Under roof ventilation of the roof: purpose and device. Roof point valve (KTV) How to count the number of ridge point valves

Principles of under-roof space ventilation.

The use of modern building materials leads to the need for forced ventilation roofing and interior spaces. Roof ventilation is not a whim, and builders know it. Thermal insulation becomes damp, even if the roof does not flow. The reason for this is water vapor, which is always present in the room air and, rising up, condenses on the lower surface of the roof, despite the presence of a vapor barrier. Thermal insulation is saturated with water vapor and loses its properties, which increases heating costs accordingly. If the roofing is metal, then corrosion centers appear accordingly, which leads to the gradual destruction of the roofing material. With coatings made of bituminous material, in the warm season, water vapor, heating up, increases in volume, and swellings form on the surface of the roofing carpet and delamination of the material is possible. Throughout the year, the roof experiences strong temperature fluctuations and repeated cycles of freezing and thawing, which also leads to the appearance of condensate inside. roof structure.

Based the above it follows that all roofs made of modern hermetic materials must be equipped with ventilation outlets.

VILPE aerators implement the basic principles of a "breathing" roof:

- remove the water vapor rising to the roof of the interior before it has time to harm the structure;

- reduce the pressure that occurs in the roof structure and leads to the formation of bubbles on soft flat roofs;

- prevent the formation of condensate on the lower surface of the waterproofing, which subsequently flows into the heat-insulating layer.

Depending on the design of the roof, the principle of operation of the roof deflector VILPE is based on:

- on creating draft in the fan pipe due to the formation low pressure thanks to external wind currents;

- on the use of an external pressure gradient and pressure in the roof structure.

In roofs with under-roofing insulation and steam and waterproofing, ventilation of the space between the roofing material and the insulation is mandatory! There are problems associated with condensation that are common to all roofing. For example, getting into the insulation, moisture significantly reduces thermal insulation properties the last one. Moisture is also harmful to rafters and other wooden structures roofs, causing fungus and rotting.

Let us consider this issue separately in relation to various roofing coverings.

metal tile .

If you do not remove the condensate from under metal tiles, then, accumulating on inner surface metal, it inevitably leads to the occurrence of foci of corrosion, which become noticeable when a through hole appears. Usually, when mounting metal, scratches and scuffs are inevitable. polymer coating. FROM outer side they are noticeable and painted over during installation. Screw holes (about 8 per square meter) is also a weak point in terms of corrosion. On short slopes, this problem can be solved; it is enough just to use the wavy surface of the material as a draft device. To do this, it is necessary to ensure the inflow of air at the lower edge of the roof and the outflow from under the ridge. For long slopes, valves must be installed. Finnish company SK TUOTE OY produces such valves for all types of metal roofs, including profiled sheets and seam roofs (PELTI KTV , CLASSIC KTV , MAXI KTV ).

Soft bituminous roofs .

The situation with them is more complicated than with metal tile. The roofing material is laid on a continuous crate, and the space under it is closed (we do not take into account roofs with an attic and without insulation directly under the roofing material). Moisture in the under-roof space is absorbed by plywood (or tongue-and-groove board, depending on the material used for solid battens). Apart from the fact that this leads to rotting of the wood, with repeated cycles of freezing and thawing, this leads to delamination roofing and roof leaks. Without additional elements ventilation is no longer necessary.

For soft roofs SK-TUOTE manufactures valves both for already assembled (CLASSIK KTV ), and for a roof that is in the process of installation (HUOPA KTV).The valves are produced in two types - in the form of a low (300 mm) pipe with a deflector on top (they must be used on roofs with a small angle of inclination - deflector ALIPAI ridge and inclined) and in the form of a decorative tile (under the name KTV ) for use on roofs with a slope of 25 degrees.

Cement-sand tiles.

This is one of the most reliable and durable roofing materials. Accordingly, the requirements for design and installation are quite high. There is an opinion among consumers that tiles are not suitable for our climate, because they crack and crumble in the cold in winter. This is due to condensate, which is absorbed into the tiles and in winter, when frozen, increases in volume and destroys the tiles. The problem is solved with the help of valves for the under-roof space. Branded VILPE valves are supplied for natural tiles- TIIL KTV.

