Ventilated soft roof. Ventilation of pitched roofs. Metal roof ventilation device

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

Competently executed roofing structures- this is not only a guarantee warm home and a comfortable atmosphere, but also the durability of other elements of the structure.

Roofing is an important stage in the construction of buildings.

Physical heat transfer processes

In a heated house, temperature changes and the presence of moisture in the air in the form of steam and condensation are inevitable. Steam is produced by human or animal activity and penetrates into building construction, cools and moisturizes them. The vast majority of building materials are permeable to some degree. Therefore, any residential building, individual or multi-apartment, is an air volume in which warm air rises upward through all structures.

In the high multi-storey buildings a traction effect appears. 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 steam condenses in structures into water, which not only moistens them, but also has the ability to flow down, filling the cavities in the structures. The main function of condensing water vapor is assumed by the top part buildings - roof. In winter, this process occurs intensively and constantly, and in summer, mainly during the cool night time.

The most modern and effective method prevent or significantly reduce moisture condensation in the roof - make it ventilated naturally or forcefully. Natural cold ventilation

Ventilation removes warm, moist air into the surrounding space, thereby leaving supporting structures and insulation dry, extending service life and providing thermal insulation. We need to manage this process, which is done using the so-called roofing pie.

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

If the attic is a cold, uninsulated part of the building, it is done in several successive layers. The following tools will be required for the work.

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

A waterproofing film (not to be confused with a vapor barrier) is laid on the upper side of the rafters. The film sag should be 20-40 mm to drain condensate. It is secured along the rafters with a counter-lattice 30-50 mm thick and a width equal to 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 bottom to top and with an overlap of 100-150 mm. The junctions of the strips are glued, creating a continuous web. The water generated from condensation will flow down the film to the roof eaves.

After installing the waterproofing layer, a lathing is sewn across the rafters onto the counter-lattice for roofing. The width of the boards and the gap between them are selected depending on the roofing material.

1. For ceramic and soft tiles, use an inch board 100 mm wide for the sheathing. It is laid with a gap of 50-100 mm, after which the top is completely covered with building board or waterproof plywood with a thickness of at least 9 mm. Under soft tiles The underlying layer is still being laid.
2. Lathing made of boards 30x100 and in increments of 300-400 mm is made under metal tiles or corrugated sheets;
3. For a metal seam roof, use a lathing made of an inch board 150-250 mm wide, sewn onto a counter-lattice with a minimum gap of 20-50 mm.

Finally, they are laid directly on the sheathing or building slab. roofing material. It is attached with special nails, screws or clamps to the sheathing. The roof fastening points are protected with sealants, and the sheathing is pre-treated with an antiseptic. Additionally, you can perform rough filing along the rafters from the attic side.

Between the roof there was a ventilation gap equal to the total thickness of the sheathing and counter-lattice. This is 55-80 mm of the height of the under-roof space along the slope of the rafters. In winter, warmer attic air, partially penetrating through the waterproofing, will rise to the roof ridge and be released 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 dormer windows, arranged on the gables from different sides. Ventilation of the living space, attic and under-roof space are interconnected, and one of their goals is to reduce steam and condensation in the roofing pie.

Ventilated insulated roof design

Often the attic space is used as an attic and is insulated from the roof side. In this case, several more layers are added to the roofing pie. 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 don't accept additional measures Once it is removed, there will be much more condensate and the structures will begin to get wet. Thermal insulation materials will cease to perform their functions and the air in the room will be cold. We'll have to turn up the heating.

In addition to those layers that are already made in cold roof, add a thick layer of insulation, laid between the rafters on the 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 sag, which reaches 40 mm. If there is a touch, water flowing down the insulation will get into the insulation. To increase the thickness of the layer, timber of the required thickness is sewn onto the rafters and insulation is added.

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

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 causing harm to the roof structures. And if the warm room itself is not ventilated, where will the steam go? Through all sorts of microscopic pores and cracks it will still go up to the roof. This will also be facilitated by the excess pressure generated in the warm attic room.

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

Ventilated cornice device

The longitudinal ventilation channels of the roofing pie will not work effectively if, on the one hand, in the lower part, near the eaves, there is no influx of atmospheric air. On the other hand, it is necessary to allow the humidified air to escape from the very top part of the roof - from the ridge.

Waterproofing film is the strongest of all types of films used in home construction, so it does not allow water or moisture to pass through, even under high pressure.

