Installation of aerators on the roof and their purpose. Roof aerator for soft roof How to install a roof aerator
The installation of aerators on the roof is necessary, since their presence prevents the destruction of the roofing carpet under the influence of moisture, which forms in the under-roof space.
The desire to save on the arrangement of roof ventilation leads to many problems: first of all, the roof begins to leak, icicles collect on the cornices, and the smell of dampness appears in the house. As a result, the expensive coating material breaks down very quickly. The fact is that moisture enters the thermal insulation layer and the elements of the truss system.
This problem can be solved by installing a roof aerator, which is an artificial ventilation duct. Air circulates through it, while pulling out excess moisture and drying the construction cake from the inside.
Causes of moisture in the roofing pie
Manufacturers finish coatings for roofs, they position their materials as airtight, where does moisture appear in the roofing cake, and in fact it contains layers of vapor and waterproofing?
Unfortunately, the presence of wet vapors is present in any apartment or house. They are formed as a result of cooking, eating water procedures, washing and breathing people. According to scientific studies, it has been found that in houses where a family of 4 lives, at least 2 liters of water vapor are formed per day. It partially settles in the under-roof space.
When warm vapor comes into contact with cold surfaces, condensation forms. As a result, water droplets impregnate the materials and structural elements of the roof, into which they can penetrate. First of all, the pairs reach the insulation, the rafter system and the batten.
Another way of penetration of moisture is the outer side of the roof. Warm steam accumulates in the attic and heats the roofing from the inside. Snow gathering in winter period on the roof, it starts to melt. When the air temperature drops, ice forms on the roof, and under certain conditions it can also melt. Water penetrates into the smallest gaps between the joints of the coating and leaks form on the roof.
The roofing material begins to gradually become covered with microcracks, into which moisture penetrates. At sub-zero temperatures, it freezes and breaks the roof finish. Cracks grow larger and turn into through cracks. As a result, the roof covering becomes unusable.
What is a roof aerator
This device consists of a pipe with a diameter of 6–11 centimeters, made of stainless steel or polypropylene. A cap is installed on top of it, which protects the fan from penetration into its precipitation. The aerator contributes to the drying of the heat-insulating layer and accelerates the process of condensate evaporation.
These devices are used in regions with different weather conditions, since they have good operational parameters and withstand temperature changes in a wide range, from +90 to -50 degrees.
The roof aerator for metal tiles and other types of roof coverings is intended for the following purposes:
- ventilation of the layers of the roofing cake;
- evaporation of condensate;
- removal of moist air;
- prevention of processes leading to the destruction of the roof;
- preventing leakage.
The principle of operation of aerators is the appearance of draft in the pipe, which occurs due to low pressure created by external air currents.
Types of roof ventilation devices
According to the features of the design solution, there are several types of roof fans:
- Point. Such devices are mushroom-shaped, they are equipped with fans. They are mounted in a place where access is limited - it can be a complex roof configuration or skylights. Dot products are divided into ridge and pitched. The first of them are mounted under the ridge - they are designed to remove condensate and vapor along the entire structure of the ridge. This type of aerator is installed in areas that require increased air circulation.
- continuous. They are placed evenly over the entire roofing surface and thus provide ventilation for all layers of the "pie", as well as areas of attics and attics. The most demanded of the continuous aerators are moisture-resistant ventilation tape, which is installed in the waterproofing layer, and a ridge fan.
- Turbine. They are produced in the form of a pipe and equipped with an electric fan or an electric hood. Experts advise giving preference to aluminum products, as they are resistant to corrosive processes and do not change shape under the influence of high temperatures.
When choosing an aerator model, the roof slope is taken into account. Usually this information can be seen on the packaging of the product.
Choosing an aerator
A certain type of device is used for different roofing. For soft materials, aerators made from weather-resistant and impact-resistant polypropylene are suitable (read also: ""). Usually they are placed equidistant from each other at the highest points of the roofing or at the junction of thermal insulation boards.
Such a device performs the following functions:
- reduces pressure in the under-roof space;
- removes steam from the layers of the "pie";
- prevents condensation.
The aerator fan housing for metal tiles is produced from materials that are resistant to corrosion and aggressive environments, exposure to different temperatures and ultraviolet radiation. These requirements are met by polypropylene and stainless steel.
For corrugated board coatings for the deflector body, the same materials are used as for metal roofs.
Installation of ridge aerators
Installation of devices of this kind is simple, and for this there is no need to make complex calculations. The ridge aerator is placed along the entire length of the ridge. Experts recommend using this product for roofs with a slope of 12 to 45 degrees. It is mounted exclusively on the ridge and thus provides air ventilation in the attic space.
Conditions for using the ridge aerator:
- In order to ensure the flow of air, it is necessary to have air vents on the overhangs.
- The device should be mounted along the entire length of the ridge - its segments are connected into a single structure.
- A ridge tile is laid on top of the assembled product, and therefore appearance roof will not suffer from the presence of a fan on it.
Arrangement of a ridge aerator for metal tiles or soft roof perform in a certain sequence:
- To cut the ventilation slot, use circular saw. There can be either one hole (at the top of the ridge) or two (on both sides). Depending on the recommendations of the manufacturer of a particular aerator model, the total thickness of the gap should be from 3 to 8 centimeters. The slots are cut out so that they do not reach the edge of the ridge about 30 centimeters. As a result, the roof on its sides is solid.
- In the place on the ridge, where the gap was not made, ridge tiles are laid.
