Dormer window on the roof: design features (21 photos). Lucarne or roof dormer Lucarne project

Lucarna gives an expressive appearance to the roof of the building and allows you to illuminate the attic room in the daytime. Consider the features of the construction of this structure.

Lucarna (also called a dormer window) - a superstructure on a roof slope, in the front part of which a vertical window is provided. Lucarne is a decoration of the building, as well as a way to illuminate the attic and increase the volume of its space, since the roof of the lucarne is located above the slope of the main roof. Lucarna is an alternative to a roof window (or a combination of such windows), having a number of advantages and disadvantages in comparison with it. It is more interesting in architectural terms, besides, a vertical window can be opened to ventilate the room at any time of the year, while snow can lie on the roof window built into the roof in winter, which does not allow it to be opened and prevents light from entering the room. At the same time, a vertical lucarne window does not illuminate the room as evenly as an inclined attic window of the same size, since the side walls and roof of the lucarne narrow the light flux. Of course, the degree of illumination of the attic with a lucarne will depend on many factors, including the size of the window, the slope of the main roof and the method of sloping, but in any case there will be more darkened areas in the room than when using a dormer window. In addition, it is much easier to build a dormer window into the roof than a lucarne. It should be noted that its construction involves many structurally complex units, so the lucarne should be built on the basis of a detailed project, trusting the installation only to highly qualified specialists.

Design features

In most cases, the walls of the lucarne are made in the form of a frame made of wooden beams, fixed on the truss structure of the roof of the building. The width of the lucarne, as a rule, corresponds to several inter-rafter spans, which means that its device involves a gap in the truss system. In order for the roof to retain the necessary load-bearing capacity, it is necessary to strengthen it in the lucarne zone in one way or another, the choice of which is carried out by the design organization based on information about the slope length, roof slope, rafter pitch, lucarne load, etc. Often provide additional vertical racks. If the layout of the attic does not allow the presence of such racks, then reinforced unsupported runs are installed (for example, in the form of double rafter legs or beams made of glued wood) and the side walls of the lucarne are supported on them. The wooden frame of the walls is filled with insulation - usually slabs of stone or glass fiber, which are placed at a distance between the elements of the frame. In places where the lucarne frame adjoins the rafters, it is necessary to use trimmed plates, carefully sealing them during installation. According to a number of experts, this is a problem node in the design of the lucarne. Even with high-quality installation work, gaps between the plates and the wooden frame are not excluded, which is fraught with freezing of the walls of the lucarne in these areas. Moreover, the use of alternative materials capable of creating a continuous heat-insulating layer (for example, sprayed polyurethane foam or blown ecowool) is not economically justified if the main roof is insulated with stone or glass fiber slabs.

From the inside of the room, the fibrous insulation is covered with a vapor barrier film (fixing it with staples or nails to the rafters), on top of which the base for finishing is fixed, and then the finish itself. The vapor barrier is laid with an overlap of sheets of at least 100 mm, the places of overlaps and junctions of the film are sealed with special materials (one- and two-sided tapes, adhesives, pastes). From the side of the street, the thermal insulation is covered with a hydro-windproof membrane (it is also fixed with staples or nails), then a counter-lattice is usually installed, and then a substructure for exterior decoration and the finish itself. The counter-lattice allows you to provide a ventilation gap of 30-50 mm. By design, the roof of the lucarne in most cases does not differ from the main roof of the building and also involves a layer of insulation between the rafters, vapor barrier, hydro-wind protection, a ventilation gap formed by a counter-lattice, a crate (solid or step), on top of which the roof is laid. Vapor barrier and ventilation gap - measures necessary to protect the insulation and wooden elements from moisture due to the condensation of water vapor, tending from the attic towards the street. An important question when arranging the walls of a lucarne: how to organize the inflow and exhaust of air from the ventilation gap? One of the options is to connect the ventilation ducts in the walls of the lucarne with the ventilation ducts of the slope located under it, as well as with the ventilation ducts in the roof of the lucarne. Then the air will enter under the roof on the overhang of its cornice, move along the ventilation gaps and be removed either through a ventilated ridge on the roof of the lucarne, or - if it is not ventilated - through the ridge of the main roof, to which air from the roof of the lucarne should flow freely. (For this, in the design of the roof of the lucarne, in particular, gaps in the line of bars of the counter-lattice are provided so that air can freely penetrate from one inter-rafter span to another.) Recall that the air flow under the roof of the lucarne is carried out through the gaps on the overhang of its eaves or holes in its pediment . If the lucarne is small in size, and a room with high humidity is not supposed to be in the attic, then, according to some experts, it is possible to do without ventilation of its structure at all, provided that it is well-insulated and a reliable vapor barrier is created. Let us also note the following point: the lucarne itself is an obstacle to the movement of air in the ventilation gap of the main roof, and therefore, to enhance its inflow and exhaust, additional ventilation elements are installed on the roof slope (aerators, ventilation tiles, etc.). ). They are placed in front of the lucarne and after it. The more lucarens on the roof, the more difficult it is to achieve full ventilation of its structure.

