25.11.201727.05.2017

Textbook Edited by Doctor of Economics, Professor A.N. Asaula. - SPb .: Humanistika, 2005 .-- 288p.

Section 2. Reconstruction and modernization of residential buildings

Chapter 6. Modernization of functional purpose and design solutions of apartments, adaptation of dormitories and non-residential facilities for apartment buildings

6.2. Installation of attic floors

Special types of reconstruction include changes in the volume of buildings, their movement, lifting and demolition. They are used as urban planning measures when they want to change the density of the housing stock and buildings or the position of the house on the ground, free up the site for punching a highway, building a new building or landscaping the territory.

The volume of buildings is changed by building on them or erecting a number of extensions and outbuildings.

A superstructure is an increase in the number of storeys of a house or its parts. The use of the third building dimension is an effective measure, since it allows to increase the usable area of \u200b\u200bbuildings without compaction of the building area, and this intensifies the use of urban land. Such an event is possible even in a densely built-up area, which is important for the reconstruction of the central districts of cities, where land is valued not only in terms of prestige, but also the cost of rent.

The decision to increase the height of the building is usually made taking into account the urban planning restrictions imposed by the concept of the territory development. First of all, there is a restriction on the number of storeys and population density.

Superstructures are of particular importance as a means of creating unified ensembles. The number of storeys of buildings can be leveled by the superstructure of some of them, partial and complete. Or vice versa, one of the volumes is underlined, for example, a corner house at the intersection of streets. If at the same time the gaps between buildings are filled, then the building takes on a finished look.

The superstructure is simplified when the floors in adjacent buildings are located at the same level. However, combined solutions are also possible in buildings with floors at different levels. In these cases, the vertical displacement of window openings must be masked by horizontal divisions of facades, decorative spots or other architectural techniques.

There are three types of uses for the third dimension of a building - its height:

1) the device of attics, that is, the location of housing in the under-roof space, in the place of the rebuilt attic;

2) the superstructure itself;

3) placement on a functionally operated roof of a recreational space, which allows you to create places for outdoor recreation. It kind of expands the adjoining plots, which is important in the conditions of densely built-up territories.

Terrace layout - open space on the roof of the apartments top floor varied. Usually lawns, areas for recreation and games are laid, pergolas or gazebos are installed.

An example of such a solution is Fig. 6.8. Here the apartments are equipped with an over-roof terrace with an area of \u200b\u200bonly 20 m. However, in the practice of urban planning there are examples of exploited roofs with significant landscaping.

a - the first tier; b - the second tier.

Figure: 6.8. -Recreational areas on a flat exploited roof of a pre-revolutionary building, the upper floor of which, together with the roof space, was turned into a solution with bunk apartments

They create not only summer gardens, but also winter gardens and greenhouses. In urban planning, the principle of multi-level organization of the landscape in the dense development of city centers is gradually being established. Man-made "above-ground territories" are used. In relation to this, the term "artificial gardening" was formed in landscape architecture. Green spaces that cannot develop naturally are supported by engineering and biological means, by creating artificial foundations, favorable regimes: insolation, aeration and temperature and humidity.

During terraced construction, additional loads appear, therefore, strengthening of the supporting structures is required. At the same time, a promising increase in green mass and root system is envisaged, which occurs as the plantings grow.

Attic device.

Atticare satisfied using four methods. The easiest way to place them is in buildings where the upper floor is technical. Its height is then used as part of the height of the housing (Figure 6.9 a).According to the second method, the last floor of the house is converted into the lower floor of a bunk apartment, which makes it possible to place the sleeping area of \u200b\u200bthis apartment under the new roof (Fig.6.9 b).

a - over a building with a technical upper floor; b - with the device of two

Figure: 6.9. - Attic device options

storey apartments by converting the existing upper floor into a daytime zone and placing a sleeping area in the under-roof space; in - with the placement of two-storey apartments under a high roof; r - a solution that combines the attic with the superstructure of one floor.

The reconstruction according to the third method provides for one- or two-story apartments to be entirely located under a roof with broken slopes (Fig.6.9 in),but with inclined outer walls. According to the fourth method, the attic is combined with the superstructure of one floor (Fig.6.9 d).

In all variants in Fig. 6.9. shows solution schemes with two-story (bunk) apartments. When designing apartments on one level, the principle of placement of under-roof housing is preserved. The choice of this or that solution depends not only on the social order of users, but also on the possibility of installing an elevator, since according to the current standards, the floor marks of the entrances to the apartments of the upper floor and to the vestibule of the staircase should not differ by more than 13.5 m.

Windows in the attic rooms are easiest to lay along the slope of the roof slope (Fig. 6.10 a).However, methods of their vertical installation are more often used (Fig. 6.10 b-d).In one case, the lintel is extended as shown in Fig. 6.10 b,in the other, it is installed in a plane that is built up along the height of the facade wall (Fig. 6.10 in).Often the lintel of a vertical window opening with a door is left in the plane of the roof slope. Then part of the outer fence - the walls are pushed into the building, and a balcony is arranged in front of the window, shown in Fig. 6.10 r,and sometimes an increased drain - a roof over this balcony, the width of which can reach 1.5 m.

a - in the plane of the roof slope; b - vertically with the window frame extending from the roof plane; in - the same, with building outer wall building; r - the same, with a latch of window blocks deep into the room and the arrangement of balconies

Figure: 6.10. - Placement of window openings in the roofs of buildings

with attics

In rooms with inclined outer walls, “dead zones” appear at the junction with the floors, which are not accessible to people. In this case, the lower part of the wall is made vertical, and its height is taken equal to 0.9-1.4 m.

In practice, they use not only those solutions where the second tier of apartments does not go beyond the dimensions of the first, but also with a mismatching outer outline, the combination of apartments in one and two levels in the roof superstructure is characteristic. The planning feature of two-level apartments is that only the entrance hall with an intra-apartment staircase and pe

a - marching (plans); c - e - screw ( in - various configurations in terms of; r - vertical breakdown diagram; e - winder steps); 1,2,3 - configuration in terms of steps for spiral staircases; 4 - the same, marching runners; 5 - walls; 6 - overlap.

Figure: 6.11. - Intra-apartment stairs

The supporting structures of the attic as an under-roof space are usually made in wood. Use frame rafter system with struts, not layered. In Fig. 6.12. the solution of such a one-story frame is shown, but it can be made with a height of two floors. Then the interfloor beams will serve as braces that reduce the free length of the racks.

1 - lathing; 2 - tiles; 3 –Steel roof; 4 - black box; 5 - frontal board with cladding; 6 - sealing gasket; 7 - window block; 8 - support bar; 9 - rafter leg; 10 - insulation; 11 - finishing layer slabs; 12 - holes for ventilation of the under-roof space; 13 - rack; 14 15 - floor beam, which is at the same time tightening the frame; 16 - struts - rafters; 17 - frame struts; 18 - diagonal boards; 19 - the form of the coating; 20 - run; 21 - filly.

Figure: 6.12. - Frame supporting structure of the attic with a span of 6-12 m.

