Aerators can be equipped with a roof passage device adapted to a specific type of coating

The product can be equipped with a fan - it is necessary to create forced draft in roofs with a small slope (convection is weak in them due to the small height difference) or with complex shapes, where natural draft is not enough to overcome the aerodynamic resistance of fractures.

To prevent the ingress of precipitation and insects, the aerator opening is protected by a filter. The diameter of the aerators varies from 63 to 110 mm.

Calculation of roof ventilation

The task of calculating ventilation is to determine the necessary parameters under which the volume of incoming air will be sufficient for effective removal pair.

The height of the ventilation ducts above the roof is determined taking into account their proximity to the ridge or parapet:

Roof ventilation device

The ventilation system of the roof is arranged in accordance with the type of roof.

Mansard roof ventilation

The attic roof is insulated. The layout of the ventilation gap in such a roof depends on what material is used as waterproofing.

Roof with waterproofing from a polymeric vapor-proof film

If the insulation is covered with a conventional film that does not allow water or steam to pass through, ventilation gaps are arranged on both sides of it: from above - to the roofing and from below - between the film and the insulation. Due to the presence of a gap between the waterproofing and the insulation, the latter is prevented from getting wet if moisture condenses on the film.

The lower and upper ventilation gaps must communicate in the region of the ridge, so the waterproofing film is not brought to it by 5 cm.

In order not to accidentally lay the heat insulator plates close to the waterproofing barrier, it is recommended to drive limiting carnations into the rafters.

When using a simple waterproofing film, it is necessary to arrange ventilation gaps on both sides

Roofing with superdiffusion membrane as waterproofing

A superdiffusion membrane is a polymer film in which microscopic conical holes are made. The membrane passes steam only in one direction, so it is important to lay it on the right side. There is no need to make a gap under it - the insulation is laid close to the membrane.

The height of the ventilation gap in the attic roof depends on the angle of inclination of the slope and its length.

Table: ventilation gap height for different roof slopes (in cm)

Length stingray roofs, m	Roof slope
Length stingray roofs, m	10°	15°	20°	25°	30°
5	5	5	5	5	5
10	8	6	5	5	5
15	10	8	6	5	5
20	10	10	8	6	5
25	10	10	10	8	6

Video: ventilated ridge device in a mansard roof

hip roof ventilation

The hip roof differs from the usual gable roof in the absence of gables, instead of which there are two triangular end slopes. The line of intersection of the end and longitudinal slopes is called the ridge. Roof ventilation is carried out according to the same principles as for gable roof, taking into account the following:

Installation of an aerator on different roof coverings

Installation Requirements ventilation elements depends on the type of roofing material.

Installation of an aerator on a metal tile

Installation of an aerator or ventilation outlet on a roof with a metal tile coating is carried out as follows:

On the roof, mark the installation sites of aerators. They should be no more than 60 cm from the ridge. The frequency of installation depends on the brand of the aerator and is indicated in its passport.
In the marked place, a template is applied to the coating (it is included in the kit), which must be circled with chalk or a marker.
In order to outline the contours of the hole to be cut out, use the template that is included in the aerator kit.
The outlined section of the roofing is cut out. Alternatively, you can first drill a series of small diameter holes along the contour, and then cut the gaps between them. You can do this with scissors for metal or a jigsaw.
A passage hole is cut along the drawn contour
The area adjacent to the resulting hole is cleaned of dirt and dust, and then treated with a degreasing compound.
A hole is cut in the casing (part of the aerator kit) with a diameter 20% smaller than the diameter of the element pipe. Thus, the casing will be put on the pipe with an interference fit, so the connection will be tight.
The pipe is inserted into the casing, after which the complete assembly of the aerator is carried out.
The edges of the hole in the cover, on which the skirt of the casing will be installed, are lubricated with a sealant for outdoor use.
The fungus is installed in place, while the casing is screwed to the roof with self-tapping screws.
The aerator casing is fixed to the crate from the outside and from the inside
The pipe is brought to a vertical position according to the level and fixed. As a result, the deflector fixed on it should be at a height of at least 50 cm relative to the roof.
The head of the aerator should rise above the ridge by 50 cm
It remains to check the correct fastening of all elements from the inside, that is, from the side of the attic. Found defects or distortions must be corrected.

