Attic under-roof ventilation, grid, device, variations, photo

Thanks to the ventilation of the roofing space, the long-term operation of the roof is ensured and the microclimate in the house is favorable. Owners often find out about the improper construction of the roof with a great delay, only from smudges on the ceiling and moisture in the attic. These are indicators of poor roofing ventilation, but they are not the most negative.

Attic under-roof ventilation, grid, device, variations, photo

In the absence of ventilation, condensate collects under the roof, which causes the materials to rot and freeze in the winter

What is the need for under-roof ventilation? spaces

The cold attic of the building can be converted into a convenient additional floor. Attic can be turned into a comfortable room, a cozy bedroom, an art workshop with the original execution of the walls and ceiling. The difficulty lies in the fact that many owners are hesitant to arrange the ventilation of the space there, suggesting to save money on this.

There is an erroneous opinion that ventilation is an extra attribute and cost.

Indeed, many old houses without ventilation still look pretty good. The thing is that there is a well-organized natural ventilation of the attic space. In the attic there are dormers, additional gaps and openings for the circulation of incoming and outgoing air flow.

In the absence of ventilation in the attic or when it is not operating, soon all the people living there will feel it.

Attic under-roof ventilation, grid, device, variations, photo

Improper ventilation and poor quality insulation have unpleasant consequences.

Lack of ventilation in the attic leads to the following problems:

  • trapped air;

  • unpleasant smell rot;

  • mold manifestations on the ceiling and walls of the attic;

  • rotting roofing elements;

  • appearance condensate ;

  • icing and icicles in winter.

Due to the unfavorable microclimate, living quarters, in addition to an unpleasant smell, are replete with bacteria and mold.

This is not the last disappointment, because it will soon require repair of the roof with rotten wooden structures, a soaking insulation, and the attic will not be suitable for its direct use.

To prevent unnecessary costs in the future, ventilation is done immediately after arranging the attic room. This will prevent possible harm to the health of family members and reduce family expenses. Well, even if there is no sudden collapse of the roof.

What is the ventilation of the attic room

Considering that the attic belongs to the living room, then the arrangement of this attic area should be proper. The room must be kept safe, and insulation should be carried out taking into account year-round living.

Attic under-roof ventilation, grid, device, variations, photo

The ventilation scheme of the attic floor

To ensure a favorable microclimate and comfortable conditions of stay, the ventilation of the attic under-roof space should be carefully considered. It is necessary to air not only the rooms, but also the roof itself for the long-term preservation of the roof elements in proper condition.

Ventilation of the attic room can be:

  1. Natural . In this case, natural thrust is used, which is formed when the channels and ventilation holes are correctly positioned. This is the less expensive option of all. It is equipped with grates, aerators, spotlights, ventilation pipes and other elements.

  2. Forced . It takes place with the help of mechanical impact using fans for inflow and outflow, additional devices for heating cold air from the street. This is the most expensive way to ventilate the attic room, especially when using climate equipment with wide functionality (temperature, humidity, humidity, ionization, heating indicators).

  3. Mixed . There is only one mechanical process (air inflow or outflow). Mechanical exhaust with the launch of fresh air in the form of gravity.

Attic under-roof ventilation, grid, device, variations, photo

Work ventilation of mixed type
On our site you can find contacts of construction companies that offer the service repair and design of the roof. Directly to communicate with representatives, you can visit the exhibition of houses "Low-rise Country".

Ventilation device

There are several types of under-roof space arrangement and each of them has its own ventilation technology more suitable.

For a cold roof

This is an easier option because the attic contributes to the free circulation of air masses.Vents under the eaves, under the ridge plate help the air to move naturally :

  • cold air masses are drawn into the attic from the street through the eaves;

  • warm air masses rise from the ceiling of the house upward under the roof and go out through the ridge vents.

Usually the number of vents at the top and bottom of the roof slope is the same. For normal circulation of air masses, the total area of ​​the outlet should be 1/300 of the area of ​​the slope.

With a warm roof

In this version, ventilation of the attic room is a little more complicated. This design does not provide for free circulation of air flow.

Circulation of air mass of the roofing space is carried out by convective flow, directed from the eaves to the ridge. For its smooth passage in the roofing cake between the heat-insulating and waterproofing layers, additional space is created with the use of counter grills and a batten. The height of the gap must be at least 5 cm.

Attic under-roof ventilation, grid, device, variations, photo

The additional space between the attic room circuit and directly covering the roof provides a constant flow and outflow of air

Then a ventilated circuit is formed in the space under the roof (ensuring the inflow and outflow of air masses):

  • the inflow is provided in places of the overhang bottom of the roof, above the windows of the attic, in the area of ​​the valley and other parts of the contour interruption;

  • the outflow of occurs in the area of ​​skates, under the windows of the attic on the premises, the junction where they need special accommodation.