The external enclosing structures of the attic rooms are performed as shown in Fig. 6.13. Window and door openings are filled, constructively solving in accordance with this figure.

When arranging an attic, window openings are best done according to the Velux system. In combination with the excellent Andulin type coating, the Velux roof windows give the building a magnificent view. In the attic it is possible to arrange terraces by cutting the roof and offsetting the new wall from the line of the old wall. The structures of the attic rafter elements are made in any version: wood, reinforced concrete, metal.

The roof window is part of the roof. Due to its tilted position, such a window illuminates more space than usual.

When calculating the size and location of roof windows, it is important to know two things. First, the size of the window depends on the slope of the roof: the smaller the slope, the longer the window should be. Secondly, the window should be placed at a distance of 90-110 cm from the floor, and not higher. The slopes of the skylights should in no case be parallel to each other - this will greatly damage the illumination of your attic. The lower slope should be strictly vertical, and the upper slope should pass horizontally to the floor, forming an angle with the glass that is much larger than the right one. The battery located right under the window is not a tribute to traditional thinking, but an engineering necessity. A properly installed battery will prevent condensation by allowing a stream of warm air to wash over the glass.

1 - lathing; 2 - tiles; 3 –Steel roof; 4 - black box; 5 - frontal board with cladding; 6 - sealing gasket; 7 - window block; 8 - support bar; 9 - rafter leg; 10 - insulation; 11 - finishing layer slabs; 12 - holes for ventilation of the under-roof space; 13 - rack; 14 - walls of an existing building; 15 - floor beam, which is at the same time tightening the frame; 16 - struts - rafters; 17 - frame struts; 18 - diagonal boards; 19 - the form of the coating; 20 - run; 21 - filly.

Figure: 6.13. - Structural diagram of the frame for the attic and its enclosing structure

The addition of attics is currently taking place everywhere, even without reconstruction and changes in the building plan. In a number of cases, the construction of attics took place even without resettling the residents of the house or stopping the work of the administrative building.

In residential buildings, the attic space can be converted into new apartments or added to the top floor space, creating magnificent duplex apartments for large families.

Quite often, the attic houses the workshops of architects, artists and designers, less often - scientists, composers and writers. IN public buildings additional space for offices and other services is added with the addition of attics.

If the building had a rather high pitched roof, then it can be safely replaced with a two-level attic, but at the same time the area of \u200b\u200bthe upper level is very small and, as a rule, a bedroom is located in it.

The device of two-level apartments is not difficult, since all types of spiral and winding staircases, both wooden and metal, are on sale. The most difficult option is to add an attic with an additional floor. This is already a serious load on the old walls of houses, and the appearance of the building is changing a lot. Such a decision is rarely approved by the architectural heritage protection inspectorate. However, in an urban planning situation, there are cases when it is necessary to align the silhouette of a building, raising the number of storeys to 5-6 floors. If in the old building there are weak walls and foundations, and their strengthening does not give any effect for the construction of the superstructure, then in this case they resort to a solution for the construction of additional foundations. They are built with great care and without dynamic loads, on which columns are installed inside the volume, if the image of the house cannot be changed. A new building is being completed on high pillars, but with the organization of an entrance through the old building. As a rule, in this case, new monolithic ceilings are arranged and a new staircase is erected taking into account fire safety standards. In some cases, when the number of storeys rises by more than a height from the floor mark in the vestibule (13.5 m), it is necessary to arrange an elevator, and this is additional difficulties. But in the practice of reconstruction of buildings there are no easy options.

In the practice of superstructures of buildings with flat roofs, there are options when small rooms are built on them for clubs, auxiliary structures for canteens, mini-cafes, and, consequently, recreation areas with landscaping and fountains. These measures necessitate the strengthening of the overlap over the last floor and the creation of conditions for the operation of the roof, green spaces are displayed in tubs, and lawns are made of roll carpets. Pools with fountains are made of floor type, naturally, not deep, but rather decorative, but they require special reinforcement of structures, even the introduction of additional beams, and, of course, enhanced waterproofing of the bath. Therefore, they are made of polyethylene coated metal. The add-in is clearly executed by load-bearing walls... If they are not designed to withstand the new load, they are reinforced with an additional pilaster device.

The main design principle of the attic is the principle of the unity of internal and external. The possibilities of interior design of the attic are very closely related to architectural and engineering solutions. In order not to regret the missed opportunities later, remember: the design and design of such unusual spaces as the attic must be rigidly interconnected. Even at the stage of project approval, you can ask the architect to increase the roof slope. For the general appearance of the house, this factor is not so significant, but for the internal structure of the attic it is fundamental. The higher the ridge of your roof, the more spacious the attic rooms will be and the more opportunities you will have to “play” with the height.

"Attic" is a French word. In 1630. French architect François Mansart was the first to use the attic for residential purposes. Such an attic floor was named after him "MANSARD".

In accordance with SNiP 2.08.01-89 * "Residential buildings" - "Mansard floor ( attic) - a floor in an attic space, the facade of which is completely or partially formed by the surface (surfaces) inclined or sloping roof, in this case, the line of intersection of the plane of the roof and the facade should be at a height of no more than 1.5 m from the level of the attic floor ".

Attic floor may occupy the entire area of \u200b\u200bthe building, or part of it, but, as a rule, within the boundaries of the underlying walls of the base building. Architectural and planning solutions can have a wide range, and premises - any area and configuration.

Today, the choice in favor of attic spaces in individual construction is justified by a number of reasons. Device attic allows the most optimal use of living space, significantly saving space, and the money spent on construction. The device of an attic floor in the place of an attic or on a flat roof of buildings reduces heat loss through the roof within 7-9%. If you observe all the technological subtleties of the device mansard roof , you can significantly reduce the costs associated with roof repairs.

Device mansard roof has its own differences, which are due to the fact that it is exposed to various influences not only from above, but also from below: warm humid air from living quarters rises and falls in the form of condensation on the inner surface of the roof. In this regard, it is necessary to strictly comply with the requirements for the construction of the attic roof, namely, to take care of the device of thermal insulation, waterproofing and vapor barrier. The attic floor has the largest total surface of contact with the external environment, therefore it requires effective and thorough thermal insulation.

Functions and planning solutions

The functional and planning aspect of using the attic floor is determined mainly by the purpose of the building, and the planning features are associated with the structure of the building and with the rooms below. The attic floor can occupy the entire area of \u200b\u200bthe building, or part of it, but, as a rule, within the boundaries of the underlying walls of the base building. Architectural and planning solutions can have a wide range, and premises - any area and configuration.

When designing an attic floor, the choice of a planning option should be based on an analysis of the planning scheme of the base building, determined in the study of the social needs of this residential formation and executed in accordance with the current regulatory requirements.

There are three main types to be distinguished attic floors:

· Attic floor with the formation of a separate floor in one level;

· Attic floor with two-level development;

· Attic floor with the spatial organization of the mezzanine floor with a two-level development of the upper floor of the base building.

Attic floor structures

The design and geometry of the roof determines the architectural form of the crowning part of the building, and this, in turn, the need to create a unity of structural and architectural solutions in conjunction with the internal space, due to the functional purpose.

