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 a 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 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 of a 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 are used, the roof will be sealed, which will contribute to the formation of condensation and, as a result, fungal mold.
In addition, condensation will destroy the 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, in this case from steam to water. This occurs 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.
An essential factor for the formation of condensation is wet air, which penetrates through the ceiling into attic space. Be that as it may, the damage that dew causes to the rafter system and metal roofing is neutralized air circulation.
Eaves lined with vinyl soffits
When installing simple attic ventilation systems in a private home, you 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 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 is 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 because warm air spent on heating 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 the case and if we're talking about regarding the ventilation gap under the roof, the 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 breaths 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
Typically, owners of private houses rarely think about the need for ventilation of the under-roof space. Although the correct calculation of attic ventilation allows you to solve a number of problems in the future, for example, such as:
- formation of moisture in the attic due to condensation of vapors;
- mold formation and, as a consequence, damage to the truss structure;
- formation of ice on the eaves overhang;
- shortened service life of roof waterproofing coatings;
- unstable and unbalanced temperature regime, if the attic is located above the attic.
At the stage of building a house, you should design the entire ventilation system, including the attic. The services of professionals should not be neglected, since the absence or improperly designed ventilation system of a private house will create many problems for its residents in the future:
- lack of fresh air flow;
- violation of air exchange of the supply and exhaust system;
- formation of condensation on different surfaces;
- formation of “stale” air in rooms;
- improper removal of air from the kitchen, bathroom, etc.
If the attic is not used in a private house, then in this case there should be good thermal insulation between residential and non-residential premises. Natural air circulation is used to ventilate cold attic spaces, as in the photo below.
Through special vents under the overhangs of the roof structure there will be an influx of fresh air. Through special ventilation holes or grilles, moist warm air is removed to the street. The holes can be made on the roof slope or on the gables at the top.
Attention: for every 500 square meters The area of the attic space must provide an area of ventilation openings of at least 1 m². If you do not follow these recommendations, the ventilation will not be effective enough.
Ventilation for heated under-roof space
If the attic is used and heated, then in this case it is necessary to ensure effective ventilation of the under-roof space.
If the attic provides living space with year-round accommodation, then experts advise using a supply and exhaust ventilation system. For the under-roof space, a counter-lattice should be installed using ventilation gaps.
General diagram of ventilation of a private house in case of application supply and exhaust systems should also include an attic space. In addition, not only the volume of the premises is taken into account, but also the type of roof, thermal insulation material and other nuances. All system development work supply and exhaust ventilation must be performed by qualified personnel. It is very important to do the right system supply and exhaust ventilation that would work effectively on each floor of the house, incl. and in the attic.
Air exhaust to the outside
To remove air from the attic, a ventilated grille is used in the gable. It is used for unused cold attics. Suitable for hip, pitched and gable roofs. Such gratings are open all year round, which ensures constant exhaust and removal of air from the attic.
A special roof ridge is the most universal method, which is used for both warm and cold roofs.
In this case, a special grid is created on the metal tiles or corrugated sheets under the ridge strip. Thanks to this design, condensation that will form during the cool season will not enter the room, but will flow down the slope onto the roof.
Special aerators – additional elements, which are installed directly on the roof and serve to remove exhaust air from the under-roof space.
Attention: special aerators not only allow you to effectively remove exhaust air, but also prevent the penetration and formation of condensation.
In the aerator, air is discharged through the ventilation hole in the roof quite quickly due to the special design of the element.
Tip: the aerator can be installed when a private house has been in use for a long time, and ventilation for the attic was not provided or was not efficient enough.
Air supply
Elements such as special vents for eaves provide fresh air under the roof. The installation of the vents is carried out vertically, as shown in the photo below, and a strip for the cornice with small gaps is installed on top of them.
Please note: when installed correctly, eaves vents not only provide ventilation attic floor, but also effectively remove condensate.
Ventilation soffits are special barrier grilles that provide an influx of fresh air.
Soffits are installed at the lower end of the overhang using special barrier grilles.
The more often ventilation holes are installed in the soffit, the more effective the flow of cold air into the attic and under-roof space will be.
