The requirements are related to the design of attic floors. Attic floor

SEI SPO "Podolsky College"

Serpukhov branch

by discipline

"Features of constructive solutions"

"Design and construction of the attic floor"

Student of the group 140/1 "SEZiS"

Baibakov DM

Teacher: Balakina II

Evaluation ______________________

Date "___" _____________ 2008

Introduction

Design attic floor

Design of the attic

Construction of attic

Heat insulation of attics

Steam insulation device

Additional insulation of existing attics

Mansard lighting

Interior

Reference material

Bibliography

Introduction

Attic is the part of the building that is in use, the enclosing structures of which simultaneously perform the functions of the roof.

"Mansard" - this is the French word. In 1630 French architect Franzois Mansar first used an attic space for residential purposes. Such an attic floor was named after his name "MANSARD".

In accordance with SNIP 2.08.01-89 * "Residential buildings" - "Floor attic ( attic) - a floor in the attic space, the facade of which is completely or partially formed by the surface (surfaces) of an inclined or broken roof, while the intersection line of the roof plane and the facade should be no more than 1.5 m above the floor level of the attic floor. "

Attic floor can occupy the entire area of the building, or a part of it, but, as a rule, within 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 mansard premises in individual construction is justified by a number of reasons. Device mansard allows you to optimally use the living space, significantly saving space, and money spent on construction. The design of the attic floor in the attic space or on the flat roof of buildings reduces the 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 repairing the roof.

Device mansard roof has its differences, which are caused by the fact that it is exposed to various influences, not only from above, but also from below: warm moist air from residential premises rises and falls in the form of condensate 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, take care of the device of thermal insulation, waterproofing and vapor barrier. The attic floor has the largest overall contact surface with the external environment, therefore requires effective and thorough thermal insulation.

Functions and planning solutions

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

When designing the attic floor, the choice of the planning variant should be based on the analysis of the planning layout of the building-base, determined in the study of the social need of the given residential formation and carried out in accordance with the current regulatory requirements.

It is necessary to distinguish 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 the two-level development of the upper floor of the building-base.

Design attic floor

The design and geometry of the roof defines the architectural form of the crowning part of the building, and this, in turn, necessitates the creation of a unity of constructive and architectural solutions in interrelation with the internal space conditioned by the functional purpose.

The choice of this or that architectural and construction system of the attic floor includes the definition of the bearing structure and fencing, as well as the organization construction works at the site in the built-up part of the city.

For mansard 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 weight of the structures must be minimal, taking into account the load that will be transferred to the existing building.

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

The roofing covering should correspond to the same prerequisites, that is, it should be made mainly of light materials in the form of metal sheets, metal roofing and the like. In cases where it is necessary to preserve the environment of the existing building, the covering is made of clay or cement-sand tiles, non-ferrous metal and other materials.

The inner lining of the attic fence is mainly made of gypsum boards. Internal partitions are expedient for carrying out by element-wise assembly with facing by gypsum cardboard sheets on racks from thin-sheeted profiles.

The attic floor is more exposed to heat losses than the lower floors for the simple reason that there is no "heat cushion" above it. It has a large common contact surface with the external environment. Therefore, for reasons of comfort and economy, effective and thorough thermal insulation is necessary. With higher thermal insulation, more stringent requirements are imposed on thermal compaction and its implementation. Such a seal does not allow warm air to penetrate the sealing layer. For thermal insulation, an effective insulation must be used, for example, a plate of mineral wool, c = 0.004 W / m oC according to the calculation. On the inside of the heater (turned to the room) provides a layer of vapor barrier, and on the outside - waterproofing. It is also important that between the upper side of the insulation layer and the underside roofing there was a sufficiently effective ventilation space that would facilitate ventilation and remove the inevitable flow of moist warm air that would penetrate through the steam barriers and the thermal insulation layer.

Design of the attic

· 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 placing attic rooms is their interrelation with the communication structure of the building - the foundation.

· Designed and there is a need interaction engineering systems and ensuring their joint work. (In the case when the attic functions do not coincide with the functions of the main building, special technical solutions are required).

· Of particular importance are the shape and dimensions of the premises, the choice of translucent fencing (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 the attic details are determined taking into account the unity of the structure and the architectural forms of the building-base (The use of light structures, parts and products is the main requirement).

· An attic with a steeply sloping roof requires a special approach to choosing roofing material, providing heat protection, sealing and waterproofing.

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

Construction of attic

· The design and geometry of the roof determines the architectural form of the crowning part of the building, and this, in turn, is the need to create a unity of constructive and architectural solutions in interrelation with the internal space conditioned by the functional purpose.

· The choice of this or that architectural and construction system of the attic floor includes the definition of the bearing structure and fencing, as well as the organization of construction works on the site in the built-up part of the city.

· For mansard 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 weight of the structures must 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. The use of stone and concrete materials to create a load-bearing structure of the attic floor on the restored and newly constructed building is not recommended.

· The roof covering should correspond to the same premises, that is, it should be made mainly of light materials in the form of metal sheets, metal roofing and the like. In cases where it is necessary to preserve the environment of the existing building, the covering is made of clay or cement-sand tiles, non-ferrous metal and other materials.

