What is a dormer window for? Dormer window on the roof: step-by-step installation instructions

Dormer windows are most often installed in the roof to provide ventilation in the attic or attic space. At the same time, they are one of the design elements of the roof and building.

Dormer windows (dormer) on the roof, design, drawings of which may differ, depending on general outline They are a glass frame arranged in the roof plane. Thanks to the large number of design solutions for such windows, each building has its own original style, individual appearance.

In this article

Varieties, design features, use of dormer windows

Such window structures are mainly intended for pitched roof structures. Attic (sloping) products, in addition to ventilation provision, are intended to be created in a living space arranged directly under the roof of a house, natural light.

The first window structures mounted on the roof were intended solely for attic ventilation. Today, when attics began to be converted into living rooms, dormer windows perform additional functions:

They provide an opportunity to get out onto the surface of pitched roofs.
Serve for ventilation of the attic, attic room, provide them with natural light.
In small attics with a low roof, dormer windows provide an opportunity to increase space. If the walls start from the floor, at the same time the approach to the window openings is easier.
Attic options give the roof a special attractiveness, unusualness, and also allow you to create an original layout residential premises under the roof.

Types of dormer window designs

The type of dormer window is selected depending on design features the roof itself:

Application

The main function of dormer windows is to ventilate non-residential attic spaces to prevent rotting wooden elements roofing structure.
They are also used as an emergency exit to carry out repair work on the roof.
If the attic is converted into living room, then dormer windows are used for natural daylight. According to experts, such openings allow less light to pass through, unlike attic windows (the side walls prevent the penetration of sunlight into the room).

Roof window options

Viewing windows can be mounted on almost any type: single-, gable-, broken, etc. There are many options for combining roofing structures with window openings different sizes, geometric parameters. They can be placed on the roof surface itself and on the pediment.

When selecting the design in the drawing, it is worth taking into account the need to equip the drain with additional gutters. The roof slope in this case should be at a slope of about 5-15º.
Quadrangular window structures for single- and gable roofs are structurally similar to products for a flat roof, but the roof slopes must be at a slope of 15º or more.
Triangular options are often used for roofing dachas, country houses. Here the slopes replace the side walls. In such a situation, during installation there are fewer joints, which means less light enters the attic (attic) space.
The windows are quite attractive round shape, give to the general appearance unusual structures.
An interesting option is a skylight. Differs in appearance, its own performance characteristics. As a result, the building becomes visually much lighter, airier, and a large amount of natural light penetrates the room.
Attic options can be mounted between the rafters. They are used when the slope slope is 15-20º. But they create a barrier to water flow, so their design is quite complex. It is almost impossible to make such a window structure yourself, so it is better to order it from specialists.

Design of standard dormer windows

The traditional option is a roof superstructure that resembles a small house. In this case, a rough calculation of the parameters is made according to the attic illumination technology. Products are installed only without disturbing the beam system, so several windows are usually installed between the beams. They are made of glass, louvered.

When arranging window structures based on blinds, the opening can be combined with ventilation system. For normal ventilation of the attic space in a natural way, it is enough to temperature difference between the street and the room was 5-10º. If the difference is greater, then condensation becomes more intense, which requires the use of additional material in the “roofing cake” that is able to regulate the level of humidity.

Dormer windows on the roof, two types of designs

Shed structures for flat roofs, slope slope of about 15º. The water flow is directed towards the window opening. This simple design, but in this case it is necessary to arrange a significant overhang of the roof over the house in order to prevent water from leaking.
Gable dormer window designs are more complex. Here it is necessary to correctly calculate the joining angles of the roof. But, if all seams are properly sealed, the water flow will be distributed more efficiently. Products with a dome or radius design look solid - these are also options for gable windows.

In order not to disturb the harmony of the roof design, materials similar to roofing are used to produce roof windows. At the same time, their installation is carried out both during the construction of a new roof, but also when repairing an old one.

Construction, frame installation

Installation begins with the creation of a frame onto which it will subsequently be attached. But it is not considered a separate component, but is designed as a component of the overall frame of the roof structure, the basis of which is the ridge beam and the rafter system.

Recommendation. In areas where dormer windows are installed, the rafters are significantly strengthened (double and triple rafter legs are installed). This is necessary to increase the rigidity of the structure as a whole, according to the safety of its operation.

