How to install roof ventilation correctly. Height of ventilation pipe above the roof

It’s not even worth talking about the need for roof ventilation. Everyone knows this. But this article will discuss how to make it effective, durable, and also install it yourself, using advanced engineering practices.

Why do you need roof ventilation?

The importance of the roof is difficult to overestimate. Therefore, when erecting a building, experienced builders arrange the roof with special care, ensuring it reliable insulation, insulation and ventilation system.

During the operation of the house, steam is generated indoors, which, according to the laws of physics, rises into the under-roof space. And if there is no properly adjusted roof ventilation, then steam settles on the roof structures, rendering them unusable and destroying the load-bearing elements of the building.

A roof without ventilation is dangerous. Increased humidity will lead to the formation of mold and mildew on the walls, wetting of the insulation, and therefore deterioration of thermal conductivity and freezing of the house. A well-established roof ventilation system will help to avoid this, which will remove condensation outside and prevent it from ruining the entire structure.

In order to extend the life of the roof, it is equipped with a high-quality ventilation system

Home ventilation can be spot or continuous, natural or forced. The most common sources of air circulation include:

• dormer windows;
• ridges of pitched roofs;
• gaps provided in the roofing pie and eaves strips;
• exhaust fans on roofs and other piece elements of the ventilation system with holes.

For small or medium-sized roofs, natural ventilation is sufficient. Elements forced ventilation installed on large roofs, where natural air exchange in the under-roof space is insufficient.

Elements of roof ventilation system

The assembly of ventilation components (including labor) is no more than 2–5% of the cost of the roof itself, which is much less than what will be required to repair the roof, individual sections of the house, or even the entire building as a whole, if the ventilation system is not installed or installed on “maybe, I suppose, somehow.”

The main tasks assigned to the elements of the ventilation system:

• removal of steam entering the under-roof space from interior spaces Houses;
• decline heat flow penetrating under the roof due to its heating in the sun;
• equalizing the temperature of the roof to prevent the formation of icicles on the edges of the eaves and ice on the roof surface.

The ventilation system of a building consists of various elements that perform one common task: to ensure normal temperature regime roof and under-roof space

Ventilation roofing tape

The ventilation tape covers all the cracks in the roof, while ensuring sufficient air exchange and protecting the under-roof space from debris, invasion of birds and other small animals.

Ventilation tape TOP ROLL S 240 mm ensures good air circulation and protection of the under-roof space

Depending on the purpose there are:

• ridge ventilation tape;
• perforated cornice tape (overhang aero element).

Advantages of using roofing tape:

• creates good breathability;
• emphasizes decorative finishing roofs;
• Provides protection from moisture, debris and insects.

Ridge roofing tape protects the roof ridge from precipitation and snow getting under the roof. Along with this, it removes steam from the roofing pie, preventing wetting and rotting of the rafter system and covering material.

Good ventilation tape from well-known manufacturers is usually processed special compounds from UV radiation, which provides additional protection of roof joints from destructive solar radiation.

The ridge strip is laid along the edge of the roof, and the ridge is mounted on top of it. Work is carried out at air temperatures from +5 °C.

The ridge ventilation tape is placed under the metal plate of the ridge

Eaves perforated tape is used to cover eaves overhangs. It not only protects the under-roof space from rodents, birds, insects, dirt and creates free air exchange, but also increases the strength of some roofing components.

PVC ventilation strip reinforces the eaves structure

Ventilation roofing mesh

Stainless steel mesh is considered the best, as it is the most durable and strong. It is resistant to corrosion, does not spoil the exterior of the house, and has a much longer service life than analogues. The only downside is the high price compared to other types of mesh.

Ventilation mesh from of stainless steel for arranging roof ventilation is considered the most durable and durable

It is undesirable to use steel mesh, as they corrode due to condensation leaks, rot and rust. In order to save money, it is better to use both a budget option painting mesh with small cells. Its advantage is its low cost and ease of installation - the mesh is laid overlapping and fastened with a stapler to the wooden parts of the roof. However, the painting mesh is not very strong and therefore short-lived.

Fiberglass paint mesh does not have sufficient strength and is easily torn and pecked by birds, so it is best used as a temporary option.

Roof ventilation passage elements

Passing elements (penetrations) - component ventilation pipes. They are designed to seal roof openings. As a rule, they are not included in the delivery package, but are selected separately for each type of roof.

Penetrations are varied in shape, size, color, which is determined primarily by the manufacturer, and secondly by the roofing covering (soft roofing, corrugated sheeting, metal tiles). But they are all easy to install. They are installed both at the construction stages and already finished roof.

Penetrations are used to seal the joints between ventilation pipes and roofing.

Only with precisely selected passage parts corresponding to the covering material can we talk about the durability of the ventilation system, the absence of leaks in the tie-in areas and the ability of the roofing components to withstand all climatic loads.

Aerator for roof ventilation

Roofing accessories such as aerators are designed for more effective ventilation of soft roofs. These are elements of forced ventilation that reduce pressure under the roof and increase draft, which ensures the necessary air flow.

An aerator for ventilating roofs made of soft tiles reduces the pressure in the under-roof space, which ensures good ventilation of attic spaces

Aerators are selected depending on the roof area, observing the following rules:

• aerators are installed in the highest places of the slopes along the entire length of the roof for uniform ventilation of the entire under-roof space;
• the distance between adjacent devices is maintained at least 12 m;
• aerators are mounted on dowels or anchor bolts and equipped with filters that prevent the ingress of dirt, moisture and insects;
• to set up the system during roof construction, select areas at the joints of the seal;
• To prevent leaks, use sealant or special tape.

