Preface. An attic in a private house is the non-residential upper floor under the roof. In old wooden houses Old clothes and unnecessary things were usually stored in the attic. In this article we will look at how to make ventilation in the attic with your own hands. How to ventilate the attic through dormer windows in a gable and hip roof so that stored items and clothes in the cold attic of a private house are not spoiled by mold.
The classic attic in the house represents a cold non-residential premises. Insulate the attic and attic in country house, when it is planned to make a living space in the future. System natural ventilation in the attic frame house serves to remove vapors and moisture penetrating into the room through the interfloor from the first floor, as well as to prevent moisture from the thermal insulation of the roof and gable of the house.
Why do you need attic ventilation in your home?
Photo. Natural ventilation of the attic of a house
Importance proper ventilation the attic is to create a favorable microclimate in the attic. In the summer, the metal tile roof heats up and in order to feel comfortable in the house, the attic room must be ventilated. In winter, the flow of cold air should, on the contrary, be limited. Ideally, the attic ventilation above the attic should be adjustable (with the ability to close the ventilation ducts for the winter).
When building the roof of a house, immediately think about what the attic floor will be like in the future - warm or cold. This will make it possible to install all the necessary roofing elements for the ventilation and air conditioning system during the construction stage. Don't forget that you will also need to insulate the attic windows. Next, we will tell you how to ventilate a cold attic with a hip roof.
Hip roof attic ventilation
Ventilation of warm and cold attics hip roof suitable for classic two pitched roof, if it is not possible to make ventilation holes in the gables. The air entry under the roof should occur in the wind lining at the bottom, and the exit at the top at the ridge of the roof. For flexible tiles, a turtle is used for this; for ceramic tiles, a roof vent is used, and slate and corrugated sheets can be ventilated through a ridge.
If the filing is made of boards, then they should be placed with a gap of several millimeters for better air flow. If the hemming has already been installed, then you can make small holes by closing them plastic grilles. The holes can be located along the entire perimeter of the hip roof, approximately every 80 cm. An outlet for air flows from the under-roof space should be made in the roof.
Attic ventilation through gables
Let's look at how to make ventilation holes on the gable of the attic yourself. If the roof is gable, then holes should be made in the upper part of the cold triangle of the roof. The attic ventilation system for a hip roof is much more complex and labor-intensive, but anyone can handle the installation of openings in the gables. If the gables are insulated, then the holes must be made in a cold triangle.
It is most convenient to cover the openings in the gables with ventilation grilles turned downward so that rain does not flow through them into the room. It is desirable that these be adjustable grilles that can be covered for the winter. If you plan to convert the attic into a warm room, then the roof must be ventilated; see how to do this correctly in the video at the end of the article.
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Attic ventilation: overview of current schemes and methods of their implementation
Are you planning to use the attic space as a living space, but don’t know how to make it comfortable? I will talk about how attic ventilation works. With proper installation of a system for replacing stale air with fresh air, you can make the attic suitable for all-season comfortable living. In addition, instructions for installing ventilation systems will be useful to you, even if the attic in a private house is not intended to be used as housing.
Four reasons for attic ventilation
- 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, normal air exchange must be taken care of at the roof design stage.
- No condensation. Effective air exchange helps prevent the appearance of condensation on the windows, which is important if the roof space is used as an attic.
- No mold. Timely replacement of warm, humid 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 are used for finishing.
- Long service life of the roof. Excessive humidity air has a detrimental effect on the condition roofing material. Moreover, if moist air is not removed from under the roof, condensation will accumulate on the vapor barrier, which can reduce the service life of the insulation. A properly organized ventilation system will increase the service life of the roof without the need for repairs.
Ventilation of attic spaces, as it happens
| Illustrations | Varieties by type attic space |
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Cold space ventilation. The installation of ventilation systems on cold roofs does not present any problems, since the under-roof space and the living space are separated from each other by a layer of thermal insulation. The best option is supply and exhaust system, working on a natural principle, as shown in the diagram. Under the overhangs rafter roof vents are arranged through which an influx of fresh cold air is ensured, while warmer, humid air will go out into the dormer windows or other technological holes at the top of the pediment or slope. |
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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 to install counter-lattice with ventilation gaps. At the same time, air exchange in the insulated attic space is arranged separately, through a supply and exhaust system. |
Keep in mind that attic ventilation must be planned and built as a complete system. That is, the project needs to provide for an air exchange system both in the attic and in the under-roof space, as well as insulation of pipes and insulation of other communications. In addition, ventilation design must be carried out taking into account the type of thermal insulation materials used.
Types of attic ventilation
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Natural supply and exhaust system. This system is based on two vents, 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 comes out through the upper vent, while a similar volume of cold air replaces it from the lower vent.