Wooden frame.
Thermal insulation layer.
Vapor barrier.
Internal lining.
Hydrowind protection.
Counter-lattice.
Lathing.
External cladding

The roofs of lucarenes are distinguished by a variety of shapes. They are single, gable, gable hip (with triangular slopes), semicircular, with a curved surface (they are called "bat", "bull's eye"), etc. Depending on the architect's intention, the roof of the lucarne can be covered with both the same roofing material, as the main roof, and others. However, difficulties may arise in the arrangement of the roof of the lucaren. So, it is often problematic to use large-format or high-profile materials - ceramic and metal tiles (ordinary or composite), corrugated bitumen or asbestos-cement sheets, etc. It is more convenient to use coatings laid in a seam way (copper, zinc-titanium), as well as materials in the form of low-profile or flat tiles - ceramic or cement-sand tiles (in particular, "beaver tail"), slate, flexible tiles, piece elements made of copper or zinc-titanium (rhombuses, rectangles, plates in the form of "beaver tail"), etc. When installing the roof, special care should be taken to connect the lucarne cover to the main roof cover. So, if the roof of the lucarna is gable, then two valleys appear at the place where its slopes converge with the roof of the building. It is important to ensure the tightness of the roof both in the valley itself and at the junction of the lower edge of the valley with the slope of the main roof, as well as in the area where the roof adjoins the walls of the lucarne (using various solutions for this depending on the type of roofing material: for example, in the case of ceramic or cement-sand tiles - grooves made of painted aluminum or galvanized steel, corrugated tapes made of aluminum, lead, copper, clamping metal strips of a special profile, etc.). When there are several lucarnes close to each other on the roof, large snow “pockets” form between them and the risk of leaks under the roof increases with the capillary rise of melt water at the junction of the lucarne to the roof of the building.

Roof windows, regardless of type, are attached to the truss system of the building, and lucarnes also have a truss frame. Flat windows built into the roof are also called dormer windows. But windows are built only into the truss structure, and not to the window battens. The roof window can have a frame made of wood, plastic or metal-plastic. Lightweight skylight structures are installed by means of lower horizontal beams attached to the rafter system.

Installation and installation of skylights

When installing roof windows, it is important to maintain horizontal and vertical installation. At the first stage, the lower half of the roof window is leveled using a building level, then it is fixed in the corners with self-tapping screws. The second stage of installation aligns the length of the window and aligns the parallel with respect to the rafters, then in the corners of the window, preliminary fastenings are made on self-tapping screws that are not completely screwed in order to allow subsequent straightening. The final fastening is carried out only after the full alignment of all dimensions and accuracy of orientation of the entire window structure. The attic window will maintain a stable position with the exact alignment of the frame relative to the rafters - the distances must be equal, such alignment will allow the structure to be firmly held after being fully fixed. The last step is to once again check the accuracy of the installation vertically and horizontally and screw the screws completely.

For skylights, high-quality waterproofing is very important, durable and reliable, since the window is a structural part of the roof and takes on the same atmospheric influences as the roof of the house - snow, rain, wind, etc. Insulating materials are laid in a special way - only from the lower levels to the upper ones, for the most accurate fit to the window frame. Overlaps and excess waterproofing material are not needed, and all joints with insulation require additional fixation on self-tapping screws.

When installing a roof window in a corrugated roof, special profiled or corrugated rails with nozzles are used that fit exactly with the roof deck profiles. These nozzles are installed at the bottom of the frame and have side protrusions.

Double-glazed windows or skylight sashes are installed in the frame after waterproofing. Insulation of attic windows is carried out from the inside, from the room. Insulating materials are laid completely over the entire area of \u200b\u200bthe frame; foil heat-insulating materials serve as the top layer. Fastening is made on self-tapping screws and must be airtight and not create cold bridges, for this there is a special fastener.