Ventilation accessories also include an overhang ridge, which has a frequent row of teeth that protect the eaves gap and the adjacent under-roof space, as well as roof fans. They are indispensable on flat roofs with insufficient natural convection and on pitched roofs when it is not possible to arrange natural ventilation.

The overhang ridge is mounted directly under the final row of groove tiles using self-tapping screws

Video: installation of the Systemair DVS roof fan

Ventilation passage through the roof

Any ventilation duct is led to the roof of the house and forms a so-called passage unit (PU) at the exit points in the form of a pipe inserted either into the roof itself through the outlet or into reinforced concrete glasses.

Each element of the ventilation system requires a sealed unit to pass through the roof

Industrial ventilation passage units are manufactured in accordance with GOST 15150 and are:

Depending on the type of roofing and design features roofs and air vents, they differ in shape:

Along with typical elements, non-standard units are often manufactured, designed for ventilation systems that are original in structure and assembly. However, all of them must meet the requirements defined by GOST:

• metal thickness for manufacturing is at least 11.9 mm;
• the size of the support ring is 30–40 cm larger than the diameter of the pipe;
• mandatory treatment with anti-corrosion compounds;
• the length of the unit design without valve is no more than 1 m.

Recommendations for the dimensions of passage units and clearances when installing on the roof are specified in GOST 15150

The passage units for chimney ducts are arranged in strict compliance with fire safety regulations.

Ventilation gap on the roof

Many people wonder whether a ventilation gap is needed and, if so, why. Is it possible not to do it, since there is already a gap between the covering and the sheathing.

But is it really necessary to have a ventilation gap on the roof? Let's try to figure it out. Ventilation of the under-roof room consists of three gaps: the eaves, through which air flows, the gap between the roof and the insulation (the membrane does not count) and the gap at the highest point of the roof (ridge or abutment).

Their goal is to ensure good air circulation under the roof and prevent the insulation from getting wet. And if you neglect the gap on the roof, the consequences will be very disastrous - you will have to dismantle the roofing pie and change the insulation. And this is the least of all troubles.

To keep the house warm in winter and cool in summer, ventilation on the roof must be arranged according to all the rules.

Additionally, hard surfaces typically require repainting every 10 to 20 years. But if there is no gap, the resulting condensation will spoil the flooring sheets from the inside. And while painting them on top is quite simple, it is impossible to do this from the inside without dismantling the entire roofing pie and replacing the sheets completely.

So the answer to all questions is obvious - make gaps. Allow the roof to breathe to avoid problems that are initially unnoticeable but snowball. In addition, the gap on the roof must be sufficient to ensure the operation of the entire chain.

If you block the roof ridge, that is, do not create a gap, there will be no benefit from the gap between the insulation and the roof, as well as the eaves clearance.

Metal roof ventilation

A metal roof is beautiful, modern, durable and reliable, but it has one big drawback - limited air exchange, i.e. it does not allow air to pass through well. To ensure normal circulation, ventilation is installed according to the following algorithm:

Video: ventilation of the under-roof space in metal roofs

Ventilation of soft tile roofs

Ventilation of a soft roof faces the following tasks:

• removal of condensate;
• preventing overheating of the lower layers roofing covering;
• ensuring temperature balance on the roof surface.

With properly organized ventilation, cold air flows enter the under-roof space at the overhangs and exit through the ridge or aerators.

The arrows indicate the direction of air flow in the under-roof space when correct device ventilation

Ventilation of soft roofs can be single- or double-circuit. But for it to be sufficient, a number of conditions must be met:

• the thickness of the air gap between the sheathing and the insulation is calculated in advance based on the angle of inclination and the length of the slopes (but less than 4 cm);
• make additional holes along the bottom of the slope, tightening them with perforated tape, mesh, comb, lining the roof overhangs with breathable soffits;
• arrange gaps on the roof in the form of ventilated ridges or aerators for forced ventilation.

If the roof is not new, and the soft roof is being repaired, then look for places with the greatest swelling, and install aerators there.

Video: ventilation of the under-roof space in roofs made of flexible bitumen tiles

Hip roof ventilation

Ventilation hip roofs can be conditionally divided into two groups - ventilation of a cold attic and an insulated attic.

Arrangement of cold ventilation attic space will not present any difficulties. Due to the large volume of the attic, there are practically no barriers to normal air circulation. Air exchange occurs through the eaves overhang, ridge and ridge. Dormer windows covered with bars and located on opposite sides of the roof provide a draft.

Natural air circulation occurs through the ventilation gap in the roof and dormer windows

When it is necessary to increase ventilation, aerators are installed along the passage of the valleys. But they make sense if the slope angle is more than 45°. Otherwise, in difficult areas in winter, due to snow accumulation, the operation of aerators will be ineffective.

For small slopes, it is better to do forced ventilation using roof fans, inertial turbines or nozzles of sufficient height so that they are not covered with snow.

Video: how to eliminate condensation in the attic

Ventilation of insulated under-roof space (attic)

It is advisable to plan the ventilation of the attic during construction, since its arrangement is more labor-intensive than the ventilation equipment for a cold attic space. There is no free air circulation here, which is why the space for air exchange is created by the sheathing installed between the insulation and the flooring.

Air circulation in the insulated room occurs due to the ventilation gap in the roofing pie

In addition, a gap of at least 2–3 cm between the hydro- and thermal insulation is required. If the depth of the rafters does not allow for the required gap, then they are built up using boards.

But this method of air exchange is quite difficult to implement on roofs of complex shapes with many kinks and junctions. Therefore, roofers advise installing diffusion membranes (vapor-permeable) directly on the insulation, which allow moisture to pass through only in one direction.