The choice of one or another architectural and construction system of the attic floor includes the definition of the supporting structure and fencing, as well as the organization construction works at the facility in the built-up part of the city.

For attic floors, it is recommended to choose lightweight structures and materials, since, on the one hand, it is necessary to facilitate their transportation to the floor as much as possible, and on the other hand, the dead weight of the structures should be minimal, taking into account the load that will be transferred to the existing building.

These assumptions generally indicate that designs should be selected from wood based materials or thin-walled cold-formed metal profiles. Use of stone and concrete materials for the creation of the supporting structure of the attic floor on a restored or newly constructed building is not recommended.

The roof covering must comply with the same prerequisites, that is, it must be made mainly of light materials in the form of metal sheets, metal tiles, and the like. In cases where it is necessary in order to preserve the environment of existing buildings, the coating is made of clay or cement-sand tiles, non-ferrous metal and other materials.

The inner lining of the attic fence is made mainly of plasterboard sheets. It is advisable to carry out internal partitions by element-by-element assembly with plasterboard cladding on racks of thin-sheet profiles.

The attic floor is more susceptible to heat loss than the lower floors, for the simple reason that there is no "heat cushion" above it. It has a large overall surface of contact with the external environment. Therefore, for reasons of comfort and economy, effective and thorough thermal insulation is required. With increased thermal insulation, more stringent requirements are imposed on the thermal seal and its design. This seal prevents warm air from penetrating the sealing layer. For thermal insulation, an effective insulation should be used, for example, a mineral wool slab, c \u003d 0.004 W / m oС by calculation. On the inside of the insulation (facing the room) a vapor barrier layer is provided, and on the outside - waterproofing. It is also important that there is a sufficiently effective ventilation space between the upper side of the insulation layer and the lower side of the roof covering, which would facilitate ventilation and remove the unavoidable flow of moist warm air that will penetrate the steam barriers and the thermal insulation layer.

Attic design

· A huge role, depending on the level of visual perception, belongs to the lines and shapes determined by the geometry of the roof.

· An important condition for the placement of attic rooms is their relationship with the communication structure of the building - the foundation.

Interaction between the designed and existing engineering systems and ensuring that they work together. (In the case when the functions of the attic do not coincide with the functions of the main building, the development of special technical solutions is required).

· Of particular importance are the shape and dimensions of the premises, the choice of translucent fences (vertical or inclined windows), their placement, taking into account the construction of the interior in conjunction with the formation of architecture.

· The structural scheme, material of the enclosing structures and details of the attic are determined taking into account the unity of the structure and architectural forms of the base building (The use of light structures, parts and products is the main requirement).

An attic with a steeply sloping roof requires a special approach to the choice roofing material, providing thermal protection, sealing and waterproofing.

· The construction of an attic without resettling the residents of the main building requires a special method of maximum safety of work, limiting the weight of structures and parts, construction of protection and safety elements.

Attic construction

· The design and geometry of the roof determines the architectural form of the crowning part of the building, and this, in turn, - the need to create a unity of design and architectural solutions in conjunction with the internal space, due to the functional purpose.

· The choice of one or another architectural and construction system of the attic floor includes the definition of the supporting structure and fencing, as well as the organization of construction work at the facility in the built-up part of the city.

For attic floors, it is recommended to choose lightweight structures and materials, since, on the one hand, they should be as easy as possible to transport them to the floor, and on the other hand, the dead weight of the structures should be minimal, taking into account the load that will be transferred to the existing building.

· These assumptions generally indicate that structures should be selected from wood based materials or thin-walled cold-formed metal profiles. The use of stone and concrete materials to create the load-bearing structure of the attic floor in a building to be restored or under construction is not recommended.

· The roof covering must comply with the same prerequisites, that is, it must be made mainly of lightweight materials in the form of metal sheets, metal tiles and the like. In cases where it is necessary in order to preserve the environment of existing buildings, the coating is made of clay or cement-sand tiles, non-ferrous metal and other materials.

· The inner lining of the attic enclosure is made mainly of plasterboard sheets. It is advisable to carry out internal partitions by element-by-element assembly with plasterboard cladding on racks of thin-sheet profiles.

The attic is more susceptible to heat loss than the lower floors for the simple reason that there is no<тепловой подушки>... The attic floor has a large overall surface of contact with the external environment. Therefore, for reasons of comfort and economy, effective and thorough thermal insulation is required.

· With increased thermal insulation, more stringent requirements are imposed on the thermal seal and its design. This seal prevents warm air from penetrating the sealing layer. For thermal insulation, an effective insulation should be used, for example, a mineral wool slab, with l \u003d 0.004 W / m ° C, with a calculated thickness.

· On the inside of the insulation (facing the room) a vapor barrier layer is provided, and on the outside - waterproofing. It is also important that there is a sufficiently effective ventilation space between the upper side of the insulation layer and the lower side of the roof covering, which would facilitate ventilation and remove the unavoidable flow of moist warm air that will penetrate the steam barriers and the thermal insulation layer.

Warming of attics

The covering of the attic should not only protect the house from atmospheric precipitation (rain, snow), but also prevent cooling of the upper floor premises. Warm air always rises, so the air temperature under the ceiling is on average 2 ° C higher than in the middle of the room height. With the same thermal insulation capacity of the walls and roof, the heat loss through the latter will always be greater, due to the large temperature difference between the outer and inner surfaces of the attic coating. In addition, the moisture content of warm air is usually higher than that of cold air, so condensation on the ceiling of the upper floor can form when more high temperaturesthan on the inside of the wall. Therefore, more stringent requirements are imposed on the thermal protection of roof coverings than on the outer walls.

Heat loss through the attic is large enough, therefore, correctly performed insulation of its coating can bring a tangible economic effect. When comparing two typical two-story houses with an area of \u200b\u200b205 m2 with attics insulated in accordance with the old and new requirements, it was found that the modern level of thermal protection allows to reduce heat loss through the coating by more than 3 kW and thereby significantly reduce the power of the heating system and reduce costs heating the house.

Icicles hanging from the roof pose a significant danger to people. In the process of knocking down icicles, there is a high probability of damage to the roof with all the ensuing consequences. One of the reasons for the formation of icicles in winter is insufficient thermal insulation of the roof covering. The snow, heated from below by the heat passing through the poorly insulated coating, begins to melt, and the water flowing from the roof turns into icicles. Only with well-executed thermal insulation will icicles not cause trouble in winter.

Requirements for thermal protection of coatings

Rationing of thermal protection of enclosing structures, which include roofs, is carried out in accordance with SNiP II-3-79 * " Construction heat engineering"(issue 1998), taking into account the average air temperature and the duration of the heating period in the construction area. In accordance with these standards, the required reduced heat transfer resistance Ro of roofing for Moscow and the Moscow region must be at least 4.7 m2 ° C / W.

