Correct ventilation system should work independently, ensuring natural air movement from bottom to top. In this way, it is possible to normalize the circulation of air masses, which is responsible for ventilating the house and the under-roof space.
This article is about the types of ventilation, devices for providing it and how you can make ventilation on the roof yourself.
According to building codes, every residential building must be provided with at least three ventilation ducts:
Important! The methods and locations for installing ventilation ducts may be different, but most often it is customary to install them on the roof.
It has been established that natural draft will be sufficient to ventilate a house with a pipe height of more than two meters. That is why, most often, pipes are installed on the roofs of houses. In addition to the usual round pipes square boxes or shafts, flat aerators or compact deflectors can be used - all these elements are needed to enhance air flow.
The correct design of the ventilation system is easily verified by its performance. High-quality roof ventilation in winter time should prevent freezing of the roofing pie, the formation of ice and frost with inside roof, penetration of cold air into the house. At the same time, in the summer, a cool microclimate must be maintained in the attic space; every minute the heated air must be replaced by a fresh portion of air masses from the street.
The ventilation of the house and its rooms is checked normal temperature and humidity - in the summer the house should be cooler than outside, and in the winter it should remain warm.
Important! If mold appears on the walls or ceiling, condensation accumulates, this indicates a violation of normal air circulation, including improper operation of the ventilation system.
Natural draft, based on the difference in height and pressure of the air column, is often not enough to ensure normal air circulation in the under-roof space or in the house.
Insufficient circulation leads to consequences such as:
All this will soon lead to a violation of the integrity of the waterproofing and the appearance of leaks in the roof. This means that the roof will have to be repaired or replaced, so it is much more effective to immediately install a good ventilation system.
To enhance traction, special elements are used:
To bring ventilation ducts to the roof, it is necessary to make a preliminary calculation.
Attention! Often all ventilation passages leading from different parts houses are combined into one shaft. As practice shows, this method will be effective only with very competent calculation and installation of all elements of the system. When doing everything yourself, it is better to install three separate ventilation ducts on the roof.
An error in calculations or installation will lead to kitchen odors and sewer “aromas” spreading throughout the house, disrupting the microclimate and the circulation of flows in the under-roof space.
With the fact that anyone residential building ventilation is needed, it’s hard to argue - it’s always done in the form dormer windows, air, channels in the walls or using special electrical appliances, increasing traction.
But not all owners take ventilation of the under-roof space with the required seriousness. However, there are types of roofs that must be equipped with a separate ventilation system:
Having decided on the installation location, you can begin installing the ventilation system:
Important! The reliability of installation of the ventilation element should be indicated by excess sealant squeezed out from under the gasket.
You can install ventilation on the roof with your own hands. In this case, it is necessary to comply with all building codes and rules for installing the system.
Modern roofing structures are a complex system in which the elements work effectively only by closely interacting and complementing each other. When creating a roofing project from soft tiles, you need to take a lot into account: protect the insulation from getting wet, prevent rotting rafter frame and premature wear of the coating. “Warm” roofs that lack an insulating air layer deserve special attention. In order for the microclimate in such houses to be suitable for life, it is necessary to establish air circulation between the under-roof space and the atmosphere. To do this, a ventilated ridge is installed on pitched roofs, the installation of which is prerequisite forced organization.
Ventilated ridge is a device installed on pitched roofs to organize forced ventilation of the roof. It is a simple plastic device installed along the ridge of a roof made of soft tiles, corrugated sheets or metal tiles. The ventilated ridge profile has the following functions:
Note! Installation of a ridge with ventilation holes is part of the installation of a forced ventilation system for a roof made of soft tiles, corrugated sheets or metal tiles. In order for ventilation to work, vents are installed in the eaves, places where fresh air is taken from the atmosphere.
Installation of a ventilated ridge does not spoil the appearance of the roof; quality installation this element of the ventilation system cannot be seen. To make the installation site look more aesthetically pleasing, a strip of soft tiles or metallic profile, which protects the aerator from exposure sun rays and penetration of atmospheric moisture.
