It may seem silly to equip a serious ventilation system for the roof space, but in fact it must be done. The fact is that problems with the microclimate in the attic can eventually lead to problems for the entire building.

For example, an attic space can become a "shelter" for fungi and mold, which then spread to other areas of the building. This can lead to disaster, especially in a private house (rotting of the supporting elements of the building, or various wooden structures is possible).

The good news is that it is quite possible to equip attic ventilation with your own hands, and with a rather meager budget. The principles of ventilation installation for cottages, summer cottages or baths are approximately the same, which only simplifies the work.

Do you need ventilation for a cold attic, and why?

The main task of the ventilation system in an unheated attic is to prevent condensation. However, such a problem can even be in a heated attic, therefore, in this case, it is necessary to make at least a primitive ventilation system.

It is possible to prevent condensation in a cold attic by providing fresh air. And this is extremely important, because the accumulation of condensate can lead to damage to the building (for example, rotting of boards near a frame house).

Roof ventilation - the main varieties

Other advantages of a properly equipped ventilation system:

1. In winter, adequately made ventilation allows you to eliminate frost, which especially often appears on the cornice overhangs. Usually frost is the result of a lack of properly organized ventilation.
2. In summer, both forced and natural ventilation systems allow autonomous cooling of roofing materials, which is very important, because overheating of the same bitumen-containing materials is extremely dangerous.
3. Also, ventilation is necessary to prevent high humidity and, as a result, dampness. To protect wooden structures from the appearance of mold on them, which can lead to decay.

Options for arranging a ventilation system for cold attics

The classic option would be to make a ventilation system through dormer windows. Such a ventilation device is quite simple and is done independently. How to do it is another question, there are several schemes, but we will use the classic one.

Dormer windows should be mounted on opposite gables, their dimensions should be 600x800 millimeters. A fairly good installation method (due to simplicity and the level of the section, which allows for the necessary air exchange), however, it is not without problems.

The main disadvantage of the technique is the appearance of stagnant air pockets or zones. To avoid this problem, dormer windows can be made somewhat smaller, combining them with a very efficient cornice-ridge ventilation system.

It is also possible to carry out the installation of hoods, and this method is very popular in Europe. Air ducts are such openings in the building on which it is necessary to install gratings with protection against the ingress of various atmospheric precipitation or litter from the street.

In addition to gratings in the form of vents, deflectors or pitched exits can be used. The products themselves are divided into two types: ridge and eaves. Eaves are further subdivided into subtypes: slotted and point.

In addition to the use of dormer windows and vents, you can use deflectors or ventilation turbines ( forced ventilation with supply and exhaust system). The principle of their work is similar, but they provide much better traction.

Basic rules for roofing installation

Be sure to follow the rules for installing the ventilation system, no matter what kind of it you use. Ignoring the instructions is fraught with either the inefficiency of the system or its insecurity.

Basic rules and regulations:

• for a roof of any type, the area of ​​\u200b\u200bventilation ducts should be 400-500 cm² / meter, which will correspond to the required gap height of 40-50 millimeters;
• keep in mind that dust entering the gap of the ventilation system is hygroscopic, which means it can potentially lead to wetting of the insulation;
• it is imperative to additionally protect the vents if they are mounted on valleys, cornices or on skates / ridges - protection must be installed from birds, various insects, litter from the street (including foliage);
• in the case when the length of the roofing is more than 10 meters, it is highly recommended to use auxiliary structures to enhance the operation of the ventilation system;
• constantly monitor the ventilation system - if the duct is narrowed, this will negatively affect the entire system, which can eventually lead to condensation;
• do not strive to make a very large gap height - this will in no way increase ventilation, and on the contrary, it will worsen it due to the occurrence of turbulence and air resistance.

Attic ventilation method (video)

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 (vents) - installed on skates (ridge), as well as pitched, which are installed on the roof slopes, 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.

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Attic ventilation: an overview of current schemes and ways to implement them

Are you planning to use the attic space as a living space, but do not know how to make it comfortable? I'll talk about how attic ventilation works. With a competent device for replacing stale air with fresh air, you can make the attic suitable for all-season comfortable living. In addition, the instructions for installing ventilation systems will be useful to you, even if the attic in a private house is not supposed to be used as housing.