Design features

The moisture content of warm indoor air is higher than that of cold outdoor air, therefore the diffusion of water vapor (both through the attic floor and through the outer walls of the building) is directed from the room to the outside. The outer (top) part of the roofing is a waterproofing layer that poorly permeates water vapor and contributes to the formation of condensation moisture from the inner (bottom) side of the roof. The consequences will not be long in coming: despite the well-executed waterproofing of the roof, wet spots and mold will appear on the inner surface of the roofing, the thermal insulation qualities of the insulation will deteriorate, water droplets will begin to fall from the ceiling (not due to a roof leak, but as a result of condensation of water vapor) ...

Considering the negative impact of moisture on thermal insulation characteristics materials, the insulation must be protected from moisture vapor contained in the air of the room, a layer of vapor barrier material, placing it on the inner (bottom) side of the insulation. To remove moisture that has got into the thermal insulation material for some reason, a ventilated air gap should be provided between the insulation and the outer (waterproofing) layer of the roofing.

Very often non-residential attic spaces will be converted into residential attics, while maintaining the existing rafter system. At the same time, trying to minimize the additional load on bearing structures buildings, usually use lightweight insulation of reduced density. Under the influence of wind, low-density heaters are "blown through", accompanied by heat carryover, therefore, to preserve the heat-shielding characteristics of the structure, a layer of wind-proof vapor-permeable material must be placed on the surface of the thermal insulation bordering the ventilated layer.

When insulating the attic, it must be remembered that heat loss occurs not only through the coating, but also through the end wall. Therefore, the pediment of the house also needs to be well insulated in accordance with modern requirements.

Insulation of mansard coverings

Structurally, the roof of the attic consists of a system of rafters installed with a step of 600 ... 1000 mm. The space between the rafters is filled with heat-insulating material (insulation). It is recommended to use mineral wool slabs based on basalt fiber or fiberglass as an insulating material. Thermal insulation boards or mats can be stacked in one or more layers, and the total thickness of the insulation layer depends on the thermal conductivity of the insulation, the value of which must be indicated in the certificate of conformity.

A ventilated air gap is arranged between the insulation and the roofing. On the inner (lower) side, the attic covering is protected with a vapor barrier material and finished with plasterboard sheets, clapboard, etc. If the section height of the rafters is less than the required thickness of the insulating layer, wooden blocks are attached to the rafter legs on screws or nails. Insulation plates are placed between them in such a way that an air gap remains between the thermal insulation and the roof. If the height of the cross-section of the rafters is insufficient, horizontally located wooden antiseptic bars can be attached to them. In this case, one layer of insulation is located between the rafters, and the other between the horizontal bars.

Ventilated air gap device

The width of the air gap between the insulation and the roof depends on the profile of the coating material. In the case of using profiled sheets of galvanized steel, tiles, metal tiles and other corrugated sheets, the thickness of the ventilated air gap must be at least 25 mm. When installing a roof from flat sheets (asbestos-cement sheets, galvanized steel, soft bituminous shingles, roll materials), an air gap of at least 50 mm is required. Ventilation of the air gap is carried out through the holes in the cornice and in the ridge.

Protection of insulation from blowing

On the side of the ventilated air gap, the thermal insulation material must be protected with a windproof vapor-permeable membrane. As practice shows, the best results can be obtained using such roll materials as Tyvek Soft, Monarflex VM 310 and Monaperm 450 VM. Application as windproof membrane vapor-proof materials such as roofing material or plastic foil are completely unacceptable! It should be noted that Tyvek-type membranes, which perfectly transmit water vapors, do not, nevertheless, allow water in the liquid phase to pass through, and therefore prevent the insulation from getting wet as a result of moisture that condenses on the inner surface of the roofing from the side of the air gap. This property of Tyvek materials makes it possible to reduce the thickness of the air gap to 25 mm regardless of the profile of the roof covering, which is especially important when insulating the attic using existing rafters: the thin air gap eliminates the need to install additional bars on the inside of the rafter legs. The height of the rafter leg will be enough to accommodate the insulation of the required thickness and the device of a ventilated air gap.

When building a new home, the windproof material is laid over the rafter legs and attached with wooden blocks. When arranging an attic in an existing attic, a windproof, vapor-permeable material is attached with special slats to the existing rafters. "Tyvek" also protects the insulation layer from moisture precipitation (rain, snow) falling into the air gap in a strong wind or through leaks in the coating. "Tyvek" is laid on the insulation with an overlap of 150 ... 200 mm along the dotted lines applied to the material sheet, and attached to the structure with wooden slats with nails, staples or glue.

Vapor barrier device

From the inner (bottom) side, the heat-insulating material is protected from moisture by water vapor contained in the air of the room, with a vapor barrier layer - polyethylene film, glassine, roofing felt or foil vapor barrier material "Polykraft" from Monarflex. The material is laid with a 100 mm overlap and the seams are glued with adhesive tape. The use of adhesive tape not only ensures the tightness of the seams, but also allows you to reduce the amount of overlap to 100 mm (both vertically and horizontally), regardless of the slope of the roof. The film is attached to rafters or bars with thin wooden slats. Foil materials are laid with foil towards the room, and it is advisable to leave a small gap between the vapor barrier and the inner lining. In this case, the shiny surface of the aluminum foil will reflect the heat radiation coming from the room to the outside and reduce the amount of heat loss through the attic covering.

From the inside, the attic room is clad with plasterboard sheets, plywood, boards or clapboard, which are attached to wooden bars or metal profiles installed on the inside of the rafter legs.

As a rule, the attic does not occupy the entire overlapping area of \u200b\u200bthe upper floor, since its longitudinal walls are not arranged in the plane of the outer wall, but at some distance from it. The overlap area between the attic wall and the cornice, adjacent to the outer wall of the house, extends beyond the volume of the attic room to be heated, so it must be insulated. To do this, lay a vapor barrier "Polycraft" "(foil side down), polyethylene film, etc. on top of the floor boards, then a layer of insulation and a windproof vapor-permeable material. The insulation should be laid so that bridges do not form in the area where the floor joins the wall. cold ".

There are often cases when the existing attic insulation does not provide the required level of thermal insulation. High heating costs, icicle formation in winter and the drumming of raindrops in summer indicate that attic roofing needs additional insulation (and at the same time in soundproofing). You can insulate the attic by placing the insulation on top of the existing insulation in compliance with all the rules for installing thermal insulation in the attic. This option of insulation eliminates the need to reduce the height of the ceiling and the usable area of \u200b\u200bthe room to be insulated, but requires dismantling the roof and battens, as well as the construction of a supporting frame for a new roof covering.

An additional layer of insulation can be placed under the existing thermal insulation. To do this, a frame made of wooden beams is installed on the inner lining of the attic, between which the slabs are placed "by the way" thermal insulation material... The height of the bars should correspond to the thickness of the insulation layer. From the side of the room, the insulation must be protected with a vapor barrier material, which is attached to the wooden bars of the frame. From the inside, the room is finished with clapboard, plasterboard sheets, plywood, etc. This method of insulation is not associated with dismantling the roof, work can be done not only in summer, but also in winter, however, the usable area and height of the room decrease.

In some cases, the best option for insulation may be a combined method, when the attic ceiling is insulated over the existing insulation, and its inclined surfaces are insulated from the inside. In any case, we must not forget about additional insulation of the vertical walls of the attic and part of the ceiling located near the outer wall outside the heated attic room.

