In accordance with regulatory technical requirements, all rooms are equipped with an air exchange system. To ensure normal draft, the exhaust pipe must end above the ridge of the house. Accordingly, it is necessary to equip a ventilation outlet on the roof of the building. Considering that the roof itself and the outlet pipe of the ventilation shaft have a number of structural features and are made of various materials, then installing a ventilation pipe on the roof requires compliance with a number of rules. One of them is to achieve maximum tightness of all connections, since the safe operation of the house as a whole depends on this.
Reasons for installing ventilation on the roof
The end of the ventilation system above the roof of the house is explained by the following reasons:
- the need to create draft to ensure adequate air exchange in the interior;
- installation of a competent ventilation scheme.
Building regulations require complete ventilation of living spaces. If everything was taken into account correctly in the construction project, then you can find exhaust vents on the walls in the toilet, bathroom, wardrobe or pantry, as well as the kitchen. They are necessary to eliminate unpleasant odors, combustion products and excessive humidity from the premises. In order for all negative factors to be removed from the house, it is necessary to organize the end of the ventilation shafts outside the building above the roof. Otherwise, they will again enter the house with the flow of incoming air.
Ventilation pipe installation
Types of ventilation pipes
The roof ventilation pipe itself is divided into several categories. First of all, the cross-sectional shape of the ventilation ducts differs:
- round;
- rectangular;
- non-standard.
During production ventilation ducts may be applied different kinds materials. The most popular are aluminum, stainless or galvanized steel, polyester-based fabric and plastic.
Primary requirements
A number of requirements are imposed on the ventilation system, which do not bypass the air duct itself. You can find them in the list below.
- The minimum cross-sectional diameter of the ventilation duct is fifteen centimeters. A galvanized air duct with these parameters shows good efficiency work.
- In the process of setting up the system supply and exhaust ventilation it is necessary to ensure the increased annular rigidity of the pipeline in the design of the outlet part. The reason is the following - in an area that rises above the roof, the pipe constantly faces significant wind load. Therefore, the design must cope effectively with it.
- The ventilation pipe must have an increased safety margin while simultaneously having a minimum wall thickness. The smaller the thickness, the higher the overall throughput.
- Metal ventilation ducts should not become covered with a layer of rust over time. There are moisture vapors in the room that settle inside the pipeline. They should not cause the development of corrosion processes.
- The exhaust pipe itself should not emit harmful gases during operation and not become a source of fire spread.
- The structure must have a minimum weight.
It is worth noting that brick and galvanized ventilation ducts fully comply with almost all the qualities mentioned above. The brick pipeline has a weight corresponding to regulatory requirements. Metal pipe during operation it is capable of attracting dust, as static electricity accumulates on the walls.
Ventilation outlet to the roof
Stages of installation work
Before installing the ventilation pipes on the roof, it is necessary to complete the installation of the ventilation system wiring inside the building. The air duct itself must be securely fixed. The list of tools depends on the roofing material of the house. To carry out the work comfortably, you will need the following basic list of tools and materials:
- chisel;
- electric drill;
- building level;
- jigsaw (highly preferably electric);
- Screwdriver Set;
- insulation material;
- metal scissors or grinder;
- marker;
- hardware for fixing;
- sealant;
- rags;
- pass-through unit;
- individual protection means.
By doing self-installation ventilation exits to the roof, you should use the assembled passage unit, thereby greatly simplifying your work. The sequence of actions is as follows:
- Marking. Using a marker, make marks according to the template (depending on the cross-section and size of the ventilation outlet pipe to the roof) in the place where the ventilation shaft will exit.
- Creating a slot. You need to cut a hole in the roof using a specific processing tool. roofing material(usually this is a “grinder”).
- Removing the top layer of the roof.
- Drilling holes for fastening the outlet segment of the ventilation shaft.
- Marking for installation of the passage unit.
- Creation of grooves into which self-tapping screws will be placed in accordance with the previously made markings.
- Installation of the passage unit.
- It is fixed using self-tapping screws.
- Installation of the ventilation pipe, securing it using appropriate hardware.
- Insulation of all cracks and openings.
Installation Features
When planning and installing a ventilation system, it is first necessary to check the calculations for compliance with technical regulations. It is strongly recommended to entrust the design to specialized specialists who understand all the features and technical nuances building.