- They begin to install the aerator: each of its segments is fixed with roofing nails or screws, which are screwed in through pre-drilled holes made at the manufacturing plant. Separate parts of the product are assembled into a single structure in the same way as it is done with the details of the designer.
- The profile of the ventilation product is covered with ridge tiles - the petals of the roofing material are overlapped. Long special nails are used to fasten the coating to the ventilation device.
- The places of contact of the ends with the roof are treated with silicone sealant.
Features of mounting point devices on a metal tile
Aerators of this type are installed:
- on flat roofs or on roofs with a slope of less than 12 degrees;
- as an addition to another type of device in order to increase ventilation efficiency;
- if it is not possible to equip a ridge product, for example, because there is no ridge, or there is an adjunction of the roofing to walls or vertical surfaces.
Conditions for using a point aerator:
- They are mounted on slopes, keeping a distance of 50-80 centimeters from the horizontally located edge of the ridge.
- Overhangs must be provided with air flow.
- One point device is able to provide high-quality ventilation on an area of up to 5 - 100 "squares" of the roof, depending on its model. Based on this value, the required number of ventilation products is calculated.
Installation technology point devices on the roof:
- A hole is made in a continuous crate, which should match the size of the aerator's internal channel. To do this, the base skirt of the device is applied to the surface of the plywood sheet or OSB board and the contours of the gap are applied to the roof through the passage channel with a nail or pencil. An electric jigsaw cuts a hole along the drawn line.
- The skirt of the device is placed on top of it and attached with self-tapping screws or roofing nails in the amount of at least 6 pieces. Some manufacturing companies recommend using, in addition to fasteners, fixation on the adhesive composition. In this case, the reverse surface of the skirt is applied bituminous mastic, glue it, and then only use the parts for fastening.
- For the purpose of waterproofing the junctions, bituminous glue is used over the skirt.
- Shingles of tiles cut at the points of contact overlap the skirt.
- An aerator mesh is placed on top of it and fixed with self-tapping screws. Then they install a cap (cover), snap it on and again use self-tapping screws for fastening.
Other point aerators for the roof are mounted in a similar way according to the calculation made, which will eventually make up a single ventilation system.
As can be seen from the above information, installing such devices is not a difficult job - inexperienced self-taught masters can easily handle it.
Due to the presence of aerators on the roofs, water vapor is removed from the roofing cake, condensation is prevented, the spread of fungus and mold is prevented, bad smell. The absence of these unfavorable factors has a positive effect on the duration of the service life of the wooden elements of the roof structure and on the state of the microclimate in residential and utility rooms Houses.
In a two-layer roofing made of built-up materials, Polyvent aerators are installed on the bottom layer of material. In the lower layer of the material at the place of its installation, a hole is cut with a diameter equal to the diameter of the aerator tube through the screed and insulation to the vapor barrier layer. The hole is covered with expanded clay gravel. For better adhesion of the horizontal part of the aerator with the roofing carpet, heated bituminous binder (hot mastic) is applied to its surface. After the bituminous binder has cooled, the aerator is additionally fixed with screws to the screed (if there is no screed, then to the base, through the thermal insulation layer). Then, the top layer of the roofing carpet is welded in such a way that the aerator is in the place of the end overlap of the two roofing panels (150 mm overlap). The adjunction of the roofing carpet to the aerator is smeared with bituminous sealant.
When installing roofs with a base of reinforced concrete floor slabs, in a single-layer roofing, the Polyvent aerator is installed on a screed. The hole is made through the screed and insulation to the vapor barrier layer. The roofing carpet is laid without sticking to the aerator skirt. A heated bituminous binder (hot mastic) is applied to it. A patch from the upper layer of roofing material based on polyester is welded to the place where the roofing mat meets the aerator. The patch should overlap the aerator skirt and go into the roofing carpet by 150 mm. The aerator is additionally fastened with self-tapping screws, and the adjunction of the roofing carpet is smeared with bituminous sealant.
Aerator installation scheme
Video: Installation of a roof aerator
(video size 17.24 megabytes)
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- consists of 3 constituent parts. A special clamping ring to the roofing provides a thorough seal around the pipe body and significantly enhances the aesthetic properties of the coating. Designed for use in regions with significant snow cover. It is recommended to install one such aerator per 50-60 m² of roof. |
| Specifications | |
| Height, mm | 340 |
| Weight, kg | 0,317 |
| D tubes, mm | 75-55 |
| D skirts, mm | 270 |
| D cap, mm | 146 |
| - consists of 3 components. A special clamping ring to the roofing provides a thorough seal around the pipe body and significantly enhances the aesthetic properties of the coating. It is recommended to install one such aerator per 50-60 m² roof. |
|
| Specifications | |
| Height, mm | 260 |
| Weight, kg | 0,3 |
| D tubes, mm | 75-55 |
| D skirts, mm | 270 |
| D cap, mm | 146 |
| - consists of 4 components. The unique design of the cap creates additional draft in the pipe, which significantly increases the efficiency of the aerator. Designed for use in regions with significant snow cover. It is recommended to install one such aerator per 80-100 m² of roof. | |
| Specifications | |
| Height, mm | 470 |
| Weight, kg | 1,06 |
| D tubes, mm | 130-103 |
| D skirts, mm | 390 |
| D cap, mm | 146 |
Aerator “POLYVENT-SUPER”  |
Aerator “POLYVENT-SUPER”- consists of 3 components. The principle of operation of this; aerator is based on the pressure difference caused by air currents. The cap, unique in design, creates additional draft in the pipe. It is recommended to install one aerator per 80-100m² of roof. Polyvent-Super is used where the highest reliability is needed. |
Specifications |
|
| Height, mm | 470 |
| Weight, kg | 1,04 |
| D tubes, mm | 148-100 |
| D skirts, mm | 390 |
| D cap, mm | 210 |
The need to dry the roofing
The duration of the life of the roof depends on a variety of factors: high-quality performance of heat and waterproofing, proper use of the material, timely preventive inspection and repair work.