Four reasons to ventilate attics

1. The comfort of living in the attic. Clean fresh air is one of the main conditions for comfortable living indoors. Therefore, if the room under the roof is used for living, you need to take care of normal air exchange at the design stage of the roof.
2. No condensation. Efficient air exchange helps prevent condensation on the windows, which is important if the under-roof space is used as an attic.
3. No mold. Timely replacement of warm moist air with fresh air prevents the appearance of mold on building surfaces. That is, if the air does not stagnate in the attic, mold will not appear in the corners, regardless of what materials the decoration is made of.
4. Long roof life. Excessive air humidity has a detrimental effect on the condition of the roofing material. Moreover, if moist air is not removed from under the roof, condensate will accumulate on the vapor barrier, which can reduce the life of the insulation. A properly organized ventilation system will increase the life of the roof without the need for repairs.

Attic ventilation, what it is

Illustrations	Varieties by type of attic space
	Cold space ventilation. The installation of ventilation systems on cold roofs does not pose any problems, since the under-roof space and the living room are separated from each other by a layer of thermal insulation. The best option is a supply and exhaust system that works according to a natural principle, as shown in the diagram. Under the overhangs of the roof rafters, air ducts are arranged through which fresh cold air is supplied, while warmer moist air will go into dormer windows or other technological openings in the upper part of the pediment or slope.
	Ventilation of insulated space. In this case, everything is somewhat more complicated than when arranging an unheated attic. In a warm attic, you will have to ventilate not only the attic space itself, but also the roofing pie, as shown in the diagram. The preferred option when using modern roofing materials is the installation of a counter-lattice with ventilation gaps. At the same time, air exchange in the insulated attic space is arranged separately, by means of a supply and exhaust system.

Keep in mind that attic ventilation must be planned and built as a complete system. That is, the project must provide for an air exchange system both in the attic and in the under-roof space, as well as pipe insulation and insulation of other communications. In addition, the design of ventilation should be carried out taking into account the type of thermal insulation materials used.

Types of attic ventilation

Illustrations	Description
	Natural supply and exhaust system. At the heart of such a system, two air vents are used, one of which is installed in the upper part of the attic wall, and the other in the lower part. In the cold season, warm air exits through the upper vent, while it is replaced by a similar volume of cold air from the lower vent. The disadvantage of the system is excessive dependence on the temperature outside the house. That is, in the warm season, ventilation will be weak.
	Forced supply and exhaust system. At the heart of such a system, an exhaust cooler is used, which is installed in the upper part of the slope and sucks warm air out. The air withdrawn in this way is replaced by cold incoming air from the vents located below. The advantage of the forced system is that it does not depend on climatic conditions: the exhaust air will be removed with the same efficiency in winter and summer.

Methods for venting air outside

Illustrations	Description
	Air outlet through the ridge. This is a universal method that can be used on both cold and insulated roofs. Under the ridge bar on a cake made of corrugated board or metal tiles, do-it-yourself air is arranged, covered with a net. The device of the air is such that the condensate formed during the cold season will not drain into the room, but will flow onto the slope.
	Branches on the pediment. A dormer window installed in the upper part of the gable is a traditional solution that is relevant for a gable, broken and hip roof. Dormer windows are installed for air exchange only on cold unused roofs. The peculiarity of the solution is that the windows are constantly open, regardless of the season. In order to prevent the entry of animals and birds, decorative grilles are installed over the windows.
	The device of vents on the pediment of the attic. In fact, gable ventilation grilles are the same vents that are used to remove moist air from any operated premises. From the inside, a decorative grille with rotary lamellae or a check valve is installed if a fan is used for air exchange.
	Aerators in roof slopes. Aerators are mainly used on modern roofs and are designed to remove exhaust air from under the attic ceiling. The advantage of special aerators over a conventional pipe embedded in the roof is a special design that prevents the formation and penetration of condensate into the room.
	Supply valve on the attic windows. Since the attic is being built without dormer windows, it is advisable to install a supply valve on ordinary windows, which will be dosed to let in the required amount of air from the outside. On sale there are valves with manual and automated control.

Methods for arranging air vents

Illustrations	Description
	Soffit installation. Barrier grilles are attached to the lower part of the overhang to supply fresh air. You can set the intensity of fresh air supply by the ratio of the number of perforated and solid strips. The more ventilation holes in the installed spotlights, the more cold air will pass into the under-roof space.
	Installation of curtain rods. In fact, these are the same spotlights through which cold air enters under the roof. But in this case, the air vents are installed vertically, and therefore a cornice strip is attached over them with a small gap. With the right device, the eaves air in winter serves not only for ventilation, but also for removing condensate.