Video: ventilated ridge on an attic roof

Seam roof ventilation

A seam roof, like all other types of roofs, requires normal air circulation in the under-roof space. And this is ensured by a gap between the coating and the heat-insulating layer of at least 50 mm, for which a sheathing of 50x40 or 50x50 mm timber is assembled. In addition, for greater reliability, the insulation is protected with a vapor barrier film.

To remove moisture from the ventilation gap on the roof, install a ventilation outlet for a seam roof at a distance from the ridge of no more than 0.6 m.

The ventilation outlet for seam and soft roofs is used to remove moisture from the ventilation gap

A seam roof laid according to all the rules and well ventilated will last about 25 years without overhaul.

Pitched roof ventilation

To equip the ventilation of pitched roofs you need:

• supply gaps in the lower roof area;
• channels for air circulation above the insulation (due to the sheathing);
• hoods at the top of the roof have an area of ​​15% larger than the area of ​​the supply openings, since good ventilation requires reduced pressure in the attic.

It is not difficult to arrange ventilation with your own hands. General scheme one is to provide gaps under the eaves overhangs, protect them with tape or mesh, and create a gap between the sheathing and the insulation.

Further work depends on the roof slope. When the slopes have a slope of 10–45°, the exhaust gap is located in the ridge and is covered with a ridge aerator with a protective filter made of polyurethane foam. One such aerator, about 60 cm long, ventilates 25 m² of attic space.

Video: installing a ridge aerator

If the structure of the roof does not provide for a ridge or the slope of the slopes is from 5 to 12°, then it is necessary to increase the number of supply holes at the bottom of the roof, and install aerators in the upper zone at a distance of 0.5–0.8 m from the highest point of the roof.

With this arrangement, the aerator ventilates 5 m² of the attic space, but if the building is located in a well-ventilated area, then its capacity increases to 25 m².

Video: installation of a point aerator

Ridge vent size

The size of the ventilated gap depends on the slope of the slopes - than less slope roofs, so more height gap The type of thermal insulation material does not affect the size of the gap, but the type of roofing is very important. Under a hard covering (metal tiles, corrugated sheeting), you can use a counter lath for lathing a small section of 25x50 mm, since this is not a continuous covering, but has its own gaps and joints, through which air also circulates. Although experts do not advise experimenting and, for greater reliability and strength, recommend using 50x50 mm bars for all coatings, i.e., making the optimal gap height 50 mm.

How to remove a pipe through a roof made of corrugated sheets

Any home heating system, with the exception of an electric one, requires chimneys to be vented onto the roof to release combustion products into the atmosphere. Let's look at how to remove a chimney through corrugated sheeting.

1. First you need to make sure correct location chimney pipe - the exit point should be in a darkened area north side, where there is little sun.
2. The shape of the pipe and the size of its cross-section are selected, taking into account the climatic conditions of the area, the topography and the temperature of the outlet gases.
3. Then they are determined with the height of the pipe according to SNiP.
4. They make the pipe themselves, or buy a ready-made one and carry out installation.

Video: pipe passage through a corrugated roof

Height of ventilation shafts according to SNiP

When calculating the height of ventilation shafts, take into account:

• the elevation of the pipe relative to the highest point of the roof and adjacent buildings;
• total length of the smoke channel;
• head size;
• design height.

Requirements and standards according to SNiP:

If there are outlets of other ventilation ducts nearby, the height should exceed the others by 20 cm.

Video: how to calculate the height of the chimney

Ventilation aerators are special devices for ventilating the under-roof space and removing moisture and water vapor to the outside. Used on flat roofs, preventing swelling of the covering roll material due to temperature changes, and on pitched roofs for effective ventilation and removal of condensate.

Vanes (aerators) produce different sizes and designs. They are considered the most effective elements of ventilation systems. On flat roof They are installed evenly over the entire surface at the joints of the plates. On pitched structures they are placed closer to the ridge (0.6 m from it) or in places where valleys pass (on complex roofs).

On pitched roofs, aerators are installed closer to the ridge or in places where the roof breaks.

The manufacturing material is AISI 316 stainless steel or durable polypropylene, thanks to which they can withstand a wide temperature range from -40 to + 90 °C.

Installation of aerators on a flat roof

With double layer coating roll materials aerators are installed in the bottom layer:

1. A hole along the diameter of the aerator tube is cut through the screed and layers of insulation.
2. Cover with gravel and attach the aerator to hot mastic.
3. After cooling, fix with self-tapping screws.
4. The top layer of the roofing is fused in such a way that the aerator is at the point of overlap (15 cm) of the sheets, and the junctions are sealed.

Video: DIY aerator installation on a two-layer soft roof, part 1

In single-layer flooring, aerators are installed on the screed, making a hole up to the vapor barrier. The coating is laid on the skirt of the aerator, hot mastic and a patch are applied on top, covering the skirt and extending about 15 cm onto the coating. The aerator is then secured with self-tapping screws, and the joint is treated with sealant.

Video: installation of an aerator on a two-layer soft roof, part 2

Installation of aerators on metal tiles and corrugated sheets

The installation of ventilation outlets on roofs made of metal tiles and corrugated sheets is the same and is associated with damage to the roofing covering, so it must be carried out especially carefully so as not to have to change damaged sheets of covering material.

1. Apply the template (included in the kit) to the installation site, outline and carefully cut a hole along the intended line.
2. The seal is secured with screws and sealant is applied.
3. Install the aerator, secure it with hinges and additional screws.
4. From inside the attic, the passages of ventilation pipes are puttied with sealant.