Experts believe that the main disadvantage of a soft roof is the accumulation of moisture in the screed and insulation. It can lead to serious consequences.
Blistering is one of the most common defects in soft roofing. It happens for two reasons.
In warm and hot seasons, the roof surface is affected by sun rays can heat up to 90 degrees or more. The composition of rolled roofing includes bitumen-polymer materials. These are thermoplastic substances, the physical properties of which change under the influence of temperature fluctuations. The foregoing refers to such qualities as fragility, plasticity.
On the basis of research, it was found that heating above 50 degrees leads to an increase in the plasticity of the mastics included in the bitumen-polymer materials, and the increase in the degree of adhesion to the base depends on the viscosity of the mastic, and not on adhesion.
The vapor barrier layer (in the lower part of the roofing pie) and the waterproofing carpet (in the upper part), which are part of the soft roof, form a sealed enclosed space.
When the roof is heated under the influence of the heat emanating from it, the moisture in the under-roof space turns into steam, which significantly increases the pressure exerted on the roof carpet. It can reach up to 2-2.5 tons per square meter.
Due to the special qualities of the thermoplastic substances included in the waterproofing materials under conditions high temperature And high pressure blisters form on the roofing due to delamination of the bitumen-polymer coating. The destruction of the roofing carpet also begins.
Even when the installation of the waterproofing carpet is carried out at a high quality level and it is completely glued, it is not possible to avoid the formation of blisters.
The increase in the level of thermal conductivity of the insulation. accumulated under the layer waterproofing material moisture leads to a deterioration in the thermal insulation characteristics of the insulation layer.
Even when moistened by 1 or 2%, the level of thermal conductivity of the insulation increases by 30-40%. As a result, you have to spend much more money on heating.
As a result of waterlogging of the insulation, not only heat losses increase, but mold also develops rapidly.
Destruction of the waterproofing carpet and screed. The screed in most cases consists of sand-cement mortars, which are a capillary-porous material. All pores are filled with air and connected to each other. When moisture enters the roof space, the pores are partially filled with water. As the ambient temperature drops, water crystallizes and increases significantly in volume.
As a result of this process, crystallization pressure of enormous force is exerted on the walls of the capillaries, due to which microcracks are formed. Over time, the leveling screed breaks down. A similar process also occurs in the waterproofing material.
Where does moisture come from?
Humidification of the insulation layer can occur in two ways.
Moisture can penetrate into the space between the layers from the environment (fog, rain, high humidity) through defects in the roofing carpet. It also enters from the interior of the room (vapours condensing in the under-roof space) through the places of damage in the layer of vapor barrier material.
Since the amount of moisture in warm air is much higher than in cold air, then in winter time the movement of water vapor through the layers of enclosing structures occurs from the inside of the room to the outside.
It should be noted that in residential premises the air is saturated with vapors, since a person exhales about a liter of water in a vapor state per day. If we add to this indicator moisture from the process of cooking, cleaning, washing, taking a shower and bath, then the figure increases to 12-15 liters.
Availability advanced level moisture in the heat-insulating material is also due to the climatic factor - precipitation, air humidity during the installation of the roofing carpet. For example, if work is carried out in winter, then it is almost impossible to avoid getting snow or moisture under the roof.
With a significant increase in the level of moisture, eliminating its local entry through the roofing carpet and areas of intense moisture is not enough. Additional drainage of the insulation layer is necessary, otherwise the roof will have to be completely dismantled and the insulation replaced.
However, complete dismantling of the roof is not always possible.
In this case, condensate and excess moisture are removed by evaporation - without expensive and complex work to replace the waterproofing mat and insulation.
It also makes it possible to avoid leaks during repair work.
Evaporation efficiency is determined by the speed of the ventilation flow of the air mass and its circulation.
Since there is a big difference between the temperature and vapor pressure from inside the roof and outside (during the hot season, the inner layers heat up to 70 degrees, and the outer layers up to 90), measures must be taken to ensure that the external and internal air mix.
As a result, it is possible to achieve a decrease in the air temperature inside the room and a displacement of moisture to the upper layers of the insulation. This will lead to the creation of favorable conditions for its evaporation and partial drying of the insulation layer.
As the thermal insulation layer dries up, the parts of the building and the roofing carpet also dry out. Drying the insulation with the help of natural ventilation leads to the restoration of its operational properties, since this process does not affect the physical and mechanical properties of the heat-insulating layer.
The principle of operation and functions of aerators
To drain the insulation, ventilation pipes (aerators) are arranged. The principle of their operation is based on the creation of thrust in the device pipe by forming a low pressure area due to external wind flows and using the pressure difference in the under-roof space and in the environment.
Functions of aerators are as follows:
- contribute to the removal of rising from interior towards the roof of the water vapor - before it has time to cause any damage
- roof structure;
- reduce the pressure arising in the structure, which causes the formation of bubbles on flat roofs with a soft coating;
- prevent the formation of condensate (later flowing into the thermal insulation layer) in the lower part of the waterproofing material.