How to calculate air exchange

Illustrations	Description
	For cold roof. According to SNiP 31-01-2003, in basements and cold attics without an exhaust hood, air vents or dormer windows should be used. The total area of ​​the vents should be calculated as 1/400 of the floor area of ​​the room. Based on these recommendations, it is easy to measure the area of ​​\u200b\u200bthe room and calculate the size of the opening for air exchange. In large attics, the resulting airflow dimensions can be divided in two and two small windows can be spaced along two gables.
	For insulated roof (attic). The air exchange rates for an insulated roof are calculated in the same way as for ordinary residential premises, namely, taking into account the number of people at the same time and taking into account the volume of the room.

Four-slope is a constructive and functional element of the building, which is known to every builder.

The triangular end slopes have the name of the hip, which is why the main name of the roof of this type of house has gone.

They replaced the vertical gables on all sides of the building.

The reason for the popularity of hip roofs is that they are very resistant to wind loads due to its increased aerodynamics, more rigid and reliable due to triangular slopes.

In addition, it is worth noting that hip hipped roofs are quite stylish and aesthetic elements that can give any building originality by improving its external shape. Such a roof is not difficult to make.

In this article, you will learn what a four-pitched roof is.

Like any other type of roof, a hip roof has a special type of roofing cake.

It consists of the following structural elements:

• crate;
• Counter grille;
• Hydrobarrier;
• Vapor barrier;
• Drywall.

Each of the above elements perform their important function and has individual characteristics. Today, the building materials market is quite rich, therefore, as a roofing material for a hip roof, you can choose both piece and sheet products.

crate

truss system

In order for the hip roof to be sufficiently rigid and reliable, it is necessary to carry out the arrangement of all its elements in a certain way.

Slant types of rafters need to be attached to the inner corners of the walls, while diagonal ones - to the outer ones.. This is fundamentally important. Due to the fact that the rafters have a large load, their length should also be greater.

Slanted rafter legs should become a support for the shortened rafters of the slopes, which are called narozhniki. Most often they are made from two paired legs.

Diagonal rafters must be secured with one or two supports.. To do this, use racks of timber. The struts should be placed in such a way that an angle of 45 degrees is formed between them and the horizontal support.

Intermediate rafter legs should rest on one side of the ridge beam, and the other on the Mauerlat. They should be placed with steps of 1-1.2 meters. Every second rafter is best attached to load-bearing walls using twists.

They can be made from ordinary wires, the radius of which becomes 2 millimeters. Using the back bracket, the intermediate frame should be connected to the Mauerlat.

Sprockets or half-legs (as they are often called) should lean on the Mauerlat with one side, and on the diagonal leg with the other.

The device of the roof truss system of a hipped roof: drawings and diagrams below.

Drawing of the truss system

Scheme of the truss system

Knots of a hipped roof

It is important to note that there are certain rather complex nodes of the truss system, which always raise a lot of questions from builders.

This applies to fixing the rafter legs to the Mauerlat, connecting the rafter legs to each other and attaching the ridge beam to the rafter legs.

In order to fix the rafter legs to the Mauerlat, you need to use a rigid mount.

It can be done in the following ways:

• With the help of corners installed on both sides of the rafter leg;
• Driving a nail diagonally through the rafter into the Mauerlat;
• Staples specially created for this;
• Sliding attachment.

Rafter legs can be connected to each other in different ways:

• With the help of bolts after laying them over the ridge beam;
• Having made special recesses for the timber and connecting the legs above it with nails;
• Having adjusted the rafters to the chosen angle and connecting them together with metal or wooden linings on both sides.

In order for the hip side of the roof to be durable enough, it is necessary to connect the rafter legs with the timber as follows:

• Diagonal rafters are cut in such a way that it ideally fits the shape of the beam, with which they must be fastened with nails from above;
• Laying the ridge beam on the racks and fastening it on both sides with wooden overlays from the boards.

It is worth remembering that the rigidity of the entire structure is equal to the rigidity of its weakest node. Therefore, it is very important to make connections as reliably as possible.

Mauerlat mount

Conclusion

The durability of the entire structure depends on how the roof will be arranged. So work must be carried out carefully and carefully. If there is no experience in this, it is best to turn to qualified specialists or take someone who has already erected hip roofs to help you. Their device is complex, but the result is worth the effort.

In contact with

Ventilation of the under-roof space is necessary to create a balanced microclimate under the roof. It is also vital for the correct and long-term use of the entire roof structure. There are many ventilation solutions on the market today. We will consider the most effective and common ways to do this here.