There is a difference in temperature at the inlet and outlet of the ventilation duct. An increase in draft occurs inside the channel due to the difference in temperature inside and outside the room. This is the main reason that in winter ventilation tends to work with higher productivity than in summer.
Even at the design stage, you need to think about the thermal insulation of the channels that run under the roof. This is required so that the air draft does not decrease over time. This solution effectively protects the exhaust ducts from moisture accumulation. If the ventilation pipe is located along the chimney, it is necessary to take care of its heating (the quality of operation of the ventilation system as a whole changes positively). On the other hand, there is also a minus here. In such channels, the draft is different, so if the calculations are made incorrectly, you may encounter a malfunction of the ventilation.
Properly designed ventilation outlet contributes to effective air conditioning indoors. Self-installation does not cause difficulties, provided that you are familiar with the specifics of the work in advance.
Securing the top of the ventilation riser
Consequences of installation errors
Proper installation of a ventilation pipe on the roof is the key to full-fledged work the entire system. Failure to comply with recommended installation standards will result in the following negative consequences:
- weakening of traction;
- the presence of unpleasant odors in residential premises;
- accumulation of moisture in rooms;
- condensation inside the system;
- lack of oxygen;
- the appearance of fungus on the surface of the walls;
- soot deposits on facing materials installed in the kitchen;
- increasing the incidence of diseases in all residents;
- freezing of certain building structural elements.
Correct installation is the main factor that determines the usefulness of air exchange and living comfort.
The structures of almost all types of roofs, consisting of several layers that form a roofing pie, require ventilation. The passage of air flows through the gaps between the individual layers protects the insulating material from the accumulation of condensed moisture on its surface.
Some developers believe that protecting the insulation with waterproofing on one side and vapor barrier on the other is enough to prevent water from getting on it, and do not care about arranging ventilation ducts, especially since building codes They do not standardize methods for arranging roof ventilation systems. This fairly common mistake leads to a significant deterioration in the thermal insulation properties of the insulation, rotting of wooden structures and a reduction in the service life of the roof as a whole.
Where does moisture in roofs come from?
Where can moisture come from in a practically hermetic space? First of all, a certain percentage of moisture is always present in the air, and when high humidity during fogs or rains, as well as in heated indoor air, it increases significantly. Some amount humid air passes through a vapor barrier, some through foam concrete or brickwork, etc. It is almost impossible to create a vacuum between layers where air does not penetrate. Water vapor, under the influence of temperature changes, condenses on cooled surfaces, penetrates the insulating material, and destroys wooden structures. Thus, ventilation of the roof and under-roof space, with rare exceptions, must be organized.
Roof ventilation device
The most common and effective type of roof ventilation is the installation of special ventilation holes in the ridge and under the overhangs of the roof structure. Under the influence of wind and temperature changes, air enters the openings under the overhangs, passes through the ventilation gaps between the insulation and waterproofing and exits through the holes in the ridge. The size of the ventilation gap depends on the parameters of the roof and is on average 5 cm, for roofs with a slight slope - 8 cm. Such ventilation is natural, that is, it does not require additional equipment for air injection. If the system is performed correctly, the air flow can completely pass along the entire roof twice in 1 hour.
There are other ways of arranging ventilation, for example, exhaust openings are made not on the ridge, but on the slopes using special elements. For tiles or other piece roofing materials, special tiles are produced that have ventilation holes.
Roof ventilation through dormer windows
Another option is dormer windows on the slopes. This is one of the oldest methods of ventilation, which has recently been rarely used on its own - only as an addition to ventilation gaps. The fact is that when using such windows, unventilated areas are formed around the windows themselves. To make ventilation as efficient as possible, you need to make two windows - one opposite the other. Their size is usually 0.8x0.6 m. Windows are made during the installation of the rafter system, their frame is attached to the rafters using racks. The canopy above them and the “walls” are most often covered with roofing material, the same as the entire roof. “Walls” can also be lined with plastic lining. After production is completed, the opening is filled with a window frame or ventilation grill. When choosing the size and location of dormer windows, you need to take into account the design features of the roof and its appearance; you do not need to install them too close to the eaves or ridges. The distance between dormer windows on one slope should not be less than 1 m, the total number of windows should be reduced to the optimal minimum, because they greatly complicate the process of installing the rafter system.