When installing ventilation elements, you must use proprietary fasteners, which are included in the kit.

Video: installation of ventilation on metal tiles

Main mistakes in installing a ventilation system: how to avoid them

Considering that today many people install the roof of their home on their own, let’s look at the most common mistakes when installing ventilation systems.

1. SNiP standards are not taken into account.
2. Unsuitable ventilation elements selected.
3. The ventilation ducts are not located symmetrically.
4. The system throughput was incorrectly calculated and the heat balance was not taken into account.
5. Installation work was carried out incorrectly.

The basic rule when designing ventilation systems is that the more proportional and shorter the ventilation is, the more efficiently and with less noise it will work.

Overview of ventilation systems

When setting up ventilation, sometimes it becomes difficult to select components. Let's look at the most popular manufacturers whose products deserve attention.

Roof ventilation "Virplast"

WirPlast equipment is used for various purposes - installation of ventilation of rooms or fan exits ( sewer system), as kitchen hood, for installation of antennas or components of solar panels.

Advantages:

• easy installation due to the built-in spirit level, which eliminates any errors;
• complete tightness on the roof;
• stylish design;
• a variety of models for all types of coverage;
• 10 year warranty.

Ventilation equipment WirPlast is distinguished by high quality, which is confirmed by a ten-year guarantee for all products

Roof ventilation "TechnoNIKOL"

TechnoNIKOL ventilation systems are available in two variations:

• for ventilation of the under-roof space;
• For forced circulation air in attics and attics.

Advantages:

• aesthetic design and affordable price;
• increased reliability and impact resistance of all elements. Achieved thanks to additives introduced into the composition of the base material HDPE;
• easy installation with detailed instructions.

Roof ventilation Vilpe

Vilpe products are developed by the Finnish company SK Tuote Oy. Excellent as forced ventilation systems installed both during the construction stages and during renovation.

Advantages:

• made of impact-resistant polypropylene and therefore not subject to corrosion;
• resistant to ultraviolet radiation and climatic changes;
• ecologically pure material, withstands constant temperature changes from -40 to + 80 °C and occasional surges from -55 to +120 °C;
• Wide variety of colors and modern design.

Vilpe roof ventilation is made from impact-resistant polypropylene and can withstand large temperature changes

Roof ventilation Kronoplast

The success and demand for Kronoplast products is due to the fact that the company produces almost all parts for the ventilation of a private home - under-roof ventilation, kitchen outlets, vacuum cleaner outlets, sewer risers, etc.

The main feature of this product is 100% impermeability of all exits on the roof, without which full ventilation is impossible. Roofing elements are available for any coating in six basic colors.

Video: installation of ventilation on an ondulin roof

Installation of roof ventilation is an important and necessary process that requires attention and responsibility. It is not difficult to do it yourself, observing the mandatory rules and regulations. Only in this case the roof of the house will never “cry”. Good luck to you.

A fairly simple question, how the height of a ventilation pipe above the roof is determined according to SNiP, often confuses even self-confident designers, what can we say about amateur builders who have planned a refurbishment or major reconstruction of their home. The question, meanwhile, is far from idle, since the fundamental characteristic - its performance in terms of the volume of air moved - depends on the height of the ventilation pipe above the roof.

What regulates the height of the ventilation outlet?

The basic law of a vertical pipe, no matter whether it is a ventilation or a chimney, states that the greater the height of the device, the higher the draft in the pipe. Accordingly, large quantity air is exhausted by the system beyond the roof. Design specialists and most developers, when calculating the height of the ventilation pipe above the roof, are guided by several fundamental documents:

• SNiP No. 41-01-2003, clause 6-6-12, control lift for chimneys;
• SNiP No. 2.04.05-91, which determines the design of exhaust system structures in the old edition;
• SP No. 7.13130.2009 - guidelines and design rules for ventilation and air conditioning systems;
• SNiP No. 2.04.01 determines the level of ventilation output for sewer risers.

In the latter case, the method for determining the installation level of a ventilation pipe according to the provisions of SNiP is described in sufficient detail:

• On a flat roof, the rise of the exhaust pipe through which sewer gases are released must be at least 30 cm;
• For a pitched roof, the height of the stand must be at least 50 cm from the point on the roof to the cut of the pipe;
• On a roof, the surface of which is used for work or movement, the outlet cut of the ventilation system must be located above the roof plane at a level of at least 300 cm.

The outlet of the ventilation system for sewer risers, according to SNiP, must be removed from windows and air intakes at a distance of at least 4 m, everything is quite simple and understandable, because we are talking about gases and fumes that are potentially dangerous to human health.

Approximately the same approach is implemented in SNiP No. 41-01-2003 when setting out the methodology for calculating the height of the chimney pipe above the level of the ridge beam or the horizon of a flat roof.

For your information! The methodology for calculating the height of a ventilation pipe above the roof of a private house is not given in SNiP; only general recommendations are given.

Developers building codes and rules No. 41-01-2003, it is proposed that when determining the excess of the ventilation rack, one should be guided by the diagram for calculating chimneys. With one amendment, if the ventilation rack is installed in line with the chimney with a distance of up to 3 m, they must be installed at the same level.

How to determine the necessary and sufficient height of the ventilation pipe

The absence of a separate method for determining the height of the ventilation system pipe does not mean that such a calculation is not required or is not needed. The easiest way is to make ventilation according to a simplified scheme. If you follow the definitions of SNiP No. 41-01-2003, the height of the ventilation outlet should be:

• On a flat roof - at least 500 mm;
• For a pitched roof, the cut of the ventilation rack should be 500 mm above the ridge line at a distance from the ridge of no more than 1500 mm.