Why is it necessary to ventilate the attic?

Properly equipped attic ventilation with your own hands allows you to eliminate the condensate that appears on the elements of the roofing pie. When ventilating, air is provided, which just eliminates residual moisture. Due to the removal of this moisture, there is an increase in the service life of all wooden structures, which are very rich in roofing cake.

In addition, there are two more seasonal features when airing:

1. In winter, properly organized ventilation allows you to effectively deal with frost, especially on cornice overhangs. Ice may appear due to poor ventilation, as a result, excess heat will turn into condensate, and it, in turn, into ice growths.
2. In summer, a moving air stream will contribute to some cooling of roofing materials, which is especially important for materials containing bitumen.

Ways to create attic ventilation

First of all, they provide air flow, as a rule, in the eaves of the roof. To do attic ventilation with your own hands, in most cases, perforated spotlights are used. They are installed at the bottom of the roof eaves, and the perforation allows air to flow freely, but delays the possible ingress of various insects.

Soffits combine proper decorativeness and functionality, which has made them the most popular solution for airflow into the attic.

Attic ventilation in a private house also needs air outflow. For this there are the following elements:

• ventilated skate;
• inertial turbines;
• electric fans;
• roof aerators.

The roof around the entire perimeter must have a ventilation gap of at least 40-50 mm. This distance is often provided by the width of the lathing laths, which allows air to circulate freely under the roof. This method, for example, is suitable for roofs made of metal tiles, corrugated board or ondulin. The shape of these roofing materials makes it easy for air to pass under them and provide ventilation.

The area of ​​ventilation ducts should be 0.2% of the total area of ​​the ventilated room.

When using soft materials for the roof, the counter-lattice is made not continuous, but with gaps. This allows air to bypass the most problematic and difficult areas of the under-roof cake..

In the most problematic areas of the roof, for example, for a valley or a hip, it is required to make point ventilation, which is provided by aerators or turbines.

Cold attic ventilation

Ventilating a cold attic can be easily done by hand. This will require knowledge of a little theory and some practical skills. Making sufficient ventilation in a cold attic will not cause any particular difficulties due to the large air volume and the absence of barriers to normal air circulation. Air exchange can be carried out through the cornice overhang, the ridge and ridge of the roof, as well as gable windows and grilles.

For gable roofs, ventilation of cold attics is done either through gables or through loosely fitting wooden filing of cornice overhangs. If the pediments are made of stone, then holes can be made in them for dormer windows with ventilation grilles.

Dormer windows should be installed on opposite sides to ensure proper attic ventilation.

There is also an alternative, more economical option. To do this, install standard ventilation grilles (pediment vents), one of which is adjustable, and the other is turned down by the vents. To protect against insects, such a grill is equipped with a protective mosquito net.

Hip roofs do not have gables due to the shape of their design, so for them there is another option for providing ventilation in the attic - with the help of cornice overhangs. The air flow will be carried out through the filing of the roof, and its outlet will be at the top of the ridge. If the filing is made of wood with your own hands, then small gaps are left between the bars for the passage of air. When sheathing the eaves with plastic soffits, such a procedure is not necessary, due to the presence of pre-made holes on the elements - perforations.

The air outlet is made from above, through the ridge of the roof. Its design features depend on the type of roofing material used. As a rule, any manufacturer of roofing materials has its own ready-made and practical solutions.!

Valleys (grooves) are one of the problematic and complex sections of the roof. To make normal ventilation of the attic space, point aerators are installed along the passage of the valley. However, this method is acceptable for roofs with a slope angle of 45 ° or more.. On sloping roofs, there is a high probability of snow accumulation in the valley area and therefore such ventilation becomes inefficient in winter. You can fight this by installing forced ventilation - inertial turbines, electric roof fans, or use high nozzles that will not be covered with snow.

Arrangement of ventilation of a warm attic

More difficult is the ventilation of a warm attic (mansard). Ventilation layers run between the rafters. The space for ventilation between the bottom surface of the waterproofing and the heat-insulating material should be at least 20-30 mm.

If it is used as a heat insulator, then it is necessary to take into account its future increase in volume by 10-30% of the initial state.

If the depth of the rafters is not enough to provide the necessary gap between the heat insulator and the waterproofing, then their height is increased using boards or battens. But, as you understand, this method of ventilation is quite difficult to perform for roofs with complex shapes. Therefore, recently, experts prefer diffusion (vapor-permeable) membranes, which can be mounted directly on the insulation and allow moisture to pass in only one direction.