Other ventilation options
As an option, you can consider organizing a forced ventilation system using turbines or deflectors. They are mounted in such a way that it is possible to extract air directly from the under-roof space.
If the roof design provides for a small angle of inclination of the slopes, care must be taken to protect the ventilation openings from snow drifts. Usually in these cases, instead of exhaust holes, pipes are used, the length of which is chosen above the snow layer.
The method of ventilation also depends on the purpose of the under-roof space. For non-residential attics, openings along the eaves and ridge, as well as gable windows, are sufficient. For attic ventilation, aerators are often additionally used - elements that increase air exchange.
Ventilation of roof insulation
How does ventilation of the insulation layer occur and is it really so important to keep the insulation dry?
First, a few words about roof insulation. Thermal insulation layer is the thickest in roofing pie, the overall thickness of the roof, as well as its energy-saving properties, largely depends on it. High-quality insulation allows you to create and maintain the most comfortable microclimate inside the house, regardless of weather conditions. Depending on the climatic region of the building, the thickness of the insulation can vary significantly. On average, it can fluctuate between 10-15 cm.
Almost all insulation materials absorb moisture, which significantly impairs their thermal insulation capabilities, since water, which conducts heat well, pushes out air. Even with 5% moisture, the insulation loses 50% of its properties. Ideally, the thermal insulation layer is protected on both sides by hydro- and vapor barriers, as discussed above, but even they are not able to completely isolate the insulation from the ingress of steam and its condensation. That is why the surface of the insulation must be constantly dried with a flow of air, preventing drops of moisture from settling on its surface. To do this, there must be a gap between the insulation and the waterproofing layer, which is formed by the counter-lattice boards. Air enters the gap through holes in the eaves overhangs and exits through holes in the ridge. If stingrays have large area or a slight slope, for more efficient ventilation you can use deflectors to create forced draft.
What are vents and why are they needed?
Ventilation openings through which air enters the ventilation gaps and exits are called vents. As you might guess, there are cornice and ridge vents, depending on their location. It is better to make cornice vents along all the cornices. At their core, these are gaps between the roof and the wall, the width of which is about 2-2.5 cm. There are also point vents, which are not a continuous gap along the eaves, but separate holes. The diameter of such holes depends on the slope of the slope: if the slope is more than 15 degrees, it is 10 mm, less than 15 degrees - 25 mm. All vents must be closed: point vents with grilles, and slotted vents with nets or slats (soffits).
Ridge vents also come in slotted (gap width 5 cm) and point vents. Point blows are made at a distance of 6-8 m from each other. Piece roofing materials have special additional elements with ready-made ventilation holes. For example, when laying natural tiles, the second row from the ridge is laid with special ridge tiles.
Elements of the roof ventilation system can usually be purchased along with the roofing material. Many large manufacturers They produce such additional elements for all types of coatings. They match the roof color, texture, material and, when installed, fit perfectly into general form. Ventilation elements include ridge and eaves vents, exhaust openings, and passage channels.
Exhaust openings located closer to the ridge are of several types: in the form of a gable grille on the gables, or a roof outlet on the slopes. The hood can also be placed on the ridge itself in the form of an aerator. For effective ventilation, the area of the exhaust openings should exceed the area of the supply openings by 10-15%, which will increase draft. The total area of the vents is selected at the rate of 1/300-1/500 of the area of the under-roof space. In other words, for 200 m2 of attic area, you need to provide a number of vents with a total area of at least 40 cm2.
Roof aerators
One type of exhaust vent is an aerator. In principle, this is the same hole for removing air and moisture, only slightly “cultivated”. In appearance, aerators are pipes covered with umbrellas, installed near the ridge. The principle of their operation is no different from conventional vents: air also enters the under-roof space through the eaves vents and rises upward under the influence of pressure and temperature differences. Aerators are continuous and point, and the latter are pitched and ridge. Point aerators are used for local ventilation of individual areas of attic spaces. Their more modern models have a mushroom shape and built-in fans to create additional draft in the system.
Continuous aerators provide ventilation of the entire under-roof space and are placed along the entire ridge. These are usually plates with exhaust holes hidden by the roofing material. Such aerators are practically invisible from the outside.
The choice of aerator type depends on the type of roof, roofing material, and purpose of the under-roof space. There are aerators for flat roofs, natural, bitumen shingles, metal tiles, as well as universal models. They, like other ventilation elements, are often sold together with roofing materials.