Installation technology

In accordance with building codes, the lower rafters are cut flush with the plane of the main structure.
Installation of double beams, which are mounted between double rafters. To prevent a decline strength characteristics structures, cutting into rafter beams is not permitted.
During the installation of the dormer window ridge beams, the gable frames are checked for verticality.
A pair of rafter legs is cut out according to the template, then they are fixed to the gables of the window structures.
The frame is covered with waterproof construction plywood.

It is necessary to cut out a section of the roofing pie very carefully so as not to damage waterproofing material main roof structure.
It is better to finish the walls with steel siding, which can provide not only a solid appearance, but also reliable protection from atmospheric precipitation, wind loads.
All connections and joints of structural elements must be treated with sealant.
It is forbidden to make inserts, otherwise the strength will decrease load-bearing structure. You can only use nails, staples, overhead parts (corners, metal strips).
For the manufacture of frame structure materials and dimensions are used that are determined by the project drawing. It is not recommended to save on size - this may have a negative impact on finished design, which during operation may not withstand snow and wind loads.
If the roof area allows, window openings can be placed in several rows.
The higher the viewing window is installed, the better the attic space will be illuminated.
To construct the frame, you must use only quality wood: well dried, treated with special protective compounds.

Conclusion

When installing dormers, it is important to fit them harmoniously into the concept of the building itself. The same roof slopes, repeating decorative components, the same type of roofing material change the appearance of the building as a whole, giving it solidity and attractiveness.

Dormer windows are an almost integral attribute of many buildings of the last century with a pitched roof. The purpose of this element is not clear to everyone, so today we will understand the purpose, functions and necessity of constructing such windows in a private home.

What is a dormer window

The very phrase “dormer window” can be misleading, because it is not intended to listen to anything. The fact is that previously the word “hearing” was given an alternative meaning: opening, vent, that is, in fact, it meant a hole.

Dormer windows are installed in pitched roofs and there are several types. The most popular windows are those protruding from the slope to form a triangular pediment. Some modifications are supplemented with straight walls at the base, while the front part acquires a “house” profile. Depending on the architecture of the building and the configuration of the roof, dormer windows can have an arched ceiling, be covered with one longitudinal slope, and even have panoramic glazing- in a word, take any form necessary for the unity of the architectural style.

Dormer windows can also be considered dormer windows, but they have a slightly different purpose and design. The main structural difference is that the window is framed with a sealing contour and special flashings, while between the covering of the dormer window and the slope, standard methods of making roof connections are used - ridges and valleys. On the other side, dormer window provides complete lighting, it is also subject to high energy saving requirements, which is often not important for a conventional dormer window.

Purpose and functions

But why then do you need a dormer window? To answer this question, we should consider the thermal engineering model of the roof and attic floor in summer and winter.

During the cold season, when the building is heated from the inside, a certain amount of heat and water vapor penetrates through the ceiling. The attic, operated in cold mode, acts as a sealed airlock, eliminating the effect of wind on the thermal protection circuit and slightly increasing the temperature of the outside air.

However, steam entering a confined space does not go unnoticed: moisture freezes on the supporting structure and the underside of the roof because it does not have the opportunity to evaporate into the air. external environment. Thanks to the dormer windows in the attic, moderate air exchange with the street is maintained without intense flows, so the overall thermal regime of the roof does not change too much, but frost does not form.

In summer, the dormer window promotes active ventilation of the under-roof space and cooling of the attic floor. This effect may seem insignificant, but history knows many examples when dormer windows turned out to be incredibly useful. One of these was the re-equipment of the roof of the Moscow Manege, where the damage to the finishing of the ceiling of the upper floor due to overheating was eliminated by inserting dormer windows. There is an opinion that the name of the windows comes from the name of the foreman who led the team of roofers involved in this project.

It should be noted that the presence of dormer windows allows you to create a warm attic that remains airtight in winter time and is ventilated in summer. In addition, through the dormer windows in attic space hits sufficient quantity light for inspection of ceilings and rafter system. There is also access to the roof surface through the dormer openings.