Conclusion
Summarizing the above, we can draw the following conclusion: proper ventilation attic or attic room allows for durability roofing and rafter system, as well as normal air exchange.
The company "Mega.ru" accepts orders for the design of ventilation, power supply and other engineering systems for buildings and premises for public and private purposes. To clarify the details of cooperation, contact our employees by going to the section.
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
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 of area 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 explained 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
Most in a rational way To ensure uniform air exchange is the location of 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;
- application 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, and humidity concentration internal air, the state of vapor insulation of the roof 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 of house roofs, different materials have their own characteristics in organizing 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 one 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
- 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. 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 a universal method that allows 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.
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. 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 if natural ventilation 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 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 in advance on the type of attic floor. It is necessary to take care of ventilation roofing elements directly during the process of building a 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.
Ventilation of a cold attic: important nuances of quality
When modeling an attic in a private house, you need to create good ventilation. Properly installed cold attic ventilation is important to ensure a healthy microclimate under the roof of the home. Insufficient aeration significantly reduces the service life of the structure.
Do you need ventilation in a cold attic?
No amount of house sealing can completely isolate steam from entering the attic. According to the law of thermodynamics, warm air rises to the top, and steam finds a way out in any case. The floors are mainly made of wood. On wooden surfaces when moisture accumulates, it forms habitat for the development of various destructive microorganisms, mold. Unpleasant musty odors and a feeling of dampness appear. An unhealthy microclimate in the room as a whole is created.
Temperature changes contribute to constant condensation and, if there is no ventilation of the cold attic, rapid wear of the structure occurs.
Reasons for condensation:
- lack of good ventilation;
- violation of roof insulation;
- insufficient waterproofing;
- lack of ventilation ducts;
- defects in building materials.
Ventilation according to technical rules, protects the structure from damage.
Cold attic - non-residential premises under the roof of a building without decorative finishing. The issue of ventilation is important to decide during the creation of a house project, when planning the features of the roof configuration.
Ventilation functioning - depending on the selected materials
The main task of ventilating a cold attic is constant air exchange. In order for the set goal to be realized optimally, it is necessary to evaluate the quality and type of roofing material used. Each of them has features.
If slate or ondulin is chosen for laying the roof, then the air easily moves between the wavy bends into the attic area and also freely flows out.
When creating ventilation for a cold attic using metal tiles, it is important to lay a vapor barrier film, as condensation will form. The metal tiles are ventilated through the ridge seal. For a gable roof, ventilation ducts are located on the gables. High-quality ventilation is carried out with uniform distribution of gaps.
There are also some nuances when installing a hip roof. In this case, the inlet hole should be located in the hem, and the outlet hole should be located near the ridge. This type of roof is hipped and has no gables.
When working with flexible tiles, it is necessary to install a ventilated ridge, for classic “ceramics” - a roof vent.
When using overhangs of wood blocks in the filing, an interval of several millimeters should be maintained. When sewing with plastic, holes are made in the elements. The hem is called a soffit.
Is it possible to ventilate a cold attic?
Proper air exchange is necessary to:
- avoid the accumulation of fumes coming from the house;
- protect wooden frame attic from exposure to moisture;
- counteract the formation of fungus;
- maintain a constant temperature.
Provided that ventilation of the attic space is created - a cold attic
from home, moisture accumulation cannot be avoided. On uninsulated roofs, a thick layer of condensation quickly forms. Even if the roof were insulated, condensation could not be avoided, but in this case the walls of the house would become wet.
A frequently asked question is: is it possible to vent ventilation into a cold attic?
It is possible to remove it, but this type of ventilation is wrong decision and leads to disruption of the microclimate of the attic space, damage to the wooden structure, gradual rotting, and inevitable wear and tear.
- Install the necessary ventilation elements to protect the vents from debris, leaves, branches and insects - on ridges, eaves, ridges, valleys.
- Protect ventilation gaps from dust.
- Regardless of the characteristics of the roof, make the area of the ventilation channels 400-500 cm2/m.
- Check that the ventilation channels are not narrowed to avoid condensation due to insufficient air circulation.
- Use auxiliary ventilation structures if the length of the roof covering is more than 10 meters.