Simple, fast and reliable installation all elements VILPE on any of the above metal roofings, bituminous materials and tiles, a wide range of colors of products will complement your roof with modern and harmonious elements and make it really reliable and durable.

Indicators of strength, reliability and durability of roofing and construction are determined by many different components. Such an important component as ventilation in the under-roof space is most often given insufficient attention. The service life of the structure and the comfort of living completely depend on how competently and carefully the under-roof space is protected from moisture and atmospheric phenomena.

The need for under-roof ventilation

Roof structures pitched roofs require mandatory ventilation. Performing high-quality air exchange is necessary to ensure the safety wooden elements carrier frame structure consisting of a crate and rafters.

The use of even the most powerful antiseptic cannot fully protect wood from biological damage in the process of systematic moisturizing. In addition, at high level humidity, the insulation layer and the roofing material itself suffer.

Strong moistening of the insulation significantly reduces the thermal insulation performance and reduces the duration of the roof. Insufficient ventilation of the under-roof space provokes the accumulation of moisture in in large numbers, which can cause the formation of smudges and mold on the surface of the ceiling.

To get a dry under-roof space, free circulation is required air masses. Constant ventilation of the rafters and lathing prolongs the service life.

The organization of ventilation of the space under the roof requires the organization of special openings and gaps, which are made in accordance with the rules and technology and do not allow precipitation to penetrate.

The structure of the roofing cake

Roofing cake is important structural element during the construction of almost any roof.

cold roof

Ventilation device cold roof(attic)

A cold roof is characterized by a very simple design that does not require the use of insulation, vapor barrier and finishing device.

In the composition of the roofing cake for cold roof includes the following elements:

waterproofing film or;

counter-lattice and crate;

The use of microperforated films prevents the ingress of moisture from the outside, but does not delay the release of water vapor. In this case, vapor barrier is not required, and water vapor is removed by air currents.

The use of polyethylene and polypropylene films, as well as obsolete materials in the form of roofing material, are not allowed for waterproofing cold roofs.

Ventilation is provided in the process of creating a gap by means of a counter-lattice, and air flows enter the under-roof space through the cornice overhang with subsequent exit through the roof ridge.

A prerequisite is the installation of a counter-lattice, which allows you to get a gap between the film and the crate, which contributes to the unhindered passage of air flows. For good ventilation cold attic space ordinary ones are used.

Additional ventilation requires the installation of a standard supply and exhaust system.

Warm roof

Roof leaks can be prevented by eliminating the penetration of moisture into the structure. The use of fiberglass insulation is characterized by the hygroscopicity of the material, which necessitates the implementation of reliable layers - and.

Mineral wool resistant to water, but requires the installation of an additional protective layer against water vapor. The most high degree moisture resistance of extruded polystyrene foam.

To protect the insulation from moisture entering the roof, it is necessary to install a vapor barrier from a conventional vapor-permeable or "breathable" film. The first is installed with a gap, and the second can be laid directly on the insulation layer. High-quality vapor barrier is characterized by tightness and lack of damage.

Under standard conditions, the ventilation gap is arranged from roofing material to waterproofing. For this purpose, a counter-lattice with a thickness of five centimeters is stuffed. From above it is necessary to install a continuous flooring or step crate. The absence or insufficient thickness of the counter-lattice deprives the roof of ventilation.

From the waterproofing layer to the insulation, it is necessary to equip the lower version of the ventilated gap for the release of steam that rises from attic space.The width of the upper gap is about five centimeters.

Elements of roof ventilation

The use of quality elements under roof ventilation allows you to extend the durability of the roof and significantly save on the repair of the roof surface.

Cornice products

Through this element, air masses enter under the roof, pass up and exit into the atmosphere. This type of product is equipped throughout all cornice overhangs:

slotted vents, which are a gap with a width of up to 2.5 cm and located between the walls and the roof;

spot airflows performed with a roof slope of more than 15 degrees with a diameter of up to one cm. In the case of a slope of less than 15 degrees, the parameters of a standard airflow are 2.5 cm.

The roof overhang, when arranging slit-like vents, is covered by soffits, point lattices. To prevent snow from blowing in, a chute is mounted above the ventilation slot, which allows the gap to remain free even in conditions of powerful icing.