Installation of an aerator on a roof made of soft tiles

Basically, the process of installing a fungus aerator on a soft tile roof looks the same as on a metal tile one. The differences are in some details. Here's what to do:

Features of mounting the aerator on corrugated board

To install an aerator on a corrugated roof, a wooden box is usually used. The installation process looks like this:

After marking at the place of installation of the aerator, a cross-section is made in the corrugated board.
The resulting triangular petals are bent down and nailed to the rafters and other wooden elements.
According to the size of the opening, a box is knocked together from the boards. Then it is inserted into the opening and screwed with self-tapping screws to the elements of the truss system.
A fungus aerator pipe is installed and fixed in the box, after which all the cracks are filled with sealant.

Ondulin roof aerators

Ondulin manufacturers produce all the elements necessary both for ventilation of the under-roof space and for organizing access to the roof of various ventilation ducts. Here is their list:

Aerators.
Ventilation outlets of the hood with insulation. Exhaust ventilation ducts from the kitchen are connected to such outlets (the hood above the stove can also be connected here) and the bathroom. The pipe has a diameter of 125 mm and is equipped inside with a special coating that counteracts the formation of grease and dirt deposits. From above, the outlet is equipped with a deflector that protects the internal cavity from precipitation and improves traction.
Pipes for the exit of ventilation of bathrooms and kitchen hoods painted in the main colors of ondulin
Sewer ventilation outlets without insulation. These outputs are connected fan pipes sewer lines. Without communication with the atmosphere in the sewer, during a salvo descent of water, a decrease in pressure will be observed, which can lead to a breakdown of the siphons with subsequent penetration into the room unpleasant odors. The diameter of the sewer outlet is 110 mm.
Ventilation sewer outlets with insulation. Such outlets differ from the previous version by the presence of a sheath made of polyurethane or other polymer (thickness is 25 mm), which helps to reduce heat loss and thereby minimizes the amount of condensation on the inner surface.
The ventilation outlet for the sewerage can have a protective sheath made of polymer material to reduce the amount of condensate that forms

To connect the ventilation outlets to the corresponding channels, it is usually used corrugated pipes. The length of the outlet is 86 cm, and after installation, the length of the outer part, that is, the height of the outlet above the roof, is 48 cm.

Installation of ventilation outlets and aerators is carried out as follows:

There are situations when it is not possible to use a base sheet with a ready-made opening and a sealing element. Then the opening in the coating is cut out independently, and the gap between its edges and the removed pipe is sealed using the Enkryl waterproofing system, which is just designed to seal problematic joints. It is applied like this:

The area around the opening is treated with a degreasing compound.
Next, the first layer of Enkryl sealant is applied to it and to the pipe brought out into the opening with a brush.
The pipe or aerator is wrapped with a reinforcing fabric, such as viscose Polyflexvlies Roll. Here it is necessary to pause - the sealant must soak the fabric well.
The fabric wrap is covered with a second layer of Enkryl, which is also applied with a brush.

This method of sealing the passage through the roof is designed for 10 years. After this period, the waterproofing will need to be renewed.

To seal joints and crevices, instead of fabric and paste-like sealant, you can use adhesive tape"Onduflash-Super".

Video: installation of ventilation on ondulin

Installation of ventilation elements on a seam roof

For installation of roof ventilation elements on a folded roof (the covering is made of metal sheets), it is best to use a universal sealant for roof passages. It consists of a square aluminum flange on a silicone lining and a stepped pyramid attached to it made of the same silicone or a special rubber that is resistant to ultraviolet radiation and other atmospheric influences. The size of the seal must be selected so that the inner diameter of the pyramid is approximately 20% smaller than the outer diameter of the aerator or ventilation outlet.

Installation is carried out as follows:

aluminum flange universal seal is flexible, so it can be given any shape. Due to this, the element can be installed not only on flat roofs like seam, but also on wavy ones, such as ondulin, slate, corrugated board and metal tiles.