Preparing to install skylights

Before installing roof windows in the design of the attic, you should familiarize yourself with their types and the capabilities of certain models. The main requirement for structures is strength and reliability, as well as complete tightness when closed - the window should not let rainwater and moisture through.

The possibilities of the attic are huge - these are additional rooms where not only bedrooms or dressing rooms are placed, but also kitchens, and even sanitary facilities. Provide street lighting, in winter - windows help to heat from the sun's rays. Cozy and practical attic rooms usually become favorite places for relaxation for all residents of the house, since the special atmosphere of the attic - height and lightness - cannot be compared with anything. The popularity of skylights is understandable and justified, since it is window structures that save money on home lighting, while at the same time giving the home an exclusive look, originality and charm.

The orientation of the roof windows is important, in accordance with the area and the climate of the area. The southern windows will give more sun, the north-western direction will allow you to hide the room from the summer heat without creating a lack of lighting. The attic and its windows must be kept in exact proportions, combined harmoniously. All parameters and dimensions of each window should be organically combined into a common architectural composition of the building. It is easy to make a house with an attic unique and make it a designer find, to a large extent thanks to the dormer windows and their diversity.

Lucarnes and their features

Lucarnes are called window openings in attic slopes and roof domes. The name is derived from the Latin word lux - light. Lucarnes have vertical frames, closed at the sides and at the top. Lucarne frames can be in the plane of the facade walls, or they can continue these walls, or be located in parallel planes. An example of a lucarne is dormers in the attic.

The advantage of lucarnes over planar window structures is the additional volume for rooms, additional areas of attic rooms with high ceilings, as well as getting a bonus - an excellent view from the attic. The view from the lucarna allows you to see not only the sky, but the entire surrounding landscape.

The house should evoke a sense of harmony and completeness with its appearance. The number, shape, dimensions and position of lucarnes are assigned based on the main parameters:

Facade and its features, both architectural and type of decoration
roof view
Roof slope

Lucarnes radically change the entire design of skylights and are the basis of the interior design of the entire attic.

Lucarne types

Lucarnes with one slope

Shed lucarnes are built into roofs that satisfy the condition - the slope of the slope must be at least 40 degrees. If the slope is gentle, then a flat lucarne with one slope will look unattractive. The flat roof of a shed lucarne can have a considerable width. This width may even be equal to the total length of the attic room. The advantage of this design is the absence of bevels on the attic ceiling, additional volume, excellent lighting and visibility. In such rooms, it is possible to arrange a workplace near an illuminated latch wall, or a place to relax.

Lucarnes with two slopes

They look great when the slope of the roof slope is more than 30 degrees. In terms of width, lucarnes with two slopes have an architectural limitation - as a rule, they do not fit more than two rafter steps. A wide gable lucarne does not really decorate the house, the roof looks heavy and “unstable”. From the inside of the attic room, such lucarnes are usually sewn up with a flat ceiling.

Lucarnes with three slopes

Such lucarnes are in a special position, they look great on roofs that have any slope angles and any shape. From below, these window models are seen as compact and not very noticeable. The most harmonious windows for any attic. The width of such lucarnes can be more than two meters, or three intervals of rafters. The ceilings of three-pitched lucarnes are made at will and for reasons of harmony in the proportions of the attic room - flat or trihedral, repeating the three-pitched roof.

Low sidewalls for lucarnes

Vertically, the wall of the lucarne can end without reaching the floor level of the attic room - up to two meters. In such cases, the roof of the lucarne will have two slopes, and the window will have five corners. The shape of the ceiling in the niche of the lucarne will repeat the outlines of the roof. Such types of lucarnes have restrictions on the placement of high interior items and furniture near the window opening, due to the low walls of the lucarne.

Triangular lucarnes

This type of roof window is small, compact, but they do not add volume to the attic. Choose a triangular lucarne in order to ensure the illumination of stairs, bathrooms or dressing rooms. From inside the room, triangular lucarnes have similar triangular ceilings, sharp broken lines.

Semicircular windows and windows in the form of "bull's eye" in lucarnes

Very soft, streamlined shapes for the exterior, interesting architecture and an exclusive look. But the restrictions on the type of roofing are only "elastic" types of tiles - bituminous, metal and ceramic tiles. View from the street - a smooth pattern and flow around the lucarne with roofing from the top and sides, and from the inside, the ceilings in the niches of semicircular lucarnes have arched, conical or cylindrical shapes.