The roof aerator is essentially a pipe with a diameter of 63 to 110 mm, covered from above with an umbrella to protect against rainfall.
In most cases, the material for the manufacture of aerators is low-pressure polyethylene.
Varieties of aerators
Roof aerators are different models and sizes. They are used to ventilate the under-roof space, remove condensate and remove moist air to the outside.
They can be installed both during construction and on an already erected roof.
During repair work, aerators are essential to timely prevent the occurrence of foci of decay in the roof structure and eliminate the risk of roof leakage.
Installation of aerators for metal roofing is carried out in the upper part of the roof, as close as possible to the ridge. The case of the device is made on the basis of a material resistant to acid, ultraviolet radiation, corrosion, and temperature extremes. Currently the best choice are stainless steel and durable plastic.
On soft roofs, aerators are installed evenly over the entire plane at the highest points.
Roof aerators can withstand temperatures ranging from minus 50 to plus 90 degrees. They are installed on all types of roofs and roofing.
The number of required aerators is determined by their technical specifications and the area of roofing slopes, as well as the condition of the roofing carpet and the level of moisture concentration in the interior.
For buildings with a specific purpose with a high level of humidity (pools, baths, saunas, laundries), the number of necessary aerators should be calculated at the design stage of the building.
Aerators are point and continuous. With the help of devices of the first type, ventilation of individual sections of the roof is provided. Aerators of the second type are installed along the entire length of the roof and serve for general ventilation.
Point aerators
Produced in two versions:
pitched– for installation on roof slopes;
skating- for installation on a skate.
Pitched aerators are installed in areas where it is necessary to increase the movement of air masses:
- on slopes of considerable length or slopes of complex design;
- on ridges and roof valley;
- in those areas where the interruption of the ventilated gap occurs.
An obstruction to the free circulation of air can be an attic window or a lantern. In such places, it is advisable to install aerators on both sides of the interfering part.
To improve ventilation efficiency, it is necessary to take care of the correct placement of aerators. They should be located at a small distance from the ridge (about 15 cm). If the insulation of the roof structure was not carried out “under the ridge”, then a pressure chamber is formed in the upper part, in which vapors are concentrated. When using an aerator, they evaporate from the roof into the surrounding space.
Skate options are used for attics with insulation "under the skate". They contribute to the elimination of vapors throughout the ridge structure. Such aerators work on the basis of the use of convection - the properties of warm air masses to rise up. There, under the ridge, they find a way out. At the same time, cold streams penetrate through the ventilation channels from under the eaves.
One of the advantages of the ridge model of aerators is the removal of harmful fumes from bitumen, a material used in the construction of a soft roof.
Since these devices are hidden under the roof covering, they are almost impossible to notice from the outside.
How to install an aerator
The technology for installing aerators is as follows.
- In the place where it is planned to install a ventilation pipe, a window is cut out in the screed. It is necessary to ensure that it passes through the roofing carpet to the point where the insulation is located.
- If for some reason the insulation in this place turned out to be wet, it must certainly be replaced with dry material, the thermal conductivity of which meets the required standards.
- After that, in order to securely fix the aerator on the roof, a layer of special mastic must be applied to the bottom of the pipe base.
- To attach the aerator to the screed, use self-tapping screws, which must be evenly distributed around the circumference of the aerator "skirt". They will need 6 pieces.
- Protection of the base of the ventilation pipe is carried out by using an additional layer of waterproofing material.
As already mentioned, the need to install ventilation is determined depending on the shape of the roof, its dimensions, the degree of indoor air humidity, and the general condition of the vapor barrier of the roof structure.
If the roof is flat, with a simple configuration and parameters that meet the standards, then for every 100 sq. meters it is recommended to install one aerator.
It is necessary to ensure that the distance between the aerators is no more than 12 meters.
When located on a roof with a pronounced ridge and valley, aerators are installed along the ridge and at the border of the valley watershed.
Prices
The modern construction market offers a wide selection of different models of roof aerators. The minimum price for the device is 260 rubles, and the maximum can reach up to 3000 rubles.
You can navigate the cost of aerators based on the examples given.
- A three-piece aerator equipped with a special clamping ring to the roofing for absolute insulation around the pipe. The height of the device is 260 mm, the weight is 330 grams. One device is designed for 50-60 square meters roofs.
It costs 450 rubles.
- A similar device, also with a clamping ring for reliable sealing and improved aesthetics, designed for use in regions with a lot of snow. One device serves 50-60 sq. meters of roof. Aerator height - 360 mm, weight - 320 grams, cost - 550 rubles.
- The aerator, consisting of 4 parts, is equipped with a unique cap to create additional traction in the pipe, which greatly increases the efficiency of its use. It is successfully used in areas with significant snow cover. The height of the device is 470 mm, the weight is 1.23 kg. Designed for 80-100 sq. meters of roof. Price - 850 rubles.
- An aerator of 4 components (clamping ring, 2 "skirts" - bases, a cap) is used in cases where ventilation is necessary both above the insulation (especially when it is a vapor barrier) and under the vapor barrier. Designed for 50-60 sq. meters. Height - 340 mm, weight - 780 g. It costs 950 rubles.
- A 3-part aerator whose principle of operation is based on the difference in pressure caused by air currents. The specially designed cap contributes to the creation of additional traction. It is recommended to use for 80-100 sq. meters of roof. Height - 450 mm, weight - about 1 kg. Price - 1150 rubles.