· The inner lining of the attic fence is mainly made of plasterboard sheets. Internal partitions are expedient for carrying out by element-wise assembly with facing by gypsum cardboard sheets on racks from thin-sheeted profiles.

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

· With higher thermal insulation, more stringent requirements are imposed on thermal compaction and its implementation. Such a seal does not allow warm air to penetrate the sealing layer. For thermal insulation, an effective insulation, such as a mineral wool board, with l = 0.004 W / m ° C, as calculated by thickness, should be used.

· On the inner side of the insulation (turned to the room), a vapor barrier layer is provided, and on the outside - waterproofing. It is also important that between the upper side of the insulation layer and the underside of the roofing there is a sufficiently effective ventilation space that would facilitate ventilation and remove the inevitable flow of moist warm air that will penetrate through the steam barriers and the thermal insulation layer.

Heat insulation of attics

Covering the attic should not only protect the house from precipitation (rain, snow), but also prevent cooling of the upper floor. Warm air always rises, so the air temperature under the ceiling is 2 ° C higher on average than in the middle of the room. With the same thermal insulation capacity of walls and roof, the heat loss through the latter will always be greater, which is caused by a large temperature difference between the outer and inner surfaces of the attic cover. In addition, the moisture content of warm air is usually higher than that of a cold one, so condensate on the ceiling of the upper floor can be formed 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 exterior walls.

Heat losses through the attic are large enough, therefore, the correctly executed insulation of its covering can bring a tangible economic effect. When comparing two typical two-storey houses with an area of 205 m2 with attics, insulated in accordance with the old and new requirements, it is established that the current level of heat protection allows to reduce heat losses through the coating by more than 3 kW and thereby significantly reduce the heating system power and reduce the cost of heating the house.

Icicles hanging from the roof represent a significant danger to people. In the process of knocking 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 the insufficient thermal insulation of the roof covering. Snow, heated from below by heat passing through a poorly insulated covering, begins to melt, and the water draining from the roof turns into icicles. Only with a well-made thermal insulation, icicles will not cause trouble in the winter.

Requirements for thermal protection of coatings

The standardization of the thermal protection of the enclosing structures, including roofs, is made in accordance with SNiP II-3-79 * " Building heat engineering(issued in 1998), taking into account the average air temperature and the duration of the heating season in the construction area.In accordance with these standards, the required reduced resistance to Ro roofing roofing for Moscow and Moscow region should be not less than 4.7 m2 ° C / W.

Design features

The moisture content of the warm internal air is higher than that of the cold outside, so the diffusion of water vapor (both through the attic cover and through the exterior walls of the building) is directed from the room to the outside. The outer (upper) part of the roofing is a waterproofing layer that does not pass water vapor well and conduces the formation of condensation moisture from the inner (lower) side of the roof. The consequences will not be long in coming: despite the well-made waterproofing of the roof, wet spots and mold will appear on the inner surface of the roofing, heat insulation qualities of the insulation will deteriorate, droplets of water will drop from the ceiling (not because of a roof leak, but as a result of condensation of water vapor) .

Taking into account the negative impact of moisture on the thermal insulation characteristics of materials, the insulation must be protected from moisture by water vapor contained in the air of the room, a layer of vapor barrier material, located on the inner (lower) side of the heater. To remove moisture, which for some reason has fallen into the thermal insulation material, a ventilated air layer should be provided between the heater and the external (waterproofing) layer of the roofing.

Very often, uninhabited attic premises are converted into residential attics, preserving the existing truss system. At the same time, trying to minimize the additional load on the load-bearing structures of the building, usually use a lightweight insulation of low density. Under the influence of wind, a "blowing" of low-density heaters takes place, accompanied by heat loss, so a layer of windproof vapor-permeable material must necessarily be placed on the surface of the thermal insulation, which borders on the ventilated layer, to preserve the thermal protection characteristics of the structure.

When insulating the attic, we must remember that heat losses occur not only through the coating, but also through the end wall. Therefore, the gable of the house must also be well insulated in accordance with modern requirements.

Warming of attic coverings

Structurally the attic cover consists of a rafters system, installed with a pitch of 600 ... 1000 mm. The space between the rafters is filled with heat-insulating material (heater). As a thermal insulation material it is recommended to use mineral wool plates based on basalt fiber or fiberglass. Thermal insulation boards or mats can be laid in one or more layers, the total thickness of the insulation layer depends on the thermal conductivity of the insulation, the value of which is necessarily indicated in the certificate of conformity.

Between a heater and a roofing covering arrange a ventilated air layer. From the inner (lower) side, the attic covering is protected with a vapor barrier material and finished with plasterboard sheets, lining, and the like. If the height of the rafter section is less than the required thickness of the heat-insulating layer, wooden bars are attached to the rafter feet on screws or nails. Plates of insulation are laid between them so that there is an air gap between the insulation and the roof. If the height of the cross-section of the rafters is insufficient, horizontal 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 heater and the roof depends on the profile of the coating material. In the case of profiled sheets made of galvanized steel, tiles, metal tiles and other wavy sheets, the thickness of the ventilated air gap should be at least 25 mm. At the device of a roof from flat sheets (asbestos cement sheets, the zinced steel, soft bituminous shingles, roll materials), an air gap of at least 50 mm is required. Ventilation of the air layer is carried out through the holes in the cornice and in the ridge.