Skate products

This version of the vents is involved in roof ventilation and allows air masses to escape to the outside. The ridge type of air can have a continuous execution with a width of five centimeters or is made in the form of frequent holes.

Eaves and ridge vents need to be protected from debris and bird nests. For this purpose, it is necessary to install special ventilation elements.

Roof aerators

They are used to remove vapors from the under-roof space. Such elements are used with any type of coating, regardless of the shape and slope of the roof. The main functional load is to dry the insulation, remove condensate, as well as prevent decay and leaks.

Roof aerators can be mounted not only during the construction of the roof, but also on the finished roof surface. Quantity roof aerators directly depends on the roof shape and area, as well as the material used and the purpose of the attic.

Aerator for shingles

Features of the roof ventilation system

The technology for performing under-roof ventilation largely depends on the type of roofing.

For soft or flexible roofing

One of the most important problems of roofs constructed using soft cover, is swelling, which can cause leaks. Water penetrating into the space under the roof contributes to the gradual destruction of the roof. To prevent similar situations it is advisable to use roofing aerators, which not only remove moisture, but also contribute to maintaining the integrity of the roof.

In addition, to perform high-quality roof ventilation, the following can be used:

passage ventilation elements;

roof valves;

antenna type outputs;

roof fire hatches and seals for roof outlets.

For metal tiles

The upper gap for ventilation of the under-roof space in metal roofs must have standard size. Any errors contribute to the emergence of turbulent flows, which violates the direction of movement of air masses, and increases the resistance of air flows.

Certain difficulties that violate ventilation under metal tiles arise in the case of a device green facades from climbing plants or when doing external insulation. In such cases, partial overlapping of the airflow openings is possible. in an efficient way is the use of a ventilation tape and overhang air elements with a decorative grille.

Roof ventilation device

It should be borne in mind that any violations during the construction of the roof can significantly impair the operation of the ducts. To the most common mistakes relate:

the use of special adhesive tapes without gaps;

filling roofing gaps with mounting foam;

overlapping roofing film without ventilation gaps.

For a roof that is being built over attic floor, it is required to install a continuous ridge vent, regardless of the roofing material used.

The modern roofing materials market offers several types of ventilation systems for ventilation through the roof:

valved and valveless options;

thermally insulated and thermally non-insulated options;

with the presence of a controller that regulates the valves for opening / closing.

Summing up

Providing the roof of the building with durability and strength depends on well-established under-roof ventilation in combination with a high-quality ventilation passage through the roof surface. When arranging, you should familiarize yourself with the technology of work and the features of using various ventilation elements.

Roof-Point Valve (KTV), or as it is also called: a point aerator, is used on roof slopes with a slope of 30 ° or more. For flexible tiles, ridge-point valves with an even salary are used.

On gentle slopes with a slope of less than 30 degrees, the aerator may be ineffective due to the small difference in height between the ridge and the roof eaves. Also in winter time can be simply covered with snow, which can lead to the loss of the ventilation process in the under-roof space of the roof and the formation of destructive processes. For sloping roofs on skates, instead of a KVentil, they use (ridge pipes).

Roof aerators on bituminous tiles

All parts of the valve are made of high quality plastic. Exist different colors roof aerators, which can be matched to the color of the roof. Standard and compatible with all colors shingles the black color of point aerators is considered.

If the roof has a required slope of more than 30 degrees, then point valves will be appropriate in this case.

How to count the number of ridge point valves

One standard KTV-cabinet is designed to serve 50-60 m² of roof (depending on the manufacturer's company). It is calculated according to the area of the slope.

As an example, a roof valve from a popular manufacturer VILPE designed to service 50 sq.m. roofs.

By the same principle, the number of point aerators of other sizes and types is calculated. Take as a basis throughput one point valve (for example, 1 valve per 50 sq.m., 60 sq.m.; 25 sq.m., etc.) and the area of individual slopes or the entire roof.

Types of point aerators

Ridge Spot Valves for Finished Roofing

Mounted over finished roof.

Consists of a salary, a protective grid and a cap. On the underside of the salary is installed rubber gasket responsible for sealing with the roof.

