Ventilation grille on the roof of a private house. Ventilation device for the attic of a private house: air ducts, dormer windows, gratings. Methods for venting air outside

Good ventilation of the attic space is the most important design stage. It is the ventilation system that allows you to regulate heat transfer in the attic, and, accordingly, in the premises of the house, since the roof in the summer can heat up to more than 100 ° C. In the cold season, ventilation prevents the accumulation of moisture and freezing of the rafters.

In the off-season, moisture and condensate collect on the insulation structures of the attic space, quickly render them unusable and destroy them completely. As you can see, attic ventilation in a private house is important at any time of the year, regardless of whether this space is used as a residential or technical space.

Why are many people afraid to insulate a cold attic

• The first myth is that the rooms of a private house are cooled down due to ventilation. In fact, the heat escapes due to poor-quality thermal insulation of the walls and ceiling, and the ventilation of a cold attic has absolutely nothing to do with it.
• The second myth is that you need to ventilate the attic space only in the summer to save the living quarters of the house from stuffiness. This is fundamentally wrong, since it is in winter that moisture passing through the ceiling and accumulating in a cold attic will turn it into an “impenetrable forest” filled with icicles.
• The third myth is that the ventilation of a cold attic is already carried out through natural cracks in the design of the gables. In fact, in order for the ventilation of the premises to be sufficient, air should be made, the size and quantity of which is strictly calculated.

Properly organized attic ventilation in a private house allows you to save the roof structure for a long time, saves significant money on heating and air conditioning of residential premises, and also prevents snow accumulation and icing of the roof during the cold season.

The most common type of attic ventilation is ridge eaves. Convection air movement is created by openings along the entire perimeter of the cornice overhang and exhaust openings along the ridge of the building. Despite the fact that the design of such a cold attic ventilation system seems very simple, it requires proper execution and accurate calculations.

Ventilation of a cold attic through dormer windows

Attic ventilation through dormer windows is the oldest way of arranging a private house. Dormer windows are placed on opposite gables, with dimensions of 600x800 mm. This method has many advantages and is not without drawbacks. The advantages include ease of installation and sufficient cross-section for good air exchange. The disadvantage of this method is the presence of stagnant air zones. That is why such an attic ventilation system is used quite rarely. In the modern version, dormer windows are made smaller, but they create excellent air exchange, in combination with a cornice-ridge ventilation system.

Other ways to ventilate a cold attic

It is very common for domestic and European builders of private houses to use special vents for organizing ventilation in the attic. Air vents or vents in the roof of a private house are called holes into which gratings are mounted, protected from atmospheric precipitation. Also, deflectors, aerators and pitched exits can be used as vents.

Products are ridge or eaves. The name of each type tells about their location. Eaves products are of two types: slotted and point. Cornice-slotted vents are a gap between the wall of the house and the cornice, 2 cm wide, closed with a metal mesh. Cornice-point vents are made in the form of holes, the diameter of which depends on the angle of the roof slope, but not more than 2.5 cm.

Ridge vents are slots along the roof ridge, closed with perforated metal, 5 cm wide. For better air exchange, they are arranged on both sides of the ridge along the entire length of the roof. Ridge vents can be purchased with roofing material.

An equally popular solution for arranging ventilation of a cold attic is the installation of ventilation turbines, which provide traction quite well.

Advice:
If the cold attic of your private house is not equipped with dormer windows, then the only way to equip it with a natural ventilation system is to install air.

Features of the ventilation system of a warm attic space

Ventilation of the warm attic of a private house must be planned even during the construction of the roof. If a solid roof made of sheet slate, metal tiles or other sheet material is used during construction, then a ventilated space should be left between the insulation and the roofing material. To do this is quite simple by installing an additional rail on the rafters. Air flows must move freely under the entire surface of the roofing material. The entry of air masses is done in the "filing", and the exit, along the entire length of the ridge.

To improve air exchange in the attic space itself, in addition to windows, many experts recommend installing VTK valves, or installing deflectors, ventilation fungi and aerators on the roof.

Advice:
If slate or ondulin acts as a roofing material, then it is undesirable to sew on a counter-rail, since it will only worsen the free movement of air in the under-roof space. The wave-like shape of these materials, in itself, provides enough space for air movement.

How to calculate the ventilation system for the attic

I would like to note right away that only a specialist will be able to calculate the ventilation system for your attic space in the most qualitative and correct way, taking into account all the nuances. But his services cost a lot of money, so most developers make their own calculations.

You should know that for normally functioning natural ventilation, the following proportions of 1:500 must be maintained. For 500 sq.m. of the attic area, the area of ​​the ventilation openings should be 1 sq.m.

Important!
With the independent arrangement of the ventilation system in the attic of a private house, the placement of ventilation vents, which are installed depending on the shape of the roof, plays a huge role. Air distribution schemes can be found in specialized literature, but it is best not to save money and turn to professionals for correct calculations.

In winter, ventilation of the attic space prevents moisture from accumulating, and also prevents the rafters from freezing. In summer, the roof gets very hot under the influence of direct sunlight (the temperature depends on the roofing material), but with the help of properly organized air exchange in the attic, this temperature will not be felt. In a rainy autumn, excess moisture can lead to the formation of mold on the main load-bearing elements of the house - with proper ventilation this will not happen.

Choice of attic ventilation options

Attention! The attic air exchange system is a product that can be of two types (ridge, eaves). You can use a fan, it is placed on the roof. You can often find holes in the roof that serve as ventilation for the attic, a dormer window or a ventilation duct.

Roof aerators are exhaust outlets (air vents) of the under-roof space, which contribute to the release of moist air to the outside. The aerator is a pipe with a mushroom cap. They are installed on pitched roofs, the peculiarity of such a roof is that the circulation of wind masses under the roof is carried out due to the difference in temperature and pressure difference. Air through the cornice aerators rises from the bottom up and is discharged through the aerators located at the ridge.