Protection of the insulation from blowing

On the side of the ventilated air layer, the thermal insulation material must be protected with a windproof vapor permeable membrane. As practice shows, the best results can be obtained by using such roll materials, as "Tyvek Soft", "Monarflex BM 310" and "Monaperm 450V." Use as a windproof membrane of vapor-tight materials such as ruberoid or polyethylene film is completely unacceptable! It should be noted that membranes of the "Tyvek" type, which perfectly pass the water vapor, do not, however, allow the water to pass through the liquid phase, and therefore prevent the moisture from getting wet as a result of moisture condensing on the inner surface of the roof covering from the side of the air layer. This property of "Tyvek" materials allows to reduce the thickness of the air layer up to 25 mm regardless of the profile of the roofing, which is especially important when insulating the attic on existing rafters: an air layer of small thickness eliminates the need to install additional bars from the inside of the rafter legs. The heights of the rafter's foot will be sufficient to accommodate the heater of the required thickness and the device of a ventilated air layer.

When building a new house, windproof material is laid on top of the rafter's feet and attached using wooden bars. When building an attic in an existing attic, windproof vapor permeable material is fixed with special racks to existing rafters. "TYVEK" protects the warming layer and from humidification by atmospheric precipitation (rain, snow) falling into the air gap in strong winds or through leaks in the coating. "Tyvek" is laid on the heater with an overlap of 150 ... 200 mm on the dashed lines on the material sheet and attached to the structure with wooden strips nails, staples or glue.

Steam insulation device

From the inner (lower) side, the heat-insulating material is protected from moisture by water vapor contained in the room air, a layer of vapor barrier insulation - polyethylene film, pergamon, roofing paper or foamed vapor barrier "Polycraft" from Monarflex. The material is laid with the overlap of the panels of 100 mm and the joints 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. To the rafters or bars the film is fastened with thin wooden slats. Foiled materials are laid with foil towards the room, and between the vapor barrier and the inner lining it is desirable to leave a small gap. In this case, the shiny surface of the aluminum foil will reflect the thermal radiation from the room to the outside, and reduce the amount of heat loss through the attic cover.

From the inside, the attic room is faced with plasterboard sheets, plywood, boards or lining, which are attached to wooden bars or metal profiles installed on the inside of the rafters.

Additional insulation of existing attics

Typically, the attic does not occupy the entire floor area of the upper floor, because its longitudinal walls are arranged not in the plane outer wall, but at some distance from it. The section of the ceiling between the attic wall and the cornice, adjacent to the outer wall of the house, goes beyond the volume of the heated attic room, so it must be insulated. To this end, a vapor barrier "Polycraft" (foil side down), a polyethylene film, etc., then a layer of insulation and a windproof vapor permeable material are laid on top of the floor boards. The insulation must be laid so that in the zone of abutment of the overlap to the wall there are no "bridges cold ".

It is not uncommon for the existing insulation of the attic to not provide the required level of thermal insulation. Large expenses for heating, the formation of icicles in winter and the drumming of raindrops in the summer indicate that the attic coverage needs additional insulation (and at the same time in soundproofing). Insulate the attic is possible by placing the insulation over the existing insulation in compliance with all the rules for installing insulation in the attic. This option of insulation eliminates the need to reduce the height of the ceiling and the useful area of the insulated space, but it requires the dismantling of the roof and the roofing, as well as the structure of the supporting frame for the new roofing.

An additional layer of insulation can be located and under the existing thermal insulation. For this, on inner lining attic set up a framework of wooden beams, between which "" vosporsor "place slabs heat insulating material. The height of the bars should match the thickness of the insulation layer. From the side of the room, the insulation must be protected with a vapor barrier material, which is fixed to the wooden bars of the frame. From the inside, the room is finished with a lining, plasterboard sheets, plywood, etc. This method of insulation is not associated with the dismantling of the roof, the work can be done not only in summer, but also in winter, but the useful area and height of the premises are reduced.

In some cases the best option warming can be a combined method, when the roof of the attic is insulated over the existing thermal insulation, and its sloped surfaces are insulated from the inside. In any case, you should not forget about the additional insulation of the vertical walls of the attic and part of the floor, located near the outside wall outside the heated attic room.

Mansard lighting

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

Skylights pass the right amount of light with a smaller opening area, compared to traditional windows. The norms established a minimum ratio of the light area of the attic windows to the floor area of all living rooms and kitchens in the apartments and hostels of the attic floors, equal to 1:10. The light from the dormer spreads evenly throughout the room, while there are no blind side compartments that obscure the light.

Designing mansards with light flows

Vertical window structures create sharp light changes - shadow niches, which has a very negative effect on the perception of the attic as a whole, giving rise to a feeling of restraint 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, the light is shining somewhere ahead, hard, uncomfortable, and even stifling. But real problems begin when it's time to arrange furniture. If the vertical end wall is "occupied" with a window, you can not 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 question of any interior solution. Little by little old things begin to accumulate here, and eventually the attic becomes a trivial loft.