Semi-oval windows in the form of a "bull's eye" are decorations of the main facades of houses. Very effective due to the softness of smooth lines on large roof slopes. The interior layout of a room with an oval or semi-oval window is preferable with one solid window, in this case there will be a lot of light, and the room will have attractive proportions.

The sizes of skylights and lucarnes are assigned according to the initial data:

Sanitary standards require that openings be made in such a way that glazed translucent surfaces make up no less than 12.5% of the floor area of the room, this ensures minimal insolation.
With the option of opening lucarne windows, the requirements of a safe height should be met. The lower levels of the opening frames should be located no lower than 0.85 m from the floor level. If the windows are located lower than 0.85 m, then the installation of protective metal fences is required to the specified height. The fence, in addition, should be decorative and not violate the overall appearance of the attic.
To ensure a normal view of the surroundings and comfort for the viewer, it is necessary to maintain the dimensions of the attic windows within the level of the bottom of the glazing no higher than 1.20 m, and the top to a height exceeding 1.65 m from the floor level of the room. With a height of 1.75 m, a person has a line of sight height of about 1.65 m, and in a sitting position - 1.20 m. The height of the windows can also be assigned based on the height and convenience of the residents.

Often provide additional vertical racks. If the layout of the attic does not allow the presence of such racks, then reinforced unsupported runs are installed (for example, in the form of double rafter legs or beams made of glued wood) and the side walls of the lucarne are supported on them. The wooden frame of the walls is filled with insulation - usually stone or glass fiber slabs, which are placed at a distance between the frame elements. In places where the frame of the lucarne adjoins the rafters, it is necessary to use trimmed plates, carefully sealing them during installation. According to a number of experts, this is a problem node in the design of the lucarne.

The thickness of the insulation layer in the lucarne structure must be the same as in the main roof structure.

Even with high-quality installation work, gaps between the plates and the wooden frame are not excluded, which is fraught with freezing of the walls of the lucarne in these areas. Moreover, the use of alternative materials capable of creating a continuous heat-insulating layer (for example, sprayed polyurethane foam or blown ecowool) is not economically justified if the main roof is insulated with stone or glass fiber slabs.

Remember

A lucarne is an obstacle to the movement of air in the structure of the main roof, so ventilation elements must be provided before and after the lucarne

An important question when arranging the walls of a lucarne: how to organize the inflow and exhaust of air from the ventilation gap?

One of the options is to connect the ventilation ducts in the walls of the lucarne with the ventilation ducts of the slope located under it, as well as with the ventilation ducts in the roof of the lucarne. Then the air will enter under the roof on the overhang of its eaves, move along the ventilation gaps and be removed either through the ventilated ridge on the roof of the lucarne, or - if it is not ventilated - through the ridge of the main roof, to which air from the roof of the lucarne should flow freely. (For this, in the design of the roof of the lucarne, in particular, gaps in the line of bars of the counter-lattice are provided so that air can freely penetrate from one inter-rafter span to another.)

Lucarna construction:
1. Wooden frame. 2. Thermal insulation layer. 3. Vapor barrier. 4. Internal lining. 5. Hydro wind protection. 6. Counter-lattice. 7. Lathing. 8. Exterior cladding

Recall that the air flow under the roof of the lucarne is carried out through the gaps on the overhang of its eaves or holes in its pediment. If the lucarne is small in size, and a room with high humidity is not supposed to be in the attic, then, according to some experts, it is possible to do without ventilation of its structure at all, provided that it is well-insulated and a reliable vapor barrier is created.

We also note this point: the lucarne itself is an obstacle to the movement of air in the ventilation gap of the main roof, and therefore, to enhance its inflow and exhaust, additional ventilation elements are installed on the roof slope (aerators, ventilation tiles, etc.). They are placed in front of the lucarne and after it. The more lucarens on the roof, the more difficult it is to achieve full ventilation of its structure.