- Avoid significant expansion of the gap, as the resulting turbulence reduces air exchange under the roof.
- Ensure ventilation insulation in the attic so that the ventilation system pipelines are not subject to temperature changes and can function uninterruptedly.
Ventilation of a cold attic of a pitched roof of a private house with your own hands: windows or outlet through gables + Photo
No one is surprised at the need for mandatory insulation of the attic space to create a comfortable microclimate in the home. Many people don’t even think about installing a proper ventilation system in this room. But high-quality attic ventilation helps maintain the microclimate there, prevents the occurrence of fungi, rot and mold, and increases the service life of the roofing structure. Correctly calculated and thoughtful ventilation is no less important than proper vapor and heat insulation.
Attic space: the need for ventilation
The design of the ventilation system is the most important part of the design. Ventilation is involved in the heat exchange processes of the entire residential building.
During the hot season, the roof can heat up over one hundred degrees, and heated hot air enters the house, aggravating the heat in it. In cold weather, other problems may arise. Cooled air forms drops of condensation on insulated floors: this moisture negatively affects wooden elements.
Even basic ventilation can prevent premature damage to the rafters.
Attic space: ventilation
There are different buildings different types attics: They have different purposes, and their arrangement and finishing differ accordingly. Based on their main characteristics, attics are divided into two main types - warm and cold. The last type is more traditional. In such a case, the system of roofing structures is not protected in any way, since only the ceiling is insulated. The other type has only one important goal - to properly protect utility lines.
Cold attic: ventilation device
In a cold attic space, there should be controlled ventilation. To equip it, the rafters and sheathings are left uncovered. A good alternative would be special lining with gaps, allowing air to circulate freely. If slate or ondulin is used as a roofing covering, and there are no vapor and wind barrier films, then special device There is no need to worry about ventilation in the attic.
Ventilation device for under-roof space on the roof
Between the individual waves of the roof, air freely penetrates into the space under the roof and exits outside.
Metal tiles are also capable of ventilating on their own, but they can cause condensation, so the use of insulating film in this case is mandatory.
On a gable roof, ventilation ducts are located in the gables. Loose lining of overhangs can be a fairly effective way to solve the problem.
Narrow slots, evenly distributed, will facilitate high-quality ventilation of the entire attic space.
But if the lining fits too tightly, or if the gables are made of stone, holes will have to be made in the walls. It would be rational to place them on opposite sides, thereby eliminating pockets of stagnation. The total S (area) of ventilation channels should be 0.2% of the area of the entire floor.
Ventilation grille for the roof of a house
There is another option that allows you to save money. It involves the installation of standard ventilation grilles, one of which is adjustable, the other with its holes directed downwards. mosquito net will protect them from insects.
If we are dealing with a hip roof, then the ventilation arrangement will be done differently. An inlet hole is made at the bottom, in the hem, and the exit is located at the top, at the ridge. In the case where the overhang lining is made of wood, the beams do not have to be placed tightly; there may be a gap of several millimeters between them. If the sewing was carried out using plastic, then there should be holes in all components. Such panels are called soffits.
It is possible that the filing is assembled quite tightly. What to do in this case? For this purpose, special grilles equipped with mesh are produced. They have a diameter of five centimeters: they are placed every 0.8 meters along the entire length of the wind overhang. To make holes, use a drill with a suitable (round) drill bit. The top output is made from above.
How does a ventilated ridge on the roof of a house work?
In general, the types of ventilation largely depend on the type of roof. For example, a classic ridge is suitable for slate and euro slate. Elastic flexible roofing A ventilated ridge or turtle has been used successfully. A special valve is also used for ceramic tiles.
Metal tiles are perfectly ventilated using a standard ridge. It must be said that the ridge is not just an economically beneficial replacement for the valve. This is also a great way to get a ventilation system in the shortest possible time.
Sometimes special dormer windows are used, with bars or glazed, but their design is quite not an easy task, which requires theoretical knowledge and practical skills.