Everything can be different, if even at the design stage of the house to provide sloped roof windows.

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

Ventilating devices of dormer windows

Ventilating devices of roof windows allow to ventilate the room with the window closed. This is very convenient, especially when it's bad weather in the street. And when you open the attic window, the rotating frame, rotating around the horizontal axis, forms two airflows: incoming and outgoing. Thanks to the separation, these flows are not mixed, so ventilation becomes much more efficient. With vertical windows, this effect can be achieved only by arranging a good draft. In addition, the niches of the dormer windows, in themselves, impede the movement of air, significantly worsening its circulation.

To install the attic window, much less time and materials are spent than building a vertical "birdhouse". And if you remember that with the complex arrangement of the attic, the area of the windows is subtracted from the total area of the roof, then, given the high thermal and waterproofing of the roof windows, you can save a lot on insulation and roofing materials.

And, finally, the inclined window is more reliable than the vertically located "birdhouse". After all, the entire design of the roof window is designed to ensure that in any bad weather, whether it's rain, snow or wind, a person could only watch ironically the elements, knowing that in the attic it will always be light, warm and cozy.

But what to do, if in the architectural appearance of the chosen house an important role is played by vertical windows? It's okay here. With the right combination, vertical and inclined windows never "argue" with each other. Even in cases where a vertical window is indispensable, an additional installation of dormer windows will significantly improve the lighting and ventilation of the room, form an arbitrary layout of the attic. Thus, the attic as if born again, turning into the most comfortable place in the house.

Interior

When developing the interior of the attic floor, it is necessary to take into account some characteristic geometric shapes of the premises. It is about the placement of stairs, bathroom and toilet, kitchen, as well as the placement of doors. It is necessary to take into account the free height of the staircase flights with respect to the inclined roof surfaces. There are no difficulties when the direction of the ladder - parallel to the slope of the roof or staircase is located on the middle axis of the building. Free height, usually, does not represent a problem, but it is necessary to consider the placement of possible parts and assemblies roofing construction.

The furnishing of the bathroom and toilet should be taken taking into account the inclined roof surfaces that limit the height to full height.

The placement of doors can be difficult not only because of the height of the doorway itself. It is also necessary to take into account the unobstructed opening of the door taking into account the sloping wall.

Fire protection requirements

Fire safety requirements, especially the ways of evacuation of the attic floor, depend on the planning structure of the building-base: if the functions of the building-base and the functions of the attic floor coincide for evacuation routes, a staircase-elevator building is used, to which the attic adjoins; if the functions of the building-base and the attic floor do not coincide, special communication devices are required to create evacuation routes that can be inside or outside the building and have isolated exits, including between two buildings.

It is allowed that there are no outlets to the stairwell from each floor of the apartment in two levels provided that the premises are located no higher than the 6th floor and the apartment is provided with an additional exit. The device of evacuation exits in the general staircase from creative workshops is allowed provided that it is possible to communicate through the tambour.

When placing offices and offices in the attics of residential buildings that have no more than 9 floors, the entrances and evacuation exits should be isolated from the residential part of the buildings. It is allowed to take the stairwells of the residential part of the building as the second evacuation exit, while the exit is provided through a tambour with fire doors. The dormer window can serve as a rescue opening through which people from the premises can be evacuated.

Requirements SNiP to design of attic floors

Requirements for SNiP 2.08.01-89, which most fully reflect the specifics of designing attic floors over residential buildings. Guided by these requirements, Russian architects designed the attic for 10 years (since 1994, the change №2 came into force). It is known that with the entry into force of the law "On Technical Regulation", SNiPs and GOSTs will be recommendatory in nature (except for items related to security).

General indications Sanitary and hygienic requirements, illumination and insolation 1.1 *. The height of living rooms from floor to ceiling should be at least 2.5 m, for climatic subareas IA, IB, IG, ID, IIA - not less than 2.7 m. The height of floors from floor to floor for residential houses of social purpose is recommended not to take more than 2,8 m, for climatic subareas IA, IB, IG, ID, IIA - no more than 3,0 m. B. The height of intra-apartment corridors should be not less than 2,1 m. Using this norm and the rule of determining the area of the attic floor ( Annex 2, paragraph b), we can obtain a formula for calculating the possible use of an attic for residential purposes: a\u003e b + 0,7хс; where a is the area of the room with a height of more than 2.5 m, b is the area of the room with a height of 1.1 m to 2.5 m, c is the area of the room with a height of 0.8 m to 1.1 m (see Fig. .1).

Figure 1 - Rules for calculating the area of the attic floor

1.3*... Daylight should be taken in accordance with the requirements of SNiP 23-05-95. In this case, the ratio of the area of the light apertures of all living rooms and kitchens of apartments and hostels to the floor area of these premises, as a rule, should not exceed 1: 5.5. The minimum ratio should be at least 1: 8, for mansard floors, when using attic windows it is allowed to take a ratio of 1:10. This paragraph indicates that when using roof windows located in the roof slope, a 25% smaller glazing area is allowed in comparison with the use of vertical windows in the standard floor. Unfortunately, when using loukarene / dormer windows in the attic, the designers use a factor of 1: 8 in calculating the glazing area, which leads to insufficient illumination of the premises. This coefficient is provided for the calculation of translucent structures in a traditional floor with vertical walls. When using vertical windows in the attic, deep slopes form in which up to 2/3 of natural light is delayed compared to the attic window (see Figure 3).