Attic lighting

As a source of natural light for the attic floor, traditional vertical windows and specially designed for this purpose can be used. roof windows , which are installed in the plane of the roof (with a slope of the slopes from 15 ° to 90 °).

Roof windows let in the right amount of light with a smaller opening area compared to traditional windows. The norms establish the minimum ratio of the light area of \u200b\u200bdormers to the floor area of \u200b\u200ball living rooms and kitchens in apartments and dormitories of attic floors, equal to 1:10. The light from the roof window spreads evenly throughout the room, while there are no blind side compartments that obscure the light.

Design of attics taking into account light fluxes

Vertical window structures create sharp light drops - shadow niches, which has a very negative effect on the perception of the attic as a whole, giving rise to a feeling of crampedness and some general inferiority of the interior. The sensations are as if you are in a tunnel: a heavy dark roof hangs over your head, light dawns somewhere ahead, hard, uncomfortable, and even stuffy. But the real problems begin when it comes time to arrange furniture. If the vertical end wall is "occupied" by a window, you cannot put a cabinet here, at best, a desk. And all the rest of the furniture is "driven" deep into the attic, and there is no need to talk about any interior solution. Little by little, old things begin to accumulate here, and over time, the attic turns into a banal attic.

Everything may be different if, at the design stage of the house, inclined skylights are provided.

They do not restrict the flow of daylight to vertical planes, thanks to which the room is illuminated more evenly, without the shadow gaps typical of "birdhouses". It is estimated that a dormer window gives 40 percent more light than a vertical one. The main thing is to correctly calculate the size of the windows, their number, and the optimal installation (placement) height, which, by the way, is 90 cm from the floor level to the lower edge of the window. A dormer window or a spectacular combination of windows will illuminate exactly the part of the attic you want, literally adapting to your needs. You will not only light up the place where your favorite chair or bed or table will stand, but you can also admire the garden, painted with sunsets and sunrises, or simply dreamily watch the stars and clouds. And the vertical end wall now has room for a convenient cabinet, bookcase, sideboard or piano.

Ventilation devices for roof windows

Ventilation devices roof windows allow you to ventilate the room when the window is closed. It is very convenient, especially when it is bad weather outside. And when the roof window is opened, the pivot frame, rotating around the horizontal axis, forms two air currents: incoming and outgoing. Due to the separation, these streams do not mix, so the ventilation becomes much more efficient. With vertical windows, a similar effect can be achieved only by arranging a good draft. In addition, the niches of the dormer windows themselves impede the movement of air, significantly impairing its circulation.

The installation of a roof window takes much less time and materials than the construction of a vertical "birdhouse". And if you also remember that in the complex arrangement of the attic, the area of \u200b\u200bthe windows is subtracted from the total area of \u200b\u200bthe roof, then, given the high heat and waterproofing of the roof windows, you can significantly save on insulation and roofing materials.

Finally, an inclined window is more reliable than a vertically positioned "birdhouse". After all, the entire structure of the attic window is designed so that in any bad weather, be it rain, snow or wind, a person could only ironically observe the elements, knowing that the attic will always be light, warm and comfortable.

But what to do if vertical windows play a significant role in the architectural appearance of the chosen house? There is nothing wrong here. With the right combination, vertical and inclined windows never "argue" with each other. Even in cases where a vertical window is indispensable, additional installation roof windows will significantly improve the lighting and ventilation of the room, form an arbitrary attic layout. Thus, the attic seems to be reborn, turning into the most comfortable place in the house.

Interior

When developing the interior of the attic floor, some characteristic geometric shapes of the premises should be taken into account. It is about the placement of stairs, the furnishings of the bathroom and toilet, the kitchen, and the placement of doors. Take into account the free height of the flights of stairs in relation to sloped roof surfaces. There is no difficulty when the direction of the stairs is parallel to the slope of the roof or the stairs are placed along the middle axis of the building. Free height is usually not a problem, but the placement of possible parts and assemblies of the roof structure should be considered.

Bathroom and toilet furnishings should be taken with sloping roof surfaces limiting full height.

Placing doors can be difficult not only because of determining the height of the doorway itself. Here, it is also necessary to take into account the smooth opening of the door, taking into account the sloping wall.

Fire protection requirements

Fire safety requirements, especially the evacuation routes of the attic floor, depend on the planning structure of the base building: when the functions of the base building and the functions of the attic floor coincide, the staircase-elevator node of the building is used for escape routes, to which the attic is adjacent; if the functions of the base building and the attic floor do not match, to create escape routes, special communications are required, which can be located inside or outside the building and have isolated exits, including between two buildings.

It is allowed that there are no exits to the staircase from each floor of an apartment on two levels, provided that the premises are located no higher than the 6th floor, and the apartment is provided with an additional exit. It is allowed to arrange emergency exits into a common staircase from creative workshops, provided that communication through the vestibule is possible.

When placing offices and offices in the attic of residential buildings with no more than 9 floors, entrances and emergency exits must be isolated from the residential part of the buildings. It is allowed to accept staircases of the residential part of the building as a second escape exit, while the exit is provided through a vestibule with fire doors. The roof window can serve as a rescue opening through which people can be evacuated from the premises.

SNiP requirements for the design of attic floors

Requirements for SNiP 2.08.01-89, which most fully reflect the specifics of the design of attic floors above residential buildings. Guided by these requirements, Russian architects have been designing attics for 10 years (since 1994, amendment No. 2 came into force). It is known that with the entry into force of the law "On technical regulation" SNiPs and GOSTs will be of a recommendatory nature (except for items related to safety).

General instructions Sanitary and hygienic requirements, illumination and insolation 1.1 *. The height of residential premises from floor to ceiling must be at least 2.5 m, for climatic subareas IA, IB, IG, ID, IIA - at least 2.7 m. The height of floors from floor to floor for residential buildings for social purposes is not recommended more than 2.8 m, for climatic subdistricts IA, IB, IG, ID, IIA - no more than 3.0 m. C. The height of intra-apartment corridors must be at least 2.1 m.Using this norm and rule for determining the area of \u200b\u200bthe attic floor ( Appendix 2, item b), we can get the formula for calculating the possibility of using the attic for residential purposes: a\u003e b + 0.7xc; where a is the area of \u200b\u200ba room with a height above 2.5 m, b is the area of \u200b\u200ba room with a height of 1.1 m to 2.5 m, c is the area of \u200b\u200ba room with a height of 0.8 m to 1.1 m (see Fig. .one).

Figure 1 - Rules for calculating the area of \u200b\u200bthe attic floor

1.3 * ... Natural lighting should be taken in accordance with the requirements of SNiP 23-05-95. In this case, the ratio of the area of \u200b\u200blight openings of all living rooms and kitchens of apartments and dormitories to the floor area of \u200b\u200bthese premises, as a rule, should not exceed 1: 5.5. The minimum ratio should be at least 1: 8, for mansard floors, when using roof windows, it is allowed to take a ratio of 1:10. This paragraph indicates that when using dormer windows located in the roof slope, a 25% smaller glazing area is allowed compared to the use of vertical windows in a typical floor. Unfortunately, when using hatches / dormers in the attic, designers use a ratio of 1: 8 when calculating the glazing area, which leads to insufficient illumination of the premises. This factor is provided for calculating translucent structures in a traditional floor with vertical walls. When using vertical windows in the attic, deep slopes are formed, in which up to 2/3 of the natural light is retained in comparison with the attic window (see Fig. 3).