The ventilation outlet can be at the same height as the ridge if the distance does not exceed 3 m, otherwise the cut of the ventilation pipe should not be below a conventional line drawn down to the horizon at an angle of 10 degrees. If there is a chimney nearby stove heating, then the chimney and ventilation pipe must be raised above the cut of the chimney.

To understand how valid this approximation is, you can perform an approximate calculation of the performance of the ventilation duct. For example, a 16 kW/h heating boiler produces about 140 m 3 of combustion products, the flow of fresh air is provided by a chimney outlet channel with a cross-section of 200-220 cm 2.

In order to provide the required air change rate of 1.5-2 m 3 per hour for residential premises of 60 m 2 with a ceiling height of 2 m, the flow rate is 150 m 3, that is, under certain conditions, the dimensions and installation height of the chimney and ventilation pipe are approximately comparable. The comparison is quite arbitrary, but it clearly shows that the methods are at least comparable.

What affects ventilation performance

There is another way to determine the height of the pipe and, accordingly, the excess of the roof of the house above the roofing covering. This can be done using the formula for air flow depending on the pressure drop. It is known that when rising by 12 m, air pressure drops by 101 Pa. The result obtained will be valid only for an ideal ventilation system with an absolutely smooth inner surface.

In fact, for practical calculation of the parameters, height and cross-section of the ventilation duct, several important conditions will need to be taken into account:

• Air flow speed at the installation height of the ventilation pipe;
• Air temperature outdoors and indoors;
• Channel cross-sectional shape and surface quality along the entire height of the air duct;
• Roof shape.

By practical measurement it is possible to obtain the flow coefficient C. From its value and from the difference in pressure at the ground and at the installation height of the outlet ventilation rack, it is possible to calculate real consumption air.

Or vice versa, knowing C and the known air flow rate that will have to move through the air duct for a specific volume of the room, you can determine the pressure difference and, ultimately, the level of rise of the ventilation outlet.

It is quite difficult to make such a calculation, so they usually use the recommendations of reference books on the repair and design of ventilation systems, which provide approximate dependences of the air flow on the outlet pipe extension for various options roof structures and outlets.

Recommendations for determining the height of a ventilation pipe on a roof in no way relate to determining the size of the duct and the draft in the air duct. There is only one reference in the standard, which requires that the total height of the vertical part of the chimney duct be at least 5 m.

The extension of a chimney or ventilation pipe above the roofing is established by SNiP standards for completely different reasons. If you look at the terminal installation diagram recommended by SNiP, it becomes clear that the cut of the ventilation and smoke duct should be at the level of the fastest air flows. The higher the air speed, the stronger the draft, and vice versa - in calm conditions the ventilation system works extremely unsatisfactorily.

Conclusion

If the roof is flat or has a slight slope of 5-10 o, then the height of the ventilation system outlet is not important, 400-600 mm is enough. For gable systems with steep slopes, it is necessary to follow the recommendations of the regulations. For multi-level structures with dormers and complex broken slopes, in addition to following the recommendations normative document, you will have to spend time looking for a place where air flows have the most stable speed. Otherwise, the air will move jerkily in the air ducts, hum and sometimes stop moving, which obviously does not add comfort. In this case, it is necessary to install additional resonators and increase the number of ventilation leads. The performance of six outputs will correspond to two huge racks, and the uniformity of the flow is 2-3 times higher, if, of course, all racks are evenly distributed over the ramp area and not collected in one bunch.

Sergey Novozhilov - roofing materials expert with 9 years of experience practical work in the field of engineering solutions in construction.

The service life of any building and its durability largely depend on the quality of the insulated roof ventilation systems.

Traditional roof and attic ventilation using dormer windows has proven to be not very effective in practice.

A much greater effect can be achieved by installing ventilation holes in the roof ridge. Such ventilation throughout excess moisture penetrating from a warm room under the roof is removed outside. If ventilation does not work, all roof elements become wet from condensation. This moisture penetrates the layers of thermal insulation and settles on the rafter structures. All this leads to the formation of fungus and mold, which destroy wooden elements roofs, concrete and brick structures cause corrosion of metal structures. In winter, condensation causes ice to form on the roof. This in turn damages drainage system And roofing material. Protection against these unpleasant phenomena is properly equipped roof waterproofing and ventilation.

Materials and tools

Tools for installation on the roof.

To install ventilation in the ridge, you need to properly arrange the so-called roofing pie. To complete all work you will need:

• ready-made rafter structures;
• a special film used to create waterproofing;
• insulation of any type;
• wooden slats for sheathing and counter-lattice;
• roofing material;
• self-tapping screws;
• screwdriver;
• adhesive tape;
• construction stapler.

General operating principles

When arranging a roof, gaps are usually made between the waterproofing layer and the roofing material. They help remove excess moisture into the atmosphere. But along with moisture vapor, part of the heat also leaves, which leads to increased heating costs. This is especially noticeable if the waterproofing is installed incorrectly and carelessly. More often this happens on roofs with gentle slopes.

For each type of roofing material, there are ventilation elements that are mounted on. These can be ridge tiles with air channels. There are special ridge strips made of plastic or metal. All these elements are purchased together with the roofing material. Ventilation openings must be protected from branches, birds, and insects. This is done using special devices, commercially available.

When installing a ridge, under no circumstances should you fill the gaps between its elements and the roof surface with foam or seal them with sealing tape. The ridge must remain fully ventilated. Inside the attic, in the upper part of the rafter structures, in the overhangs and at the ridge, it is a good idea to make holes with a diameter of at least 20 mm or oblong slits. They also provide roof ventilation. You can also leave such holes in the ridge or install ventilation pipes on it.