Device Features

When installing a dormer window in the roof, three things need to be taken into account: the most important nuances: insertion height, connection with the rafter system and abutment roofing. With the height of the inset, everything is simple: in the area of the mauerlag there is an irrationally used volume of the under-roof space, so in most cases it is advantageous for the bottom of the opening to be located at the level of the attic floor. However, if the roof has a long eaves overhang or the rafter system is on a parapet, the window will inevitably crash at some height.

The width of the dormer window is limited by the distance between the rafters. Inserting a window on the section of the slope that intersects rafter leg, inevitably necessitates strengthening the supporting system, installing additional struts and racks. Of course, there are roofs with frequent rafter pitches and in such cases modification of the rafter system is inevitable; however, it is preferable to install several small windows rather than one large one.

Modern roofs, modern approach to their design, and the dormer windows remain unchanged. Why are dormer windows needed, is it possible to do without them, and in general, what is a dormer window? Such questions often arise during the construction of hipped roofs, the answers to which sometimes even from specialist builders are not so clear as to realize the true need for a dormer window.

What is a dormer window

A birdhouse or dormer is a small structural element (window) or attic roofs. This window has a lot of original names: rooster, train, bull's eye, bat, gnome's house, hatch, dormer. At first, the window was designed only for the purpose of ventilation of the attic space, but over time it began to serve as natural spring light in the attic, and acquired its functional and decorative significance.

Natural lighting of the attic floor gives the main determination of the location of the dormer window - the southern direction. Since the main purpose of the “gnome house” is to receive high-quality ventilation and lighting, then like this architectural element never located on the north side. Some countries have even developed recommendations on its shape, location and even decoration. Often the dormer is replaced with a large vent, which significantly changes the roof design without functional changes.

Why do you need a dormer window?

As already written above, the main function of the dormer window is to ensure sufficient ventilation of the attic. But what happens if you ignore the design recommendations and do not install, at a minimum, a ventilation duct:

1. Even with high-quality interfloor thermal insulation, heat loss into the attic space is inevitable. This heat cools sharply in the attic and falls out in the form of condensation, which, if there is insufficient ventilation, affects its accumulation.

2. A complete lack of lighting provokes the accelerated formation of mold and mildew, not to mention such unpleasant creatures: spiders and others. Therefore, even a very clean house owner, if there is no dormer window in the attic, will constantly experience such unpleasant factors.

3. Justification of the need for a dormer window from the point of view of physics and construction fundamentals:

The roof is the weakest element of the building; strong winds constantly try to destroy it, and when the roof structure is rigid enough, the wind tries to lift it.

The question arises: “How is this?”

It’s very simple: a strong wind, due to the speed of the air flow, causes a vacuum above the roof, but under the roof without a dormer window the pressure does not change (the air stands still).

Therefore the roof is like balloon tries to rise, and accordingly, the higher the wind speed, the more this phenomenon manifests itself.

Even if heavy weight roof and her Vibration inevitably appears, which negatively affects the entire structure.

From the point of view of practical construction in conditions of inclement weather weather conditions The dormer window is a kind of overpressure valve, i.e. a strong flow of wind will knock out the windows faster, thereby balancing the pressure, rather than lifting the entire roof.

Design of traditional dormer windows

1. The classic manifestation of a dormer window is a roof superstructure in the form of a small house. Moreover, a rough calculation of the size of the dormer window is carried out according to the rules of room illumination: the size of the windows should be about 10% of the area of the room and no more than 0.5 of the width of the wall.

2. Since dormer windows must be installed without disturbing or changing the beam structure, most often several windows are built in the spaces between the beams, and it is necessary to take into account the safety of ventilation wooden structures in the under-roof space.

3. Dormer windows are made either glazed or simply louvered, and the window opening is often combined with a ventilation system based on blinds. Sufficient ventilation of the attic space is considered to be a temperature difference of 5-10 degrees relative to the street. With a greater temperature difference, the appearance of condensation will be more pronounced, which will require the use of materials in the roof that can regulate humidity.

4. Structurally, dormer windows are mainly of two types:

Shed - the roof is made flat with a roof slope of about 15 degrees, which creates a flow of precipitation towards the window. This design is distinguished by its ease of manufacture, but for greater reliability against leakage it is necessary to provide a sufficient overhang of the roof over the house itself, which from the outside looks slightly comical (a large hat on a small head).