Figure 3 - The principle of calculating the glazing area

Number of storeys and degree of fire resistance 1.13 *. It is allowed to build buildings of I, II and III degrees of fire resistance with one attic floor with load-bearing elements that have a fire resistance limit of at least R45 and fire hazard class KO, regardless of the height of the buildings set in Table 1, but located no higher than 75 m. attics must meet the requirements for the structures of the building to be built. When using wooden structures, structural fire protection should be provided to ensure the specified requirements. It is believed that wooden structures in the attic floor are prohibited. In fact, with adequate protection of the structure and a building height of up to 75 m, such a ban does not exist. It is proposed to use anti-fume impregnations for wooden parts of attic structures. With the existing well-known technologies of impregnations (perhaps, impregnations with better characteristics have already been invented), this event needs to be repeated after three to five years, which is impossible with the design solutions that have become widespread in Russia. Therefore, SNiPs contain instructions to apply constructive protection. How to confirm the compliance of the selected design solution with the specified norm? Our company tested a sample of the roof and ceiling structure of the attic floor (see Fig. 2). This design has shown results (REI75 and K045) exceeding the minimum requirements of SNiPs. A similar design has been tested by other firms and the results have been confirmed. There is a simple technique that increases the fire resistance of the roof structure - it is laying a 100 mm layer of mineral wool under the wooden rafters. It serves not only as heat and sound insulation, but also to protect load-bearing structures from the effects of flame and temperature. The same technique is used in the case of load-bearing structures made of rolled steel and cold-bent metal profiles. Another question that often arises: an indication in SNiP on "one attic floor". On this issue, we consulted with Gosstroy specialists and received the following answer. The requirements specified in clause 1.13 apply to the device of one attic floor, but if, based on technical and economic indicators or architectural solutions, a multi-level attic is required, then measures to ensure safety in the building (in the attic) must be developed and agreed with the fire authorities. These measures can be summarized as follows: increasing the fire resistance of structures; compliance with evacuation requirements, including from two-level apartments;

Figure 2 - A sample of the construction of the roof and ceiling of the attic floor

1.25 *. In residential buildings of sectional type, with a total area of \u200b\u200bapartments on the section floor of up to 500 sq. m inclusively, it is allowed to provide for an evacuation exit from the section floor to one staircase. At the same time, in each apartment located at a height of more than 15 m, emergency exits should be provided according to paragraphs 20 * a), b) or c) SNiP 21-01-97 *. (6.20 * Emergency exits also include: a) exit to a balcony or loggia with a blank wall of at least 1.2 m from the end of the balcony (loggia) to the window opening (glazed door) or at least 1.6 m between the glazed openings overlooking to the balcony (loggia); b) exit to the passage with a width of at least 0.6 m, leading to an adjacent section of a building of class F1.3 or to an adjacent fire compartment; c) exit to a balcony or loggia equipped with an external staircase connecting the balconies or loggias by floor ... SNiP 21-01-97 "Fire safety of buildings and structures") For an apartment located on two levels, provide an exit to the staircase from each floor not required, provided that the premises of the apartment are located no higher than the 6th floor and the floor of the apartment, which does not have a direct exit to the staircase, is provided with an additional exit in accordance with the requirements of the above paragraph. 1.34a *. The norms of this subsection (clauses 1.29, 1.31-1.34) do not apply to existing buildings with a height of up to 28 m, inclusive, built on one m (including the attic) floor. In this case, the floor to be built must be provided with an emergency exit according to clause 6.20 * a), b) or c) SNiP 21-01-97 *. The question arises why less stringent fire safety requirements are applied to the attic compared to the standard floor. Analyzing regulatory documents different countries, we found that in many of them the requirements depend on the floor, not the number of storeys. For example, as shown in Figure 4, if the building is one-story, then fire resistance requirements are imposed on its structure for 30 minutes, if the building is 4-storey with an attic, then for ordinary floors - 60 minutes, and for the attic - 30 minutes. This is due to the fact that the attic is always the last floor: accordingly, both people from the attic and people living on this floor are evacuated through the underlying floor. The second question in this vein: fire, as a rule, spreads upward. Accordingly, the probability of a fire on the underlying floor tends to zero. To date, based on the European experience in firefighting attics, not a single such case has been recorded. Here are the objective reasons for making less stringent requirements for the attic floors and, as a result, using lightweight structures.

Figure 4 - Requirements for fire resistance of the structure

Non-residential floors

1.35. The height of public premises located in residential buildings is allowed to be equal to the height of residential premises, except for premises in which, according to the conditions for placing equipment, the height must be at least 3 m. 1.36 * ... On the top floor, it is allowed to accommodate creative workshops of artists and architects, in this case, the communication of the floor with the staircase should be provided through the vestibule. In the superstructured attic floor of buildings of the II degree of fire resistance with a total height of not more than 28 m, it is allowed to place office-type premises in agreement with local authorities, taking into account the requirements of clause 1.38. 1.38 *. Public premises, except for public premises of hostels and homes for the elderly and families with disabled people, must have entrances and evacuation exits, isolated from the residential part of the building. When placing office-type premises in the built-on attic floor, it is allowed to accept staircases of the residential part of the building as the second escape exit, while the communication of the floor with the staircase should be provided through a vestibule with fire doors. The door in the vestibule overlooking the staircase should be provided with opening only from the inside of the room. These points allow the placement of office space in the attic above residential floors in the presence of a second evacuation exit. There are the following solutions: attach an external staircase; use the back staircase in older buildings. Accordingly, for the workshops of artists and architects, an exit to one staircase is sufficient.

Reference material

The roof is the upper enclosing structure of the building, which performs load-bearing, waterproofing and, with non-attic (combined) roofs and warm attics, heat-insulating functions.

Roofing is the top element of the roof (covering) that protects buildings from all types of weathering.

The most common in both Europe and Russia are different kinds oblique or, to put it another way, pitched roofs.

The roof of the building consists of the following elements (see figure): inclined planes, called slopes (1), which are based on rafters (2) and lathing (3). The lower ends of the rafter legs rest on the Mauerlat (4). The intersection of the slopes forms inclined (12) and horizontal edges. Horizontal ribs are called ridge (5). The intersection of the slopes, forming the reentrant corners, create valleys and valleys (6). The edges of the roof above the walls of the building are called cornice overhangs (7) (located horizontally, protruding beyond the outline of the outer walls) or pediment overhangs (11) (located obliquely). The water flows down the slopes to the wall gutters (8) and is discharged through the water intake funnels (9) into the downpipes (10) and then into the storm sewer.

Varieties of roof shapes.