Roof vent installation

In the place where there is a ventilation outlet to the roof, a so-called passage unit is installed, the main task of which is to seal the gap between the pipe and the roofing. Nodes can be very different both constructively and appearance. Basically, the following varieties are distinguished:

Equipped with a valve and not having one: the presence of a valve allows you to control the movement of air in the ventilation system. The passage nodes equipped with this element are installed mainly on the roofs of administrative and industrial buildings. Units without an adjustment valve do not provide for, but they are cheaper.
With and without insulation: the first in their design have a layer of mineral wool (this insulation is non-combustible) and are used in regions with a cold climate. The presence of thermal insulation prevents moisture condensation on internal surfaces node.
With manual (mechanical) and automatic control: in the first case, the damper is moved to one position or another by the user, pulling the cable attached to it. In the second, the damper is driven by a servomotor, which is controlled by an electronic controller. Such a system, with the help of appropriate sensors, can analyze the temperature and humidity in the room and, taking into account these indicators, regulate the throughput of the ventilation ducts.

The cross section of the node can be rectangular, round and oval. When choosing this element, the following microclimate parameters are taken into account:

relative humidity;
the content of dust and chemical contaminants in the air (gas content);
temperature fluctuations in the room.

The ventilation outlet is installed in the same way as the aerator, with the only difference that it must be carried out not only through the roofing, but also through the waterproofing and vapor barrier films. To do this, proceed as follows:

Video: installation of a ventilation outlet to the roof

Installation of a ridge aerator

Ridge aerators may have different design, but in most cases the installation is done like this:

The old coating is dismantled from the ridge zone (if the roof is new, this paragraph of the instruction should be skipped).
If laid under the cover continuous crate, on it a line parallel to the ridge is drawn, spaced from it by 13 mm (on both slopes).
A cut is made along the drawn lines with a circular saw with an indent of 300 mm from the outer walls.
A ventilation cut is made on both sides along the entire length of the roof, not reaching 30 cm to the gables
Two ridge shingles are attached to the edges of the roof.
Roof aerators are bent to the desired angle, depending on the angle of the roof.
Aerators are installed with an overlap in place. During installation, it must be taken into account that the covering and covered ends are structurally different. It is not necessary to seal the overlap points. The partitions available for the aerators must lie on the floor. If this rule is not observed, water may flow under the roof.
Aerators are fastened with nails, which must be driven into specially made holes. The sides in the process of driving nails must be alternated.
The ridge aerator is fastened with nails through special holes
The last aerator is cut to length with a margin of 13 mm. Its edges are superimposed on the previous part.
The roofing is laid, which must be fixed with nails or self-tapping screws. It is necessary to drive or screw fasteners into a specially marked area on the ridge aerator. It is marked as such: “roofing fixation zone”.
The ridge aerator is covered with roofing material, which is fastened through specially marked holes
The places where the ends of the chain of aerators adjoin the roof are sealed with a special mastic, which is usually supplied with the aerator. To do this, you need to prepare a mounting gun.

Video: installation of a ridge aerator

Under no circumstances should roof ventilation be neglected. There are no elements in the roof structure, except perhaps films, that would be immune to negative impact moisture, and in the absence of high-quality ventilation, it will certainly appear. Following the recommendations outlined in this article, you will ensure a long service life of the roof and a cozy microclimate not only in the attic, but also in other areas of the house.

Large country - large volumes of housing construction. Not only multi-storey, but also private. And every developer needs and needs knowledge on general issues of construction, on norms and rules, including about roofing processes.

Competently executed roof structures are the key not only to a warm house and comfortable atmosphere, but also the durability of other elements of the structure.

The roofing system is milestone building construction.

Physical processes of heat transfer

In a heated house, temperature changes are inevitable, the presence of moisture in the air in the form of steam, condensate. Steam is produced by the vital activity of a person or animals, penetrates building structures, cools and moistens them. Overwhelming majority building materials allow air to pass through to some extent. Therefore, any residential building, individual or multi-apartment, is an air volume in which warm air rises through all structures.

In high high-rise buildings there is a traction effect. Warm air rises to the upper floors, this is especially noticeable in the entrances, and penetrates outside through windows and attics. On the lower floors, on the contrary, there is an influx of outside cold air. This process also occurs in a one-story heated house, only with less dynamics.