Gable roof structures are more difficult to manufacture due to the need to organize the correct joining of roof parts at different angles. But provided that the seams are properly sealed, they are more practical (water flow is better distributed) and visually more logical. As a variation of the gable dormer window structure, a radius or dome roof is often made, which looks more solid.

5. For the manufacture of dormer window structures so that they are not disturbed , use similar materials with the roof. Moreover, the installation of dormer windows is useful both on newly constructed roofs and on those requiring repair.

Dormer windows on the roof are installed as a source of natural light and ventilation in attics and attics. And thanks to all kinds constructive solutions they also perform an aesthetic function - the facade of the house acquires an attractive and finished appearance.

Functional purpose

Houses with a roof with a dormer window always stand out from the general development with their original, unique appearance.

Dormer windows make the building stand out from the background of ordinary houses

What is a dormer window for? Its main function is to provide ventilation and lighting of the under-roof space. When choosing the location of the source of natural light in the attic or attic, it is important to take into account the orientation of the future dormer window to the cardinal points. It should face south, then all the requirements for natural insolation of the room will be achieved.

The attic window can be replaced with a ventilation grille. The absence of even a minor element in the roof structure ventilation duct will entail significant troubles:

Heat loss will inevitably occur into the attic space, where when the air cools, condensation forms, which, due to the lack of ventilation, will accumulate in a closed room.
Due to the lack of lighting, mildew and mold will spread very quickly in the attic.

The grille can be installed on the facade of the house from any material. These can be brick, wooden, block houses.

The attic grill serves as a replacement for the dormer window

Also, a dormer window on the roof can provide access to the roof for repair or installation work.

If we talk about the architectural appearance of the building, then a hip, hip or half-hip roof by its very design suggests the installation of dormer windows.

What are they?

There are different solutions. The window structure can be built into the roof plane or it can be vertical glazing.

The use of small triangular, arched and trapezoidal openings with a fully glazed vertical plane is common.

Dormer windows on the roof, the structures of which have side walls, vary depending on the type of roof:

flat;
quadrangular single-pitched;
quadrangular gable;
triangular;
semicircular;
panoramic trapezoidal;
light lanterns;
round.

Single-pitch

This is the simplest type, characterized by the presence of a flat roof, the slope of which is less than the slope of the roof.

At the lean-to window flat roof with a slight slope

It is characterized by the presence of sufficient space under the ceiling compared to the gable option. When installing it, attention should be paid to providing high-quality drainage for rainwater and other precipitation. The disadvantage of a small slope is the reduction in the number of options roofing materials, which can be used.

The traditional solution is a window located in the wall plane on a gable roof.

The gable window design significantly reduces the space under the roof

The design itself gable roof characterized by small headroom. The window can have a pointed or rounded shape. Complex design will require greater financial costs than a single-pitched one. The downside is that the space under the roof will actually decrease.

The external design of a hip window evokes an association with a measured and comfortable life. The angle of inclination of the structure and the roof repeat each other.
The arched design gives the appearance of the house the atmosphere of a mansion. In addition to the horizontal placement of dormer windows, vertical placement is possible.
A window called "skylight" will give appearance buildings of visual lightness and airiness.

Panoramic windows on the roof provide high visibility and maximum natural light.
Fencing side surfaces trapezoidal windows are covered with roofing material.
A window called a “bat window” is better suited for window designs with a slight slope.
Dormer windows do not serve to decorate the facade. They perform the practical task of providing the attic living space with sufficient natural light and fresh air. Installation of these windows will not require the construction of auxiliary structures. In terms of waterproofing qualities, modern window systems are reliable and durable.

"Bat"

Constructive decisions

There are several basic layouts for dormer windows:

Design and installation

Before starting design, you should familiarize yourself with the requirements of SNiP II-26 and SNiP 21-01. Why do this? Compliance with them guarantees that the constructed structure will meet the requirements of reliability and durability, while the roof parameters will not lose the reliability and quality of their technical parameters.

SNiP conditions regarding the construction of dormer windows:

The roof slope must have a slope of 35 degrees - in this case, installation is considered possible.
If it is necessary to erect a superstructure, it is important to take into account the distances recommended by the standards from the external building envelope.
The minimum size of the sashes that open and are located on the window is considered to be 0.6 by 0.8 meters, therefore, the permissible parameters of the roof window will be 1.2 by 0.8 meters.
It is impossible for the window façade to hip roof and a quadrangular opening continued the wall of the building.