Shed roof rests with its supporting structure (rafter system, truss, etc.) on the outer walls at different levels. Shed roofs they are most often used in the construction of verandas and terraces, outbuildings, storage facilities.

Gable roof is the most common classical design. It is also called gable. There are roof options with hanging rafters or sloped rafters. The numerous options of this type include roofs with a uniform or uneven slope of the slope or the size of the eaves.

Hipped roof ... All the slopes of such a roof, in the form of isosceles triangles, converge at one point. The defining element in it is symmetry. It is used for buildings in the form of a square or an equilateral polygon.

Hip roof ... It has four slopes: two slopes are trapezoids, and the other two, from the side of the end walls, are triangles (they are called hips). Variety hip roof is half hip.

Multi-gable roof ... It is arranged on houses with a complex polygonal plan shape. Such roofs have large quantity ends (inner corner) and ribs (protruding corners that form the intersection of the roof slopes), which requires high qualifications when performing roofing work.

Roof roofs ... To increase the volume of a residential attic (attic), slopes of various slopes are often performed: the lower ones are steeper and the upper ones are more gentle. This type of roof structure is very popular in modern construction, because efficient use of the living area of \u200b\u200bthe attic floor is ensured.

Dome and conical roofs are used to cover buildings with a circular outline in plan.

Flat roofs find the widest application in both civil and industrial construction. Unlike pitched roofs, piece and sheet materials are not used on flat roofs. Here materials are needed that allow the device of a continuous carpet (bituminous, bitumen-polymer and polymer materials, as well as mastics).

1. Attic. Ladders. Attic construction. Manufacturing stairs: Handbook / Comp. IN AND. Ryzhenko. - M .: Onyx Publishing House, 2007.

2. Roofs, mansards, stairs, floors. Baranchikov. - M .: Phoenix Publishing House, 2004.

3. Attic and attic spaces. J. Koso. - M .: Publishing house Content, 2008.

4. Attic. Bay windows. Balconies. V.S. Samoilov, V.S. Levadny. - M .: Publishing house Adelant, 2006.

Functions and planning solutions of the attic floor. The interior of the attic floor. Attic floor design rules. Attic floor structures. Fire safety requirements for attic floors. Warming of attics. Requirements for thermal protection of attic coatings. Design features of attic roofs. Warming of roof coverings. Ventilated air gap device. Protection of the insulation against blowing. Vapor barrier device for mansard coverings. Additional insulation of existing attics.


Maisons-Laffitte Palace (1642-1651). Architect Nicolas François Mansart (1598-1666)

In architectural practice, for the first time the under-roof attic space for residential purposes was used in 1630 by one of the leaders of early French classicism, Nicolas François Mansart (1598-1666). His merit, in addition to the direct construction of buildings, is the development of a new type of urban dwelling of the nobility - "hotel" - with a cozy and comfortable layout, including a lobby, a grand staircase, a number of enfilade rooms, often enclosed around a courtyard. A feature of the Mansara hotels is high roofs, under which an additional living space was arranged - an attic, named after its creator. An excellent example of such a roof is the Maisons-Laffitte palace (1642-1651).

Functions and planning solutions of the attic floor

The functional and planning aspect of using the attic floor is mainly determined by the purpose of the building, and the planning features are associated with the structure of the building and with the rooms located below. The attic floor can occupy the entire area of \u200b\u200bthe building, or part of it, but, as a rule, within the boundaries of the underlying walls of the base building. Architectural and planning solutions can have a wide range, and premises - any area and configuration.

It is necessary to distinguish between three main types of attic floors:

attic floor with the formation of a separate floor in one level;
attic floor with two-level development;
attic floor with the spatial organization of the mezzanine floor with a two-level development of the upper floor of the base building.

Attic floor interior

Bathroom and toilet furnishings should be taken with sloping roof surfaces limiting full height.

Attic floor design rules

The choice of a planning option for the attic should be based on an analysis of the layout of the base building.

A huge role, depending on the level of visual perception, belongs to the lines and shapes determined by the geometry of the roof.

An important condition for the placement of attic rooms is their relationship with the communication structure of the building - the foundation.

It is necessary to interact between the designed and existing engineering systems and ensure their joint work. (In the case when the functions of the attic do not coincide with the functions of the main building, the development of special technical solutions is required).
Of particular importance are the shape and dimensions of the premises, the choice of translucent fences (vertical or inclined windows), their placement, taking into account the construction of the interior in conjunction with the formation of architecture.

The structural scheme, the material of the enclosing structures and parts of the attic are determined taking into account the unity of the structure and architectural forms of the base building (The use of light structures, parts and products is the main requirement).

An attic with a steep roof requires a special approach to the choice of roofing material, thermal protection, sealing and waterproofing.

The construction of an attic without resettling the residents of the main building requires a special method of maximum safety in the production of work, limiting the weight of structures and parts, the construction of protection and safety elements.

Attic floor structures

The choice of one or another architectural and construction system of the attic floor includes the definition of the supporting structure and fencing, as well as the organization of construction work at the facility in the built-up part of the city.

These assumptions generally indicate that designs should be selected from wood based materials or thin-walled cold-formed metal profiles. The use of stone and concrete materials to create the load-bearing structure of the attic floor in a building to be restored or under construction is not recommended.

The attic floor is more susceptible to heat loss than the lower floors, for the simple reason that there is no "heat cushion" above it. It has a large overall surface of contact with the external environment. Therefore, for reasons of comfort and economy, effective and thorough thermal insulation is required. With increased thermal insulation, more stringent requirements are imposed on the thermal seal and its design. This seal prevents warm air from penetrating the sealing layer. For thermal insulation, an effective insulation should be used, for example, a mineral wool slab, c \u003d 0.004 W / m oС by calculation. On the inside of the insulation (facing the room), a vapor barrier layer is provided, and on the outside - waterproofing. It is also important that there is a sufficiently effective ventilation space between the upper side of the insulation layer and the lower side of the roof covering, which would facilitate ventilation and remove the unavoidable flow of moist warm air that will penetrate the steam barriers and the thermal insulation layer.

Fire safety requirements for attic floors

Warming of attics

The covering of the attic should not only protect the house from atmospheric precipitation (rain, snow), but also prevent cooling of the upper floor premises. Warm air always rises, so the air temperature under the ceiling is on average 2 ° C higher than in the middle of the room height. With the same thermal insulation capacity of the walls and roof, the heat loss through the latter will always be greater, due to the large temperature difference between the outer and inner surfaces of the attic coating. In addition, the moisture content of warm air is usually higher than cold air, so condensation on the ceiling of an upper floor can form at higher temperatures than on the inner surface of the wall. Therefore, more stringent requirements are imposed on the thermal protection of roof coverings than on the outer walls.

Heat loss through the attic is quite large, therefore, correctly performed insulation of its coating can bring a tangible economic effect. When comparing two typical two-story houses with an area of \u200b\u200b205 m2 with attics insulated in accordance with the old and new requirements, it was found that the modern level of thermal protection allows to reduce heat loss through the coating by more than 3 kW and thereby significantly reduce the power of the heating system and reduce costs heating the house.

