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 due to the appearance unpleasant odor and dampness. In this 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 hot roof moves 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 its absence, home owners are forced to suffer from stuffiness and heat.
IN winter period ventilation helps 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 sudden temperature changes create favorable conditions for the accumulation of condensate, which subsequently forms icicles. With the onset of a thaw, they melt and moisture falls on the floor, which leads to deformation and destruction. ceiling structure and roofs, appears on the rafters.
Despite the importance of ventilation, many owners are afraid to install it because they think that air leaks through the grilles in the attic. warm air, and the room cools faster. In fact, the reason lies in poor-quality thermal insulation of the ceiling and walls, moreover, through poorly insulated ceilings Moisture is seeping into the attic.
Important: ventilation of a cold attic with a tent or hip roof needed, most often, only in the summer.
Ventilation grilles in the attic of a private house play an important role in thermoregulation. If installed correctly, they will save on heating costs, provide the required degree of cooling and protect the room from negative external influences. In addition to all the above advantages, attic ventilation prevents winter precipitation from accumulating on the roof of the building.
The principle of operation of the ventilation system
Unimpeded air circulation from the street under the roof space is possible due to openings, the most effective of which are located under the overhang and in the ridges. This arrangement allows the use of air-thermal pressure emanating from the ceiling area.
If the attic ventilation is installed according to all the rules, in an hour's time 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: if there is an insulated roof, a gap of approximately 5 cm wide is left between the roof and the insulating layer for free air exchange.
To ensure high-quality hood, a combination of installed ridge elements and vents in the ridge itself is necessary. For tiled roofs, special tiles with air exchange vents are used.
There is another way to ventilate the attic - installing ventilation turbines (deflectors) for mechanical draft. This type installation is recommended for ventilation of 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 filled with snow can be replaced with pipes that exceed the height of the snow cover.
Ventilation window
The oldest known in the attic is the ventilation window. For good air exchange, under-eaves and ridge vents, as well as dormer windows, are sufficient. A hip roof is assumed without 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 ventilation is played by the cracks in the inter-roof space. A mandatory element of such a roof is mechanical traction devices. The ventilation outlet is located in the columns.
Dormer windows
Without installing systems of vents and vents for air exchange in the attic, they can be equipped dormer windows. However, this method is not effective enough, since air can stagnate in the space under and above the window.
To improve ventilation and reduce the level of stagnant air, it is recommended to make dormer windows measuring 60x80 cm, placing them in opposite gables. You can find out how to do the installation yourself by watching the video .
In theory, it looks like this: for pre-made wooden frames, which are attached to the rafters with special racks, the roofing material is laid. For finishing openings, ordinary lining is suitable. Then a window frame is mounted into the opening. In this case, the gaps between the roof and the frame itself are tightly closed.
Rules for installing ventilation windows:
- Ventilation vents, roof and roof vents are required;
- the distance between windows is no more than 1 m;
- equal distance of windows from the cornice, sides and ridge;
- window design should not violate the overall concept appearance buildings.
Ventilation ducts
Vents are openings to provide air exchange in a cold or warm attic. They are in the roof and are the only possible way ventilation of the attic without dormer windows.
There are two types of vents: cornice or ridge. Eaves 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. Vents made in the form of holes are called point vents. 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 slotted shape up to 5 cm wide or a weather vane shape with intervals not exceeding 8 meters. This type of vents is also used in tiled coverings, with holes one row from the ridge.
Vents for the top layer of the roof are made in the form of a retractable roof outlet, aerators or a gable grille. 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 look ventilation ducts. 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 analogues.
There are point aerators, with built-in fans to ensure proper air circulation, and continuous (ridge) aerators, which are a plate with holes located along the ridge. The latter are covered from above with a roof. They provide constant air exchange and are unnoticeable.
Source: allremont59.ru 
Source: stroydom.guru
All types of roof aerators are made from:
- ceramics;
- metal ceramics;
- bitumen shingles;
- flat roof.
Aerators are usually installed in places with eaves vents. But there are other options for their placement:
- point models are installed at a distance of no further than 50 cm from the ridge;
- aerators extend beyond the slot by 25 cm from both ends of the ridge;
- aerators are suitable exclusively for roofs with a slope of 15 to 45 degrees;
- the distance from the wall or chimney is at least 30cm.