They are mounted using hexagonal ones (as for metal tiles).

Standard valves mounted together with a flexible roof

The most reliable point valves. The salary of the valve is covered with flexible tiles.

Consists of a salary, a protective grid and a cover. The design of the point valve is easily disassembled.

One standard valve designed to serve 60 m² of finished roofing.

There are similar (same type) aerators with a smaller area of the ventilation slot, designed for 50 sq.m. roofs.

For installation, roofing bituminous glue is required, which gives reliability in sealing.

Simple ridge point valve

There are simpler and cheaper Ridge Point Valves.

KVentil from TechnoNikol and Aquasystem is designed to service 25-30 sq.m. roofs:

On such valves, the covers can only be removed from the inside of the salary, so they cannot be disassembled after installation. The lid of this point valve is disposable, with plastic latches. If force is applied to the valve cover, the latches break off, and the cover needs to be replaced.

Video about roof valves:

Ridge deflectors (pipes)

For roofs with small slopes (from 35 ° and less), ridge ventilation pipes (deflectors) are used for under-roof ventilation.

Ridge roof pipes located in top point roof ridge, increase the height between the ridge and the eaves (at the points of entry / exit of air masses to / from the under-roof ventilation space), thereby increasing the force of natural air draft in the under-roof space.

One ridge deflector is designed to serve 50 m² of finished roof.

The salary of the ridge pipe has a bending rib - a regular place for fixing the pipe in the roof ridge. Thanks to the regular bend, the deflector is easily mounted, taking the outlines of the roof slopes.

Variety of roofing valves for shingles

Depending on the manufacturer, you can find a wide variety of roof valves that have both external differences and different characteristics for maintenance of the roof area.

Often a stylish living space is arranged in the attic of a one-story country house, turning it into a kind of two-story. Previously, the attic is insulated, waterproofed, and a vapor-tight layer is laid.

And they forget that good ventilation of the under-roof space is required, considering it a waste of time and money. As a result, in best case receive a room unsuitable for life.

Cold attic It is convenient to turn a country house into an additional residential floor. From the attic comes an excellent office, bedroom or art studio with a bizarre geometry of walls and ceilings.

One problem - many customers of such alterations refuse to equip ventilation there, believing that the builders want to deceive and take more money. Part of home craftsmen engaged in construction without involvement professional builders, believe that the attic does not require ventilation, because this is an extra part of the cost.

From the attic can suddenly turn out to be an excellent living space, if it is properly equipped.

This decision is justified by the fact that 50-70 years ago no one installed all sorts of aerators, spotlights and other elements that are now massively sold in all construction stores. And at home, despite the lack of ventilation in the attic, they still stand and look better than some modern cottages.

Indeed, many old houses are perfectly preserved, but not due to the lack of ventilation. Everything is just the opposite - they are perfectly organized natural ventilation attic space.

In such houses, no one equipped an additional room in the attic for permanent residence. Yes, and materials for insulation were not used here - the attic is cold, has dormer windows, additional gaps and slots for the entry and exit of incoming and outgoing air flows.

It is convenient to turn the attic space into a nursery, especially if there has been a replenishment in the family, and the purchase of new real estate is not included in the spending plans for the near future

If the attic room is not provided with ventilation or it is, but does not work, then soon all family members will become aware of this fact.

The main problems arising from the lack of ventilation of the attic space are as follows:

musty air;
the appearance of an unpleasant putrefactive odor;
mold under the ceiling and on the walls of the attic room;
rotting roof structures;
formation of condensate;
icicles and frost hanging from the roof in winter.

An unhealthy microclimate with such signs is provided to all inhabitants. As a result, instead of a bright and cozy room, a breeding ground for bacteria is obtained, bad smell and destroying everything that gets in its way.

But this is far from the worst. Such manifestations are harbingers of an early roof repair, which will occur in 3-5 years due to rotten wooden structures, wetting of the insulation and the inability to use the attic for its intended purpose.

Rotting wooden roof elements can lead to their complete destruction and collapse of the roof. Especially if everything is hidden from the inside, and the owner did not guess in time about the problem.

To avoid big expenses after arranging the attic, it is important to immediately develop a project for its ventilation. This will protect all the inhabitants of the house from health problems and save family budget. What is the solution to the problem with an unexpectedly collapsed roof - it’s good if there is no one from the household in the house.