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

When covering a cornice, ventilation holes or gaps are provided in its lower part, depending on the many options for the design of the cornice. One of the modern methods is continuous filing of the cornice plastic panels with perforations 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, complete with ceramic and metal tiles There are 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 structure 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. The bars of the oncoming slopes do not join;
• sheathing in 2 solid boards from both slopes on the ridge is also performed with a longitudinal gap of 40-80 mm;
• the waterproofing film along the ridge is cut with a margin of 200 mm for hems on both slopes;
• between the ends of the counter-lattice and the sheathing along the ridge, a ridge beam of 40x100 mm is installed vertically;
• a waterproofing sheet is attached to it and sealed with sealant;
• From above this structure is covered with a ridge according to the instructions and technology;
• Install ridge end elements on the gable side, 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. To effectively remove damaging 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, ventilation processes must be divided into sections and air flows in the roof must 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 and is only effective under wind pressure.

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

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

With constant fluctuations in daily temperature, condensation forms on some parts of the roofing. This happens especially often in winter time years, when the interior warms up and the difference between the temperatures inside and outside the building turns out to be large.

The insulation undergoes the greatest load. Its lower and upper edges experience temperatures differing by tens of degrees. In addition, the lower the degrees outside, the greater the pressure of water vapor rising from the room upward appears in the under-roof space. And the cold air does not allow the steam to move further.

As a result, the insulation absorbs a lot of moisture and stops “working” for its intended purpose.

It will help you cope with such phenomenaventilated roof. In winter, it will help reduce the costs of heating the building and optimize heat loss. In the summer, such a design will perfectly withstand the heat, since the warm air entering the roof tends to rise upward and take with it the heat that it received from the roofing coverings and the evaporating moisture that appears in the insulation.

Ventilated roof installation

Before starting work on installing such a roof, you should find out what materials will be used. This will be the determining moment for the choice of other roofing building materials.

For example, what kind of waterproofing film is suitable for a pitched roof, and how the counter-battens will be located, how many ventilated gaps will be required, and what pitch of the sheathing will be optimal. The height of the ventilated space also directly depends on the selected roofing material.

For example, if you plan to use bitumen shingles, then the ventilated channel can be made smaller than when using tiles made from natural materials.

And for metal tiles, an average size is designed between the previous two. The size of the canal varies between 5 - 10 centimeters. What is a ventilated roof? It consists of three necessary circuits:

• ventilation of the space between the waterproofing and roofing covering. With any complex roof structure, it must include all surfaces without exception in this process.
• areas located under the roof itself. This is one of the important components of the ventilation system of the entire structure.
• the gap between the waterproofing layer and the insulation. The presence of stagnant zones should be completely excluded here.

Ventilation design

Imperfect technologies of many decades in the past and flawed Construction Materials those years, led to the fact that the constructed buildings breathed due to brickwork, wooden window frames.

Thanks to this “breathing”, the heat loss of the house was significant. Breaks roll materials on the roof and all of the above factors contributed to the formation of a triple ventilation circuit.

As a result of all this, there was a draft in the rooms, dampness often appeared, and as a result, it was necessary to fight the fungus. Costs for heating buildings also increased, and Finishing work It was not always possible to do quality work inside the houses. In older houses, ventilation ducts were designed only in bathrooms, toilets and kitchens.

IN modern construction There are new roofing technologies and new materials for its insulation and waterproofing. Even at the design stage, it is necessary to pay the necessary attention to systems.

When installing a ventilated roof, you must remember the rules of the roofer: steam invariably rises upward, and water can only flow downwards.

It is necessary to pay attention to the following points that must be taken into account during design and operation.

Experts advise paying close attention to the ventilation of small rooms, making vapor barriers closer to interior spaces Houses. If the waterproofing is done incorrectly and moisture penetrates inside, the situation can only be changed by dismantling the roofing and correcting the mistakes.

Pitched roofs

When installing a ventilated roof, it must be taken into account that air flows must enter through the lower overhang of the roof and exit through the top, where the ridge is installed. This will remove excess moisture. To prevent birds from flying into the roof and leaves from getting in, eaves ridges with ventilation grilles are used.

Additional forced ventilation can be done using. This will be relevant if the roof structure is complex, where it is quite difficult to ensure free passage of air.

If the roof is covered wavy slate, then it is very simple to organize an air gap; during installation, it is formed between the ridge and the roofing sheet, due to its configuration. It is only necessary to provide lower gaps for air entry. So, an uninsulated roof consists of:

• rafter design;
• lathing, depending on the roofing material;
• waterproofing film;
• roofing material.

A waterproofing film is attached to the rafters using counter-lattice slats. She must long years protect the roof of the building from unnecessary moisture. If used properly, the film will last for many years. All this is suitable for the construction of a country house.