Why are roofing passage elements needed?
Pass-through elements or simply penetrations allow you to install fans and ventilation ducts on any roof, while ensuring the tightness of the unit due to seals. Passage elements are selected depending on the roofing material, roof structure and diameter ventilation passage. Manufacturers of roofing materials produce penetrations for tiles, soft roof, metal tiles, seam roofing. Penetrations may differ from each other in the elements abutting the roof and in the method of installation. They are usually installed in parallel with the installation of roofing material, but some models can be installed on a finished roof.
Ventilation of the under-roof space
A prerequisite for a roof to serve reliably and for a long time is to equip it with the correct ventilation system, which will ensure ventilation of the under-roof space. Ventilation can increase the service life of not only the building itself, but also the entire building. An improperly executed ventilated system can lead to a lot of negative consequences, and effective ventilation will prevent mold and premature deterioration of the material.
This article describes in detail the most important points regarding the installation and operation of the ventilation system:
- Roof service life
- Lack of roof ventilation: negative consequences
- Benefits of having a ventilation system
- Ventilation system
- Ventilation installation options
- Roof cornice: types and protection options
Roof service life
A completely natural process is the accumulation under the roof of a house. warm air, formed during washing and drying clothes, cooking and washing dishes. In summer, on the contrary, hot air penetrates into the room.
For mansard type roofs are the only thing the right way counteracting the above phenomena is to create a proper ventilation system.
A proper ventilation system should be understood as the presence of ventilation outlets on the roof from hoods and other systems, as well as ventilation of the space located under the roof. Compliance with all these conditions guarantees a longer service life of both the roof and the entire house.
Lack of roof ventilation: negative consequences
If the ventilation system is not properly installed, condensation will wet every element. And getting wooden roof structures wet can lead to very dangerous consequences.
Negative consequences of improper roof ventilation:
- Formation of mold and mildew on load-bearing elements of the roof structure;
- Destruction of metal structures by corrosion, as well as destruction of concrete parts;
- The layer of ice that forms on the roof allows moisture to penetrate under the roof covering, resulting in damage to the roof and drainage system;
- Reduction in the thermal properties of the material due to moistening of the thermal insulation layer;
- Significant heating of the air inside the building in summer due to strong heating roofing.
This is especially negative when the attic is a living space and the roofing is made of bitumen shingles.
Increased costs aimed at improving the air conditioning system inside the house.
Benefits of having a ventilation system
The main function that a ventilation system should perform is to ensure the passage atmospheric pressure, which helps to draw out heated air from under the roofing.
The extracted air ensures ventilation of the attic space. If the installation of the ventilation system is carried out correctly, then such air flow occurs naturally, and there is no need to additionally use mechanical equipment.
Thus, the presence of a ventilated space under the roof has the following advantages:
- Always keep the attic space dry and cool;
- External air from the attic is able to escape naturally;
- Load-bearing elements of the roof, coverings and thermal insulation layer are not affected by high humidity;
- No environment for the formation of rot and mold, preventing damage finishing materials coatings;
- Saving energy costs.
Ventilation system, roof ventilation
It is advisable to install a ventilation system on any roof.
To do this, you must apply the following elements and actions:
- installation of ridge or cornice vents and;
- laying a roof covering with tiles with holes for ventilation;
- ventilation skates;
- installation of the roof with gaps for ventilation;
- arrangement of a dormer window or a continuous ventilation channel along the valley (gutter);
- installation of additional elements, in particular if available chimney, ventilation shaft, which involve ventilation passing through the roof.
Ventilation installation options
Let's look at the most common methods of installing ventilation.
Roof aerators (point exhaust ducts) are installed near the roof ridge or on it. Continuous exhaust outlets can also be installed, and both can be combined with the general system of the house.
The most effective ventilation system is one where the outlets are installed along the entire length of the roof fin. The presence of exhaust outlets does not spoil the appearance of either the roof or the building, since they are usually covered with the main covering on top.
When installing ventilation of this type, you should remember some points that may reduce air inlet and outlet:
- Usage polyurethane foam or tape for sealing the ridge strip disrupts the natural ventilation of the roof.
- Roof structure made with two ventilation gaps. The film located under the roof completely prevents air flow. The solution to this problem is cutting through the roofing film.