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Forced supply and exhaust system. This system is based on an exhaust cooler, which is installed in the upper part of the slope and sucks warm air out. The air removed in this way is replaced by cold air coming from the vents located below. The advantage of the forced system is that it does not depend on climatic conditions: exhaust air will be removed with equal efficiency in both winter and summer. |
Ways to vent air outside
| Illustrations | Description |
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Air exhaust through the ridge. This is a universal method that can be used on both cold and insulated roofs. Under the ridge strip on a pie made of corrugated sheets or metal tiles, you create an air vent covered with a mesh with your own hands. The ventilation design is such that condensation formed during the cold season will not flow into the room, but will flow out onto the slope. |
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Bends on the pediment. The dormer window installed in the upper part of the gable is traditional solution, which is relevant for gable, sloping and hip roofs. Dormer windows are installed for air exchange only on cold unused roofs. The peculiarity of the solution is that the windows are always open, regardless of the time of year. In order to prevent the entry of animals and birds, decorative grilles are installed over the windows. |
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Installation of vents on the gable of the attic. In fact, gable ventilation grilles are the same vents that are used to remove moist air from any occupied premises. A decorative grille with rotating slats or check valve, if a fan is used for air exchange. |
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Aerators in roof slopes. Aerators are used mainly on modern roofs and are intended to remove exhaust air from under the attic ceiling.
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Supply valve on attic windows. Since the attic is built without dormer windows, on regular windows it is advisable to install supply valve, which will be dosed to let in required amount air from outside. Valves with manual and automated control are available for sale. |
Methods for installing vents for air supply
| Illustrations | Description |
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Installation of spotlights. To submit fresh air Barrier grilles are attached to the lower part of the overhang. The intensity of fresh air supply can be set by the ratio of the number of perforated and solid slats. The more ventilation holes in the installed soffits, the more cold air will pass into the under-roof space. |
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Installation of cornice vents. In fact, these are the same soffits through which cold air enters the roof. But in this case, the vents are installed vertically, and therefore a cornice strip is attached on top of them with a small gap. If installed correctly, the eaves vent in winter serves not only for ventilation, but also for removing condensate. |
How to calculate air exchange
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For cold roof
. According to SNiP 31-01-2003, vents or dormer windows should be used in basements and cold attics without exhaust hoods. 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 the room and calculate the size of the opening for air exchange. In large attics, the resulting dimensions of the vent can be divided in two and two small windows can be spaced along two gables. |
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For insulated roof (attic). 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 simultaneously present and taking into account the volume of the room. |
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 the cold or warm type of 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 ensure natural circulation of air flows.
Ventilation system without attic insulation
Natural circulation air through the 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 a grille is installed for ventilation of the attic space, 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 precipitation by a headband. In some cases, a check valve is also added there.
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 you need to separately provide a ventilation gap under the roofing material in view of its insulation with 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 during certain conditions from one state to another, to 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 installing simple attic ventilation systems in a private home, you should adhere to 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 8 m from the 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 not the only criterion for the need for attic ventilation. For unheated attics or for ventilation in 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 total area premises;
- 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 the attic 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
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 desired temperature indoors.
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 urgently needed in summer heat when the roof heats up more than 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 a gable 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;
- the presence of ventilation gaps, existing initially or made during the reconstruction of the roof.
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 indoor air, and the state of steam insulation roofing structure. 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 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 a 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. The arrangement of a gable roof begins with the placement of 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 mount the window in 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. Binder from 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 corrugated steel sheeting has the advantage of lower cost, but has a significant drawback - susceptibility to corrosion due to the formation of condensation.
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. Closest to the eaves, the bottom rail should have greatest thickness(by 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 the outside.
Other types of coatings
A turtle and a valve can be made with a flexible type of roof. Bituminous shingles is 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. For ceramic roof A special valve will do.
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 of low pressure is created 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 throughout 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.
Owners are often afraid to install cold attic ventilation in their private homes, guided by the following assumptions.
- Heat escapes from the house through attic ventilation grilles. There is an opinion that the building will cool down faster. But most often the problem is poor thermal insulation of the walls or ceilings. By the way, moist warm air penetrates into the attic through a poorly insulated ceiling. We will tell you what its danger is in the next chapter;
- Ventilation of a cold attic with a hip or hip roof is only necessary in summer. According to many, ventilation grilles and windows in the attic are only needed to ventilate the stuffiness. In fact, in winter, the ceiling of an unheated and unventilated attic will turn into a cave overgrown with ice stalactites;
- It doesn't matter what size the vents are. The area of ventilation windows and vents in the attic must be carefully calculated. How to do it right - read on.
Attic ventilation in a private house is essential element thermoregulation. Properly organized, it allows you to save money on heating or cooling the living space and keep the building itself intact. Attic ventilation above the attic is especially important.