Warm attic: ventilation
In modern heating systems natural circulation is virtually not used. In other words, if you plan to turn the attic space into an attic, the roof must be made entirely ventilated. For a roof made of flexible tiles or sheet material you will have to arrange a special ventilated area: a counter batten is sewn onto the rafters.
For metal-covered roofs, it is advisable to use windproof film . Slate roofing can do without a counter-rail, since the air must flow freely from bottom to top. An entrance is arranged in the filing, exit to the outside occurs through the ridge.
The attic should be ventilated in the same way as other rooms. The air enters through the windows (possibly the installation of VTK valves), and leaves the house through the ventilation holes. If they are absent in the walls, then fungi (aerators) are made at the place of the hood, on the roof.
Attic ventilation in a house: truth and fiction
Questions regarding high-quality attic ventilation have become overgrown with rumors and speculation. Which facts about proper ventilation are true and which are not?
Does heat escape through the attic of a private house?
- Is it true that warm air escapes from the house through ventilation ducts in winter? There is an opinion that the operation of ventilation in the cold season only interferes with the heating of the home. In fact, it is unlikely that the holes are the cause. In the case when a home heats up for a long time and then quickly cools down, it is not the ventilation that is to blame, but the insulation. It must be said that not very high-quality insulation can allow moist air to pass into the attic. The consequence of this phenomenon is often the formation of drops of condensation, which in turn cause damage and rotting of the wood of the floors.
- Is it true that ventilation is only required during hot weather? There is a belief that ventilation is necessary only in the summer, when the temperature rises strongly. In reality this is not the case. If you do not carry out ventilation measures in winter, this is fraught with the formation of icicles, the development of fungi and mold.
- Is it true that the size of the ventilation holes does not matter? This is also a misconception. You should not arrange channels “by eye”, since it is likely that the efficiency of such a system will tend to zero. Vents should have a ratio to ceilings as one to five hundred.
Holes located along the roof ridge should be given Special attention. Traditionally, they are located as close to the ridge as possible.
Attic ventilation in a private house: doing it right
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. Today there are many solutions on the market to provide ventilation. We will look at 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 condensation that appears on the elements roofing pie. Ventilation ensures a flow of air, which eliminates residual moisture. By removing this moisture, the service life of all wooden structures, which the roofing pie is very rich in.
In addition, there are two more seasonal features when ventilating:
- In winter, that's right organized ventilation allows you to effectively combat ice dams, especially on eaves overhangs. Ice may appear due to poor ventilation; as a result, excess heat will turn into condensation, and this, in turn, into ice build-up.
- In summer, the moving air flow will contribute to some cooling of the roofing materials, which is especially important for bitumen-containing materials.
Methods for creating attic ventilation
First of all, air flow is ensured, usually in the eaves of the roof. To ventilate your attic yourself, in most cases, you use perforated soffits. They are installed in the lower part of the roof eaves, and the perforation allows air flow to penetrate unhindered, but delays the possible entry of various insects.
Soffits combine proper decorativeness and functionality, making them the most popular solution for air flow into the attic space.
Attic ventilation in a private house also requires air outflow. For this there are the following elements:
- ventilated ridge;
- inertial turbines;
- electric fans;
- roof aerators.
The roof along the entire perimeter must have a ventilation gap of at least 40-50 mm. This distance is often ensured by the width of the sheathing slats, which allows air to circulate freely under the roof. This method, for example, is suitable for roofs made of metal tiles, corrugated sheets or ondulin. The shape of these roofing materials allows air to easily pass underneath and provide ventilation.
The area of ventilation ducts should be 0.2% of the total area of the ventilated room.
When using soft roofing materials, the counter-lattice is made not continuous, but with breaks. This allows the air to bypass the most problematic and difficult areas of the roof pie.
In the most problem areas roofs, for example, for a valley or hip, it is necessary to make point ventilation, which is provided by aerators or turbines.
Ventilating a Cold Attic
Ventilating a cold attic can be done easily with your own hands. This will require knowledge of a little theory and some practical skills. Providing 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 eaves, 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 lining of eaves overhangs. If the gables are made of stone, then holes can be made in them for dormer windows with ventilation grilles.
Dormers should be installed on opposite sides to ensure proper ventilation of the attic.