Ventilation of the under-roof space is provided by a set of devices and measures:

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Attic: what is ventilation

Given that the attic is a living space that is settled in the attic of the house, then the requirements for it should be appropriate. First, it must be safe. Secondly, it is necessary to install several layers of insulation there so that you can use the room. all year round.

Thirdly, you need to think carefully about the under-roof ventilation of the attic to ensure a comfortable microclimate and good conditions for the stay of all the inhabitants of the house. Stuffy and fetid air does not fit into the requirements for living rooms.

In houses large area often in the open spaces of the attic space they equip a bathroom, toilet, bedroom

An attic ventilation system is a prerequisite if there is no desire to overpay for roof repairs. Moreover, ventilation is required both for the rooms obtained as a result of the repair of the attic, and for the roof itself, in order to ensure a long service life of roofing materials.

Ventilation used in the attic is:

natural;
forced;
mixed.

The first option involves using the natural draft resulting from properly equipped ventilation holes and channels.

This is the most cheap option of the possible. For its arrangement, a minimum set of ventilation materials is required - grilles, aerators, spotlights, ventilation pipes and other elements.

The natural option is most dependent on weather conditions. As a result, instead of a perfectly working ventilation system, you can get condensate and frost in winter.

The forced system works due to mechanical intervention. It uses fans for intake and exhaust, optional equipment for heating cold outdoor air.

it expensive option for attic ventilation, especially if purchased with rich functionality - temperature, humidity sensors, humidification, ionization and air heating functions.

With the mechanical method of ventilation of the attic space, the main element is the fan

The mixed type of attic ventilation assumes that one process will be mechanical - the inflow or removal of air. Most often, the exhaust system is made forced, letting in fresh air by gravity.

The subtleties of designing ventilation in the attic

Before proceeding with the installation of aerators or exhaust mechanisms in attic, you should calculate everything and choose the most suitable option. To do this, you need to take into account the area of \u200b\u200bthe room and its purpose. After all, if here, for example, you have to make a bathroom, then you definitely cannot do without exhaust fans.

Project: when to create it

One of the most important points arrangement of ventilation - design. It should take place during the construction phase. Otherwise, everything will turn out more expensive - you will have to hire another team or delve into all the intricacies of the process yourself.

When a separate bathroom, kitchen or shower room is equipped in the attic, it is imperative to bring out a separate sewer ventilation duct

If all construction works already finished, and there is no ventilation, then you can’t leave everything like that. Be sure to take care of its creation - now it will still cost less than in 2-3 years, when it will be impossible to use the attic. Moreover, the first signs will appear already after 6-8 months after the start of operation of the premises.

The entrance to the attic can be located both inside the house and outside. But this fact does not at all affect the need to equip ventilation system. This is not a process to skimp on.

Moreover, with a reasonable approach, everything will cost many times cheaper than buying new materials, repairing or replacing the truss frame and laying a new coating.

Equipped attic can serve as a full-fledged second floor, only the area of \u200b\u200bthe room will be smaller

How to properly design ventilation?

Thinking about, you immediately need to think about its ventilation system, choose the most best option and develop a specific project.

When designing under-roof ventilation, it is necessary to take into account the purpose of the future premises and its area. It should be remembered that this is necessary not only for the room, but also for roofing materials. Therefore, it is important to correctly lay all layers of the roof, following the recommendations given by the manufacturer of certain materials of the roofing "pie".

Ventilation of the roof structure is provided by a counter-lattice. Air must flow into the gaps between the layers of insulation, moisture- and vapor-tight film

First of all, provide options for inflow fresh air. For this, it is extremely important correct design roof, so that you can make one ventilation gap provided by the counter-batten. Its total value should be 1/100 of the roof area. To form a gap, a bar with sides of 30, 40, 50 mm is used.

Sometimes the counter-lattice is made not continuous, but with breaks - in the form of separate segments. It is constructed from the cornice overhang to the ridge in order to more effectively wash the elements of the system with air currents.

To optimize the "ventilation" made of wood frame system roofs in the side of the rafters additionally drill holes Ø 2 - 2.5 cm through. Drilling is done after 30 - 50 cm.