In a household where people live even in winter, it is necessary to lay a diffuse waterproofing film, which is mounted on top of the attic floor insulation. Such a film will allow steam to escape from the room, but water will not get inside through it. It is also possible to use anti-condensation film. It can be used with any roofing material. It will protect against moisture, soot and dust.

This material includes:

• propylene fabric, which is resistant to UV rays;
• non-woven moisture-absorbing material;
• 2 layers of laminated film

Flat roofs

Ventilated flat roofs began to be used in the 80s of the twentieth century. Then insulation with built-in ventilation ducts appeared, which help quickly remove excess moisture.

Ventilation here occurs thanks to the holes located along the edges of the roof. They must be covered with nets so that insects cannot get inside. If the structure uses wooden parts, then a vapor barrier should be laid under the thermal insulation layer.

Almost every person who builds a house should know what a ventilated roof is?

It consists of three main ventilation circuits:

1. ventilation of the space, which is located between the waterproofing layer and the coating, and also covers almost all planes, despite the degree of complexity of the roofs;

1. ventilation of the space directly under the roof, which is considered one of the elements of the home ventilation system;

1. ventilation of the space located between the waterproofing layer and insulation, in which stagnant zones are absolutely excluded.

Ventilation design and installation

For many decades, with imperfect technologies and building materials, houses were built that breathed through brick, wood, cracks in windows, in doors, masonry, in cracks between layers of rolled materials - roofing felt, glassine, in which all three ventilation circuits were united.

As a result of these technologies, the house had constant drafts, increased heating costs and some restrictions on the finishing of the premises. Quite often dampness and fungus appeared in some places. Ventilation ducts in houses were installed only in kitchens and bathrooms.

This issue was resolved by high level modern building materials for roofing.

For your attention! When designing your home, you should pay special attention to the ventilation system.

For those who want to independently examine the project, there are two basic rules for a warm roofer:

• Steam always rushes upward

• Water always flows down.

The consequences of these rules are as follows:

When installing a vapor barrier, there is little overlap of roofing materials on each other, on the load-bearing elements and walls of the structure, the joints are taped with a special tape;

When there is no indoor ventilation, sometimes even gluing cannot prevent moisture from penetrating into the insulation if the vapor pressure is high. Ventilation allows “steam to escape from the boiler.”

The walls of the house should not “breathe”, since moisture, which is retained in the outer layers of the walls, often leads to delamination when frozen and easily penetrates through the walls into the “roofing pie”.

Advice!You should pay attention to the ventilation of small rooms and spaces.

Installation of vapor barrier should be carried out closer to the interior of the house.

If errors occur during the installation of waterproofing, then it is necessary to dismantle the roof covering, correct the errors, and provide access from inside the house to the vapor barrier.

Roofing device

Roof ventilation prevents the formation of ice crust on the ridge and roof ledges.

The flow of fresh air provides a ventilated space, and in summer time When the roof heats up, the air picks up moisture and carries it out. For such a system to work well, it is necessary to carefully think through the sheathing on which the ventilated roof is applied.

If the rafter system has already been installed, then it is worth thinking about choosing a roof. If you are building premises such as a garage or warehouse that are not heated, then the ventilation in them will be natural and the service life of this building will be limited by the service life of the selected materials.

In order for the building to last a long time, it is necessary to arrange forced ventilation and insulate the room.

An uninsulated roof consists of the following elements:

• rafters;
• lathing;
• roofing material;
• waterproofing films.

The waterproofing film is fixed to the rafters using slats. Even when the roofing covering wears out, it protects against moisture from entering the building and has a long service life.

Such material will be indispensable even if you build a small country house, covered with slate, this film will last more than 50 years.

In private homes, a special “” device is required.

In addition to insulation, a diffusion waterproofing film is applied for ventilation. This film does not allow moisture to pass into the under-roof structures and ensures the passage of steam through the smallest pores of the material.

It also reliably protects the structure from the wind, having excellent waterproofing properties.

Only when installing gaps between the heat-insulating structure, roofing and film, good ventilation is ensured by the use of diffusion film for waterproofing. Otherwise, it will not allow water vapor to pass through.

You can use anti-condensation film for waterproofing.

It will prevent the formation of condensation well and is used for constructing a ventilated roof when using any roofing covering.

The structure of this material consists of 4 layers:

• ultraviolet resistant polypropylene fabric;
• non-woven moisture-absorbing material;
• laminated film – 2 layers.

Anti-condensation film protects not only from the penetration of moisture into the room, but also from the accumulation of dust and the formation of soot.