Ventilation calculation
Before installing attic ventilation, it is recommended to carry out accurate calculations. Only a specialist can guarantee results. But if you still decide to calculate and carry out the installation yourself, our recommendations and advice will undoubtedly help you.
To create a comfortable microclimate in a living space, attic ventilation is required. This measure is also necessary to maintain strength rafter system, roofing material and an obstacle to the formation of condensation, regardless of cold or warm type building. The ventilation system is designed simultaneously with the box and other components and communications.
To ventilate a room under the roof, it is not at all necessary to create complex engineering systems or install exhaust fans. As a rule, in such cases, ordinary vents are made in the attic, which are able to provide natural circulation air flow.
Ventilation system without attic insulation
Natural air circulation through vents
Adjusting the air flow in accordance with the need at one time or another is very important, so you should leave free access to the grilles without blocking it with rafters. You also need to make dampers on the ventilation ducts, which will allow you to increase, decrease or even block the air flow.
Such an adjustment system is necessary for a hermetically sealed roof, for example, corrugated sheets or metal tiles, where the sheets fit tightly at the joints. In the event that the overlap is made of materials such as wave slate or ondulin (in the absence waterproofing film), vents should not be made - there are enough gaps between the waves for air circulation.
Ventilation on the gable through a dormer window
All gable and mansard roofs have gables, where the grille for ventilation of the attic space is installed, and on one side it is placed with the holes down, and on the other, adjustments are made. In cases where the structures have hip, half-hip or multi-gable gables, as a rule, there are no gables, but, nevertheless, a dormer window can be made there where a grille can be placed.
Pipe device (aerators) for roof ventilation
If the entrance is from the street cold attic missing, and there are no dormer windows, which is often found in modern architecture private housing construction, then install roof fans– aerators. Such a device is a pipe in the form of a glass, protected from above from ingress atmospheric precipitation headband. In some cases there is also added check valve.
Ventilation system for a warm attic space
The situation with air circulation in a heated attic, that is, an attic, looks somewhat different. In the room itself, the air exchange process occurs, as in living rooms- through doors, windows, vents and specially designed grilles (possibly with forced exhaust). But here it is necessary to separately provide a ventilation gap under the roofing material in view of its insulation from the bottom side.
Air circulation diagram in the attic with heating
If the roofing material on your house is ondulin or slate, then to ensure good circulation it is enough to maintain a distance of 20-30 mm between the roof and the insulation (waterproofing) - the air will pass through the wave joint. But in cases where corrugated sheeting, metal tiles, seam or soft coverings, the roof will be sealed, which will promote the formation of condensation and, as a result, fungal mold.
In addition, condensation will destroy metal coating, and moisture can also penetrate inside through a loose connection of the waterproofing. In such cases, gaps for air circulation are left at the eaves hem (below) and under the ridge (above). For metal, additional waterproofing is also used during its installation.
What you need to know when installing ventilation
When arranging ventilation for cold and warm attics, it is important to understand that this is not done for the sake of fresh air, but for the sake of creating acceptable operating conditions for certain materials. Therefore, during installation you should set a specific goal to achieve a specific result.
In what cases does condensation form?
The word “condensate” (from the Latin “condensatus”) means the transition of a substance under certain conditions from one state to another, into in this case from steam to water. This is due to the difference in air temperature between the inside and outside of the room, and this formation can occur even in unheated attics in the absence of ventilation.
A significant factor for the formation of condensation is moist air that penetrates through the ceiling into the attic. Be that as it may, the damage that dew causes to the rafter system and metal roofing, is neutralized by air circulation.
Eaves lined with vinyl soffits
When settling in simple systems Attic ventilation in a private house should adhere to the following rules:
- the grille or roof pipe for air circulation can be torn off by strong winds, therefore, it is important to pay attention to the strength of the fasteners;
- soffits on eaves are covered with aluminum or plastic (PVC) mesh - materials that are not subject to corrosion;
- Vents between the rafters protect against the formation of frost (frozen condensation). Make sure that they are not clogged with debris;
- if necessary (temporarily or permanently), you can install the fan at a distance of 8m from supply system;
- dampers installed on a pipe or grille will allow you to regulate not only the intensity of circulation, but also the air temperature in the attic.
Three Main Misconceptions and Removing the Consequences
In order for attic ventilation in a private house to be done correctly, in addition to knowledge of the basic requirements, it is necessary to get rid of the misunderstanding of its purpose. There are three main misconceptions that have falsely received the status of rules and are used in the design and construction of houses in the private sector.