There is an alternative, more economical option. To do this, install standard ventilation grilles (pediment vents), one of which is adjustable, and the other is turned with the vents down. To protect against insects, this grille is equipped with a protective mosquito net.
Hip roofs do not have gables due to the shape of their structure, so for them there is another option for providing ventilation in the attic - using eaves overhangs. The air flow will be through the roof lining, and its exit will be from above at the ridge. If the filing is made from wood with your own hands, then small gaps are left between the bars for the passage of air. When covering the cornice with plastic soffits, such a procedure is not necessary, due to the presence of pre-made holes on the elements - perforations.
The air exits from above, through the roof ridge. His 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 (valleys) are one of the problematic and difficult areas of the roof. To ensure normal ventilation of the attic space, point aerators are installed along the valley. However, this method is acceptable for roofs with slope angles of 45° or more.. On flat roofs, there is a high probability of snow accumulating in the valley area and therefore such ventilation becomes ineffective in winter. You can combat this by installing forced ventilation - inertial turbines, roofing electric fans, or using high nozzles that will not be covered with snow.
Ventilation of a warm attic
Ventilation of a warm attic (attic) is more difficult. Ventilation layers run between the rafters. The space for ventilation between the lower surface of the waterproofing and the thermal insulation material must be at least 20-30 mm.
If a mineral wool board is used as a heat insulator, then it is necessary to take into account its future increase in volume by 10-30% from its original state.
If the depth of the rafters is not enough to provide the required gap between the heat insulator and the waterproofing, then their height is increased using boards or slats. But, as you understand, this method of ventilation is quite difficult to implement for roofs with complex shapes. Therefore, recently, experts give preference to diffusion (vapor-permeable) membranes, which can be mounted directly on the insulation and allow moisture to pass through only in one direction.
The space for ventilation is created by installing lathing, the thickness of which must be at least 40-50 mm. Air for ventilation is taken in through soffits or other elements on the roof eaves, and its natural way out occurs through the roof ridge.
Recommendations of modern roofers for attic ventilation
To properly ventilate your attic with your own hands, follow these tips from experienced roofers:
In conclusion, we note that ventilation of the attic space is one of the most important and key factors. When arranging it with your own hands, take it very seriously to avoid common mistakes and blunders.
It may seem stupid to equip a serious ventilation system for the under-roof space, but in fact it needs to be done. The fact is that problems with the microclimate in the attic can ultimately lead to problems for the entire building.
For example, an attic space can become a “haven” for fungi and mold, which will then spread to other rooms of the building. This can lead to disaster, especially in a private house (possible rotting of the supporting elements of the building or various wooden structures).
The good news is that it is quite possible to install attic ventilation yourself, and on a fairly meager budget. The principles of installing ventilation for cottages, summer houses or bathhouses are approximately the same, which only simplifies the work.
Is ventilation necessary 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 occur even in a heated attic, so even in this case it is necessary to create at least a primitive ventilation system.
You can prevent condensation in a cold attic by providing fresh air. And this is extremely important, because the accumulation of condensation can lead to damage to the building (for example, rotting of the boards of a frame house).
Roof ventilation - main types
Other advantages of a properly equipped ventilation system:
- In winter, adequate ventilation allows you to eliminate ice dams, which especially often appear on eaves overhangs. Usually, ice is the result of a lack of properly organized ventilation.
- IN summer period both forced and natural system ventilation allows for autonomous cooling of roofing materials, which is very important, because overheating of the same bitumen-containing materials is extremely dangerous.
- Ventilation is also 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 rotting.
Ventilation system options for cold attics
The classic option would be to make a ventilation system through dormer windows. This ventilation device is quite simple and can be 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. Enough good way installation (due to the simplicity and level of the cross-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, you can make dormer windows of somewhat smaller sizes, combining them with a very effective cornice-ridge ventilation system.
You can also install vent hoods, and this method is very popular in Europe. Vents are openings in a building on which it is necessary to install grilles to protect against the entry of various atmospheric precipitations or debris from the street.
In addition to gratings in the form of vents, you can use deflectors or pitched exits. The vents themselves are divided into two types: ridge and cornice. Cornices are further divided into subtypes: slotted and point.