In a ventilated roof, vents are left to achieve a good effect, and also holes and ventilated ridges are installed in the lower part of the eaves, which well connects the ventilated gaps of the roof with the atmosphere.

The ventilated roof structure consists of finishing material and roof insulation. The steam that leaves the room reaches the insulation, which, absorbing moisture, loses its thermal insulation qualities.

The moisture that has accumulated in the thermal insulation layer mainly penetrates back into the room and appears in the form of drops on the ceiling and walls.

And in the summer it heats up very quickly and the heat enters the room through the roof structure. To avoid this, this is why a ventilated roof is installed.

Today, the requirements for modern roofing materials are very stringent. They should protect the room from moisture penetration into the layer, and if this happens, then facilitate the rapid removal of moisture to the outside.

Therefore, a ventilated roof must be well insulated.

From ancient times to the present day, the purpose of the roof was to protect any structure from the destructive effects of wind, precipitation and scorching sun. Therefore, the qualities that were required of it were appropriate: maximum resistance to gusts of wind and tightness. The first is to eliminate drafts, and the second is to prevent melt or rain water from leaking from the roof into the attic (if there is one) and into the living quarters.

The technologies for the production of roofing materials are based on these principles. The coatings offered today are airtight and more than reliably protect the house from precipitation. But usually modern roofs consist of several layers, and the more airtight the top covering of the roof, the worse the ventilation of the under-roof space will be. Lack of ventilation will lead to increased humidity levels, which can cause roof structures to become unusable. To avoid this problem, install a roof ventilation system.

Ventilated roof installation

The roof of a house is a complex and multi-layered structure. Made conscientiously, it will protect the house from heavy rain, withstand the fall of heavy branches broken by a hurricane, and in winter it will allow you to save on heating due to heat-proof materials and high-quality insulation. As a rule, it consists of a layer of roofing and two insulating layers, one made of waterproof material, the second of heat-proof material. In turn, insulating materials can also be multilayered.

A ventilated roof is designed based, first of all, on the characteristics of the roof:

• IN pitched roofs a gap is left for the free movement of air along the entire length of the slope, and the air flow must pass from the overhang to the ridge. This direction of ventilation allows the use of insulation from any material, although it is better to give preference to vapor-tight insulation boards. When installing ventilation on such roofs, it is imperative to use protective grilles, since the air channels can easily become clogged with debris falling on the roof - branches, leaves, etc.;

• If the house has a flat roof, you need to take care of installing small ventilation holes along the edges of the roof. Air will circulate through them. The total area of ​​the ventilated layer must be at least 5-6 cm, and the total area of ​​the channels for air movement must be at least 0.2% of the roof area. If we talk about insulation, then the most suitable material in this case is mineral wool.

Materials used for ventilated roofs

The good thing about roofing with artificial ventilation is that any roof covering is suitable for its construction. The size of the ventilation holes depends on the thickness of the selected material: the thicker the roofing material, the larger the holes should be. On average, their diameter ranges from 5 to 10 cm. For example, a metal tile roof will require small holes, since its sheets are quite thin. But for a roof made of natural tiles, large diameter holes are already needed. In addition to the thickness of the roofing material, the size of the ventilation gaps and their number also depend on its weight and density.

Waterproofing materials

The choice of insulation material depends entirely on the roof covering. The main purpose of insulation layers is to prevent heat from escaping outside and water from seeping inside. Waterproofing membranes are available in anti-condensation and diffusion types. The former are used with euro slate and metal tiles, that is, with materials for which contact with condensate is undesirable. The latter can be used with natural materials that are not afraid of contact with moisture, for example, ceramic or bitumen shingles. Right choice materials for waterproofing are the key to the durability of the roof of your home!

Thermal insulation materials

Granular materials such as polystyrene, perlite or mineral wool are ideal for insulating a ventilated roof. The thickness of the insulating layer should be at least 25, or even 30 cm. When laying insulation on a flat roof, you need to ensure that the ventilation holes do not become clogged when blowing in granules. It is better to entrust this work to a specialized installation team.

Advantages of roofing with artificial ventilation

For those who still doubt the need for ventilation in the roof, it would be useful to familiarize themselves with the results that the use of such a design gives.

1. By preventing the formation of condensation in the roof layers, ventilation ensures the durability of the roof.
2. Due to air gaps and thermal insulation, the possibility of additional heat loss is minimized.
3. Thanks to the constant circulation of air in the inter-roof layers, the ventilated roof does not heat up in summer.
4. No air stagnation – a healthy atmosphere throughout the whole house!

Construction technology numbers more than a dozen engineering solutions concerning the design. The comfort of residents depends entirely on how well and competently it is done. All the power of the elements - rain, wind, and hail - falls, first of all, on the roof, so its design should be very carefully thought out.