On the other hand, warm air vapor condenses into water in the structures, which not only moistens them, but also has the ability to flow down, filling the cavities in the structures. The main function for the condensation of water vapor is assumed by the most top part buildings - roof. In winter, this process is intensive and constant, and in summer it is predominantly at cool night time.

The most modern and effective way to prevent or significantly reduce moisture condensation in the roof is to make it ventilated naturally or forced. Natural cold ventilation does not require energy costs, so its design is preferable. However, there are roofs of complex architecture that lack the power of natural ventilation, then forced ventilation comes to the rescue.

Ventilation removes warm wet air into the surrounding space, thereby leaving bearing structures, heaters dry, prolonging the service life and providing thermal insulation. We need to manage this process, which is carried out with the help of the so-called roofing pie.

The concept appeared relatively recently and denotes a multilayer roof structure, in which the leading place is given to the creation of ventilation ducts. There are two types of roofing cake: for heated and insulated rooms and for cold roof. Each layer is interconnected functionally with other layers, and the absence of any reduces protective properties the whole pie.

If the attic is a cold, uninsulated part of the building, it is carried out in several successive layers. The following tools are required for work.

a hammer;
drill with drills 4-12 mm;
wood saw;
stapler (stapler) electric or mechanical with staples 14x8 mm;
level, meter ruler, square;
scissors;
screwdrivers of different sizes;
flute brush for antiseptic cutting of wooden parts;
construction sealant.

Laying is carried out on the upper side of the rafters waterproofing film(not to be confused with vapor barrier). The sag of the film should be 20-40 mm to drain condensate. It is fixed along the rafters with a counter-lattice 30-50 mm thick and as wide as the thickness of the rafters themselves. It is better to glue the film at the attachment point with double-sided tape.

To reduce waste, the film can be laid in horizontal rows from the bottom up and with an overlap of 100-150 mm. The joints of the strips are glued, creating a continuous web. The water formed from the condensate will flow down the film to the roof eaves.

After the installation of a waterproofing layer, a crate for roofing is sewn across the rafters on the counter-lattice. The width of the board, the gap between them is selected depending on the roofing material.

For ceramic and soft tiles on the crate, use an inch board 100 mm wide. It is laid with a gap of 50-100 mm, after which it is completely sewn up from above with a building board or waterproof plywood with a thickness of at least 9 mm. Under soft tiles still lay the underlying layer.
The crate from the board 30x100 and with a step of 300-400 mm is performed under a metal tile or corrugated board;
For a metal seam roof, a crate is used from an inch board 150-250 mm wide, sewn onto a counter-batten with a minimum gap of 20-50 mm.

At the end, roofing material is laid directly on the crate or building slab. It is fastened with special nails, screws or clamps to the crate. The roof attachment points are protected with sealants, and the crate is pre-treated with an antiseptic. Additionally, you can perform a rough filing along the rafters from the side of the attic.

Between the roof and a ventilation gap appeared in the total thickness of the battens and counter-battens. This is 55-80 mm of the height of the under-roof space along the slope of the rafters. In winter, the warmer attic air, partially penetrating through the waterproofing, will rise to the roof ridge and be discharged into the atmosphere without having time to condense moisture. And in summer, the air heated by the roof is also removed from under the roof.

Attic ventilation is important for the under-roof space. It is carried out through the dormer windows, arranged on the gables with different parties. Ventilation of the living space, attic and roof space are interconnected, and one of their goals is to reduce steam and condensation in the roofing pie.

Ventilated insulated roof construction

Often attic space used as an attic, insulated from the side of the roof. In this case, several more layers are added to the roofing cake. Now there is no attic air gap between the living space and the roof. Warm and humid attic air immediately penetrates into the under-roof space. And if you do not take additional measures to remove it, there will be much more condensate and the structures will start to get wet. Thermal insulation materials cease to perform their functions and the air in the room will be cold. We'll have to increase the heating.