The first misconception is about the seasons
- Hot weather is not the only criterion for the need for attic ventilation. For unheated attics or for ventilation warm rooms it is necessary to maintain a minimum difference between the internal and external temperatures;
- When it gets cold outside, the lack of flowing air circulation leads to the formation of condensation. This moisture contributes to the formation of dampness and fungal mold, and in winter - frost;
- This situation is extremely dangerous because microbial spores can enter the living space through the ceiling. It will be extremely difficult to deal with the consequences.
The second misconception is that it will be cold in the house.
Ventilation in the attic helps cool the living space, since warm air is used to heat the floors:
- In fact, the reason for cooling rooms is insufficient thermal insulation of walls, floors and ceilings. The room, to a greater extent, cools not from the loss of warm air, but from the penetration of cold;
- In addition, in the absence of waterproofing on the ceiling, not only heat but also moisture passes through it, which serves as an additional reason for the formation of condensation in the attic.
Misconception number three: size doesn’t matter
The size of the holes for air circulation does not matter:
- this is not so, and if we are talking about a ventilation gap under the roof, then minimum distance to the insulation should be 20mm. It is set by choosing the cross-section of the slats for the counter-lattice;
- when arranging vents for cold attics, you should adhere to the norm - 1 sq. m of ventilation holes (in total) per 500 sq. m of total room area;
- If you meet these requirements (ventilation gap or vent area), then you can get rid of condensation while avoiding critical losses of warm air.
Way out of poor ventilation
Frozen condensation on the rafter system and sheathing
If ventilation was made taking into account the above misconceptions, then in the cold season condensation will form, which freezes in winter, as shown in the top photo. In such cases, you have to correct the situation, but there is a way out, and it leads to good results with simple actions.
The simplest roof aerator
You can make additional vents or dormer windows, protecting them with bars so that pigeons do not fly into the attic and nest (they can also nest in the vents, if there is space there). But the most convenient thing, especially if the roof is made of metal (corrugated sheeting, metal tiles or seam roofing), is to install the simplest passive aerator. If desired, of course, you can purchase and install an electric or turbine hood of this type.
Depending on the roofing material, the base of the hood is selected - it can be wavy, like slate or ondulin, or flat, like corresponding roofing materials. As a rule, such devices are equipped with installation instructions from the manufacturer, a set of self-tapping screws, and outdoor sealant for fastening.
Attic ventilation is a necessity
To install this ventilation system in the attic you need to cut a hole in the roof, the area of which should not be less than the hole in the hood, but not exceed the dimensions of the mounting base. For cutting use an angular grinding machine(grinder), and the disc is selected in accordance with the roofing material (metal or diamond-coated).
To summarize, we can say that ventilation in attic, this is not an arrangement for luxury homes, but an urgent need of every building, on which the comfort in the rooms depends. And the availability of doing the work yourself significantly reduces the cost and allows you to quickly correct the situation with poor air circulation.
Video: attic ventilation
Regardless of whether the under-roof space is used as a residential or technical one, organizing attic ventilation is a prerequisite for comfortable living in the house and maintaining the performance qualities of individual elements of the building. Proper ventilation will prevent air stagnation and increased humidity in the attic, thereby protecting the materials used in construction from destruction. Both natural and forced methods can be introduced here.
Attic ventilation
If the under-roof space is residential (attic), the same ventilation principle can be used as in the case of technical rooms. It is necessary to organize a convective air flow in the attic, the direction of which can be traced from the eaves to the ridge. The unobstructed passage of air flows can be ensured by the layer between the base of the roof and the insulation, and its width should be more than 5 cm. Attic ventilation in a private house consists of installing special ventilation grilles to move air along the eaves. The place where the gratings are inserted is the lining of the eaves overhang; another option is the installation of roof aerators and soffit strips.
When the attic is needed only as a technical room, it is advisable to improve natural ventilation, since there is a strong wind pressure on the roof line, which serves as a stimulus for the movement of air flows.
The most common, in this case, the inlet openings are located under the roof overhang along the perimeter of the room, and along the ridge, where there is minimum pressure air flows, exhaust openings are provided. To an outside observer, this design seems too simple, but its design still requires some experience.
Video review - attic ventilation
The location of the ventilation holes, their number and shape depend on the following factors:
- Attic volume;
- Types of hydro- and thermal insulation used in construction;
- The intensity of introduction of air flows from residential premises.