Types of aerators

• Point aerators (ventilators) - are installed on skates (ridge), as well as pitched, which are installed on the slopes of the roof, in a certain area. They are different in shape, but more often found in the form of a hat mushroom, inside of which a fan is built.
• Continuous aerators (air vents) - they are oblong and continuously stretch along the ridge. Thanks to the holes, air will circulate along the entire roof. This type of ventilation is visually hidden, because it is covered with a roof from above. By the way, when buying a roof, you can immediately pick up a suitable aerator.

Supply and output ventilation of the attic in a private house occurs through aerators (cornice and ridge) in the pitched roof. Moreover, eaves are installed not on one, but on both sides of the cornice overhangs. They represent a gap with a diameter of 2.5 cm between the wall of the building under construction and the roof.

When installing point aerators, the hole diameter should be no more than 10 mm. Although it all depends on the slope of the roof, if it is 15 degrees, then the hole can be 25 mm. If aerators are installed on a roof slope, gratings and grids are fixed on them. Ridge aerators can be made solid, or they can be installed every 6 m (wind vanes).

Attic ventilation through dormer windows

Many roofers believe that this type of ventilation is not very effective because it cannot provide ventilation for the entire attic and air stagnation is formed. In the project of the house, it is necessary to place dormer windows on opposite sides of the roof. The optimal window dimensions should be 800 x 600 mm. To begin with, the wooden case is fixed to the rafters with the help of racks. Then sheathed with a roof. The last step is to install the stack package into the window box.

You should carefully examine the joint between the roof and the frame of the dormer window, you need to make sure that there are no gaps, so a strip of roofing metal is attached in this place. The window is not placed near the ridge, as well as the roof eaves. It is recommended to install windows at a distance of 1 m from each other; they can be equipped with a ventilation grill made of polymeric materials.

hip roof cold attic ventilation

A hip roof is a design in the form of a classic gable roof, 2 more additional slopes are added from the end of the roof. This type of roof is divided into:

• half hip;
• tent;
• broken line.

Each type of roof has its own characteristics of attic ventilation. For example, it is impossible to apply the ventilation rules of a gable roof to a hip roof. For this type of roof, 2 holes are made (inlet in the filing and outlet near the ridge beam). If the roof has a slope greater than 45 degrees, the air masses are circulated due to the temperature difference. With a small slope, ventilation is carried out by mechanical devices (fans), turbines.

The type of roofing material is also of great importance. So, if the roof is covered with slate, then it is not necessary to install additional ventilation in the attic. Wind masses will freely penetrate into the attic. Ventilation is installed if the roof is equipped with metal tiles, because a film vapor barrier is laid under it.

Important! The crate and rafters are not sheathed with insulation from the inside, because the ventilation of a cold attic in a private house protects them from environmental factors. Edged board can be used for sheathing wooden beams. However, it is necessary to make small gaps in the skin that will allow air to pass through.

Is it possible to bring ventilation to a cold attic

To answer such a request, let us once again recall the role of proper air exchange. Ventilation in the attic is designed to solve such problems:

• prevents the accumulation of fumes formed in the house;
• protects the insulation from the formation of fungus, as well as the main elements of the roof from destruction under the influence of moisture;
• helps to maintain a constant temperature in the attic.

If a ventilation duct is brought out of the house to a cold attic, then moisture will accumulate in its space. As a result, wooden structures will gradually begin to rot and require replacement. In a word, in a cold attic, removing home ventilation is unacceptable.

What is special about the calculation of vents

Do-it-yourself ventilation in the attic of a private house is calculated taking into account a number of parameters:

• attic area;
• types of insulation that were used during construction;
• the volume of warm air coming from living rooms.

Slotted vents play a key role in bringing ventilation to the attic. The ratio of their area to the area of ​​the attic is 1:500. In this case, the airflow area cannot be less than 0.05 m.

Attention! An important role is given to the height of the roof slopes. For example, there is a rafter 20 m long. Then the area of ​​​​ventilation slots on the cornice overhang is 400 square meters. cm/m. Another example: a rafter 7 m long, then we get an area of ​​​​200 square meters. cm/m. Conclusion: The total area of ​​the holes through which the supply wind masses enter is less than the total area of ​​the ventilation outlets.

When building a roof, there may be errors, so the calculations should be with a margin of 5 cm. These tips apply to a standard gable roof.

What are the features of an insulated roof

Do you need ventilation in a cold attic if you plan to insulate the attic to equip the attic? When warming will be performed, it is necessary to adhere to the following basic rules:

• The distance between the insulation and waterproofing should not be less than 30 cm. This rule must be taken into account when laying the roofing "pie".
• For mineral wool insulation, it is necessary to leave a small space, since over time the volume of the insulation will increase by a third. With the help of rails, you can increase the length of the rafters.
• Diffusion membranes are necessary in cases where the roof structure is complex. Installation can be done directly on the heater.
• On the crate, the height of the bars must be at least 40 mm so that the air masses entering through the siphons exit through the ridge.

Ventilation of a cold attic in a private house differs significantly from the arrangement of ventilation when insulating an attic. In order for ventilation to work as expected, it is necessary to calculate the strength of the roof elements. It is better to mount spotlights from aluminum or plastic, since such panels are not afraid of corrosion. Ventilation between the rafters is necessary so that there is no freezing and frost formation in the attic. In order to avoid clogging the air ducts with air, it is necessary to protect them with a mesh or grate. The heat exchanger will allow you to regulate the temperature inside the attic.

No one is surprised at the need for mandatory insulation of the attic space to create a comfortable microclimate in the home. Many do not even think about the installation of a proper ventilation system in this room. But high-quality ventilation of the attic helps to maintain a microclimate there, prevents the occurrence of fungi, rot, and increases the life of the roof structure. Properly calculated and thought out is no less important than competent vapor and thermal insulation.