“The walls and roof of the lucarne are adjacent to the slope of the roof of the building, and the places of these junctions are quite complicated in terms of design and installation. In order to avoid problems during the operation of the house, it can be recommended to the customer to demand from the design organization a detailed drawing of the lucarne structure, and also to involve only professional roofing companies for its construction. So, it is very important to correctly complete the section where the valley formed by the slope of the lucarna and the cornice overhang of this slope converge. Often, unscrupulous performers do not glue the overlaps of the hydro-windproof film here, equip the valley itself in violation of the technology, do poor-quality filing of the cornice overhang, etc. Meanwhile, snow “bags” form in this area in winter, and during the thaw there is a danger of capillary penetration of moisture under the roof. Only the correct and accurate performance of roofing work will avoid leaks in this area.

The roofs of lucarenes are distinguished by a variety of shapes.

They are single, gable, gable hip (with triangular slopes), semicircular, with a curved surface (they are called "bat", "bull's eye"), etc. Depending on the architect's intention, the roof of the lucarne can be covered with both the same roofing material, as the main roof, and others. However, difficulties may arise in the arrangement of the roof of the lucaren.

So, it is often problematic to use large-format or high-profile materials - ceramic and metal tiles (ordinary or composite), corrugated bitumen or asbestos-cement sheets, etc. It is more convenient to use coatings laid in a folded way (copper, zinc-titanium), as well as materials in the form of low-profile or flat tiles - ceramic or cement-sand tiles (in particular, "beaver tail"), slate, flexible tiles, piece elements made of copper or zinc-titanium (rhombuses, rectangles, plates in the form of "beaver tail"), etc. When installing the roof, special care should be taken to connect the lucarne cover to the main roof cover.

So, if the roof of the lucarna is gable, then two valleys appear at the place where its slopes converge with the roof of the building. It is important to ensure the tightness of the roof both in the valley itself and at the junction of the lower edge of the valley with the slope of the main roof, as well as in the area where the roof adjoins the walls of the lucarne (using various solutions for this depending on the type of roofing material: for example, in the case of ceramic or cement-sand tiles - grooves made of painted aluminum or galvanized steel, corrugated tapes made of aluminum, lead, copper, clamping metal strips of a special profile, etc.).

When there are several lucarnes close to each other on the roof, large snow “pockets” form between them and the risk of leaks under the roof increases with the capillary rise of melt water at the junction of the lucarne to the roof of the building.

An alternative to lucarnes - installed on roofs with a slope of 15 to 90s. Their frame and sash are most often made of glued wood. Double-glazed windows are usually single-chamber, energy-saving. For hermetic connection of the window with the roof, as well as for draining rainwater from the window, the window is completed with a salary (in the standard version - aluminum with a polymer coating), suitable for a certain roofing material. You can install a combination of windows on the roof.

A dormer window is nothing more than the most common window located on the roof of a house. Each of us can see it in the nearest private house with an attic, which is why it is called a dormer window in the common people. But this modern name is not suitable for the windows present on buildings and cathedrals built in past centuries. They are the progenitors of modern such windows. And they called them an interesting word - lucarne.

Dormer photo

Lucarna: what is it?

A dormer or a lucarne is the same thing, but they are separated by a time frame. Lucarne was widely used in the architecture of the 19th-20th centuries, but it is known that it began to be used as early as the 15th century in England on roofs with a gabled structure. Lucarna has its own distinctive features - it is a superstructure on the roof of the house, in the front part of which a window was installed. The facade itself was decorated with lush stucco and was the hallmark of the whole house. Later, this unique architectural element began to be used on the roofs of rich houses and seemed to signal the status of its owners.

Lucarne window photo

The word lucarne is French (lucarne), but has a Latin origin from the word lux - light. The practical significance of the design: at that time it was the only way to provide lighting for the attic, if we exclude torches and candles.

Lucarna photo

Dormer window: why is it called that and what is it for?

A dormer window is already the domestic name for a window on the roof, it is designed less pompously and is more likely to have a practical meaning than an aesthetic one. There are two versions of why this window was called that:

First version: earlier the word "hearing" had a slightly different meaning and meant an opening, an opening. Which explains the purpose of such a window - lighting with natural light and airing the room.

Second version is directly related to the name of the master Slukhov, who during the reign of Alexander I managed the work on the construction of the roof on the Moscow Manege. According to this version, the roof of the building was originally built without a ventilation system, which led to its deformation under the influence of external environmental conditions. Later, when the tsar himself found out about this, Rumors soon corrected the situation by building such windows, which were named after him.