When buying aerators, it is better not to try to save money, to purchase a quality model. In this case, it will be possible to avoid unscheduled repairs of the roof and ceilings of the premises of the upper floor.
CONCLUSIONS:
- The aerator is a device for freeing the under-roof space from excess moisture and protecting the roof structure from decay and destruction.
- Removal of excess moisture is necessary, since it leads to the formation of bubbles, an increase in the level of thermal conductivity of the insulation, and the destruction of waterproofing and screed.
- In order to evaporate moisture, measures must be taken to mix the external and internal air.
- For effective drainage of the insulation, ventilation pipes, or aerators, are arranged.
- Aerators are point and continuous.
- Point aerators are divided into pitched and ridge.
- Installation of aerators can be carried out both during construction and on an already operated roof.
- Prices depend on the specific model and vary between 260-3000 rubles.
Video instruction on how to mount a point aerator on a flexible tile.
Roof aerator is a device whose purpose is to remove excess moisture from the under-roof space.
Aerators are installed on roofs with different slope angles and different types roofing.
Their installation on flat (soft) roofs helps to prevent damage to parts of the roofing and destruction of the roofing carpet, which can occur as a result of exposure to moisture coming from the interior, penetration from the outside (through microcracks in rolled coatings) rainwater.
Why aerators are needed in new buildings and optional in old ones
Many people think that installing aerators is an overkill and more a tribute to fashion than a necessity.
Indeed, these devices did not exist before. The fact is that 20-30 years ago the attic remained cold, there were no living quarters in it - therefore, there was no need for insulation either.
As a result, there was a lot of space under the roof where air could freely circulate and go outside through the non-insulated roof, since there were always gaps in the ridge, gables, and cornices.
Thus, the truss system was protected from moisture.
As for new buildings, their construction is carried out according to other principles, namely:
- to prevent heat loss and save money on heating the interior, the roof is insulated as efficiently as possible;
- the attic space in most cases is converted into residential;
- The rapid pace of construction meant that the installation roof structures produced without preliminary thorough drying of the wood, as a result of which the parts continue to “ripen” already in finished form;
- in order to insulate the roof, a roofing pie is being installed, the structure of which involves the imposition of layers of various materials on top of each other, necessary to preserve heat, protect against water and steam. As a result, the vapor barrier closes all possible ways for air to escape, moisture remains in the under-roof space and begins to have a destructive effect on the rafter system. Add to this the possibility of rainwater penetrating from the outside - and the picture is ready: mold, fungus, rotten rafters that need urgent replacement if the owner does not want to be left without a roof over his head.
Sources of high humidity
- The insulation layer accumulates moisture coming from external environment. The reason for its penetration inside is the presence of defects or damage in the roofing.
- Moisture also comes from the interior due to a violation of the integrity of the vapor barrier layer.
- The accumulation of moisture and wetting of the insulation also occur due to climatic conditions: high humidity, high rainfall.
In the classic version, the soft roof is a multilayer cake. One of the most common problems during the operation of these roofs is the appearance of swellings on the roofing carpet, which further lead to the formation of leaks.
Blisters occur under the influence of moist air vapors that rise from the upper residential floors through the ceilings into the space under the roof, after which they penetrate through defects in the vapor barrier layer and settle there in the form of droplets (i.e. condense) into insulating material and cement-sand screed.
Under the influence of moisture, the insulation loses its thermal insulation qualities, which leads to a loss of 30-40% of heat, an increase in heating costs and mold formation.
Moisture can penetrate into the under-roof space during roofing work. Caught in closed space, between the layers of the roofing cake, under the influence of heating, it passes into a vaporous state and from the inside begins to exert pressure on the structure, which can lead to its separation from the base and the formation of blisters.
When a large amount of water accumulates in a layer of thermal insulation material, its drying becomes possible only using special methods. The same applies to parts of the roof exposed to increased moisture.
To replace damaged insulation, homeowners have to completely disassemble and repair the roof. This process is quite laborious, besides it costs a significant amount.
Why are aerators needed?
One way to get rid of excess moisture is to dehumidify. It allows you to avoid replacing the waterproofing carpet and insulation.
Evaporation prevents possible leaks, which in most cases appear as a result of construction and repair work.
Drying of the insulation becomes possible when using ventilation aerators. The principle of their operation is based on the difference between internal and external air pressure, as a result of which draft is created in the aerator pipe, which is formed due to a decrease in pressure under the influence of an external wind flow.
Despite the fact that these devices are very simple, they prevent swelling of the roofing. Aerators remove moisture in advance and do not allow it to accumulate and further condense in the under-roofing space and in the layers of the roofing pie, since the accumulation of moisture will lead to a breakdown in the connection between load-bearing structure and topcoat.
Against the background of the foregoing, it becomes obvious that it is necessary to install a roof aerator already at the stage of building a house, without waiting for the formation of mold, fungus and damage to the entire structure.
If the aerator was not installed at the stage of roof installation, you can do it later.
Roof aerators are essential also in case of flat roof widely used in civil and industrial construction.
Its layered structure includes a bearing slab based on reinforced concrete, covered with insulation, vapor barrier and screed - cement-sand mortar.
The waterproofing layer in many cases are rolled materials.
The duration of the operational life of this type of roof depends on a number of circumstances, including the quality of work on hydro-, thermal insulation and installation of roofing.
Practice shows that the main disadvantage that comes to the fore during the operation of a soft roof is the formation and accumulation of a large amount of moisture in the screed and insulation material. The use of a roof aerator can significantly reduce its amount.