Naledi, the “destroyer” of the majority building materials, is not formed if the roof eaves heats up quickly enough, that is Special attention When ventilating into the attic, it is necessary to use slot vents.
To ensure effective and uninterrupted attic ventilation, it is necessary to accurately calculate the required area of the openings; the main indicator here will be the height of the slopes. For example, if the length of the rafters is 20 meters, the area of the gaps for ventilation on the eaves overhang is about 400 sq.cm/m, if the length of the rafters is 7-10 meters - respectively, 200 sq.cm/m. The total area of the supply openings should be less than the total area of the exhaust openings.
If we take into account the errors inherent in masonry, it can be observed that the dimensions of the calculated gaps ultimately become larger compared to the real ones, therefore it is recommended to leave in advance the possibility of organizing holes whose dimensions exceed 5 cm.
All the above rules and calculations are applicable only for the organization attic ventilation standard form . Currently popular architectural additions can change the intensity and characteristics of fresh air flows, so for such buildings or coercive systems ventilation, or installing deflectors above the exhaust openings to enhance draft.
To ensure comfortable living in a private home, you need to make it warm. Therefore, when planning a building, close attention is paid to air exchange and maintaining the desired temperature inside the room.
In order to avoid many troubles (the appearance of condensation, deformation of the house), it is necessary to carefully consider the attic ventilation system
Neglecting ventilation in a cold attic can lead to undesirable consequences in the form of heat loss and condensation. This is also the reason for the deformation of the house, the appearance of mold and mildew.
Causes of condensation
A sign of condensation is the characteristic musty smell of dampness. The formation of condensation and all the accompanying problems are affected by the following installation errors:
- no good ventilation;
- the roof does not have high-quality thermal insulation;
- improper vapor barrier, waterproofing;
- defects in building materials.
The accumulation of condensation under the roof leads to the fact that the insulated ceilings begin to rot, mold and mildew develop. This may also be due to insufficient ventilation holes.
Normally, it is necessary to have 1 square meter of ventilation holes for every 500 square meters area of the attic space. In order for moisture to begin to evaporate, it is necessary to create conditions for mixing internal and external air.
The system is extremely necessary in the summer heat, when the roof heats up over 100 degrees. Very often people neglect ventilation, assuming that heat leaks through it during the cold season.
Heat loss is due to poor thermal insulation. Cold, damp air entering the under-roof space serves as a condition for the inevitable formation of mold. Therefore, it is necessary to ventilate the attic not only in summer, but also in winter.
Ventilation methods
The most rational way to ensure uniform air exchange is to locate vents along the perimeter of the building, as well as along the entire length of the roof ridge.
A division of the ventilated volume into a zone of positive and negative pressure is formed. In the first zone there are supply openings, and in the second - exhaust openings. To protect the vents from birds, they are covered with nets and bars.
There are several ways to ventilate the under-roof space:
- making dormer windows in the attic;
- creating ventilation for the ridge of two pitched roof, which is also good for the attic;
- cornice type of ventilation;
- specially shaped skates;
- the use of individual elements with holes for ventilation;
- roof fans;
- Availability ventilation gaps, existing initially or made during roof reconstruction.
One of the ventilation options is dormer windows.
Proper ventilation of the attic space will protect the cold attic from destructive processes.
The type of organization of the ventilation system for a cold attic depends on the type of roof, its area, the humidity concentration of the internal air, and the state of the roof structure's vapor insulation. But the choice of method and the material from which the roof is made also influences.
There is an approximate division of the material into hard and soft. Clay and metal tiles are hard materials, but each of them has its own characteristics. The first is a very fragile material, and the second is of the sheet type and is susceptible to corrosion in places where the protective coating is destroyed.
Ventilation construction
To create normal air exchange, prevent condensation accumulation, and heat loss, you need to design the necessary elements. Design features different types roofs of houses, various materials have their own characteristics in the organization of ventilation.
Ventilation of the under-roof space in a cold attic
To ensure regulation of the cold attic ventilation system, do not cover the rafters and sheathing. Air exchange can be ensured by lining with gaps.
A functional air exchange system is based on creating gaps of about 4–5 cm. Free air circulation in the space under the roof can be ensured by sheathing slats. This way you can create roof ventilation from corrugated sheets, ondulin, and metal tiles.
A roof covered with slate or ondulin allows you to do without ventilation holes. The circulation of air currents occurs between the waves of roofing material. However, metal tiles can accumulate condensation, so it is necessary to use a vapor barrier film.