Special requirements for roof construction are imposed in regions with high humidity, frequent rain or fog. Exposure to moisture significantly reduces service life wooden structures and roofing pie even despite treatment with special compounds and device. However, it is quite possible to minimize the problem of dampness; installing a ventilated roof will help with this.

The design of a ventilated roof has been developed quite a long time ago, its high efficiency has been proven by many years of practice. The popularity of this technology is due to the following advantages:

• high degree of protection of all layers of the roofing cake from getting wet;
• no swelling of the roof covering;
• possibility of using organic;
• economical due to the possibility of installation on top of an old roof.

If a ventilated roof is built on top of an old structure, then the latter “comes back to life”: wooden elements become dry again, moisture is removed from the roofing materials. As a result, the roof appears to be double, its resistance to adverse weather conditions increases, and the whole house becomes truly warm and cozy.

The design of a ventilated roof provides for air circulation:

• between layers of insulation and waterproofing;
• between waterproofing and roofing material;
• in the attic space (as part of the general ventilation of the house).

Thus, the entire roof structure is very well ventilated, due to which it is not only possible to get rid of excess moisture, but also maintain optimal temperature regime. In this case, competent installation of the sheathing plays a decisive role.

The ventilated roof design has a number of varieties, which are related to the purpose of the building. For garages or outbuildings, use a non-insulated option, which consists of the following components:

• rafter system;
• lathing made of wooden slats;
• waterproofing;
• roofing covering.

Polyethylene film is used as waterproofing, which is attached to the rafter legs on slats.

For heated buildings added to the roof structure slab insulation and anti-condensation film, which protects wooden elements from condensing moisture. In general, the order of layers in such a roof is as follows:

• two layers of laminated film;
• non-woven material with high moisture absorption capacity;
• polypropylene fabric.

An important part of this type of roof is the vents located in the lower part of the eaves, as well as the ventilated ridge.

Project development procedure

During design work When installing a ventilated roof, the following must be provided:

• Proper drainage. The roof structure must be such that water flows freely from its surface. This is especially true for flat roofs, where, due to improper installation, depressions often form in the covering in which water accumulates.
• Steam removal exclusively through the roof.
  

  Contrary to traditional concepts, the walls of a house with a ventilated roof should not breathe. For this purpose, their design contains a reinforced vapor barrier layer.

Such roofs began to be built in the 80s of the last century. It was during this period that it became possible to install a heat insulator with ventilation ducts to remove excess moisture. Roofs of this type were most widespread during construction apartment buildings. The roof structure consists of the following layers:

• reinforced concrete floor slab, which is also the basis for the roofing pie;
• vapor barrier;
• a slab heat insulator made of mineral wool, inside of which there is the head of an aerator - a ventilation pipe (excess moisture is removed through this pipe);
• screed made of cement-sand mortar;
• waterproofing based on bituminous materials;
• polyurethane;
• a layer of polyurethane-based mastic;
• roofing material

The roof structure is complemented side parapets, which are separated from the roofing pie by bulk or sprayed material. In modern construction polyurethane foam plays this role, providing high insulation and sealing. It is also used to insulate the terminals of aerators.

Advantage flat roof is low cost and quick installation. Disadvantages: necessity frequent repairs and poor thermal insulation.

Pitched roofs

The design of this type of roof provides excellent air circulation, which penetrates into the under-roof space through the lower overhangs and exits through the ridge. This way it is possible to avoid the accumulation of dampness, which causes rotting or fungus on the parts rafter system and roofing materials.

In some cases, a forced ventilation device is required. For this purpose, roof fans are installed on the roof.

As a covering Mostly lightweight materials with a wavy surface are used. Pitched roof can be either cold or insulated. The difference between these two options is the presence of an insulating layer. Mineral wool boards are usually used as an insulator.. Insulation with this material provides the following advantages:

• ease of installation;
• insulated coating;
• absence of cold “bridges”.

The list of roof installation operations is as follows:

1. Preparing the base. At this stage, work is carried out to level the surface, eliminate cracks, chips and potholes. A screed made of cement-sand mortar or asphalting floor slabs is best suited for this purpose. The result should be a smooth surface with a slope of 2-3 degrees.
2. Laying vapor barrier film and insulation. These layers must be laid in a continuous mass; cracks or breaks are not allowed.
3. Installation of a waterproofing layer and cement-sand screed.
4. Laying roofing. For flat roofs Fused roll materials are used as coating. During installation, the bitumen included in the coating is melted using gas burner