In the old days, builders did not even think about installing a ventilated ridge, since air naturally circulated through cracks or gaps in building materials and designs. or corrugated sheeting requires almost complete tightness; installation is carried out in the form of a kind of “pie”, in which there is a layer of insulation, waterproofing and vapor barrier. This design does not leave a single chink for air, which is why a stuffy, humid microclimate is established inside the house. To solve this problem, it is necessary to develop high-quality ventilation at the project approval stage. Depending on the type of roof, there are 2 options for ventilation systems:
Important! Forced ventilation was developed based on physical properties gas Its operation does not require power sources, since the draft is created according to the law of convection: warm air rises up and cold air falls down. To achieve maximum efficiency of the ventilation system, its elements are placed evenly over the entire area of the roof made of corrugated sheets, metal tiles or rolled materials.
The design of the ventilation system depends on the area of the slopes, the nature of the use of the under-roof space and the type of roofing material. Installation of ventilation for “warm” attic roofs is more difficult and more expensive than for cold ones. To determine optimal composition And mutual arrangement elements, perform installation based on determining the volume of air in attic. The following types of aerators are used to equip a ventilated ridge:
Note! The simplest and inexpensive way ventilated ridge equipment - use of corrugated ventilation tape. It is sold in rolls, and on the underside of the tape there is a self-adhesive layer with a protective film. To perform installation, you need to remove protective film, glue the tape on both sides of the ridge, and then install the metal ridge strip.
To a non-professional craftsman, ridge ventilation may seem like an unnecessary extravagance and additional cost, but experienced roofers know that this simple measure increases the service life of the rafter frame and roof covering. A properly designed and installed ventilation system performs the following tasks:
Note! Dormer windows installed when organizing natural ventilation are located half the height of the slope, which is why stagnant zones are formed under the very ridge, where air does not circulate at all. When installing forced ventilation, this problem does not arise, since aerators are installed directly on the ridge connection, which is the highest point of the roof.
Moisture can enter the house from the outside in the form of precipitation and from the inside as condensation. Its presence in the premises leads to the spread of harmful microorganisms and mold, which will be difficult to cope with. Prevent this and increase the lifespan of your home with warm attic A roof ventilation system will help.
When arranging the roofing pie of a household with a residential attic, experts observe the principle of complete tightness, arranging the materials in layers, overlapping each other. Thanks to the design of such a system, it is created reliable protection from moisture and heat remains indoors.
At the same time, the “pie” is an obstacle to exhaust through the roof. That’s why they make a forced ventilation system in a residential building, which is installed in accordance with the requirements specified in SNiP.
This design solves a number of problems:
Functioning forced ventilation according to the principle of convection: since warm air is lighter, its currents move upward, while making room for cooler air masses with greater weight. Often it is also installed to facilitate air circulation.
According to the provisions of SNiP, in order to ensure exhaust, the following elements of roof ventilation will be required:
Roof ventilation elements for a heated attic and a cold attic are significantly different. For non-residential premises two dormer windows and eaves vents will be enough.
If a residential attic is designed, then installation of a more complex system will be required, consisting of:
According to SNiP, the number ventilation holes determined taking into account the area of the roofing surface at the rate of 1 - 2 pieces per 25 “squares”.
These devices are placed on roof slopes to remove heated air from the attic space and moisture from the layers of the roofing pie.
Deflectors consist of the following elements:
Install air ducts on the roof at a distance of 50 centimeters from the ridge - like this warm air It will be easier to go outside. Even on roofs whose area does not exceed 25 square meters, you will need to install 2 deflectors.
In order for the ventilation installed on the roof of the house to function efficiently, ensuring the circulation of air masses inside the attic room, you must adhere to several simple rules:
The creation of such ventilation does not require energy costs, so its arrangement is preferable. However, in Lately roofs of complex architecture are being erected more and more often. They lack natural roof ventilation and then there is a need to create a forced system.
As practice shows, how comfortable it is to live in a house depends to a greater extent on the proper arrangement of the roof than on the choice of covering material. Creating high-quality roof ventilation is the key to its long service life.