Attic ventilation ensures the mixing and equalization of the temperatures of the roof structure and the external environment. It prevents the formation of ice during the melting of the snow cover, the gathering of "avalanches" and the appearance of large icicles. The arrangement of a high-quality air exchange system is actually extremely important.

Attic space: ventilation

In different buildings there are different types of attics: they have a different purpose, respectively, their arrangement is different and. According to the main feature, attics are divided into two main types - warm and cold. The last type is more traditional. In such a case, the system is not protected in any way, since only the ceiling is insulated. Another type has only one important goal - to properly protect engineering.

Cold attic: ventilation device

In the cold room of the attic, an adjustable one must be present. To equip it, leave it open and. A good alternative is a special lining with gaps that allows air to circulate freely. If, however, or are used as a roofing, and there are no vapor and wind insulation films, in this case, you don’t have to worry about a special ventilation device in the attic.

Roof space ventilation device

Between the individual waves of the roof, the air without interference penetrates into the space under the roof and exits.

It is also able to ventilate on its own, but it can cause condensation, so the use of an insulating film in this case is mandatory.

At the ventilation ducts are located in the gables. Loosely located sewing overhangs can be quite an effective way to solve the problem.

Narrow slots, evenly distributed, will favor high-quality ventilation of the entire attic space.

But if the lining adjoins too tightly, or in the case when the gables are made of stone, holes will have to be made in the walls. It would be rational to place them on opposite sides, thereby ensuring the exclusion of pockets of stagnation. The total S (area) of the ventilation ducts should be 0.2% of the area of ​​the entire floor.

There is another option that allows you to save money. It involves the installation of standard gratings for, one of which is adjustable, the other is directed downward with its holes. A mosquito net will protect them from insects.

If we are dealing with, then the ventilation device will be made differently. Below, in the filing, an inlet is made, and on top, at the ridge, there is an exit. In the case when the filing of the overhangs is made of wood, the bars do not have to be placed tightly, there may be a gap of several millimeters between them. If the stitching was carried out using plastic, then there should be holes in all components. Such panels are called spotlights.

A situation is possible when the binder is assembled quite tightly. How to be in that case? For this, special gratings equipped with a mesh are produced. They have a diameter of five centimeters: they are placed every 0.8 meters, along the entire length of the wind overhang. To make holes, use a drill with a suitable (round) drill. The upper conclusion is made from above.

In general, the types of ventilation largely depend on the type of roof. For example, a classic skate is suitable for and euroslate. In an elastic flexible roof, a ventilated ridge or turtle is successfully used. Also, a special valve is used for ceramic tiles.

Perfectly ventilated with a standard ridge. I must say that the ridge is not just an economically beneficial replacement for the valve. This is also a great way to get a ventilation system in the shortest possible time.

Sometimes special hearing rooms are used, with bars or glazed, but their arrangement is a rather difficult task, which requires theoretical knowledge and practical skill.

Warm attic: ventilation

In modern heating systems, natural circulation is not actually used. In other words, if it is planned to turn the attic space into, the roof must be made entirely ventilated. For a roof made of flexible tiles or sheet material, you will have to equip a special ventilated area: a counter-rail is sewn onto the rafters.

For roofs with a metal coating, it is desirable to use a windproof film.. A slate roof can do without a counter-rail, since air must flow freely from the bottom up. An entrance is arranged in the filing, the exit to the outside occurs through the ridge.

The attic should be ventilated in the same way as other rooms. Air enters through the windows (possibly the installation of VTK valves), and leaves the house through the ventilation openings. If they are absent in the walls, then fungi (aerators) are made at the place of the hood, on the roof.

Attic ventilation in the house: truth and fiction

Questions relating to high-quality ventilation of the attic space are overgrown with rumors and speculation. Which facts about proper ventilation are true and which are not?

• Is it true that warm air escapes from the house through the ventilation ducts in winter? There is an opinion that the operation of ventilation in the cold season only interferes with the heating of the home. In fact, it is unlikely that the holes are the cause. In the case when the dwelling heats up for a long time and then quickly cools down, it is not the ventilation that is to blame, but the insulation. I must say that not too high-quality insulation is able to pass moist air into the attic. The consequence of this phenomenon is often the formation of drops of condensate, causing, in turn, damage and decay of wood.
• Is it true that ventilation is only required during hot weather? There is a belief that the work of ventilation is necessary only in summer, with a strong increase in temperature. In reality, this is not so. If you do not carry out ventilation measures in winter, this is fraught with the formation of icicles, the development of fungi and.
• Is it true that the size of the ventilation holes does not matter? This is also a delusion. You should not equip the channels "by eye", since it is likely that the efficiency of such a system will tend to zero. Airflow should be related to floors as one to five hundred.

From the author: hello dear readers! After living in a private house for a couple of years, many owners decide to install ventilation in the attic, primarily because of the appearance of an unpleasant smell and dampness. In the article we will tell you how to make ventilation for a cold attic in a private house with your own hands.

Reasons for installation

The attic in a private house must be equipped with a ventilation system. This fact is important for the premises at any time of the year.

In summer, the heat from the red-hot roof passes into the room and sometimes heats it up to 150 degrees. The main share of heat is distributed at the top, and the air conditioner operates in enhanced mode. And in his absence, the owners of the house are forced to suffer from stuffiness and heat.

In winter, ventilation helps to remove accumulated moisture. According to technical safety requirements, the temperature in the attic and the street should differ by no more than 4 degrees, since sharp temperature drops create favorable conditions for the accumulation of condensate, which subsequently forms icicles. With the onset of a thaw, they melt, and moisture gets on the floor, which leads to deformation and destruction of the ceiling structure and roof, appears on the rafters.

Despite the importance of ventilation, many owners are afraid to install it, because they think that warm air escapes through the grates in the attic, and the room cools faster. In fact, the reason lies in poor-quality thermal insulation of the ceiling and walls, in addition, moisture penetrates into the attic through poorly insulated ceilings.