Please note that for absolutely all roofing coverings, standard elements are produced, which are aimed at ensuring effective ventilation.
These elements include:
- Tiles equipped with air channels;
- Aeroelements;
- Ventilation rolls.
All these elements provide ventilation of the under-roof space. But a more effective system will be one that has a fully ventilated ridge, that is, ventilation through the roof. Using only individual elements does not provide enough high-quality ventilation.
Roof cornice: types and protection options
Architects and designers usually do not like the various ventilation grilles and strips that are located on the eaves overhang. But it is precisely such details that provide sufficient area of entrances, allowing air penetration and creating excellent ventilation of the roof.
There are the following types of cornice ventilation:
- The gap left between cornice board and the wall of the house;
- Cutting plastic ventilation grilles into soffits;
- Laying special material with vents slightly above the overhang of the cornice.
When laying insulation in the eaves, the ventilation vents will be closed. The passage of air masses is also obstructed by green carpets of plantings located on the eaves. This should always be remembered so as not to disturb the ventilation system of the building.
Methods for protecting roof eaves ventilation ducts:
- Overhang aero elements or grille;
- installation of devices on the roof to retain snow;
- drainage system, which is located under the roofing.
The most difficult part of the roof to ensure reliable ventilation is the valley.
When arranging a roof with a short eaves overhang, long valleys, as well as two gaps for ventilation, ventilation difficulties may arise, since almost all the places where the slopes and valleys adjoin are completely deprived of the possibility of ventilation.
To avoid such difficulties, it is necessary to make openings in the film in the rafter spans to provide air flow, or to equip a continuous ventilation channel along the groove.
Important! To avoid disruption of ventilation, aeration elements can also be installed along the valley. True, these measures will be effective only for roofs with a slope angle greater than 45 degrees.
This type ventilation systems are ineffective for flat roofs. It would be preferable for this type of roof to install roofing electric fans, high ventilation nozzles or inertial turbines.
It should also be noted that every additional element ventilation system increases the overall cost of arranging the roofing. Therefore, the cheapest option is natural ventilation of the under-roof space.
The most common type of ventilation system is a dormer window (hole), which can provide not only high-quality ventilation of the attic space, but also an aesthetic appearance of the roof.
It is customary to distinguish between the following types of auditory openings:
- triangular;
- semicircular;
- trapezoidal;
- rectangular;
- single-pitched;
- gable.
Single-pitch ventilation openings are suitable for any type of roofing. Gable openings are suitable for metal and soft roofs. Complex ventilation windows more efficient and durable.
In conclusion, it should be noted once again that the reliability and long service life of the roof is influenced not only by the design of the rafters, the roof covering, but also by the ventilation of the space under the roof.
Even a minor mistake in the roofing design can cause premature failure of the roof and building.
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, providing it with reliable insulation, insulation and a 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. High 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.
Sufficient for small or medium roofs natural ventilation. Forced ventilation elements are installed on large roofs, where natural air exchange of 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 the interior of the house;
- reduction in 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: ensure normal temperature conditions of the 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 famous 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
For pitched roofs, in addition to proper air exchange, protection from insects is also an important task. Hornets, wasps and small birds populate the under-roof space, build nests, thereby creating not only a noise effect and unsanitary conditions, but also interfering with the natural ventilation of the roof. To combat such a scourge, a ventilation mosquito net with cells measuring 2–3 mm is designed.
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 made of of stainless steel for arranging roof ventilation is considered the most durable and durable Steel mesh It is undesirable to use them, since they corrode due to condensate leaks, rot and rust. In order to save money, it is better to use a painting mesh with small cells as a budget option. Its advantage is its low cost and ease of installation - the mesh is laid overlapping and stapled to wooden parts roofs. 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
Pass-through elements (penetrations) are an integral part of 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 of the roofing;
- 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 of hip roofs can be divided into two groups - ventilation of a cold attic and an insulated attic.
Arranging ventilation for a cold 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 time Due to the accumulation of snow, 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 required clearance, then they are built up using boards.
But this method of air exchange is quite difficult to do on roofs complex shapes with many breaks 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, the insulation protects for greater reliability 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 in accordance with all the rules and well ventilated will last about 25 years without major repairs.
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 - the lower the roof slope, the greater the height of the gap. View 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 durability they recommend using 50x50 mm bars for all coatings, i.e. optimal height gap 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.