In addition to those layers that have already been completed in cold roof, add a thick layer of insulation, laid between the rafters with inside. If ordinary rafters are 150 mm wide, then the thickness of the insulation between the rafters can be no more than 100 mm. The reason is the need to leave a minimum gap (do not touch) until the waterproofing sags, which reaches 40 mm. If there is a touch, the water flowing down the insulation will enter the insulation. To increase the thickness of the layer, a timber of the required thickness is sewn onto the rafters and a heater is added.

Then it is covered with a vapor barrier film. The goal is to minimize the ingress of steam from the room into the insulation so that it does not get wet. Wet insulation is no good, it does not hold heat and, in addition, moisturizes the surrounding structures. First, a rough, and then a finishing lining is sewn onto the vapor barrier.

Now the path of wet steam to the roof is blocked, and although a small part of it still penetrates, it is carried out into the atmosphere by the under-roof ventilation air flow without harming the roof structures. And if the warm room itself is not ventilated, where will the steam go? Through all sorts of microscopic pores and crevices, it will still go up to the roof. This will be facilitated by the excess pressure formed in the warm room of the attic.

To relieve excessive pressure, reduce the moisture content in the living room and thereby help under-roof ventilation to remove moist air into the atmosphere will allow the ventilation of the room itself.

Ventilated cornice device

The longitudinal ventilation ducts of the roofing pie will not work effectively if, on the one hand, in the lower part, at the very cornice, the flow of atmospheric air is not provided. On the other hand, it is necessary to let humidified air out from the very top of the roof - from the ridge.

The waterproofing film is the most durable of all types of films used in building a house, so it does not allow water or moisture to pass through even under high pressure.

The waterproofing film is removed and glued with a sealant to a metal cornice strip installed in the plane of the crate. The roof is fixed on top. Air flow is carried out in 3 ways. Firstly, through the gaps of the roofing material profile, secondly, through the gable overhangs and, thirdly, through the micropores of the waterproofing film, drawing steam out of the insulation.

When sheathing the cornice, ventilation holes or gaps are provided in its lower part, depending on the many options for the design of the cornice. One of modern ways- this is a continuous filing of the cornice plastic panels perforated for roof ventilation.

Creating a ridge hood

Depending on the design of the roof covering, the air flow from under the roof is collected in the ridge and discharged into the atmosphere either through structural gaps along the length of the ridge or through gable openings. For example, a set of ceramic and metal tiles includes special ridge elements with ventilation gaps. Additionally, there are additional elements for a non-standard ridge shape.

This is the outer part of the roof. The internal device is performed in a certain sequence.

the counter-lattice along the rafters is not brought to the geometric height at the same distance of 20-40 mm. Bars of oncoming slopes do not join;
crate in 2 solid boards from both slopes on the ridge is also performed with longitudinal clearance in 40-80 mm;
the waterproofing film along the ridge is cut with a margin of 200 mm from both slopes;
between the ends of the counter-lattice and the batten along the ridge, a 40x100 mm ridge beam is vertically installed;
a waterproofing sheet is fixed to it and glued with a sealant;
from above, this structure is closed with a ridge according to the instructions and technology;
end elements of the ridge are installed from the side of the gables, in which ventilation holes or gaps are provided.

Some features of a ventilated roof

Roof ventilation is not an independent process. On the contrary, ventilation or its absence in the premises directly affects the air exchange in the roof. In order to effectively remove destructive moisture from residential premises through the roof, it is necessary to consider the ventilation of all elements of the building as a single process.

If the shape of the roof is complex, has many transitions, valleys, the ventilation processes must be divided into sections and air flows in the roof should be formed separately. As a result of effective ventilation, the air in the under-roof space should be replaced approximately 2 times within an hour.

The effectiveness of a ventilated roof depends on the slope of the slopes. The steeper they are, the stronger the ventilation process occurs. And, conversely, in roofs with a slope of less than 20%, under-roof ventilation is unstable, effective only under wind pressure.

It is always useful to install additional exhaust elements (aerators) on the roof to help strengthen natural ventilation roofs. They should be placed on roofs of complex shape, when conventional means are no longer enough. Aerators are installed near the ridge.

The thermal insulation properties of the insulation and the durability of roof structures directly depend on the presence of moisture in them. Therefore, a ventilated roof and the design of ventilation of the premises is economically beneficial even in the case when it is necessary to install forced air exchange.