The accumulation of moisture leads to a number of negative consequences. The most frequent of them:
- Swelling of the surface of a flat roof.
This shortcoming is the most common. It occurs for the following reasons:
- Heating the roof during the hot season leads to a change in the quality characteristics of bitumen-polymer materials: under the influence of high temperature, they become more plastic. In this case, the adhesive strength depends on the viscosity of the mastic. In any case, it is significantly reduced.
- Simultaneously with this process, steam is formed in the under-roof space, between the waterproofing layer and the vapor barrier located under it. It is the result of heating the water accumulated here. Steam begins to exert pressure on the roofing from the inside.
The result of the described processes is the delamination of both the bitumen-polymer material and the roofing. Elimination of defects in the form of blisters requires high-quality attachment of the waterproofing layer to the roofing base. And to avoid all these problems, you can simply use a roof aerator.
- Increase in thermal conductivity.
The moisture accumulated in the waterproofing layer and under it significantly reduces the thermal insulation qualities of the roof.
Practice shows that an increase in the level of humidity by only 1 or 2% increases the thermal conductivity of the material by 35-40%, which leads to the need to increase costs during the heating season. It is possible to avoid this in a simple way: install aerator.
- Destruction of the screed and the layer of waterproofing material.
The screed is carried out using a cement-sand mortar, which in structure is a capillary-porous material. The pores communicate with each other, and the space between them is filled with air. Penetrating inside, moisture fills free space. At low air temperatures, the water in the pores undergoes crystallization, expands, becoming much larger in volume, as a result of which it begins to exert pressure from the inside, which leads to the formation of microcracks and further destruction of the screed. Similar processes can occur in a waterproofing carpet.
What is the function of aerators?
- Aerators contribute to the rapid removal of water vapor rising from the interior to the top, and even before the moment when it causes damage to the roof structure.
- The use of these devices reduces the pressure that builds up in the roofing cake and leads to the formation of bubbles on the finish coat.
- Roof aerators prevent the formation of condensate at the bottom of the waterproofing layer, which can penetrate into the thermal insulation layer and cause Negative influence on its quality.
- By themselves, aerators do not remove moisture, but are a channel that provides effective air exchange. The circulation of air masses leads to the drying of the internal spaces of frame-type roofs and maintains an optimal level of humidity.
- Aerators retain their functionality in any conditions. Even during rain, the humidity of the air in the external environment is less than the humidity of the air mass locked in the under-roof space. The aerator helps internal moisture to get out and prevents the penetration of moisture from the environment.
Types of aerators
The roof aerator is essentially a pipe, the diameter of which ranges from 63-111 mm. An umbrella is attached to the top of the pipe, protecting the device from the penetration of atmospheric precipitation.
Aerators are made mainly on the basis of low-density polyethylene.
Depending on the specific purpose, they can be of several types.
- Point- contribute to the ventilation of individual sections of the roof.
- continuous- provide general ventilation. Their installation is carried out along the entire length of the roof.
The point variety of devices is designed for roof slopes (pitched aerators) and ridge (ridge aerators).
pitched models mounted at points where it is necessary to activate the movement of air:
- long slopes;
- slopes of complex configuration;
- ridges;
- valleys;
- places where the ventilated gap ends: an attic window or a lantern installed on the roof can block the air flow. In these parts, aerators must be installed on both sides of the "obstacle".
To ensure good ventilation, pitched aerators should be installed near the ridge (at a distance of 15 cm). In the case when the insulation of the roof structure was not carried out “under the ridge”, an area of \u200b\u200bhigh pressure is formed in the upper part - a chamber in which evaporation accumulates. The aerator will help them evaporate quickly.
Ridge aerators are used for attics, in which the insulation is carried out “under the ridge”. Devices help to remove steam from the entire ridge part. This type of aerator works thanks to the principle of convection: due to the tendency of warm air upwards, it accumulates under the ridge, from where it is brought out. At the same time, through ventilation ducts cold streams take the place of warm ones.
Ridge aerators perform another important function: they remove harmful fumes from bitumen used in soft coatings from the roof structure.
These devices are located under the roofing and are invisible from the outside.
Continuous aerators are an addition to the ventilation system on roofs covered with natural tiles.. Their installation is carried out along the entire length of the ridges, cornices, ridge.
At the same time, a special ventilation tape for the ridge is used. With its help, both horizontal and diagonal skates are waterproofed.
Due to its elasticity, the tape repeats all roofing bends. The adhesive base prevents the penetration of moisture and precipitation into the ridge element.
The tape provides not only waterproofing, but also ventilation, since a strip of a special “breathing” membrane passes through its center, thanks to which vapors can freely circulate in the roof structure and go outside.
For cornice overhangs, an aerator with a ventilation bar is designed.
This device promotes free movement of air and at the same time is a sealant between the ridge and rows of tiles, battens and tiles.
Due to the presence of ridges, the aerator prevents dry leaves, debris from entering the under-roof space, as well as the penetration of birds.
Some important aspects of roof ventilation
The need for ventilation depends on several factors:
- the shape and size of the roof;
- the degree of humidity in the room;
- condition of the vapor barrier of the roof structure.
For a flat roof with a simple configuration and standard parameters, it is enough to install one aerator per 100 sq.m.
The minimum distance between aerators should be 12 meters.
In the presence of pronounced valley and ridge elements, aerators are installed:
- in the valley - on the border of the watershed;
- in the ridge run - along the ridge.