It is necessary to ensure the continuity of the contour to eliminate the formation of "stagnant places", favorable zones for the formation of condensate.

It might be interesting! In the article on the following link, read about which roof is better for a private house.

Ventilating roofing grid

Sloping roofs, besides proper air exchange, should be equipped with nets for ventilation of the roofing space and protection from insects. Wasps, hornets, small birds can build nests in the under-roof space, which, apart from discomfort to residents, can still be detrimental to natural roofing ventilation.

The stainless steel mesh is better recognized, it is more durable and durable, although more expensive than others.

Steel meshes are subject to corrosion, rotting, rust.

What to consider when installing roof ventilation is described in the video:

Subtleties of ventilation design in the attic

Before installing aerators or mechanical hoods in the attic must be carefully thought out and the choice of the best option. The area of ​​the room, its purpose is taken into account.


Design is crucial in arranging ventilation. It is performed during construction work to avoid additional costs. Even if the construction is already completed, and ventilation is not done, it is better to equip it immediately, so as not to wait for future problems when the attic becomes unusable.

Regardless of the location of the entrance to the attic room, inside or outside the building, ventilation will be required in any case.

How to carry out the design of ventilation correctly

First of all, provide for the possibility of fresh air intake. This is influenced by the implementation of the correct design of the roof for the device of a single ventilation gap, provided by the counter lattice. It is sometimes used not solid, but intermittent (in separate segments).

Attic under-roof ventilation, grid, device, variations, photo

This is what a wood counterbattle looks like

In this case, the diffusion or micro-perforated film is not brought to the edge of the eaves, it ends just behind the wall for the free passage of fresh air masses.

Another way of inflowing fresh air is a gap around the entire perimeter of the roof between the waterproofing and the roof itself. The interval of 3-5 cm should be observed throughout the entire length, as well as at the entrance and exit. This rule is observed with the warmed roofing systems and not having a heater.

Having designed the air flow, the development of the optimal outflow variant begins:

  • the upper section of the roof is equipped with ventilation channels , point aerators, aeration turbines operating with the least gust of wind;

  • waterproofing film along the ridge girder, and make a break for easy outflow of air from under the roof;

  • if long edov (internal angle), then air is supplied along the whole line to the ventilation gap, arranging a continuous ventilation This contiguity

  • also arranges continuous ventilation of the ridges (joining elements of the roof slope) and ridges (intersections of two roof slopes).

Attic under-roof ventilation, grid, device, variations, photo

Air flow through the ridge

All necessary ventilation elements, their number, can be counted only depending from the square of its attic. All calculations are individual, because all buildings have a different roof shape, which is of great importance for the design of ventilation in the attic room.

Instructing at installation of ventilation systems

When installing ventilation attic by a professional team, they can tell about their preferences and check the work done. It is necessary to verify whether there is sufficient inflow and outflow of air.

The air flow into the attic is effectively carried out with the help of valves built into the window structures. Their device allows airing, even when the window is closed. There are valves for vertical and sloping (dormer) windows.

It may be interesting! In the article on the following link read about the types of roofs.

Roofing ventilation methods

are used for air circulation in the under-roofing space :

  • roof outlets ventilation;

  • piece roof covering with ventilation holes;

  • roof fans ;

  • ventilation gap of the roofing pie;

  • dormer windows .

Now there are a lot of roofing exits and ventilation ducts of continuous and spot type.

Attic under-roof ventilation, grid, device, variations, photo

Aerators for continuous ventilation of the roof

Continuous aerators include ridge and curtain rods, their combination brings maximum efficiency.

The operation of this scheme is wind and thermal pressure. With proper roofing ventilation within an hour, the air flow passes the entire surface of the roof twice.

Upstairs, airways are applied with roofing material so that they do not spoil the appearance and prevent precipitation.

Where does the moisture come from

The insulation can be wetted for two reasons:

  1. Due to the penetration between layers of moisture from the street ( precipitation, fog, high humidity) through the defects of the roofing carpet.

  2. Due to the formation of moisture inside the room (condensing vapors of the roofing space) through the places of damage to the layer of vapor barrier material.

Warm air contains much more moisture than cold, so in winter water vapor through the layers of the structure comes out of the interior to the outside.

In general, living quarters are saturated with vapors formed during cooking, washing, cleaning, taking a bath.

About the correct placement of the roofing layers and the ventilation system in the following video:

It might be interesting! In the article on the following link read about how to cover the roof of the house.


The installation of under-roof ventilation is an extremely important and necessary procedure that requires attention and responsibility, and that the roof of the house “does not cry” must comply with all rules and regulations.


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