- First you need to make sure correct location chimney pipe - the exit point should be in the darkened northern side, where little sun reaches.
- 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.
- Then they are determined with the height of the pipe according to SNiP.
- 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 - special devices for ventilation of the under-roof space and removal of moisture and water vapor to the outside. They are used on flat roofs, preventing swelling of the covering roll material due to temperature changes, and on pitched roofs for efficient ventilation and condensation removal.
Vanes (aerators) are produced in different sizes and designs. They are considered the most effective elements of ventilation systems. On a flat roof, they are installed evenly over the entire surface at the joints of the slabs. 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:
- A hole along the diameter of the aerator tube is cut through the screed and layers of insulation.
- Cover with gravel and attach the aerator to hot mastic.
- After cooling, fix with self-tapping screws.
- Surfacing upper layer roofing decking in such a way that the aerator is at the point of overlap (15 cm) of the sheets; the junction points 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.
- Apply the template (included in the kit) to the installation site, outline and carefully cut a hole along the intended line.
- The seal is secured with screws and sealant is applied.
- Install the aerator, secure it with hinges and additional screws.
- 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.
- SNiP standards are not taken into account.
- Unsuitable ventilation elements selected.
- The ventilation ducts are not located symmetrically.
- The system throughput was incorrectly calculated and the heat balance was not taken into account.
- 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 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.
WirPlast ventilation equipment is different 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 air circulation 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.
Main feature This product is 100% impenetrable on the roof of all exits, without which full ventilation is impossible. Roofing elements 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 make it yourself, following mandatory rules and standards. Only in this case the roof of the house will never “cry”. Good luck to you.
When building a house, it is very important to properly arrange the roof: reliably insulate it and insulate it. No less important is roof ventilation, which allows the steam generated in the house to be removed into the under-roof space.
If this is not provided for, then moisture will settle on the roof elements, gradually rendering them unusable and destroying them. bearing structures Houses.
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Consequences of poor ventilation
Not all owners of private houses decide to install a roof ventilation system, thinking that there is no particular need for it. Nevertheless, it is needed in every building in which at least someone lives. When people and animals sweat and breathe, wash, wash, cook, clean, and other processes that use water, water vapor is released.Under the influence of the laws of physics, he finds himself under the roof, from where he cannot escape, since the roof is always vapor-tight. Therefore, to get rid of steam, special devices are needed.
If no measures are taken for this, steam will condense on the cold inner part of the roof, leading to various consequences. Here are some of them:
- In winter, ice will form, which can destroy the roofing elements and the shafts and pipes built into it;
- the roofing material can be damaged - if it is metal, then rust will form on it, and if it is ceramic, then you should expect mold to appear;
- thermal insulation materials, e.g. mineral wool, will become saturated with water and lose their beneficial properties;
- All wooden structures, exposed to water, will gradually begin to rot.
To prevent all this from happening, a ventilated gap is installed on the roof, and attic space ventilated.
A ventilated ventilation gap in the roof allows steam to escape from the building to the outside. In addition, it has additional useful features. In winter, it promotes uniform heat distribution along the slope, preventing water from melting and the formation of icicles. In summer, it creates a kind of protection from the heat: thanks to it, the heat from the hot roof will not penetrate into the house.
Similar holes are installed in dormer windows, under the roof ridge and on the eaves overhangs. To ensure effective air circulation through them, use different devices roof ventilation. They are not always needed in small or medium-sized roofs, where natural ventilation is sufficient, but on large roofs they are simply necessary.
Roof ventilation from Metal Profile
Main components
There are several basic elements of roof ventilation. They should be selected depending on the type of roof. There is no need to save on their purchase: as a rule, they cost no more than 2-5% of the cost of the roof, including installation. The scale of their functionality is much higher, and with them the roof will last much longer without repair.
Roofing tape. This tape reliably protects the under-roof space from the penetration of dust, dirt, small birds and other living creatures. With its help, you can close all the cracks and at the same time provide ventilation to the inside of the house. Such tapes come in perforated eaves (for overhangs) and ridge tapes.
Ridge tapes protect the roof from the effects of precipitation in any weather and remove steam to the outside, which negatively affects the covering material and the rafter system. High-quality varieties are also impregnated with a composition that repels ultraviolet rays and provides reliable protection from solar radiation. Usually they are laid along the edge of the roof, and then the ridge is mounted on top.