Roof fans are often used. It is very effective to install inertial wind turbines. They rotate from any breath of wind and pull everything well

Another element that provides a constant supply of fresh air is spotlights under overhang. Here the feature is diffusion film or the micro-perforated film is not brought to the edge of the cornice. It should immediately break off behind the wall so that a stream of fresh air can quietly penetrate.

Soffit filings are convenient to use, easy to mount. They immediately combine utility and decorative effect.

Another method for inflow is a gap along the entire plane of the roof between the waterproofing and the coating itself. The height of the vent can be from 3 to 5 cm.

The size of the hole must be equal at the inlet, outlet and all along this ventilation duct. It is customary to observe these rules during the construction of roofs without insulation.

The gap must be closed with a special grate to prevent insects, birds and other unwanted visitors from entering the ventilation system.

When it was possible to decide on the design of the inflow, they begin to develop the most suitable option for removing air.

Most often used:

in the upper part of the roof - ventilation ducts, point aerators, aeration turbines that operate from the smallest gust of wind;
in waterproofing film along the entire length along the ridge run, a gap is formed for the free removal of air mass from under the roof;
if the valley is long, then it is necessary to ensure the flow of air along its entire line into the lower ventilation gap, making a continuous ventilated junction;
strive to make continuous ventilation of skates and ridges.

The total cross section of the ventilation holes, together with dormer windows and aerators should be approximately 1/300-1/500 of the attic area.

Ventilated ridge - some part raised above the main roof, which provides the necessary clearance. Sold already finished item or you can do it yourself

You need to calculate how many and what kind of ventilation elements you need only based on the area of \u200b\u200byour attic space. All this is very individual - after all, houses and cottages have the most different shape roof, which should also be taken into account when designing a ventilation system for a fitted attic.

Instructions for the installation of the ventilation system

You can do the installation of the ventilation system yourself or invite specialists with outstanding experience roofing works. You should not turn to cheap craftsmen - the quality of their services may not correspond to even the most minimal cost.

If you contact unfortunate masters, you will have to pay three times - for their work, for a damaged roof, for correcting mistakes by real specialists

In the case when a team of builders will be involved in the installation work, you can voice your preferences to them and check the project, which they will subsequently provide. It is necessary to pay attention to whether the proposed option for the inflow and removal of air masses suits.

An effective option for inflow into the attic room is valves built into the window structure. They are designed in such a way that they can ventilate the room even when the sash is closed. Manufacturers offer models for vertical and inclined (roof) windows.

Ventilated windows ensure a reliable supply of fresh air into the the right amount to the attic

For window installation, it is better to use an installation service, especially if it is big size. Doing this yourself may void your warranty. In the event of any problems, there will be no one to present a claim.

If the decision is made to self-assembly ventilation systems in the attic room, then you have to follow the instructions for the elements that need to be installed.

Most often, spotlights and a ventilated ridge are mounted with their own hands. Depending on the type of material, the set of tools for their installation will also differ. To install aerators on the roof, they usually turn to specialists who have the equipment to make the appropriate holes.

Aerators produce the most different sizes, shapes, colors. This allows them to fit in perfectly without being out of place. colors roofing

For use sealant to isolate the joints well. AT exhaust system often put a fan or wind turbine. The exhaust fan is to be placed directly into ventilation duct, fixing and connecting it according to the attached instructions.

With self-arrangement of attic ventilation, it is important to remember that the total area exhaust openings should be 20% more than the supply. Otherwise, there will be a problem with traction.

The color and shape of roof fans allow them to be used for installation on any type of roofing.

If there are doubts about own forces, then it is better to turn to specialists who will correctly design and equip the attic space. This will be the key to a long service life of the attic and the whole house, as well as provide a healthy atmosphere in the room.

If a team of builders is engaged in the construction of the house, then ventilation issues can be entrusted to them, having previously included this clause in the contract. It is important to remember that after the completion of construction, the organization of ventilation will cost an order of magnitude more expensive.

Tell us about how the ventilation system was built when arranging your own attic. Share useful technological nuances not mentioned in the article. Please write comments in the block below, post photos on the topic, ask questions.

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