This perforated membrane helps eliminate moisture from entering the rafter system, and the insulation is also capable of allowing vapors to pass through from the attic. Until condensation forms, the air carries them outside. On roofs of this type, ridge vents are made to provide regular draft for ventilation.
For pitched roof it is necessary to make a gap between the rafter system and the roof. If it is done correctly, then spontaneous traction can be achieved due to the difference in height. Arrangement gable roof starts with placement ventilation ducts in the gables.
Collectively, the opening area should be 0.2 percent of the total roof area. You can use loose sewing of the bevels. To ensure uniform ventilation of the pitched roof attic, the gaps should be small.
Dormer windows are a common method of organizing attic ventilation
Dormer windows can be made from stone in gables. This is one of the common methods of organizing attic ventilation, but it is a little more complicated than installing a ridge. But you won’t need to create a system of gaps, holes, or vents. You need to follow the rules:
- window size - from 60x80;
- place - opposite gables;
- maintaining an equal distance from the sides of the building, ridge, cornice;
- the gap between the nearest windows is from 1 m;
- You can install a window in the ventilation grille.
Ventilation of a cold hip roof
Ventilation of a cold attic with a hip roof, a hip roof, is done using a different method. Houses with hip and hip roof do not have pediments. Gaps for air entry must be made around the entire perimeter. Each of the slopes must be ventilated. Two types of holes need to be made.
The entrances are made in the filing, the exits are at the top, at the ridge. The lining of wooden beams can be made with gaps of several millimeters. If the lining was made without gaps during installation, you can use plastic panels with holes, the so-called soffits.
When the filing is tightly assembled, gratings with mesh cells of 5 cm are used. They are located along the length of the wind overhang at a distance of 90 cm. Depending on the type of roof, the pitch may be different. The top terminal is installed outward.
Ventilation of a cold attic made of metal tiles
Cold attic covered with metal tiles requires treatment wooden elements antiseptic structures. No vapor barrier is used for the rafters; they are left open.
To organize free access of air flow to wooden structures, the sheathing must be fastened at intervals. The space under the metal tile is sufficiently well ventilated with air, but condensation occurs. Therefore it is recommended to use roll waterproofing under the roof.
When covering with metal tiles or slate, you can install a classic ridge, which is universal method, allowing you to get ventilation very quickly and inexpensively.
For this, a ridge board is used to separate the two roof slopes. The area of the ridge vents should be equal to the area of the ventilation slots at the eaves.
Ventilation of a cold attic of a rafter roof made of corrugated sheets
The organization of air exchange with such a coating is carried out using a natural method. In the area of the eaves overhang, air flow penetrates into the space under the flooring. Next, the air flows up to the ridge and is discharged.
Covering in the form of steel corrugated sheets has the advantage of lower cost, but has significant drawback- susceptibility to corrosion due to condensation formation.
To create a waterproofing carpet, you can use roofing felt
Ventilation of a cold attic space is carried out by laying ventilation slats on a layer of waterproofing carpet; you can use roofing felt. The bottom rail closest to the eaves should have the greatest thickness (50 percent) compared to the rest.
The waterproofing should not reach the ridge of the roof so that vapors can escape unhindered. This type of roof must be equipped with elements in the form of vents, a ventilated ridge, aerators or deflectors. The ridge is sealed with a “top roll” system to prevent water from flowing in from outside.
Other types of coatings
A turtle and a valve can be made with a flexible type of roof. Bituminous shingles is a soft material. Trying to give it strength, the coating is laid on concrete base, or a continuous sheathing is installed under it. But then the ventilation system fails.
Excess incoming moisture leads to delamination of the material, its detachment from the base. This depressurization of the roof causes roof leaks. Therefore, it is necessary to make gaps in the sheathing. A special valve is suitable for a ceramic roof.
Modern methods of ventilation
Roof aerator is ventilation pipes, new way freeing the space under the roof from excess moisture. They help create proper air exchange in a cold attic room if natural ventilation is not enough.
The device looks like a pipe in which an area is created low pressure due to external wind movement. The technology of action is based on the use of the difference in pressure between the outside air and the under-roof space.
To ensure ventilation of local areas of the roof, point aerators are used. To create general ventilation, continuous type aerators are used along the entire length of the roof. Point type aerators, depending on the installation location, are divided into pitched and ridge.