Important: ventilation of a cold attic of a tent or hip roof is needed, most often, only in the summer.

Ventilation grilles in the attic of a private house play an important role in thermoregulation. With proper installation, they will save on heating, provide the desired degree of cooling and protect the room from negative external influences. In addition to all the above advantages, attic ventilation does not allow winter precipitation to accumulate on the roof of the building.

The principle of operation of the ventilation system

Unobstructed air circulation from the street under the roof space is possible due to the holes, the most effective of which are located under the overhang and in the ridges. This arrangement allows the use of air-thermal pressure coming from the ceiling area.

If the attic ventilation is installed in accordance with all the rules, in an hour period the air flow passes under the roof of the room twice - the movement is directed from the bottom up to the ridges with holes from the vents.

Advice: in the presence of an insulated roof, a gap of about 5 cm wide is left between the roof and the insulating layer for free air exchange.

To ensure a high-quality hood, a combination of installed ridge elements and vents in the ridge itself is necessary. For tile roofs, special tiles with air exchange products are used.

There is another way to ventilate the attic - installing ventilation turbines (deflectors) for mechanical draft. This type of installation is recommended for ventilation of an insulated attic space above the attic.

Source: growinggarden.ru

Important: when installing ventilation, you need to pay attention to the slope of the roof. Ridge vents covered with snow can be replaced with pipes that are higher than the snow cover.

ventilation window

The oldest known in the attic is a ventilation window. For good air exchange, under-eaves and ridge vents, as well as dormer windows, are sufficient. The hip roof is assumed in the absence of gables. In this case, there is no room for ventilation windows, and such attics are ventilated with eaves and ridge vents.

The situation is more complicated with attic ventilation under the attic. In this case, the role of air is played by gaps in the inter-roof space. An obligatory element of such a roof is mechanical traction devices. The ventilation outlet is located in the columns.

Dormer windows

Without installing a system of vents and vents for air exchange, dormer windows can be equipped in the attic. However, this method is not effective enough, since air can stagnate in the window sill and above the window space.

To improve ventilation and reduce the level of stagnant air, it is recommended to make dormers 60 × 80 cm in size, placing them in opposite gables. How to make a montage with your own hands, you can find out by watching the video .

In theory, it looks like this: roofing material is laid on pre-made wooden frames, which are attached to the rafters with special racks. For finishing openings, ordinary lining is suitable. Then a window frame is mounted in the opening. At the same time, the gaps between the roof and the frame itself are tightly closed.

Rules for installing ventilation windows:

• ventilation vents, roof and roof vents are needed;
• window-to-window distance - no more than 1 m;
• equal distance of windows from the eaves, sides and ridge;
• window design should not violate the general concept of the appearance of the building.

Ventilation products

Air ducts are openings to ensure air exchange in a cold or warm attic. They are located in the roof and are the only possible way to ventilate the attic without dormer windows.

Products are of two types: cornice or ridge. Cornices are located on both sides of the eaves and, in fact, are a gap between the wall and the roof, the width of which is approximately 2 cm. They are called slotted. Air, made in the form of holes, are called point. The width and diameter of the vents should be no more than 2.5 cm, depending on the slope of the slopes.

Ridge vents have a slit shape up to 5 cm wide or the shape of wind vanes with intervals not exceeding 8 meters. This type of product is also used in tile coverings, with holes through one row from the ridge.

Vents for the upper layer of the roof are made in the form of a retractable roof outlet, aerators or a gable grid. All these elements can be purchased along with the rest of the building material.

Aerators

The roof aerator is by far the most convenient and modern type of ventilation products. Aerators provide good air exchange by removing excess moisture, steam and stagnant air in the cold attic of a private house; they are installed on roof slopes, replacing ridge counterparts.

Aerators are point, with built-in fans to ensure proper air circulation, and continuous (ridge), which is a plate with holes located along the ridge. The latter are covered with a roof from above. They provide constant air exchange and are hardly noticeable.

Source: allremont59.ru

Source: stroydom.guru

All types of roof aerators are made from:

• ceramics;
• cermets;
• bituminous tiles;
• flat roof.

Aerators are usually mounted in places with eaves. But there are other options for their placement:

• point models are installed at a distance no further than 50 cm from the ridge;
• aerators go beyond the slot by 25 cm from both ends of the ridge;
• aerators are suitable only for roofs with a slope of 15 to 45 degrees;
• the distance from the wall or chimney is at least 30cm.

Ventilation calculation

Before starting the installation of attic ventilation, it is recommended to make accurate calculations. Only a specialist can guarantee the result. But if you still decide to calculate and carry out the installation yourself, our recommendations and advice will undoubtedly help you.

Open attic roofs

In the design of the roof with an open attic, the attic floor is thermally insulated, and outside air enters it through holes measuring 700 × 300 mm, located along the perimeter of the attic with a step of 1 m. This air is removed through the exhaust. The principle of operation of an open attic is that a mass of dry outside air enters the attic space and removes moisture from the premises. A feature of the open attic is the combination of warm and cold attic systems.

Advantages of open attic roofs:

 a significantly small number of intersections of the roof with protruding elements, ensures the reliability of the roof;

 maintenance of normal operating conditions in residential premises;

 relative simplicity and simplification of the construction of the coating, which is made of thin-walled panels without thermal insulation;

 the possibility of using any insulation, with free laying on the attic floor;

But a roof with an open attic, unfortunately, has a number of significant drawbacks, such as:

 weak exhaust ventilation of the upper floors of the house due to insufficient pressure in the ventilation system with a low headroom height;

 lack of thermal efficiency in winter;

 Possibility of falling into the attic space of atmospheric precipitation.

Roofs with an open attic are best used in southern regions.