GOST assumes the use of different facing materials: copper, sheet metal, roof tiles. Windows can be equipped with overhangs, their own roofing or gutters.

In some cases, it is possible to arrange a balcony on the roof

If the opening is of sufficient size and there is a building envelope, it is possible to construct a balcony.

Frame development

After determining the parameters of the opening, it is necessary to begin developing a drawing of the future structure, which should be not only functional, but also aesthetically attractive.

The width of the auditory opening is taken so that it exceeds half the width of the attic room.

Frame installation

The installation of a dormer window should occur at the stage of installation of the load-bearing system of the main roof of the building.

Structurally, the dormer opening is a roof in miniature. Its roof is equipped with its own load-bearing structures, lathing and, if necessary, a ridge.

The window frame contains the same elements as the roof truss system

First of all, gables are made on the roof surface. Then the ridge beams and rafters are fastened, and openings are made in the designated places.

It is necessary to fence the openings using strong rafters, which will distribute the main load. The rafters can be double or triple.

The racks are placed on the beam located below, connected at the top using a block. As a result, the structure must be connected using beams to the upper beam.

The result will be a frame that does not yet have its own rafter system.

To ensure that the rafters do not lose their load-bearing capabilities, all elements must be fastened using metal fasteners.

After checking the frame in all directions, you can begin installing the ridge beam and the supporting roof structure.

Peculiarities

Moisture-resistant material is used to cover the side walls of the structure. The roof covering is laid at the stage of installation of all roofing material.

To avoid leaks, it is important to properly waterproof the joints using membranes, silicone sealants, clamping strips.

Dormers can be seen on many pitched roofs. Let's find out the purpose, functions and whether it is necessary to build such windows in a private house.

What is a dormer window

Dormers are installed in pitched roofs and come in several types. The most popular windows are those protruding from the slope to form a triangular pediment. Some modifications are supplemented with straight walls at the base, while the front part acquires a “house” profile.

Depending on the architecture of the building and the configuration of the roof, dormer windows can have an arched ceiling, be covered with one longitudinal slope, and even have panoramic glazing - in a word, take any shape necessary for the unity of the architectural style.

On the other hand, a roof window provides full lighting; it is also subject to high energy saving requirements, which is often not important for a conventional dormer window.

Purpose and functions

But why then do you need a dormer window? To answer this question, you should consider the thermal engineering model of the roof and attic floor in summer and winter.

However, the entry of steam into a confined space does not go unnoticed: moisture freezes on the supporting structure and the underside of the roof because it does not have the opportunity to evaporate into the external environment.

Thanks to the dormer windows in the attic, moderate air exchange with the street is maintained without intense flows, so the overall thermal regime of the roof does not change too much, but frost does not form.

One of these was the refurbishment of the roof of the Moscow Manege, where the damage to the finishing of the upper floor ceiling due to overheating was eliminated by inserting dormer windows. There is an opinion that the name of the windows comes from the name of the foreman who led the team of roofers involved in this project.

It should be noted that the presence of dormer windows allows you to create a warm attic, which remains sealed in winter and ventilated in summer. In addition, through the dormer windows, a sufficient amount of light enters the attic space to inspect the ceiling and rafter system. There is also access to the roof surface through the dormer openings.

Device Features

When installing a dormer window in the roof, three important nuances must be taken into account: the height of the insert, the connection with the rafter system and the junction of the roof covering. With the height of the inset, everything is simple: in the area of the mauerlag there is an irrationally used volume of the under-roof space, so in most cases it is advantageous for the bottom of the opening to be located at the level of the attic floor.

However, if the roof has a long eaves overhang or the rafter system is on a parapet, the window will inevitably crash at some height.

The width of the dormer window is limited by the distance between the rafters. Inserting a window on a section of the slope that is intersected by a rafter leg inevitably necessitates strengthening the supporting system and installing additional spacers and racks.

Of course, there are roofs with frequent rafter pitches and in such cases modification of the rafter system is inevitable; however, it is preferable to install several small windows rather than one large one.published

If you have any questions on this topic, ask them to the experts and readers of our project.