The attic in a private house needs ventilation both in winter and in summer.
So, in the hot season, a hot roof heats the air in the attic to 150 degrees. Most of this heat is transferred to the ceiling top floor, the air conditioner has to work harder to eliminate excess heat. If there is no air conditioning, the owners languish in the heat and stuffiness.
In winter, air exchange is necessary to remove excess moisture. According to technical requirements, the temperature difference between the street and the attic should be 4 degrees or less. Temperature differences between residential floor and the street contributes to the accumulation of condensation on the roof rafters. The moisture gradually freezes, creating entire cascades of icicles. When it thaws, they melt and moisture drips onto the attic floor. Destroyed support structures roof and ceiling. On wooden rafters mold develops.
By the way, high-quality ventilation of a cold attic prevents accumulation of snow and ice on the roof of the house.
What is attic ventilation?
Free air exchange between the under-roof space and the street is carried out through gaps and holes. Holes in the ridges and under the roof overhang work most effectively. Positioned in this way, they use the pressure of wind and heat emanating from the ceiling of the house.
If the ventilation of a cold attic in a private house is equipped correctly, in one hour the air goes around the entire roof twice from the inside. The movement of flows is directed from below from the vents under the eaves upwards to the ridge plates with special holes. If the roof is insulated, a gap of up to 5 cm wide is left between the roofing material and the insulation for the free passage of air.
The best exhaust is ensured by a combination of vents in the ridge and pitched elements mounted near the ridge. For tiled roofs Tiles are made with vents for air exchange.
And another way to ventilate attics in private homes is to install deflectors (turbines for ventilation) that provide mechanical draft. The method is good for ventilating an insulated attic above the attic.
The slight slope of the roof must also be taken into account when planning the ventilation of a cold attic. Vents in the ridge can be covered with snow, so they are replaced with pipes, the height of which should be higher than the snow cover.
The most ancient method of ventilation is a ventilation window in the attic. To ensure excellent air exchange in a cold attic, a combination of vents under the eaves, in the ridge and dormer windows is quite sufficient.
Ventilation of the cold attic of houses with a hip roof is different in that the house does not have gables. Therefore, there is nowhere to install ventilation windows in the attic. Thus, cold attics under hip roofs ventilated using ridge and cornice vents.
It is more difficult to arrange the ventilation of the attic above the attic. Here the vents are provided by cracks in roofing pie and mechanical means of traction. The ventilation outlet to the attic is hidden in the columns.
Attic ventilation through dormer windows
For attic ventilation, only dormer windows can be used without installing a system of vents and vents. This option is not very effective, since air can stagnate under and above the windows.
To improve air exchange and reduce the volume of stagnant places, the size of the dormer windows is made 60 cm x 80 cm. They are mounted in opposite gables. First they are made wooden frames, attached by racks to the rafters. The roofing material is attached to the frame. Windows decorated with the same materials as the roof look better. Lining is well suited for finishing openings around windows. Window box it is installed in the opening last. All gaps between the window frame and the roof should be carefully closed.
Rules for placing ventilation windows:
- windows are placed at equal distances from the ridge, cornice and sides;
- there should be a distance of more than one meter between windows;
- the window design should fit harmoniously into the overall appearance of the building;
- You can install an attic ventilation grille in the window, painting it to match the roof.
Vents in the roof and roof
Vents are openings in the roof for ventilation of cold or warm attic. Vents can be ridge or cornice, depending on their location. Eaves are installed on both sides of the eaves and represent gaps between the roof and the wall about 2 cm wide. They are called slotted. If the vents are made in the form of holes, they are called point vents. The smaller the slope of the slopes, the larger the diameter or width of the vents, but not more than 2.5 centimeters.
Ridge vents are made in the form of slits up to 5 cm wide or in the form of weather vanes at intervals of up to 8 meters. Ridge vents are also installed in roofs with piece coverings, such as tiled roofs. Special tiles with holes are placed one row from the ridge.
Vents for the upper part of the roof are made in the form of aerators, gable grilles or retractable roof outlets. Ridge aerators and pitched exits can be purchased along with the roofing material.
Products- This is the only way to ventilate an attic without dormer windows.
Ventilation aerators
The roof aerator is a modern and comfortable view products. It is a pipe covered with a cap on top. Aerators remove steam, moisture and stagnant air, providing ventilation for a cold attic in a private home. Aerators are installed on roof slopes, where air movement is ensured by differences in temperature and pressure, replacing ridge vents. Aerators can be continuous or point. Point aerators are equipped with fans and guarantee good air movement. Outwardly, they resemble fungi.