Figure 3 - The principle of calculating the glazing area

Floors and degree of fire resistance 1.13 *. It is permitted to build the buildings of I, II and III degrees of fire resistance with a single attic floor with load-bearing elements having a fire resistance rating of at least R45 and a fire hazard class KO, regardless of the height of buildings set forth in Table 1, but not more than 75 m. The attic must meet the requirements imposed on the structures of the superstructure. When using wooden structures, constructive fire protection should be provided to ensure these requirements. There is an opinion that wooden structures in the attic floor are prohibited. In fact, with proper protection of the structure and height of the building to 75 m, this prohibition does not exist. It is proposed to use antiperspirant impregnation for wooden parts of the attic. With existing known impregnation technologies (it is possible that impregnations with better characteristics have already been invented), it is required to repeat this operation three to five years later, which is impossible with constructive solutions that have become widespread in Russia. Therefore in SNiPah there is an instruction to use constructive protection. How to confirm the conformity of the selected constructive solutions specified norm? Our company tested a sample of the structure of the covering and overlapping of the attic floor (see Figure 2). This design showed the results (REI75 and K045), exceeding the minimum requirements of SNiPs. A similar design was tested by other firms, and the results were confirmed. There is a simple technique that increases the fire resistance of the roofing structure - it is laying under the wooden rafters 100-millimeter layer of mineral wool. It serves not only as heat and sound insulation, but also for protecting the load-bearing structures from the effects of flame and temperature. The same method is used in the case of load-bearing structures from rolled and cold-bent metal profiles. Another issue that often arises: an indication in the SNIP of "one attic floor". On this issue, we consulted with Gosstroy experts and received the following answer. The requirements specified in clause 1.13 apply to the installation of a single attic floor. If, on the basis of technical and economic indicators or architectural decisions, a multi-level attic is required, then measures should be developed and agreed with firefighting authorities to ensure safety in the building (in the attic). These activities can be summarized as follows: increase the fire resistance of structures; fulfillment of requirements for evacuation, including from two-level apartments;

Fig. 2 - Sample of the structure of the covering and overlapping of the attic floor

1.25 *. In residential buildings sectional type with a total area of apartments on the floor of the section to 500 square meters. m inclusive, it is allowed to provide an evacuation exit from the floor of the section to one staircase. At the same time, in each apartment located at an altitude of more than 15 m, emergency exits should be envisaged as per item 20 * a), b) or c) SNiP 21-01-97 *. (6.20 * The emergency exits also include: a) access to a balcony or loggia with a blind partition not less than 1.2 m from the end of the balcony (balcony) to the window opening (glazed door) or at least 1.6 m between the glazed openings exiting on the balcony (loggia); b) an exit to a crossing not less than 0.6 m wide 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 that connects the balconies or loggias floor by floor ... SNiP 21-01-97 "Fire safety of buildings and structures") For an apartment located on two levels, provide access to the staircase from each floor is not required provided that the premises of the apartment are located no higher than the 6th floor and the floor of the apartment that does not have direct access to the stairwell 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 up to 28 m in height inclusive of one m (including mansard) floor. In this case, the superstructured floor must be provided with an emergency exit as per item 6.20 * a), b) or c) SNiP 21-01-97 *. The question arises, why to the attic in comparison with the standard floor less stringent requirements for fire safety are applied. Analyzing the regulations different countries, we found that in many of them the requirements depend on the floor, and not on the number of storeys. For example, as shown in Figure 4, if the building is one-story, then its requirements for fire resistance are 30 minutes, if the building is 4-storey with an attic, then to regular floors - 60 minutes, and to the attic - 30 minutes. This is due to the fact that the attic is always the last floor: accordingly, people from the attic are evacuated through the underlying floor, as well as people living on this floor. The second question in this vein: fire, as a rule, spreads upwards. Accordingly, the probability of ignition of the underlying floor tends to zero. Based on the European experience of fire extinguishing of attics, no such case has been recorded so far. Here are objective reasons for making less stringent requirements to the attic floors and, as a result, to use light structures.

Figure 4 - Requirements for fire resistance of the structure

Non-residential floors

1.35. The height of public buildings placed in residential buildings may be taken equal to the height of living quarters, except for premises where the equipment must have a height of at least 3 m in terms of equipment location. 1.36 * ... On the top floor, artists 'and architects' while the message of the floor with the stairwell should be provided through the tambour. In the superstructured attic floor of buildings of II degree fire resistance with a total height of not more than 28 m, it is allowed to locate offices of office type in coordination with local authorities, taking into account the fulfillment of the requirements of paragraph 1.38. 1.38 *. Public premises, except public facilities for hostels and homes for the elderly and families with disabilities, must have entrances and evacuation exits isolated from the residential part of the building. When placing office premises in an overbuilt attic floor, it is allowed to take staircases of the residential part of the building as the second evacuation exit, with the message of the floor with a staircase to be provided through a tambour with fire doors. The door in the vestibule, facing the stairwell, should be provided with opening only from the inside of the room. These points allow the placement of office space in the attic above the residential floors in the presence of a second evacuation exit. There are the following solutions: to attach the external staircase; Use the black staircase in the old buildings. Accordingly, for studios of artists and architects, it is sufficient to access one staircase.