Air outlets with moisture vapor through the elements of the roof ridge can be continuous or point-like. Point exits (they are also called roofing aerators) are made on the ridge itself or next to it. Often these aerators have a fan and are combined with the ventilation system of the whole house. But ventilation with continuous outlets works more efficiently. A continuous outlet is mounted along the entire length of the ridge. In this case, it is only necessary to ensure unobstructed air passage from the very bottom of the cornice to the ridge. The total cross-sectional area of ​​the ventilation gap in the ridge must be at least 0.05% in relation to the total area of ​​the roof slopes.

To ensure effective ventilation of the attic space, it is most rational to place ventilation holes under the very eaves of the roof evenly along the entire perimeter of the building, and at the ridge - along its entire length.

The ridge not only protects the opening between the roof slopes from precipitation, but also ventilates the attic.

Ridge ventilation is installed in the following order:

1. The rafter system is being installed.
2. Across rafter legs waterproofing made of a special film is attached. The upper strips of the film lie on the lower ones, overlapping them by 15-20 cm. The seams are taped with a special connecting tape. Such insulation will be very reliable.
3. Along the legs of the rafter system, a counter-lattish is placed, then a sheathing.
4. The main roofing material is laid - ondulin, metal tiles, corrugated sheets, slate, etc.

The space between the roof and the waterproofing film should be at least 2, and preferably 4-5 cm. It is the presence of this gap that ensures ventilation through the ridge openings.

Complete ridge systems

For the convenience of home owners and builders, special skates with ventilation have been launched. They look elegant and are easily assembled from individual elements. Their surface is treated to protect them from atmospheric influences. The ventilation system has no moving parts and consumes no energy. Each element is 1220 mm long and does not require end caps. This ridge can be installed on any roof with a slope of 15-53 degrees. The warranty period is 20 years. The markings on this skate are VentSure Rigid Strip.

There is a roll version of the VentSure Rigid Roll skate. It is also very easy to transport and can be easily installed on a roof with a slope of 10-60 degrees. Available in rolls of corrugated special plastic. Roll length 6 m.

Properly arranged waterproofing, thermal insulation and ventilation are the key to the longevity of the roof.

Living spaces in the attic can be as comfortable as those on other floors. But in order to create comfortable conditions here, it is necessary first of all to insulate the roof, and also (no less important) to take measures to install reliable waterproofing and ensuring effective ventilation. At the same time, two important conditions must be met in relation to roof structural elements: protect them from moisture (inside and outside) and ensure its removal in case of penetration.

Causes of moisture

The roof over an unfurnished attic, consisting of rafters, sheathing and roofing, does not require the measures discussed here. The attic floor is constantly ventilated, the temperature and humidity of the air inside the attic practically do not differ from the corresponding indicators of the outside air, and if they differ, it is insignificant.

Rice. 1. When laying thermal insulation between the rafters, it is better to use their entire depth. A second, thinner layer of thermal insulation, laid below the rafters, increases the insulation efficiency. Red color indicates under-roof waterproofing, and blue color indicates vapor-proof film.

The picture changes when installing thermal insulation, which separates the internal environment from the external one. In this case, the indoor temperature and humidity attic floor and outside begin to differ significantly. Therefore, problems arise that force us to take additional measures to protect roof elements.

One of these problems- an increase in air humidity resulting from human activity. When cooking and washing, washing and wet cleaning, breathing and sweating, the air is saturated with moisture in the form of particles of invisible steam (unlike the steam coming out of a boiling kettle, which we can observe). This moisture, together with warm air, rises, accumulates there or escapes out through leaks in the roof.
The amount of moisture in the form of water vapor that the air can absorb depends on its temperature. The warmer the air, the more moisture it contains per unit volume. When the temperature drops sharply, the air can no longer retain this moisture, and it falls out in the form of water droplets.

The same phenomenon can be observed and when water vapor penetrates from living spaces into structures, where it comes into contact with the colder lower surface of the roof. This leads to the appearance of condensation droplets on it. Moisture spoils the appearance of structures and finishes, deteriorates thermal properties insulation, provokes putrefactive processes.

Rice. 2. A vapor-proof layer is necessary to prevent the penetration of water vapor from the attic to the roof elements. 1 - relative humidity 50%; 2 - relative humidity 80%.

Rice. 3. Wet air from the interior of the house through loose joints of the vapor barrier can penetrate to the roof elements. When the air cools, condensation forms here with all the ensuing consequences. Therefore, it is very important to lay the vapor barrier as tightly as possible.

Penetration of moisture to roof elements is facilitated by, for example, inaccurate laying of a vapor-proof layer on the inner surface of the insulation, insufficient overlap of vapor barrier strips, their loose connection to walls and pipes, accidental ruptures and other circumstances. Therefore, the first thing you should take care of when insulating the roof is installing a reliable vapor barrier on the interior side. On the roof side, the insulation must be protected from moisture by a layer of waterproofing, which is laid along the rafters or on a special flooring.

This double-sided protection of an insulated roof is quite reliable., but even this is not enough. It is also necessary to create conditions for the removal of moisture that accidentally penetrates here. And this is achieved, as a rule, due to air circulation in two cavities, one of which is located between the roof and the under-roof waterproofing layer, and the other between the under-roof layer and the thermal insulation. But the air circulation system, naturally, can function only if there is a free flow of air into these cavities from the street and its removal. To do this, vents are installed in the roof overhang and in the upper part of the roof.