In addition to using dormer windows and vent openings, you can use deflectors or ventilation turbines (forced ventilation with supply and exhaust system ). The principle of their operation is similar, but they provide much better traction.
Basic rules for roof installation
Be sure to follow the rules for installing the ventilation system, regardless of what type of system you use. Ignoring the instructions can result in either the system becoming ineffective or unsafe.
Basic rules and regulations:
- for any type of roof, the area of the ventilation ducts should be 400-500 cm²/meter, which will correspond to the required gap height of 40-50 millimeters;
- Please note 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, eaves or on ridges/ridges - protection must be installed from birds, various insects, litter from the street (including foliage);
- in cases where the length of the roof covering 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 air duct is narrowed, this will negatively affect the entire system, which can ultimately lead to condensation;
- do not try to make the gap height very large - this will in no way enhance ventilation, and even on the contrary, will worsen it due to the occurrence of turbulence and air resistance.
Attic ventilation method (video)
A hipped roof is a structural and functional element of a building that is known to every builder.
The triangular end slopes are called hips, which is where the main name for the roof of a house of this type comes from.
They replaced vertical gables on all sides of the building.
The reason hip roofs are so popular is that they are very resistant to wind loads due to their increased aerodynamics, they are more rigid and reliable due to the triangular slopes.
In addition, it is worth noting that hip hip roofs are quite stylish and aesthetic elements that can give any building originality, improving its external shape. Such a roof is not difficult to make.
In this article you will find out what the device is hipped roof.
Like any other type of roof, hip roof has a special type of roofing pie.
It consists of the following structural elements:
- Lathing;
- Counter grille;
- Hydrobarrier;
- Vapor barrier;
- Drywall.
Each of the above elements perform their important function and has individual characteristics. Today the market building materials rich enough, therefore, as a roofing material for a hip roof, you can choose both piece and sheet products.
Lathing
Rafter system
In order for the hip roof to be sufficiently rigid and reliable, it is necessary to arrange all its elements in a certain way.
Sloping types of rafters must be attached to internal corners walls, while diagonal - to the outer. This is fundamentally important. Due to the fact that the slanted rafters bear a large load, their length should also be greater.
The 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 supported by one or two supports. For this purpose, racks made of timber are used. The struts should be placed in such a way that an angle of 45 degrees is formed between them and the horizontal support.
The intermediate rafter legs should rest on one side of the ridge beam and the other on the mauerlat. They should be placed in steps of 1-1.2 meters. Every second rafter is best connected to load-bearing walls using twists.
They can be made from ordinary wires, the radius of which is 2 millimeters. Using a reverse bracket, the intermediate frame should be connected to the Mauerlat.
The half-legs or half-legs (as they are often called) should rest on the mauerlat on one side and on the diagonal leg on the other.
Construction of a hipped roof truss system: drawings and diagrams below.
Drawing of the rafter system
Rafter system diagram
Knots of a hipped roof
It is important to note that there are certain rather complex components of the rafter system that always raise a lot of questions among 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:
- Using corners installed on both sides of the rafter leg;
- By driving a nail diagonally through the rafter into the mauerlat;
- Specially created brackets for this purpose;
- Sliding fastening.
Rafter legs can be connected to each other in different ways:
- Using bolts after laying them on top of the ridge beam;
- Having made special recesses for the timber and connecting the legs above it with nails;
- By adjusting the rafters to the selected angle and connecting them together with metal or wooden plates on both sides.
To ensure that the hip side of the roof is durable enough, it is necessary to connect the rafter legs to the beam 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 on top;
- Laying the ridge beam on the posts and fastening it on both sides with wooden overlays from boards.
It is worth remembering that the rigidity of the entire structure is equal to the rigidity of its weakest unit. Therefore, it is very important to make connections as securely as possible.
Mounting the Mauerlat
Conclusion
The durability of the entire structure depends on how the roof is constructed. That's why work should be carried out carefully and carefully. If you have no experience in this, it is best to turn to qualified specialists or take help from someone who has already built hip roofs. Their device is complex, but the result is worth the effort.
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