A separate type of roof can be distinguished as a non-rolled reinforced concrete roof - this design has an impassable, semi-passable or walk-through attic and a coating of special reinforced concrete elements. The design of the rollless floor does not have an attic, it is replaced by a coating of reinforced concrete elements that perform enclosing and heat-insulating functions, and protects the premises from atmospheric influences. In non-rolled roofs, waterproofing compounds only protect the concrete surface of the coating from premature destruction by the atmosphere, and the water resistance of the joints of the roofing panels and their interface with the enclosing structures is solved by constructive methods. Rollless reinforced concrete coating consists of supporting elements - trusses, frames, pitched beams, etc. and reinforced concrete slabs under mastic waterproofing insulation. Rollless reinforced concrete roofs are divided into:

According to the method of drainage- with a central drainage tray made of separate trough-shaped panels, three-sided panels and a funnel tray with a drain funnel; with drainage trays located at the parapet walls; with external unorganized drainage system.

By type of mating roofing slabs- with sides located above the shelf of the roofing panel; with grooves along the edges of the roof panels.

According to the method of adjoining roofing slabs to frieze panels- with the use of additional elements; with removal along the edges of the building to the frieze panels.

Roof panel design- single-layer from heavy or light concrete; multilayer or with heat-insulating liners; with conventional reinforcement.

The attic spaces formed between the ceiling of the upper floor and the roof are used to accommodate various equipment: chimneys and central heating pipes, ventilation ducts and shafts, machine rooms of elevators. To enter the attic in high-rise buildings, ordinary stairs and doors are made, and in low-rise buildings, entrance hatches and ladders are made. To illuminate and ventilate the attic space, attic (dormer) windows are arranged, which are used to exit to the roof. The supporting structures of attic pitched roofs are layered rafters or roof trusses. The enclosing structure of the roof consists of a roof arranged on a solid (flooring) or sparse (batten) base. Laminated rafters are made in the presence of intermediate supports (walls, pillars, girders) and with a relatively small distance (span) between them. Over narrow buildings, layered rafters of shed roofs can also be arranged in the absence of intermediate supports. The beams form the slope of the roof, and the remaining elements serve as supports for the rafter beams and create the overall stability of the structure. Rafters are made from softwood in the form of boards, beams, and sometimes logs. The most economical use of sawn timber. Attic floors in the presence of trusses are made suspended by attaching them to the lower nodes of the trusses. The gap between the roof slab and the internal joint is filled with a sealant. An internal joint bar can be mounted on the internal joint. It is fixed with screws over the profile wave in increments of 300-500 mm. The plank is not compacted. Before the roof ridge is fixed, make sure that all roof slabs are installed and fixed, and the sealing tape is nailed under the ridge strips. It is important to ensure that the sealing tape and the first row of fixing screws are covered by the ridge strip. The ridge bar is fixed with screws through one profile wave.

23. Wooden and reinforced concrete rafters

The roof of the building has a bearing and enclosing parts. The load-bearing part consists of wooden or reinforced concrete rafters, wooden, steel construction trusses or reinforced concrete panels.

Wooden rafters. The cross section of the rafters is selected in accordance with the project, it all depends on the length of the span and the design of a particular roof, but in any case, the width is usually not less than 150 mm., The thickness is from 50 mm. Like all wood, wooden rafters must be antiseptic before installation. The general principle of mounting wooden rafters is that sawn and prepared rafters are laid at several points. The lower point is a Mauerlat, the upper one is a ridge beam leveled at the right height, the middle point can be a chair already made at the right level or a temporary support installed at the right level for several rafters, usually under a whole roof slope. If the mauerlat and chair are permanent elements that will remain in the roof structure, then the ridge beam, as well as temporary supports, can be removed after mounting and fixing the rafters. The roof ridge can be mounted without a ridge beam, immediately joining the wooden rafters from opposite roof slopes, but this should be allowed by the design of a particular roof. In many roof structures, there are diagonal wooden rafters, which usually go from the ridge to the corner of the building and must be set immediately in two planes of adjacent roof slopes. In turn, they are attached to the diagonal rafters at an angle, shorter rafters from two slopes roofs.

The lower part of the rafters, that is, from the Mauerlat and below, where the roof box will be, is usually produced a little longer than necessary. And when all wooden rafters are exposed and fixed, they are sawn off exactly in a straight line. All rafter fastenings must be of high quality and reliable. The cuts must be accurate, with a snug fit. It is not allowed to use various linings, substrates and other elements that can fly out, deform and so on over time. The rafters are fastened to each other, to the Mauerlat, to armchairs, chairs, braces and stretch marks using metal plates, corners, special brackets, bolts or threaded studs. For bolts and nuts, washers or metal plates must be used to prevent the nut from sinking into the wood. As overlays, pieces of plywood can be used instead of metal plates. Fastenings only on nails or screws are allowed only as temporary, during the installation of rafters. And they must be replaced with fasteners using angles, plates and bolts. If wooden rafters are extended in length, then the connection is made with an overlap (rafter to rafter) of at least 1 meter and twisted with at least two bolts.

The lower fastening, where the wooden rafters lie on the Mauerlat, is performed by sawing the so-called “saddle” in the rafter, which should fit snugly on the Mauerlat. Washed down is usually done no deeper than 1/4 of the width of the rafter. The fastening of the rafters on the Mauerlat should keep the roof from being lifted by gusts of wind and from the load on the Mauerlat of the severity of the roof and is carried out using special metal corners.

Ventilation system in multi-storey buildings

According to the same principle, a knot is made where the rafters lie on a vertical chair. The fastening of the rafters to each other, on the ridge is done end-to-end and fixed with metal plates. Stretch marks - elements that work in tension and usually protect the walls of the building from excessive roof pressure, which can even squeeze out capital walls building. Stretch marks are attached to the rafters with an overlap, always with the help of bolts.

The braces usually prevent the rafters from buckling and stiffen the entire roof structure, butt-fastened with the help of lining plates.