Rice. 4. So that air can circulate freely between the roof and the layer of under-roof waterproofing, counter battens are laid along the rafters, the thickness of which determines the size of the air cavity. Air enters this cavity through holes in the side overhangs of the roof: 1 - under-roof waterproofing; 2 - counter-lattice; 3 - thermal insulation; 4 - vapor-proof layer.

Rice. 5. To allow air to escape from the cavities above and below the layer of under-roof waterproofing, so-called ventilation tiles are laid near the ridge or gaps are provided when installing the ridge itself: 1 - ventilation tiles; 2 - skate; 3 - under-roof waterproofing; 4 - vapor-proof film.

Thermal insulation materials

The most popular thermal insulation materials for roofs are mineral fiber mats, polystyrene foam and polyurethane foam boards. All of them must have hygiene certificates. Typically, the labels of these materials contain data confirming their suitability for use indicating the thermal conductivity group, which is usually equal to 0.40 or 0.35 W/(m-K). To achieve the required thermal insulation value, you can use either a material of thermal conductivity group 0.35 of a smaller thickness, or a material of a thermal conductivity group of 0.40 of greater thickness.

Rice. 6. Insulating the roof with laying thermal insulation between the rafters. Under-roof waterproofing is installed along the rafters (above) or along a continuous wooden flooring(below): 1 - under-roof waterproofing; 2 - counter-lattice; 3 - sheathing; 4 - thermal insulation; 5 - vapor barrier; 6 - ventilation tiles; 7 - ventilating ridge; 8 - wooden flooring.

Methods of roof insulation

You can insulate a roof, the frame of which is a rafter system, using one of three ways: laying insulation between the rafters, on the rafters or under the rafters. Most often, thermal insulation is laid in the simplest way - between the rafters.

The insulation must be continuous, including in areas adjacent to walls, chimneys and windows built into the roof plane. The width of the air gap between the thermal insulation and the under-roof waterproofing should be at least 2 cm in all areas of the insulated surface. At the same time, attention should be paid to ensuring that the waterproofing material does not sag too much, which would become an obstacle to effective air circulation. When using mineral fiber mats as insulation, you must also take into account the fact that after installation, the thickness of this material can increase by 10-30%.

The vapor-proof film on the inside of the insulation prevents the penetration of moisture into the structural elements of the roof and walls.

If the depth of the rafters is less than necessary for laying thermal insulation without compromising air circulation, they can be increased by nailing overlays from boards or bars. Another option is to divide the insulation into parts and lay one part between the rafters and the other under them.

The modern market offers insulation systems, assembled from heat-insulating panels, which already provide waterproofing. The use of such systems makes it possible to refuse one of two levels of air circulation, since in this case a layer of under-roof waterproofing is not installed.

The main condition for the normal functioning of such systems is the creation of a reliable vapor-tight layer on the inside of the roof.

Rice. 7. Insulation of the roof with installation of thermal insulation under the rafters. Under-roof waterproofing is installed along the rafters (above) and along continuous wooden sheathing (below).

Rice. 8. Laying thermal insulation above the rafters on solid wood sheathing with waterproofing protective layer. Here, only one level of air circulation is required - between the thermal insulation and the roof. The air cavity is created by a counter-lattice, the slats of which are laid parallel to the rafters: 1 - wood paneling; 2 - hydro- and vapor barrier; 3 - counter-lattice; 4 - thermal insulation.

Rice. 9. Insulation of the roof with thermal insulation panels in addition to the existing thermal insulation. To create a cavity for air circulation, the distance between the old and new thermal insulation should be 50 mm. Special elements are placed under the top row of tiles to ensure air circulation: 1 - thermal insulation panels; 2 - previously laid thermal insulation; 3 - thermal insulation elements that provide ventilation.

Such thermal insulation is laid above or below the rafters, connecting the individual elements into a rebate. The disadvantage of the lower position of the panels when insulating the roof is the reduction in the volume of the attic floor to be equipped.

When insulating the roof from the upper side of the rafters, the roof structural elements are located indoors and are reliably protected from atmospheric and temperature influences. This method is also interesting because it allows you to use open rafters when creating an interior.

Preparing the roof frame

Isolating a roof from moisture and insulating it is quite a complex job, therefore, before starting it, you should make sure that the rafter system is in good condition and, if necessary, carry out its sanitization. Often, wooden roof elements, especially in old houses, are affected by pests. This can be judged by the presence of wormholes in the wood. If they are detected, the infected wood must be treated with chemical protective agents, after consulting with a specialist. Severely damaged structural elements are replaced.

Rafter structures, especially in old houses, also need to be checked for statics. And here you cannot do without the help of a specialist.

When constructing private buildings with a small number of floors, it is important to draw up in advance a design of all engineering systems and components that ensure the functionality and durability of the facility. It is imperative to consider where the ventilation outlet to the roof will be located, since without this component the building will not meet regulated sanitary and hygienic requirements.

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general information

If you plan to build a turnkey private house or cottage from scratch, you need to determine the optimal place where you can install a ventilation outlet. This type of natural ventilation does not require the purchase of expensive devices and systems, and there will always be a comfortable microclimate inside the room, enriched with fresh air.

In addition, you can equip the structure with a small fan that operates on the principle forced exhaust. But if you install the fungus correctly roofing structure, then you simply don’t have to buy additional devices.

The effectiveness of natural ventilation directly depends on the location of the pipe. Accordingly, the higher the unit is installed, the stronger the thrust in it.

Very often, designers do not draft the installation of risers well enough and select the height above the roof structure. In this regard, various problems may arise in the future. Among them:



If the ventilation pipe is installed incorrectly on the roof structure, the rafters and sheathing may be deformed. Moreover, there will be gaps where the shaft cover is installed, which will increase the risk of rainwater entering the room. Therefore, in order to avoid such consequences and keep the roof in good condition, it is necessary to responsibly approach the issues of arranging ventilation outlets to the roof.