Requirements for thermal protection of attic coatings

The standardization of thermal protection of enclosing structures, which include roofs, is carried out in accordance with SNiP II-3-79 * "Construction heat engineering" (issue 1998), taking into account the average air temperature and the duration of the heating period in the construction area. In accordance with these standards, the required reduced heat transfer resistance Ro of roofing for Moscow and the Moscow region should be at least 4.7 m2 ° C / W.

Design features of roofing attic

Taking into account the negative effect of moisture on the thermal insulation characteristics of materials, the insulation must be protected from humidification by water vapor contained in the air of the room with a layer of vapor barrier material, placing it on the inner (bottom) side of the insulation. To remove moisture that has got into the thermal insulation material for some reason, a ventilated air gap should be provided between the insulation and the outer (waterproofing) layer of the roofing.

Very often, non-residential attic spaces are converted into residential attic, while maintaining the existing rafter system. At the same time, in an effort to minimize the additional load on the supporting structures of the building, lightweight insulation of low density is usually used. Under the influence of wind, low-density heaters are "blown through", accompanied by heat carryover, therefore, to preserve the heat-shielding characteristics of the structure, a layer of wind-proof vapor-permeable material must be laid on the surface of the insulation bordering the ventilated layer.

Insulation of mansard coverings

Structurally, the roof of the attic consists of a system of rafters installed with a step of 600-1000 mm. The space between the rafters is filled with heat-insulating material (insulation). It is recommended to use mineral wool slabs based on basalt fiber or fiberglass as an insulating material. Thermal insulation boards or mats can be laid in one or several layers, and the total thickness of the insulation layer depends on the thermal conductivity of the insulation, the value of which must be indicated in the certificate of conformity.

A ventilated air gap is arranged between the insulation and the roofing. On the inner (lower) side, the attic coating is protected with a vapor barrier material and trimmed with plasterboard sheets, clapboard, etc. If the height of the rafter section is less than the required thickness of the insulating layer, wooden blocks are attached to the rafter legs with screws or nails. Insulation plates are placed between them in such a way that an air gap remains between the thermal insulation and the roof. If the height of the cross-section of the rafters is insufficient, horizontally located wooden antiseptic bars can be attached to them. In this case, one layer of insulation is located between the rafters, and the other between the horizontal bars.

Ventilated air gap device

The width of the air gap between the insulation and the roof depends on the profile of the coating material. In the case of using profiled sheets of galvanized steel, tiles, metal tiles and other corrugated sheets, the thickness of the ventilated air gap must be at least 25 mm. When installing a roof from flat sheets (asbestos-cement sheets, galvanized steel, soft bitumen tiles, roll materials, ...), an air gap of at least 50 mm is required. Ventilation of the air gap is carried out through the holes in the cornice and in the ridge.

Protection of insulation from blowing

On the side of the ventilated air gap, the thermal insulation material must be protected with a windproof vapor-permeable membrane. As practice shows, the best results can be obtained when using such roll materials as Tyvek Soft, Monarflex VM 310 and Monaperm 450 VM. The use of vapor-proof materials such as roofing felt or plastic foil as a windproof membrane is completely unacceptable! It should be noted that Tyvek-type membranes, which perfectly transmit water vapors, do not, nevertheless, allow water in the liquid phase to pass through, and therefore prevent the insulation from getting wet as a result of moisture that condenses on the inner surface of the roofing from the side of the air gap. This property of Tyvek materials allows to reduce the thickness of the air gap to 25 mm, regardless of the profile of the roofing, which is especially important when insulating the attic using existing rafters: the thin air gap eliminates the need to install additional bars on the inside of the rafter legs. The height of the rafter leg will be enough to accommodate the insulation of the required thickness and the device of a ventilated air gap.

When building a new home, the windproof material is laid over the rafter legs and attached with wooden blocks. When arranging an attic in an existing attic, a windproof, vapor-permeable material is attached with special slats to the existing rafters. Tyvek also protects the insulating layer from moisture precipitation (rain, snow), falling into the air gap in strong winds or through leaks in the coating. "Tyvek" is laid on the insulation with an overlap of 150-200 mm along the dotted lines applied to the sheet of the material, and attached to the structure with wooden slats with nails, staples or glue.

Mansard vapor barrier device

On the inner (bottom) side, the heat-insulating material is protected from humidification by water vapor contained in the air of the room, with a layer of vapor barrier - polyethylene film, glassine, roofing felt or foil vapor barrier material "Polykraft" by Monarflex. The material is laid with a 100 mm overlap and the seams are glued with adhesive tape. The use of adhesive tape not only ensures the tightness of the seams, but also allows you to reduce the amount of overlap to 100 mm (both vertically and horizontally), regardless of the slope of the roof. The film is attached to rafters or bars with thin wooden slats. Foil materials are laid with foil towards the room, and it is advisable to leave a small gap between the vapor barrier and the inner lining. In this case, the shiny surface of the aluminum foil will reflect the heat radiation coming from the room to the outside and reduce the amount of heat loss through the attic covering.

From the inside, the attic room is clad with plasterboard sheets, plywood, boards or clapboard, which are attached to wooden bars or metal profiles installed on the inside of the rafter legs.

Additional insulation of existing attics

As a rule, the attic does not occupy the entire overlapping area of \u200b\u200bthe upper floor, since its longitudinal walls are not arranged in the plane of the outer wall, but at some distance from it. The overlap area between the attic wall and the cornice, adjacent to the outer wall of the house, extends beyond the volume of the attic room to be heated, so it must be insulated. To do this, lay a vapor barrier "Polycraft" (foil side down), polyethylene film, etc. on top of the floor boards, then a layer of insulation and a windproof vapor-permeable material. The insulation should be laid so that "cold bridges" do not form in the area where the floor joins the wall.

There are often cases when the existing attic insulation does not provide the required level of thermal insulation. High heating costs, the formation of icicles in winter and the drumming of raindrops in summer indicate that the attic flooring needs additional insulation (and at the same time soundproofing). You can insulate the attic by placing the insulation on top of the existing insulation in compliance with all the rules for installing thermal insulation in the attic. This option of insulation eliminates the need to reduce the height of the ceiling and the usable area of \u200b\u200bthe room to be insulated, but requires dismantling the roof and battens, as well as the construction of a supporting frame for a new roof covering.

An additional layer of insulation can be placed under the existing thermal insulation. For this, a frame made of wooden beams is installed on the inner lining of the attic, between which plates of heat-insulating material are placed between them. The height of the bars should correspond to the thickness of the insulation layer. From the side of the room, the insulation must be protected with a vapor barrier material, which is attached to the wooden bars of the frame. From the inside, the room is finished with clapboard, plasterboard sheets, plywood, etc. This method of insulation is not associated with dismantling the roof, work can be done not only in summer, but also in winter, however, the usable area and height of the room decrease.

In some cases, the best option for insulation may be a combined method, when the attic ceiling is insulated on top of the existing insulation, and its inclined surfaces are insulated from the inside. In any case, we must not forget about additional insulation of the vertical walls of the attic and part of the ceiling located near the outer wall outside the heated attic room.