Reference material

Roof - this is the upper enclosing structure of the building, performing load-bearing, waterproofing and, with uncrossed (combined) roofs and warm attics, heat-insulating functions.

Roof - this is the top element of the roof (covering), protecting buildings from all kinds of atmospheric influences.

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

Roof The building consists of the following elements (see the figure): inclined planes called skates (1), which are based on rafters (2) and lath (3). The lower ends of the rafter legs rest on the Mauerlat (4). Crossing of skates forms inclined (12) and horizontal ribs. The horizontal edges are called the ridge (5). Crossing skates, forming incoming corners, create valleys and valleys (6). The edges of the roof above the walls of the building are called cornice eaves (7) (are located horizontally, protrude beyond the outline of the outer walls) or gable overhangs (11) (located obliquely). The water along the slopes flows down to the wall troughs (8) and is diverted through the water intake funnels (9) into the drain pipes (10) and further into the storm sewer.

Types of roof shapes.

Shed roof is supported by its supporting structure (rafter system, farm, etc.) on the external walls located on the different levels. Shed roofs are most often used in the construction of verandas and terraces, outbuildings, warehouses.

Gable roof is the most common classical construction. It is also called gable. There are variants of roofs with hanging rafters or with inclined rafters. To numerous variants of this type it is necessary to attribute roofs with a uniform or non-uniform angle of inclination of a slope or the size of a cornice overhang.

Tent 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. Used for buildings in the form of a square or an equilateral polygon.

Hip roof . It is four-sloped: two slopes are trapezoids, and the other two, on the side of the end walls, are triangles (they are called hips ). Variety hip roof is semi-royal.

Multi-hood roof . It is arranged on houses with a complex polygonal plan. Such roofs have more end (inner corner) and ribs (protruding corners, which form the intersection of the roof slopes), which requires high qualification when performing roofing works.

Mansard roofs . To increase the volume of a residential attic space ( mansard), often slopes of various slopes are made: the lower ones are steeper and the upper ones are more flat. This type of roof construction is very popular with modern construction, t. effective use of the living area of the attic floor is ensured.

Dome and conical Roofs are used to block buildings in a circular outline in plan.

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

Literature Lists

1. Attic. Stairs. Construction of the attic. Making stairs: Reference / Comp. IN AND. Ryzhenko. - Moscow: Onyx Publishing House, 2007.

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

3. Attic and attic rooms. J. Coso. - Moscow: Publisher Kontent, 2008.

4. Attic. Eckers. Balconies. V.S. Samoylov, V.S. Levadnyi. - M .: Adelant Publishing House, 2006.

"Mansard" - this is the French word. In 1630 French architect Franzois Mansar first used an attic space for residential purposes. Such an attic floor was named after his name "MANSARD".

Functions and planning solutions

It is necessary to distinguish 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 the two-level development of the upper floor of the building-base.

Design attic floor

The choice of this or that architectural and construction system of the attic floor includes the definition of the bearing structure and fencing, as well as the organization of construction works on the site in the built-up part of the city.

The attic floor is more exposed to heat losses than the lower floors for the simple reason that there is no "heat cushion" above it. It has a large common contact surface with the external environment. Therefore, for reasons of comfort and economy, effective and thorough thermal insulation is necessary. With higher thermal insulation, more stringent requirements are imposed on thermal compaction and its implementation. Such a seal does not allow warm air to penetrate the sealing layer. For thermal insulation, an effective insulation must be used, for example, a mineral wool board, c = 0.004 W / m oC as calculated. On the inside of the heater (turned to the room) provides a layer of vapor barrier, and on the outside - waterproofing. It is also important that between the upper side of the insulation layer and the underside of the roofing there is a sufficiently effective ventilation space that would facilitate ventilation and remove the inevitable flow of moist warm air that will penetrate through the steam barriers and the thermal insulation layer.

Design of the attic

· 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 placing attic rooms is their interrelation with the communication structure of the building - the foundation.

· It is necessary to interact the projected and existing engineering systems and ensure their joint work. (In the case when the attic functions do not coincide with the functions of the main building, special technical solutions are required).

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

Construction of attic

Heat insulation of attics

Requirements for thermal protection of coatings

The standardization of the thermal protection of the enclosing structures, to which the roofs belong, is also made in accordance with SNiP II-3-79 * "Construction Heat Engineering" (issued in 1998), taking into account the average air temperature and the duration of the heating period in the construction area. In accordance with these norms, the required reduced resistance to Ro roofing roofing for Moscow and Moscow region should be not less than 4.7 m2 ° C / W.