Installation of a ventilation duct in a private house, calculation of the cross-section, diameter and height of the ventilation ducts above the roof



Drafting

You need to begin work on installing a fungus for ventilation on the roof with a preliminary drawing up of the project. It is important to carefully consider the fundamentals of the entire construction, and only after that begin installing the components.

If there is a need to replace the roof as part of the reconstruction, and through the roofing structure it is necessary to remove hoods from all parts of the house, then many may have a question : Is it possible to combine all channels into one? and not separate them into four separate passes?

But experienced experts They argue that this approach will not do anything good, so it is much more reasonable to arrange a separate ventilation passage for each of the air vents. In this case, the problem is with unpleasant smell in living rooms it will simply disappear when weather conditions change.



Purpose and main types

When arranging an exit, you should know about the main subtleties of the upcoming work, understand the types of structures and their purpose. Roof penetrations can be used in different types ventilation systems:

1. 1. In the interior rooms of the cottage.
2. 2. B fan pipe sewer riser.
3. 3. In the attic.

Moreover, sometimes these passages are necessary for laying smoke shafts and television antennas. At the end of the air exhaust system there is a special ventilation outlet, which is equipped taking into account all the requirements for the system.

The purpose of such a design is to ensure effective exhaust of air from the room and prevent any leaks. At those points where it is necessary to make a ventilation passage through the roof, special passage elements are placed that correspond to the specific roofing material.

Currently, it is possible to buy ready-made sets of ventilation outlets for their further installation on roofing structures made of solid and soft materials. Such products allow you to quickly and efficiently build a ventilation riser to protect the roof from possible leaks, as well as maintain its aesthetic appeal. Moreover, such devices are a natural protection of ventilation ducts from the penetration of various dirt and precipitation.

The height and shape of the passages through the roof are determined by the individual characteristics of the roof structure. In addition to pipes with a round cross-section, rectangular structures are used.

To ensure that the ventilation pipe does not lead to a violation of the roof’s tightness, it is necessary to follow a certain sequence of actions and take into account the established requirements.



Node device

If we consider the simplest ventilation outlets on the roof, they represent a small metal pipe, which is located in a pre-made hole and is fixed using fasteners. The roof penetration itself can be equipped with a locking valve and a ring that collects condensate.

At the bottom of the pipe, an outlet channel is connected using a flange, and on top there is a deflector or a regular protective umbrella. You can also consider an option with insulation, which uses mineral wool.

On modern market More advanced types of roof ventilation systems are offered that meet a new level of quality. At the same time, in terms of design features and operating principles, they practically do not differ from traditional solutions, but have a lot of advantages.

Ventilation. Roof outlets and aerators.

Lids from the manufacturer “Vlipe Vent” are in particular demand. The list of advantages of such products includes the following points:



In some circumstances, when the passage element is not included in the kit and is purchased as an additional unit, the type and profile of the roofing covering must be carefully assessed in order to select the optimal unit. A high-quality passage element will be the best solution to ensure design versatility on any type of roof. Such products guarantee maximum stability and tightness of the ventilation outlet.

INSTALLING AN AERATOR FOR ROOF VENTILATION

The task of aerators

It is no secret that during the cold season there is a possibility of condensation forming inside the roof structure. To prevent the penetration of dampness into the room, to avoid the formation of fungal manifestations and mold, it is necessary to properly arrange internal ventilation under the roof.

The roof ventilation device looks very simple: the air masses must naturally move from bottom to top. To supply new portions of fresh air, special openings in the eaves are used, while the flows exit the room through aerators with a lid. They are located in the roof directly at the ridge.

To prevent precipitation from penetrating under the roofing pie, it is necessary to find a suitable type of pipe cover. The best option is a ventilation fungus on the roof, which performs not only a practical function, but also a decorative one. There are a lot of varieties of such structures on the market, so choosing a beautiful and effective roof ventilation fungus is not difficult.

Guest house, ventilation

Optimal location

Professional builders recommend placing the pipe directly above the riser. In this case, the productivity of the system will be maximum, which is due to the absence of bending of the channel. If it is not possible to make such an installation for correct connection nodes will need to use special corrugated adapters.

On pitched roof made of metal tiles, it is better to install the penetration near the ridge itself. So the long part of the pipe will be under the roof, insulated from external influences. The remaining short element will be able to withstand any wind blows and other processes.

At the installation stage, it is also important to consider the height of the shaft above the roof. An indicator that is too small will negatively affect traction, and one that is too high will be exposed to gusts of wind and quickly deform. In addition, it will have to be additionally secured with guy wires and other fasteners.




According to current construction standards, the optimal height of the shaft above sloping roof should be no more than 50 centimeters. If the roof is flat, the height indicator is 30 centimeters. When using the roof to create open areas for recreation, the ventilation outlet must rise at least 2 meters.

House ventilation, roof ventilation. VILPE ​​ventilation solutions. how to make ventilation in the house

By following the above guidelines, you can perform high-quality, reliable and durable installation of the ventilation outlet. In this design, it will serve the owner of the premises for a long period of time.

Based on the above, there are practically no difficulties in installing a ventilation duct on the roof. If you draw up the correct project in advance, carry out calculations and study the installation instructions, the future ventilation system will work the best way. At the same time, the service life of the roof, which has gone through a lot of changes due to the appearance of a new unit, will not be reduced in any way. But for this you need to take the upcoming work responsibly and follow the basic installation rules.