Reinforced concrete rafters. Prefabricated reinforced concrete rafters have a number of positive qualities - they are fireproof, durable, relatively easy to install. However, such rafters are not widely used, primarily due to the large weight, many details and a complex combination of reinforced concrete and wooden elements. The main element of prefabricated reinforced concrete rafters are reinforced concrete beams of rectangular or tee section with a narrow wooden block on top, to which the crate is attached with special brackets or nails. The beams are laid on longitudinal walls and a ridge run, which, in turn, rests on reinforced concrete or brick pillars. Prefabricated reinforced concrete rafters are connected by welding of embedded parts to each other. In the case when the distance between the supports (external or internal) is more than 7.5 m, in civil buildings the roof trusses are the supporting basis of the roof. Roof trusses are a flat, geometrically unchanging lattice system, consisting of separate interconnected elements (rods). In civil buildings, mainly triangular trusses are used. Roof trusses can be wooden, metal-wood, steel and reinforced concrete. Wooden trusses are called hanging rafters. Trusses are called metal-wood trusses, in which the compressed elements are made of wood, and the stretched ones are made of steel. Steel trusses are made from paired corners of the usual assortment, fastened in knots with welded seams, using sheet steel gussets. Such trusses usually cover spans of 7.5; 9; 12 and 15; 18 and 21 m. Hanging rafters and trusses are placed at a distance of 3-6 m from each other. For the device of the crate, runs are installed, and rafter legs from the boards are installed along them. To form a ceiling, an attic floor is arranged, which is suspended, it consists of girders suspended from the nodes of the lower belt of hanging rafters or trusses, beams resting on them, and inter-beam filling. Light material should be used for insulation - mineral wool, porous slabs, etc. Most often, metal and reinforced concrete rafters are used in the construction of a stone or reinforced concrete house.

The reinforced concrete rafter legs of the layered rafters are laid at one end on the outer wall of the building, and at the other end on a prefabricated reinforced concrete run supported by brick columns. The lower ends of the rafter legs protruding beyond the wall can carry the cornice overhang of the roof. When choosing a material for the manufacture of rafters, many factors must be taken into account: the length of the rafter leg, the distance between the rafters, the weight of the roof, etc.

Roof device with a cold attic

Most pitched roofs in our country have a cold attic in their design. This name is due to the air temperature in the attic, which should not differ much from the air temperature outside the house. With such an arrangement of the attic, a sufficiently large buffer air zone is formed, which allows you to effectively control the temperature in the attic with its proper arrangement.

Cold loft design

When building the roof of a house, many people think about making a cold attic or attic under it? The easiest way to organize a roof with a cold attic. Building an attic will cost several times more and will require more labor costs.. Although, it is undeniable that the attic will significantly expand the living space.

Cold loft roofs have the following main ingredients in their pie:

1. roofing;
2. attic outer walls (applicable for gabled roofs with gables);
3. insulated ceiling between living space and attic.

Ventilation is provided by eaves and ridge ducts. The air passing through the cornice openings is called supply air, and the air exiting through the ridge is called exhaust air. Additionally, ventilation can be done through dormer windows on gables or roof slopes. Windows are equipped with louvered grilles for the possibility of adjusting the intensity of ventilation.

Dormer windows are located on opposite roof slopes so that there are no unventilated areas.

Dormer windows can be rectangular, triangular and semicircular. Their lower part should be at a height of no more than 0.8-1.0 m from the floor in the attic, and the upper part should not be lower than 1.75 m from the floor in the attic. They can also serve as an exit to the roof of the house to inspect the roof, ventilation and chimney elements.

Steam and thermal insulation of a cold attic

For a roof with a cold attic, it is most important to minimize heat loss through the attic floor. For both wooden and reinforced concrete floors, vapor barrier is mandatory. It is laid on the ceiling itself and protects the insulation from vapors that can condense in the heat insulator, passing through the ceiling of the living room. As a heater, plate and bulk materials can be used. The ceiling pie consists of a vapor barrier, floor beams and insulation.

The following types of heat insulators are often used in ceiling ceilings:

• polystyrene and foam boards;
• mineral wool boards or mats;
• expanded clay granules;
• fuel or granulated slag;
• sawdust with lime or clay;
• pumice.

The thickness of the required insulation layer is selected depending on the calculated winter temperature using the table below.

Winter temperature is calculated according to SNiP 2.01.01-82 (construction climatology and geophysics) or is selected by regions of the Russian Federation from the corresponding climate maps.

Insulation is placed between the joists or beams of the ceiling, and a plank flooring is made on top for attic passages. Logs are usually 50 mm thick, and deck boards are 25-35 mm thick.

For ventilated attic spaces, soft or semi-solid heat-insulating materials are considered the most optimal.

Attic waterproofing device

Waterproofing roofs with a cold attic, according to many experts, is a controversial issue. Some say that waterproofing must be present under the roofing material, and someone categorically recommends abandoning it. Much here depends on the type of roofing material and the angle of inclination of the roof slopes.

Metal roofs are most susceptible to corrosion that occurs with possible small leaks or from condensation. Therefore, once again we draw your attention to the fact that ventilation plays one of the main roles in the fight against condensate.

For flat metal roofs, experts recommend installing superdiffusion membranes. It will prevent moisture from entering the outside of the roof when blowing snow or rain. No matter how well the roof is laid, there is always the possibility of minimal leaks. That is why, having overpaid a little, you will receive additional protection against moisture ingress on the insulation in the ceiling of a cold attic.

Possible leaks or condensate when it gets into hydrophobic heaters significantly reduce their heat-insulating properties.

If, for example, slate is used as a roofing material, then waterproofing can be abandoned. There is also a corrugated board with an anti-condensation coating on the market, which can hold up to 1 liter of water per 1 m 2. For our part, we recommend that you always use waterproofing membranes, because this is the cheapest and easiest additional way to protect your roof from possible leaks.