Dormer photo

Dormer window on the roof photo

Dormer window on the roof: shape and design features

The traditional dormer window with the whole structure, when viewed from the side, resembles a house. After all, it has exactly its shape, so the lucarne performs not only the function of lighting and ventilation, but also increases the space in the attic. In addition, it is much easier to open such windows, since hinged frames are used for them, and not sliding ones, as with modern skylights installed in the roof plane. Therefore, they are called vertical dormer windows.

Dormer window on the roof photo

Such a lucarne window can be located in any part of the roof of a modern house, no matter if it is the main plane or the end. Its size and shape are also determined by the design features of the roof and the style of the exterior of the whole house. The height of the roof and the area of the attic are also taken into account. And of course they are not built on roofs with a small angle of inclination.

roof window

Another type of lucarni is a recessed window into the superstructure structure. This is usually done on large windows to build a balcony. The only disadvantage of this design is that it does not increase the living space. Therefore, it is relevant only in the attic of a large area.

Lucarna photo

A dormer window can also be made in the plane of the roof, which gives them the right to be called dormer windows. They are good because they do not form an additional structure on the roof, which in turn facilitates its cleaning from snow in winter. Also, such windows increase the degree of illumination of the attic by exactly half. Therefore, they are not recommended to be arranged on the sunny side of the roof, but on the shady side they are very welcome. But it is worth saying that such windows require good waterproofing with a precipitation drainage system and, of course, are supplied with no less high-quality thermal insulation.

Roof window photo

It is also worth mentioning that lucarne windows can have a very different shape, in addition to traditional squares and rectangles, in architecture you can also find them in a triangular shape, polygonal, round and oval. This diversity is due to the peculiarities of the exterior style.

Lucarna on the roof

Dormer windows or lucarne windows have firmly entered the architecture of suburban private construction. It is worth saying that they can be built already on the erected house, it is only necessary to change the design of the truss system. Well, when erecting them, it is worthwhile to strictly focus on the features of the roof and, in general, the entire architecture of the building is taken into account.

Dormer window on the roof photo

Lucarna is an alternative to a roof window (or a combination of such windows), having a number of advantages and disadvantages in comparison with it. It is more interesting in architectural terms, besides, a vertical window can be opened to ventilate the room at any time of the year, while snow can lie on the roof window built into the roof in winter, which does not allow it to be opened and prevents light from entering the room. At the same time, a vertical lucarne window does not illuminate the room as evenly as an inclined attic window of the same size, since the side walls and roof of the lucarne narrow the light flux. Of course, the degree of illumination of the attic with a lucarne will depend on many factors, including the dimensions of the window, the slope of the main roof and the method of sloping, but in any case there will be more darkened areas in the room than when used. In addition, build a roof window into the roof much easier than a lucarne. It should be noted that its construction involves many structurally complex units, so the lucarne should be built on the basis of a detailed project, trusting the installation only to highly qualified specialists.

Visualization: Mavlyuda Melnikova/Burda Media

Lucarne - a structure that should form a single whole with the roof of the building. This means that when installing a lucarne, it is necessary to hermetically connect its roof to the main roof, perform high-quality insulation and installation of vapor and waterproofing, and, if necessary, provide for ventilation of the walls, roof of the lucarne and additional ventilation elements for full ventilation of the main roof structure in the area where it is interrupted by a lucarine. I will note an important point: when creating a vapor barrier, all seams and joints should be glued with special materials (tapes, adhesives, pastes). Their choice depends on the type of surface to which the vapor barrier film adjoins. In particular, on rough substrates (e.g. unplaned wood), the film is glued with adhesives and pastes. The use of one- and two-sided tapes in this case is unacceptable.

Valery Nesterov

CEO of Dörken

DESIGN FEATURES

Filled with insulation - usually stone or glass fiber slabs, which are placed at a distance between the frame elements. In places where the frame of the lucarne adjoins the rafters, it is necessary to use trimmed plates, carefully sealing them during installation. According to a number of experts, this is a problem node in the design of the lucarne. Even with high-quality installation work, gaps between the slabs and the wooden frame are not excluded, which is fraught with freezing of the lucarne walls in these areas. Moreover, the use of alternative materials capable of creating a continuous heat-insulating layer (for example, sprayed polyurethane foam or blown ecowool) is not economically justified if the main roof is insulated with stone or glass fiber slabs.