When construction is carried out at a high level professional level in compliance with all necessary standards, then the coating material will become a reliable barrier to precipitation and strong winds. Roof structure whether made from cheap slate or expensive metal tiles, it helps retain heat in the house and prevents the penetration of excess moisture from the outside.
In turn, the presence in the premises of the house large quantity moisture indicates serious problems with the roof and that the ventilation gap in the roof was incorrectly created or that it was completely forgotten about.
The reasons for the malfunction of the roofing pie may be the following:
There is only one way to eliminate the shortcomings: by dismantling the roofing pie and then creating it again.
The roof ventilation system has three components, each of which has its own functional purpose:
After installing the roofing pie, vapor and moisture begin to seep into it from both sides. The ventilation system should be designed in such a way as to prevent this phenomenon or so that if water gets in, it can erode. By the way, the steam does not move perpendicularly, but slightly to the side. As for the water, it is not directed strictly downward, but deviates slightly.
Often these features are not taken into account when ventilating an insulated roof and a number of mistakes are made when forming the “pie”:
Even if there are air gaps in the roofing pie, ventilation is not able to ensure the removal of all moisture if, during installation of waterproofing or vapor barrier film mistakes were made. These materials are similar in appearance, but they have different functional purposes. If insulation products are mixed up, then the following can happen.
Let's say that instead of a waterproofing film, a layer of vapor barrier was used. This material does not allow steam to penetrate from both sides. If you lay it on top of a heat insulator, the moisture that gets from the air into the insulation will remain in it, since it will not find a way out. As a result, it will become increasingly wet and, over time, lose its functional characteristics. Property owners will have problems with large heat losses.
Suppose instead vapor barrier material for ventilation of pitched roofs
a diffusion membrane was installed. Waterproofing films have one side that is waterproof, and the other side that “breathes.” They are placed under the roof covering with the breathable side facing the insulation. In this case, a ventilation vent must be left between the layers.
In this case, the moisture partially leaves through air gap, and the remainder will fall under the roof through a funnel-shaped hole in the film, from where it will evaporate. When water as a result of a leak penetrates through roof covering, it will settle and will not be able to pass further and will not be removed similarly to moisture from the insulation.
If waterproofing film laid the other way around - with the breathable side away from the heat insulator, moisture entering from outside will penetrate through the funnels into the insulation layer and there will be no way out from there. As a result, arranging a roofing pie will lose its meaning.
When, instead of a vapor barrier material, a waterproofing material is used and it is placed with funnels inside the room, then the steam will quickly enter the insulation. If it’s the other way around, the moisture from the heat insulator will return to the under-roof space.
Often, due to ignorance, not as many layers are created in the “pie” as required for a particular roofing covering. Thus, ventilation of the under-roof space of corrugated sheeting requires a gap between the waterproofing layer and the covering material, since condensation cannot collect on the back side of it.
To do this, instead of a continuous sheathing, slats (bars) are stuffed, leaving gaps for the movement of air masses. When water gets under the roof, this layer of ventilation helps the moisture evaporate through the ridge. In this case, anti-condensation films are used as a waterproofing material - they do not release steam from the heat insulator under the roof, due to which the roof covering gets rid of additional condensation.
But here a problem arises with removing moisture from the insulation if it does not have the possibility of exiting under the roof, so they create another layer of roof ventilation from corrugated sheets - an air cushion is left between the heat insulator and the anti-condensation film. The use of diffusion and superdiffusion membranes for waterproofing is not allowed, since they are designed to allow vapors to pass under the roof, which can lead to corrosion.
Ventilation hip roof from a soft roof is created taking into account the fact that such structures are not afraid of condensation, which means that serious construction is not required between the covering and the waterproofing air gap. When laying this roofing material, a continuous sheathing is installed using boards, plywood sheets, etc.
Wood materials allow air to pass through well, so natural ventilation will be ensured in any case. For soft roofs anti-condensation films are not used - they are used diffusion membranes. Often installed, which will be an additional advantage.
There are several ways to install roof ridge ventilation:
Regardless of the design option, ventilation must provide:
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