Continuous aerators are a plate along the ridge with holes. Being covered from above with a roof, they are practically invisible and provide intense air movement thanks to large area holes.
Various types of aerators are created specifically for roofing from:
- bitumen shingles;
- flat roof;
- metal ceramics;
- ceramics.
Aerators are installed only where eaves vents are provided. There are other conditions for their installation:
- Only roofs with a slope of 15 - 45 degrees are suitable;
- a distance of at least 30 cm is maintained from the chimney or wall;
- aerators look 25 cm above the slot at both ends of the ridge;
- point models are mounted no further than 50 cm from the ridge.
Calculation of attic ventilation
Those who decide to equip attic ventilation with their own hands need to carry out calculations before starting work. Only a specialist can guarantee the best result. And for the bravest ones, we have prepared a hint:
The ratio of the vent area to the attic area is 1:500.
For 500 sq. meters of attic area should be 1 sq. meter of ventilation holes. As a last resort, you can be guided by a proportion of 1:300, per 200 square meters. meters of the attic should be at least 0.4 square meters. meters of air. The calculations take into account the area of true ventilation, that is, even the width of the grilles, whose ribs disrupt the movement of air flows, is excluded.
Exceeding the area of the vents is just as undesirable as not having enough. Openings that are too large can allow snow and rain to get in, because these are the most vulnerable areas of the roof, which must be remembered.
The area of the hood (ridge and pitched grilles) should be 12–15% greater than the area of the inlet (eaves vents).
DIY cold attic ventilation
Many owners think about how to ventilate the attic after just a few years of living in the house. The musty smell and dampness in winter make you take up your tools. We will tell you about constructing ventilation for any attic with your own hands.
At gable roof The easiest way is to equip attic ventilation with your own hands by making vents in the gables. Pediments, as a rule, are made of wood and this greatly facilitates the work. The wind overhangs on the sides of the roof are also covered with wood. All cracks must be made evenly, ensuring airflow throughout the entire attic area.
There are no cracks in the stone gables, so you will have to arm yourself with a tool and drill out two dormers. They are covered with bars and mosquito nets.
When installing attic ventilation with your own hands, the placement of the vents largely depends on the shape of the roof. Various options suggested in the diagram above.
There is no need to worry about how to ventilate the attic if slate, tiles or ondulin are used as roofing materials. The wave shape provides enough voids for air to pass through. And the sheets are laid on the sheathing with gaps through which air flows pass. Metal tiles, although they have a wave-like shape, collect condensation when the temperature changes, so they cover it from below with a vapor barrier film.
Proper ventilation in the attic is no less important than its installation. AND Special attention attention should be paid to pipe insulation.
Insulation of ventilation pipes
Ventilation pipes must be insulated in the attic and above roof level. This procedure is carried out to avoid the accumulation of condensation, which will accumulate on the internal walls and flow down. Since the joints ventilation pipes are not made airtight, moisture will penetrate bearing structures, will ruin the finish and lead to the gradual destruction of the building. Yes, and ourselves ventilation ducts suffer from contact with moisture if they are made of galvanized pipe.
In winter, the opening of the ventilation duct becomes overgrown with frost and in just a month a standard pipe with a diameter of 15 cm will completely close.
The appearance of condensation in ventilation ducts is inevitable: people exhale water vapor, wash dishes, bathe and do laundry. This releases moisture into the air. The humidity of warm air in a residential building can reach 100%. When water comes into contact with the cool surface of ventilation shafts, it settles on it.
To prevent this process, the ventilation pipes in the attic are insulated. This is where the border between warm air home and a cold, unheated attic.
Most cheap option insulation: mineral wool. It does not burn, but when wet it completely loses its qualities. Corrugation with mineral wool insulation is easier to install.
Polystyrene foam in the form of special removable “shells” is very easy to install and inexpensive. But it burns well, emitting toxic smoke, so it is not recommended for residential buildings.
Best materials for insulation of ventilation ducts: polyurethane foam, polyethylene foam, polypropylene foam.
And, towards the end, several important advice for those who are interested in how to properly ventilate an attic:
- All ventilation elements must be resistant to any weather conditions;
- Be very careful about the location of the ridge vents. They are installed as close as possible to the ridge;
- Continuous soffits work effectively as cornice vents. The best materials for them are non-rusting aluminum or plastic. The surface of the spotlights is covered with a fine mesh;
- When installing attic ventilation without dormer windows, special attention should be paid to the vents between the rafters. It is important that during operation they do not become clogged with debris and dust;
- Hire a professional to calculate attic ventilation above the attic;
- Install decorative ventilation windows in the attic to add charm and special style your home;
- Conclusion supply ventilation equip the attic according to all the rules. The air handling unit should be installed in the very clean place, no closer than 8 meters from the exhaust pipe.