Design features

Very often uninhabited attic rooms are converted into residential attics, preserving the existing roofing system. At the same time, trying to minimize the additional load on the load-bearing structures of the building, usually use a lightweight insulation of low density. Under the influence of wind, a "blowing" of low-density heaters takes place, accompanied by heat loss, so a layer of windproof vapor-permeable material must necessarily be placed on the surface of the thermal insulation, which borders on the ventilated layer, to preserve the thermal protection characteristics of the structure.

Warming of attic coverings

Ventilated air gap device

The width of the air gap between the heater and the roof depends on the profile of the coating material. In the case of profiled sheets made of galvanized steel, tiles, metal tiles and other wavy sheets, the thickness of the ventilated air gap should be at least 25 mm. When constructing the roof of 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 layer is carried out through the holes in the cornice and in the ridge.

Protection of the insulation from blowing

On the side of the ventilated air layer, 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 BM 310" and "Monaperm 450V." Use as a windproof membrane of vapor-tight materials such as ruberoid or polyethylene film is completely unacceptable! It should be noted that membranes of the "Tyvek" type, which perfectly pass the water vapor, do not, however, allow the water to pass through the liquid phase, and therefore prevent the moisture from getting wet as a result of moisture condensing on the inner surface of the roof covering from the side of the air layer. This property of "Tyvek" materials allows to reduce the thickness of the air layer up to 25 mm regardless of the profile of the roofing, which is especially important when insulating the attic on existing rafters: an air layer of small thickness eliminates the need to install additional bars from the inside of the rafter legs. The heights of the rafter's foot will be sufficient to accommodate the heater of the required thickness and the device of a ventilated air layer.

Steam insulation device

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

Typically, the attic does not occupy the entire floor area of the upper floor, since its longitudinal walls are not arranged in the plane of the outer wall, but at some distance from it. The section of the ceiling between the attic wall and the cornice, adjacent to the outer wall of the house, goes beyond the volume of the heated attic room, so it must be insulated. To this end, a vapor barrier "Polycraft" (foil side down), a polyethylene film, etc., then a layer of insulation and a windproof vapor permeable material are laid on top of the floor boards. The insulation must be laid so that in the zone of abutment of the overlap to the wall there are no "bridges cold ".

It is not uncommon for the existing insulation of the attic to not provide the required level of thermal insulation. Large expenses for heating, the formation of icicles in winter and the drumming of raindrops in the summer indicate that the attic cover needs additional insulation (and at the same time in soundproofing). Insulate the attic is possible by placing the insulation over the existing insulation in compliance with all the rules for installing insulation in the attic. This option of insulation eliminates the need to reduce the height of the ceiling and the useful area of the insulated space, but it requires the dismantling of the roof and the roofing, as well as the structure of the supporting frame for the new roofing.

An additional layer of insulation can be located and under the existing thermal insulation. For this purpose, a skeleton of wooden beams is installed on the inner covering of the attic, between which the plates of heat-insulating material are placed, the height of the bars must correspond to the thickness of the insulation layer.On the side of the room, the insulation must be protected with a vapor barrier material, which is fixed to the wooden bars of the frame. lining, plasterboard sheets, plywood, etc. Such a method of insulation is not associated with the dismantling of the roof, the work can be done not only in summer, but also in winter, eznaya area and ceiling height are reduced.

In some cases, the optimal method of insulation can be a combined method, when the roof of the attic is insulated over the existing thermal insulation, and its sloped surfaces are insulated from the inside. In any case, you should not forget about the additional insulation of the vertical walls of the attic and part of the floor, located near the outside wall outside the heated attic room.

Mansard lighting

Designing mansards with light flows

Everything can be different, if even at the design stage of the house to provide sloped roof windows.

Ventilating devices of dormer windows

Interior

When developing the interior of the attic floor, it is necessary to take into account some characteristic geometric shapes of the premises. It is about the placement of stairs, bathroom and toilet, kitchen, as well as the placement of doors. It is necessary to take into account the free height of the staircase flights with respect to the inclined roof surfaces. There are no difficulties when the direction of the ladder - parallel to the slope of the roof or staircase is located on the middle axis of the building. Free height, usually, does not represent a problem, but it is necessary to take into account the placement of possible parts and components of the roof structure.

The furnishing of the bathroom and toilet should be taken taking into account the inclined roof surfaces that limit the height to full height.

Fire protection requirements

Requirements SNiP to design of attic floors

General indications Sanitary and hygienic requirements, illumination and insolation 1.1 *. The height of living rooms from floor to ceiling should be at least 2.5 m, for climatic subareas IA, IB, IG, ID, IIA - not less than 2.7 m. The height of floors from floor to floor for residential houses of social purpose is recommended not to take more than 2,8 m, for climatic subareas IA, IB, IG, ID, IIA - no more than 3,0 m. B. The height of intra-apartment corridors should be not less than 2,1 m. Using this norm and the rule of determining the area of the attic floor ( Annex 2, paragraph b), we can obtain a formula for calculating the possible use of an attic for residential purposes: a\u003e b + 0,7хс; where a is the area of the room with a height of more than 2.5 m, b is the area of the room with a height of 1.1 m to 2.5 m, c is the area of the room with a height of 0.8 m to 1.1 m (see Fig. .1).