When installing waterproofing membranes, a counter-lattice is used. It performs the function of a fixing rail and, due to its height, provides the necessary clearance for ventilation of the under-roof space. The device of the crate of a cold attic is no different from insulated roofs. The dimensions of the crate and its pitch determine the type of roofing to be installed.

Temperature regime of a cold attic

To prevent ice and icicles from forming on the roof, it is necessary to maintain the correct temperature and humidity conditions in the attic. With insufficient thickness of the heat-insulating material, significant heat losses occur through the ceiling. Warm air, heating the roofing, causes snow to melt and ice to form. By choosing the right layer of insulation, this can be avoided.

You can evaluate the effectiveness of a heat insulator using a temperature measurement of the top layer of insulation. An electronic thermometer is immersed in a heater by 10-20 mm. The temperature readings taken must match the values ​​in the table below.

As you can see, the arrangement of a cold attic pie does not differ in particular constructive complexity. The main task is to provide the necessary intensity of ventilation and the thickness of the heat-insulating layer in the ceiling ceiling.

Features of attic ventilation in apartment buildings

The design features of apartment buildings require special attention to the ventilation system. For high-quality air exchange in residential premises, it is required not only to rationally design the ventilation system of the house, but also to make sure that the attic and basement are in proper condition.

Often, attic spaces are not given importance, but they are extremely important, especially when you consider that the ventilation of the attic of an apartment building is responsible not only for the comfort of the residents of the upper floors, but also for the safety of the entire structure.

Consequences of improper ventilation

Failure to comply with attic ventilation standards in an apartment building leads to the following consequences:

• Violation of ventilation in the summer. Under the bright sun, the roof overheats, due to this, the air in the attic heats up. If the air exchange is not properly organized, then living in the apartments of the upper floors in the summer becomes uncomfortable, which is why the tenants are forced to supply the rooms with additional air conditioning systems.
• Exhausting the apartments of the upper floors in winter. Due to the temperature difference in the apartment, the humidity rises, condensation forms. This situation is especially familiar to the owners of plastic windows. Condensation damages wallpapers, appliances and furniture, causes mold, fungi and microorganisms harmful to health. Unfortunately, in this situation, the organization of additional heating of the room does not save the situation.

In the attic of an apartment building, high humidity is:

• Condensation is the reason for the slow destruction of the building, an aid to the development of corrosion inside reinforced concrete elements and rotting of wooden structures.
• The development of mold and fungi that enter apartments through ventilation shafts and cause various diseases.
• Violation of the natural ventilation system of the entire building.
• Rapid wear of heat-insulating materials, overheating or hypothermia of apartments.

Ventilation of attic spaces in new buildings and in houses of the secondary housing stock

Considering the question of how to make ventilation in the attic of an apartment building, one should take into account not only the need to design high-quality natural ventilation, but also the costs that are required to organize and maintain an artificial ventilation system (supply, exhaust or combined).
The modern rhythm of life is very different from what it was under the Soviet regime, when most apartment buildings were built. These buildings were designed for a different level of noise and air pollution; other materials and technologies were used for construction. This also influenced the creation of ventilation systems.
As for new buildings, in some cases additional artificial ventilation is immediately laid down, it becomes a condition for comfortable living indoors and a guarantee of the safety of the home in the future.

The most inexpensive way to solve the problem of attic ventilation in apartment buildings

Maintenance of standard mechanical ventilation is an additional load on the power grid, an increase in the payment for electricity required for general house needs.

Of course, modern technology can provide an effective alternative. Solar energy has made it possible to create models of solar collectors, which are becoming indispensable assistants in organizing ventilation both in houses under construction and in the existing housing stock.

Due to its compact dimensions, the collector does not take up much space. The simplicity and aesthetics of the design minimizes maintenance costs. The use of a renewable resource - solar energy - is:

• opportunity to improve the quality of life;
• contribution to the ecology of the region and the city;
• significant savings in electricity consumed for general house needs.

The presence of properly organized ventilation in the attic will avoid the installation of additional climate control systems in apartments, help reduce the need for space heating in winter, minimize the load on the power grid and boiler rooms, and allow the use of attic space for the needs of the administration (for example, rent) and residents.

Cold attic ventilation: important quality nuances

When modeling an attic in a private house, it is necessary to create good ventilation. Properly installed cold attic ventilation is important to ensure a healthy microclimate under the roof of a dwelling. With insufficient aeration, the life of the structure is significantly reduced.

Do you need cold attic ventilation?

No sealing of the house can completely isolate the flow of steam from the dwelling to the attic. According to the law of thermodynamics, warm air rises, and the steam finds an outlet anyway. The floors are mostly made of wood. On wooden surfaces, with the accumulation of moisture, a natural environment is formed for the development of various harmful microorganisms, mold. There are unpleasant musty odors, a feeling of dampness. An unhealthy microclimate of the room as a whole is created.

Temperature fluctuations contribute to constant condensation and, if there is no ventilation of a cold attic, the structure wears out quickly.

Causes of condensation:

• lack of good ventilation;
• violation of the thermal insulation of the roof;
• insufficient waterproofing;
• lack of ventilation ducts;
• defects in building materials.

Ventilation, performed according to technical rules, protects the building from damage.

Cold attic - non-residential premises under the roof of a building without decorative finishes. The issue of ventilation is important to address during the creation of a house project, when planning the features of the roof configuration.

Functioning of ventilation - dependence on the selected materials

The main task of ventilating a cold attic is constant air exchange. In order for the goal to be optimally realized, it is necessary to evaluate the quality and type of roofing material used. Each of them has features.

If slate or ondulin is chosen for laying the roof, then the air easily moves between the wavy bends into the attic area and also freely exits.

When creating ventilation of a cold attic from a metal tile, it is important to lay a vapor barrier film, as condensation forms. The metal tile is ventilated through the ridge seal. For a gable roof, ventilation channels are located on the gables. High-quality ventilation is carried out with a uniform distribution of gaps.