CONCLUSIONS:
- Aerator - a device for removing excess moisture from the under-roof space.
- The features of new buildings make the installation of aerators a necessity.
- Moisture penetrates into the under-roof space both from the external environment and from the interior.
- Excess moisture renders the insulation layer unusable and can cause rotting of the truss system.
- The main function of aerators is to ensure good ventilation of the roofing pie and the under-roof space.
- These devices also help to avoid the formation of blisters in the roofing mat and the destruction of the leveling screed.
- Aerators are point and continuous.
- Point, in turn, are divided into pitched and ridge.
- For a flat roof of a simple form, it is enough to install one aerator per 100 square meters. meters.
- The distance between two aerators must be at least 12 meters.
Learn how to properly mount the aerator on the roof from the video.
The roof must always be dry. But now we are not talking about its outer side, but about the multiple inner layers of the roofing pie. At the same time, it must be dry, regardless of the materials used for finishing, whether it be slate, or a soft bituminous coating. Condensation and moisture accumulated in the under-roof space can quickly render the entire roof unusable and significantly reduce its service life. To avoid excess moisture inside the cake, you will have to install aerators for a soft roof. Consider what they are and how they are installed.
To understand why under any roof it should always be dry, you first need to figure out where water can come from there, condensation can form. Indeed, during the construction of the roof, craftsmen always try to make it as tight as possible, lay various waterproofing and vapor barrier materials under the roofing, which, in theory, should provide reliable protection.
The whole point is that in a residential building there are various processes associated with human life. People breathe, cook food, take a shower or bath. And during all these processes, the air in the house is saturated with steam - in other words, it becomes humid. Warm air rises and enters under the roof if it cannot escape through the vent. At the top, microscopic droplets of water settle on various materials This is how condensation forms. At the same time, air saturated with water vapor easily penetrates even into the most hard-to-reach places through microcracks.
On a note! During the day, a person exhales about 1 liter of liquid into the air in the form of vapor. Adding to this amount all the water that enters the air during cooking, mopping or taking a bath, you can get a huge figure - up to 15 liters of water enters the air in the house during the day.
The accumulation of condensate under the roof poses a certain danger to all materials that make up the roofing pie. Wooden elements begin to be saturated with water, which causes decay processes. Such an environment is also favorable for the development of fungus and harmful microorganisms that are dangerous to the health of people living in the house.
Metal elements (for example, fasteners) inside the roofing pie, due to the increased level of humidity, begin to corrode and gradually collapse. If the water in the under-roof space, accumulated during the summer, freezes in the winter, it can easily damage some parts of the structure (even concrete floors), since, expanding, it will exert a pressing effect on the materials. Due to severe damage, the roof may even have to be completely dismantled and rebuilt.
Also, the effect of moisture is detrimental to insulating materials. If they get wet, then their thermal conductivity will increase significantly. This means that such a roof will no longer be able to retain heat well. In some cases, the insulation will need to be completely changed, because it will no longer be possible to fully dry it.
Moisture can get to the structural elements of the roof and outside. During heavy rains, melting snow, water can still find a loophole and get under the roof or into the roofing pie, even if its outer surface is well sealed. It is not worth excluding this option of additional "moisturizing".
On a note! From the point of view of vulnerability from excess moisture under the roof, any soft roof suffers the most.
Prices for various types and manufacturers of shingles
Flexible roof tiles
Soft roof and water
As for the soft roof, under it moisture actively accumulates in the insulating layer. At least because of this, the roof can bubble, especially if it is a soft bituminous coating laid on a flat concrete roof. In this case, bubbles can occur here is why: in summer, the roof can easily heat up to 90 degrees or more. Soft materials always contain bitumen, which is a thermoplastic substance - it reacts sharply to changes temperature regime(may become brittle in cold weather or soft and ductile in hot weather). When the material is heated above 50 degrees, plasticity increases, and the quality of adhesion of the coating to the base depends, to a large extent, not on adhesion at all, but on the viscosity of the components included in the material or the mastic on which the coating was glued.
Defect of an ordinary roof - the formation of swelling of the roofing carpet
There is a closed hermetic space between the vapor barrier and waterproofing in the roof pie. As the temperature rises, the pressure in this area increases to 2-2.5 t/m 2 . The waterproofing rises, lifts the roofing, and thus swelling is formed.
To get rid of all the above problems, it is necessary to install an aerator during the installation of the roof. It will ensure the removal of air to the outside, and with it - and moisture. The device will allow you to dry the heat and waterproofing layers and prevent the accumulation of condensate.
What is an aerator and how does it work?
A roofing aerator is a design that serves to remove moisture from under the roof, including the one that was formed in the roofing pie itself, and not just in the house. This element can be installed on a variety of roofs, having all kinds of slope angles and covered different materials. An aerator on a soft roof will prevent premature destruction of the entire roof structure due to moisture.
Traction is created inside the installed aerator due to the formation of a low pressure area due to external wind flows and the pressure difference in the space under the roof and the street. The main functions of this design are as follows:
- removal of water vapor from the house to the outside;
- reduction of the pressure arising inside the roof between the layers (the risk of blisters on flat roofs is reduced);
- reducing the risk of condensation on waterproofing materials.
Externally, the aerator is a pipe with a cross section of 63-110 mm, having an umbrella on top, which protects the structure from rain and snow getting inside. It can also be presented in the form of a ridge bar with a lattice on the sides. The first aerator is placed on the roof slope, and its second variation is installed along the roof ridge.