When constructing a lucarne, it is important to consider the issue of ventilation of its roof. This is a measure to protect the fibrous insulation and wooden structural elements from moisture. The flow of air under the roof is usually organized due to gaps in the overhang of the eaves and / or holes in the gable of the roof. In order to achieve effective ventilation of the roof, in many cases two contours of the counter-lattice are arranged (it is its bars that create gaps for air movement), placing them in two directions. The first contour is perpendicular, and the second is parallel to the cornice overhang. This is guaranteed to ensure the movement of air entering under the roof from both the cornice and the gable. For the hood, depending on the shape of the roof, it is possible to provide a ventilated ridge or pitched ventilation elements installed in the upper part of the roof slopes. Another option is to direct the air flow into the main roof slope, from where it will be removed through a ventilated ridge. To do this, the ventilation gaps of the roof of the lucarne are combined with the ventilation gaps of the roof of the house.

Mikhail Chernyshov

Head of Technical Service at Rheinzink

An important question when arranging the walls of a lucarne: how to organize the inflow and exhaust of air from the ventilation gap? One of the options is to connect the ventilation ducts in the walls of the lucarne with the ventilation ducts of the slope located under it, as well as with the ventilation ducts in the roof of the lucarne. Then the air will enter under the roof on the overhang of its cornice, move along the ventilation gaps and be removed either through a ventilated ridge on the roof of the lucarne, or - if it is not ventilated - through the ridge of the main roof, to which air from the roof of the lucarne should flow freely. (For this, in the design of the roof of the lucarne, in particular, gaps in the line of bars of the counter-lattice are provided so that air can freely penetrate from one inter-rafter span to another.) Recall that the air flow under the lucarne is carried out through the gaps on the overhang of its eaves or holes in its pediment.

If the lucarne is small in size, and a room with high humidity is not supposed to be in the attic, then, according to some experts, it is possible to do without ventilation of its structure at all, provided that it is well-insulated and a reliable vapor barrier is created. We also note this point: the lucarne itself is an obstacle to the movement of air in the ventilation gap of the main roof, and therefore, to enhance its inflow and exhaust, additional ventilation elements are installed on the roof slope (aerators, ventilation tiles, etc.). They are placed in front of the lucarne and after it. The more lucarens on the roof, the more difficult it is to achieve full ventilation of its structure. The roofs of lucarenes are distinguished by a variety of shapes. They are single, gable, gable hip (with triangular slopes), semicircular, with a curved surface (they are called "bat", "bull's eye"), etc.

The walls and roof of the lucarne are adjacent to the slope of the roof of the building, and the places of these junctions are rather complicated in terms of design and installation. In order to avoid problems during the operation of the house, it can be recommended to the customer to demand from the design organization a detailed drawing of the lucarne structure, and also to involve only professional roofing companies for its construction. So, it is very important to correctly complete the section where the valley formed by the slope of the lucarna and the cornice overhang of this slope converge. Often, unscrupulous performers do not glue the overlaps of the hydro-windproof film here, equip the valley itself in violation of the technology, do poor-quality filing of the cornice overhang, etc. Meanwhile, snow bags form in this area in winter, and during the thaw there is a danger of capillary penetration of moisture under the roof. Only the correct and accurate performance of roofing work will avoid leaks in this area.

Konstantin Simonov

CEO of Skif

Depending on the architect's intention, the roof of the lucarne can be covered with the same roofing material as the main roof, or with another one. However, difficulties may arise in the arrangement of the roof of the lucaren. So, it is often problematic to use large-format or high-profile materials - ceramic and metal tiles (ordinary or composite), corrugated bitumen or asbestos-cement sheets, etc. It is more convenient to use coatings laid in a seam way (copper, zinc-titanium), as well as materials in the form of low-profile or flat tiles - ceramic or cement-sand tiles (in particular, "beaver tail"), slate, flexible tiles, piece elements made of copper or zinc-titanium (rhombuses, rectangles, plates in the form of "beaver tail"), etc. When installing the roof, special care should be taken to connect the lucarne cover to the main roof cover.

Alternative to lucarnes

An alternative to lucarnes is skylights. They are installed on roofs with a slope of 15 to 90 °. The frames and sashes of skylights are usually made from laminated timber. Double-glazed windows are usually single-chamber, energy-saving. For hermetic connection of the roof window with the roof, as well as for rainwater drainage, the product is completed with a salary (in the standard version - aluminum with a polymer coating), suitable for a certain roofing material. It is possible to install a combination of skylights on the roof.