There are some nuances when installing a hip roof. In this case, the inlet should be placed in the filing, and the outlet should be near the ridge. This type of roof is hipped and there are no gables.

When working with flexible tiles, it is required to install a ventilated ridge, for classic "ceramics" - a roof valve.

Using overhangs of wood bars in filing, an interval of several millimeters should be observed. When sewing with plastic, holes are made in the elements. Hemming is called soffit.

Is it possible to remove ventilation - a cold attic

Proper air exchange is essential to:

• avoid the accumulation of vapors that come from the house;
• protect the wooden frame of the attic from moisture;
• counteract the formation of fungus;
• keep the temperature constant.

Provided that ventilation of the attic space is created - a cold attic
from home, moisture accumulation cannot be avoided. On uninsulated roofs, a thick layer of condensate quickly forms. Even if the roof was insulated, condensation cannot be avoided, but in this case the walls of the house would become wet.

Often there is a question: is it possible to bring ventilation to a cold attic?

It is possible to withdraw, but this type of ventilation is the wrong decision and leads to a violation of the microclimate of the attic space, damage to the wooden structure, gradual decay, and inevitable wear.

1. Install the necessary ventilation elements to protect the air from debris, leaves, branches and insects - on skates, cornices, ridges, valleys.
2. Protect ventilation gaps from dust.
3. Regardless of the features of the roof, the area of ​​\u200b\u200bventilation channels should be made 400-500 cm2 / m.
4. Check if the ventilated ducts are narrowed to avoid condensation due to insufficient air circulation.
5. Use auxiliary ventilation structures if the length of the roofing is more than 10 meters.
6. Avoid a significant expansion of the gap, because due to the resulting turbulence, the air exchange under the roof is reduced.
7. Provide ventilation insulation in the attic so that the pipelines of the ventilation system are not subjected to temperature changes and can function smoothly.

insulation of the cold attic of an apartment building

There is a task of warming the cold attic of an apartment building

The house is large-panel, built in the seventies, the attic is cold with natural ventilation. Heat dissipation from below. There is nothing in the attic except pigeons.

According to the project, the ceiling (flooring) of reinforced concrete buckets, the thickness in the center of the whole

5 cm + expanded clay is poured on top (according to the project, really xs) - that's all the insulation of the residential, 9th floor, then a cold attic. The apartment on the 9th floor is cold in winter + condensation (very humid). The roof itself does not leak, the roof covering was repaired.

How to properly and well re-insulate? from the side of the attic. Styrofoam or cotton wool, film (vapor barrier, is it necessary or not), how much of what and in what sequence to put?

Reinforced concrete slabs allow a small amount of water vapor to pass through, but it is very insignificant. Therefore, I would not contact the films at all. Further, I would not stack highly combustible materials (foam plastics) in "publicly accessible" premises.
Therefore, the best choice of insulation is mineral wool or glass wool with a layer of 10-15 cm.
But then you need to calculate for yourself what is more profitable for you:

• or expensive hard-type mineral wool covered with sheets of plywood for walking;
• or cheap mineral wool / rolled glass wool (ISOVER KT37, KT40), but it will be necessary to build some kind of logs from the bars and cover with the same plywood or at least unedged board.

Nobody walks there at all, the height of the attic is 60 cm, only when crawling, so you don’t have to stop at this moment. There is no access to the attic of the tenants.

I am confused by the moisture in the apartment, obviously due to the temperature difference in the apartment and in the attic, apparently due to the thermal insulation that has lost its properties (there used to be leaks)

Walls, seams, window - everything is ok, it looks like the problem is from above

Minplita or other glass wool only. Styrofoam mice and pigeons will spoil. And fire safety is also impossible. Leaks must be eliminated on the roof. Although I had to see the attics, those floors where the film was stretched under the place of the leak and the flow of the collected water was organized.

And, well, if 60 cm, then everything is perfect. The moisture that you now have is condensate from INSIDE of the apartment, gathering on the cold ceiling. As soon as you insulate everything will dry out.
Since no one will walk, I would lay 3 layers of mineral wool, 50 mm each, of a soft type and cover with sheets of 12 mm plywood so that, if anything, you can crawl through.

evgenygrig wrote:
The moisture that you now have is condensate from INSIDE of the apartment

evgenygrig wrote:
The moisture that you now have is condensate from INSIDE of the apartment, gathering on the cold ceiling. As soon as you insulate everything will dry out.

Sorry,
it seemed to me that the moisture in the apartment was due to the fact that the “hot living apartment - cold attic” ceiling was poorly insulated and the dew point was inside the apartment or in concrete close to the apartment. and condensation forms and is humid. Or is it one and the same? Moisture all the same from the INSIDE? If it is good to insulate this ceiling, then where will the moisture go if it is from INSIDE?

Or are we talking about different things?
Wet and condensate in the apartment, not in the attic.

About the same thing, but in a different way.
You described the condensation process absolutely correctly. Only 1 clarification is required: moisture condenses on a cold surface, which is contained in the air INSIDE a warm room - it falls to the surface like dew. This is not moisture that supposedly seeped through the ceiling. It is important to understand this difference in order to decide whether surface waterproofing is required or not. In your case, no. It is enough to achieve insulation so that the temperature of the ceiling does not fall below the dew point - and moisture will cease to condense on it (namely, “condense on it”, and not “flow through it”). The humidity in the apartment will remain unchanged.
If it seems to you that the apartment is excessively humid, then ventilation must be combated with this. At the same time, it is also possible to achieve a cessation of condensation on the ceiling even without its insulation, but due to the dryness of the air, which is not always comfortable; and establishing good and comfortable ventilation can be more difficult than insulating the ceiling.

Thanks for the answer,

I am also embarrassed that the condensate does not form on the ceiling, but mainly on the wall, which is external (goes out) along its entire height and on the windows (double-glazed windows). So in all rooms (i.e., the option of a hole in some place of the front wall is possibly excluded).

In addition to high humidity, the apartment is cold.