On a note! The aerator can be installed during the construction process or on a finished roof.
Varieties of aerators
Aerators may differ from each other in the materials of manufacture and design features. Most commonly used plastic products, however, there are also metal ones (made of steel) on sale, which are usually mounted on roofs made of metal tiles. In fact, all aerators are resistant to sunlight, rust, and temperature extremes.
Table. Types of aerators depending on the design features.
| Type | Description |
|---|---|
| This type of aerator looks like a small pipe or low flat design with lattice. This is the most commonly used option. Such a design functions in a separate area and is usually installed where there are problems with natural ventilation (on long slopes, complex roofs, in the area of attic windows, valleys, etc.). Such aerators are pitched and ridge. In the first case, they are installed on the slopes, in the second - on the ridge. For soft tiles the ridge version is usually purchased - it is able to provide ventilation of about 20 sq. m. roofs. Pitched aerators are usually mounted at a small distance from the ridge - about 15 cm. |
| Such aerators are located along the entire length of the roof and provide maximum ventilation for the entire roofing pie, as well as the attic. The continuous form includes ridge types, as well as ventilation tapes. The latter inserts are mounted in the waterproofing layer. At the same time, they do not pass water at all. |
| This is a kind of ventilation. It can be a hood or a pipe with an electric drive. The model is selected depending on the angle of inclination of the slope. |
On a note! The market for aerators is now quite extensive and makes it possible to choose this structural element in such a form that it can look organically on a roof of a certain type or style.
Prices for various types of ridge aerators
Ridge aerator
How to install?
Installation of aerators can be carried out both during the installation of the roof, and at the end of the work. In general, this structural element is not difficult to install if you know how to do it. The instructions will help you understand the installation steps ( installation of a point aerator in the finished roof).
Step 1. On the surface of bituminous tiles, a template is fixed using self-tapping screws, cut to the size of the section of the lower part of the aerator. It can be circled with a marker or further actions can be performed directly along its contour.
Step 2 According to the shape of the template, a hole is cut in the roof using a jigsaw. During cutting, it is important not to damage the waterproofing and insulation layers.
Step 3 If the template was screwed, then after cutting a hole in the roof, it is unscrewed and removed.
Step 4 Cut out pieces of roofing and battens are removed.
Step 5 With the help of a vacuum cleaner, particles of debris and sawdust are removed from the surface of the roof and from the resulting hole.
Step 6 A rubber-based adhesive is applied around the perimeter of the base of the aerator.
Step 7 The aerator is turned over and glued around the perimeter of the hole cut in the roof.
Step 8 The base of the aerator is additionally fixed on the roof surface with self-tapping screws. For convenience, the top cover can be removed from the aerator.
Step 9 After the aerator has been securely fixed to the roof surface, the top cover is returned to its place and screwed on.
Prices for popular models of screwdrivers
Screwdrivers
Attention! If several aerators are installed on the roof, it is important to ensure that the gap between them does not exceed 12 m. In general, 1 aerator is used per 100 m 2 of a flat roof. On a roof with ridges and valleys, aerators are mounted near the ridge.
Video - Installation of an aerator on a soft roof
Installation of a ridge aerator-tape
Let's also consider an example of how ridge aerator installation.
Step 1. The base of the roof is being prepared for the installation of a ridge aerator. An opening 5 cm wide is made along the ridge, 2.5 cm on each side. On each side of the ridge, 20 cm are measured along it. This is the minimum distance that should not be cut.
Another photo of the process - 20 cm is measured
Opening width - 2.5 cm on each side
Step 2 For roofs with central beams, a 9 cm wide slot is made, 4.5 cm on each side of the ridge.
Step 3 The ridge is ready for ventilation installation when the remains of tiles and beams, as well as all debris, have been removed from the surface.
Step 4 The ridge aerator is quite flexible and is sold in reels. It rolls along the entire length of the skate from edge to edge, including places without slots.
Step 5 The edge of the ventilation tape is fixed with nails, two from each slope.
Step 6 The fixed tape is well stretched and fixed at the other edge of the ridge. If the roof is long, then you can fix the tape in stages.
Step 7 Excess aerator tape is cut off.
Step 8 End caps are installed. On both sides, mastic is applied to them. They must cover both ends of the moisture-proof membrane between the end cap and the bottom vent.
Step 9 The tape and end cap are nailed to the base of the roof as shown in the image. At least two nails must go through the tape and plug.
Step 10 A layer of mastic is applied between the roof covering and the ventilation tape.
Step 11 The not yet fixed part of the tape is nailed to wooden base roofs. The nails must penetrate to a depth of at least 1.5 cm.
Step 12 To close such ventilated ridges, you will need bituminous tile segments, 3 tile elements are stacked together on top of each other.
Attention! If work is carried out in the cool season, then the tiles must be preheated.
Step 13 Tiles are laid on the ridge, starting from the most windy side. The first three-layer element is nailed to the roof through the aerator. An indent of 2.5 cm is made from the edge of the tile - a nail is hammered into this point.
Step 14 The second in a row three-layer tile element is laid so as to cover the nails on the previous element.
Step 15 The entire skate is made in the same way.
Video - Installation of a ridge aerator
A roof aerator installed on the roof will provide the house and the roof itself with good ventilation. It will not allow condensation to accumulate, will not allow water to destroy structural elements roofs. Installing an aerator is not difficult, anyone who has carefully studied the instructions above will cope with the task.