Ventilation of a cold attic in a private house is necessary to protect its structure from premature destruction. Therefore, you need to decide on the type in advance attic floor. It is necessary to take care of the ventilation roofing elements directly during the construction of the house.
In order for the service of the rafter system to last as long as possible, and the microclimate in the house to be normal, it is recommended to arrange good ventilation.
In private homes, attics play a special role. As a rule, they are used for storing rarely used household equipment, seasonal clothing, family “antiques” that are difficult to get rid of for one reason or another, for storing canned or dried vegetables. Often the room under the roof is converted into a recreation room, mini-gym or workshop. In fact, there are quite a few ways to use additional square meters and each owner fills the space at his own discretion. But so that things do not deteriorate and become saturated with the smell of mold, but structural elements buildings did not feel the harmful effects of moisture, well-organized ventilation in the attic will be required. It will help create an optimal microclimate and ensure proper thermoregulation.
Truths and misconceptions about attic ventilation
Good ventilation of the room under the roof will eliminate the appearance of condensation, which will increase the service life truss structures, lathing and ceilings top floor. In the summer, the roof overheats, but thanks to ventilation, the heat evaporates without having time to penetrate into the living quarters. Myself roofing pie under the influence of a draft it cools, which has a beneficial effect on bitumen-containing materials.
In winter, snow melts on a ventilated roof more evenly, since the heat coming from the house has time to be distributed without creating concentrated pockets of condensation above the heated rooms. Air circulation eliminates ice build-up on eaves, preventing excess moisture from turning into ice build-up. In addition, when competent organization ventilation system, snow will not stick to the roof surface.
Owners who do not know the issue make a number of mistakes when installing ventilation associated with common misconceptions. Many people believe that ventilating the attic in winter contributes to the formation of significant heat loss. But in fact, the fault is not ventilation, but poor-quality thermal insulation.
A ventilated attic located between the roof and living spaces is air gap, smoothing out temperature differences.
Another misconception is the statement that the size of the ventilation openings can be made to any size. And this is not true. If the area of the holes is insufficient, the ventilation effect will be reduced to zero, and a large number of them will lead to excessive heat loss. Experts recommend performing calculations based on the ratio of 1 sq.m of ventilation holes per 500 sq.m of roof, which is 0.2%.
Elements of an attic ventilation system
From the school physics course we know that warm air rises, and cold air, meanwhile, occupies the free space. Attic ventilation is performed based on this fact. This means that supply openings should be provided in the lower part of the roof, and exit openings closer to the ridge should be provided for air outflow. Ventilation of the attic in this case occurs due to the temperature difference.
Depending on the design features roofs, to organize a ventilation system they use:
- perforated soffits;
- roof aerators;
- ventilated skates.
To increase the speed of air flows, electric fans and inertial turbines are often installed on roofs. Laying loose sheathing or counter-lattice promotes additional air circulation above the attic. The same effect is obtained when corrugated or profiled sheets are used as roofing material.
Cold attic
The method of ventilating a cold attic depends on the shape of the roof. For gable structures on opposite gables it will be enough to make dormer windows or vents with ventilation grilles. Ventilation, in this case, is carried out due to horizontal air flows. Additional air exchange occurs through eaves vents formed by the discharged sheathing. They help get rid of stagnant foci located under the dormer windows.
Ventilation of the hip roof is provided by gaps in the eaves overhangs and openings located under the ridge, or by special roofing elements installed at the top of the roof. When the roof slope is more than 45 degrees, ventilation of the attic space occurs due to the temperature difference. If the angle of inclination is small, then the ventilation system is reinforced with inertial turbines or electric fans.
Warm attic
The roof above the attic has a different ventilation principle. In this case, the air gaps should run along the rafters between the thermal and waterproofing. Builders often encounter difficulties when constructing such roofs, since in order to comply with the dimensions of the required ventilation layers, the rafters have to be increased using counter-battens.
Myself warm attic can be ventilated using windows, like other rooms in the house. If there are no openings, then it should be provided forced ventilation with installation of equipment in external walls.
Inlet ventilation holes must be located in a clean area. This applies to both the outside of the house and the interior space.
Under-eaves soffits can be made of plastic or aluminum, but they must be equipped with a screening mesh. Elements can be installed continuously or alternated with solid cladding.
Holes intended for air outflow must be placed as close to the ridge as possible.
Along with their main function, dormer windows often play a decorative role, giving the facade an individual look.