The air temperature during these works should exceed 5 degrees Celsius. Perforated cornice strips cover the overhangs of the cornices. In addition to other properties that are inherent in both types, this tape also increases the strength of supporting structures.
Safety net
One of the main problems of a pitched roof, in addition to air exchange, can be called insect infestation. If you do not properly protect your home, hornets and wasps, as well as small birds, will fly into your home.They can not only visit a home once, but also build a nest and start living there. Removing a wasp nest is not an easy procedure, and it is better not to let it get to that point. It is precisely to eliminate such troubles that an anti-mosquito net with cells no larger than 2-3 millimeters is designed.
It is best to lean towards stainless steel mesh, which is considered to be the most durable and durable. It differs from analogues for a long time operation and increased resistance to corrosion. In addition, it fits well into the interior of the house. The only noticeable disadvantage is its high cost. It is not advisable to replace a stainless steel mesh with a regular steel one. This material will be susceptible to corrosion due to accumulating condensate, and will gradually rot and rust.
More suitable budget option can be called a fine-mesh painting mesh. Its main advantage is ease of installation: it is attached with an overlap, attaching it to the roof parts with a regular stapler.
However, this is still a temporary option: it is not very durable and is easy to tear. Birds also easily peck at it, so over time it is necessary to update the product or replace it with one more resistant to external influences.
Pass-through elements
The passage elements of the ventilation system (penetrations) are included in the pipes. They are used to seal holes in the roof. Usually they are not included in the kit, but are specially selected separately.Penetrations come in different shapes, colors and sizes. These parameters depend on the manufacturer and the material with which the roof is covered (corrugated sheeting, soft roofing, metal tiles). They can be installed both during the construction process and after its completion on the finished roof.
They are very easy to install. The only difficulty is to select suitable elements - the ability of the ventilation system to withstand any climatic changes, the durability of ventilation and the absence of leaks in the areas where they will be embedded depend on this.
Forced aeration
In many cases, natural ventilation is sufficient to remove steam, but sometimes it is necessary to install forced air elements - aerators. They are usually installed on soft roofs. They reduce pressure and increase draft, making high-quality ventilation possible.
To select and install aerators correctly, the following rules must be followed:
- the distance between two adjacent devices must be at least 12 meters;
- so that the entire under-roof space is ventilated evenly, you need to install them along the entire length of the roof on the highest sections of the slopes;
- to prevent dirt, dust and insects from getting inside, you need to install special filters on them;
- aerators are attached to anchor bolts or dowels;
- You can use special tape or sealant to close gaps and avoid leaks.
In addition to aerators, for the same purposes, an overhang ridge with teeth can be installed to protect the gap and the under-roof space. Roof fans are also often used - they are good on pitched roofs, where natural ventilation is impossible, and on flat roofs, where ventilation is not strong enough.
Rules for installing aerators
The conditions for installing aerating devices depend on what material the roof is made of. They must be followed to ensure that the house is optimally ventilated.
Installation on a tile roof. Ventilation of metal roofing can be done using aerators or mounting. Wherein you need to follow certain rules:
It is best to carry out this operation in good sunny weather. If it rains, the final quality may suffer.
The process of installing an aerator on a roof with soft tiles is almost no different from working with a metal-tiled building. However, the installation methods are still not completely identical.:
- 1. Using the template attached to the aerator, the outline of the future cut is drawn in the coating.
- 2. The covering is cut through to the waterproofing barrier.
- 3. The edges of the hole are coated with sealant, after which a fully assembled mushroom aerator is installed into it. Its casing is screwed on using self-tapping screws.
- 4. The outside of the casing is coated with bitumen and covered with soft tiles.
Mounting on corrugated board
To ensure ventilation of a corrugated roof using aerators, a wooden box is usually used.
In this case installation consists of the following steps:
- 1. Markings are applied to the corrugated sheet at the location where the aerator is installed.
- 2. A cross cut is made in the marked area.
- 3. The petals resulting from the cut are folded down and nailed to wooden elements designs with nails.
- 4. A box corresponding to the size of the opening is knocked together from the boards. It is inserted into the hole and screwed with self-tapping screws to the rafter system.
Since many roof materials do not tolerate moisture well, you need to carefully consider the selection and installation of roof ventilation. This will extend the life of the building and improve the internal climate in the house.