Figure 1 - Rules for calculating the area of the 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 the light apertures of all living rooms and kitchens of apartments and hostels to the floor area of these premises, as a rule, should not exceed 1: 5.5. The minimum ratio should be at least 1: 8, for mansard floors, when using attic windows it is allowed to take a ratio of 1:10. This paragraph indicates that when using roof windows located in the roof slope, a 25% smaller glazing area is allowed in comparison with the use of vertical windows in the standard floor. Unfortunately, when using loukarene / dormer windows in the attic, the designers use a factor of 1: 8 in calculating the glazing area, which leads to insufficient illumination of the premises. This coefficient is provided for the calculation of translucent structures in a traditional floor with vertical walls. When using vertical windows in the attic, deep slopes form in which up to 2/3 of natural light is delayed compared to the attic window (see Figure 3).

Figure 3 - The principle of calculating the glazing area

Floors and degree of fire resistance 1.13 *. It is permitted to build the buildings of I, II and III degrees of fire resistance with a single attic floor with load-bearing elements having a fire resistance rating of at least R45 and a fire hazard class KO, regardless of the height of buildings set forth in Table 1, but not more than 75 m. The attic must meet the requirements imposed on the structures of the superstructure. When using wooden structures, constructive fire protection should be provided to ensure these requirements. There is an opinion that wooden structures in the attic floor are prohibited. In fact, with proper protection of the structure and height of the building to 75 m, this prohibition does not exist. It is proposed to use antiperspirant impregnation for wooden parts of the attic. With existing known impregnation technologies (it is possible that impregnations with better characteristics have already been invented), it is required to repeat this operation three to five years later, which is impossible with constructive solutions that have become widespread in Russia. Therefore in SNiPah there is an instruction to use constructive protection. How to confirm the compliance of the chosen constructive solution with the specified norm? Our company tested a sample of the structure of the covering and overlapping of the attic floor (see Figure 2). This design showed the results (REI75 and K045), exceeding the minimum requirements of SNiPs. A similar design was tested by other firms, and the results were confirmed. There is a simple technique that increases the fire resistance of the roofing structure - it is laying under the wooden rafters 100-millimeter layer of mineral wool. It serves not only as heat and sound insulation, but also for protecting the load-bearing structures from the effects of flame and temperature. The same method is used in the case of load-bearing structures from rolled and cold-bent metal profiles. Another issue that often arises: an indication in the SNIP of "one attic floor". On this issue, we consulted with Gosstroy experts and received the following answer. The requirements specified in clause 1.13 apply to the installation of a single attic floor. If, on the basis of technical and economic indicators or architectural decisions, a multi-level attic is required, then measures should be developed and agreed with firefighting authorities to ensure safety in the building (in the attic). These activities can be summarized as follows: increase the fire resistance of structures; fulfillment of requirements for evacuation, including from two-level apartments;

Fig. 2 - Sample of the structure of the covering and overlapping of the attic floor

1.25 *. In residential buildings sectional type with a total area of apartments on the floor of the section to 500 square meters. m inclusive, it is allowed to provide an evacuation exit from the floor of the section to one staircase. At the same time, in each apartment located at an altitude of more than 15 m, emergency exits should be envisaged as per item 20 * a), b) or c) SNiP 21-01-97 *. (6.20 * The emergency exits also include: a) access to a balcony or loggia with a blind partition not less than 1.2 m from the end of the balcony (balcony) to the window opening (glazed door) or at least 1.6 m between the glazed openings exiting on the balcony (loggia); b) an exit to a crossing not less than 0.6 m wide 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 that connects the balconies or loggias floor by floor ... SNiP 21-01-97 "Fire safety of buildings and structures") For an apartment located on two levels, provide access to the staircase from each floor is not required provided that the premises of the apartment are located no higher than the 6th floor and the floor of the apartment that does not have direct access to the stairwell 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 up to 28 m in height inclusive of one m (including mansard) floor. In this case, the superstructured floor must be provided with an emergency exit as per item 6.20 * a), b) or c) SNiP 21-01-97 *. The question arises, why to the attic in comparison with the standard floor less stringent requirements for fire safety are applied. Analyzing the normative documents of different countries, we found that in many of them the requirements depend on the floor, and not on the number of storeys. For example, as shown in Figure 4, if the building is one-story, then its requirements for fire resistance are 30 minutes, if the building is 4-storey with an attic, then to regular floors - 60 minutes, and to the attic - 30 minutes. This is due to the fact that the attic is always the last floor: accordingly, people from the attic are evacuated through the underlying floor, as well as people living on this floor. The second question in this vein: fire, as a rule, spreads upwards. Accordingly, the probability of ignition of the underlying floor tends to zero. Based on the European experience of fire extinguishing of attics, no such case has been recorded so far. Here are objective reasons for making less stringent requirements to the attic floors and, as a result, to use light structures.

Figure 4 - Requirements for fire resistance of the structure

Non-residential floors

Reference material

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

Roofing is the top element of the roof (covering), protecting buildings from all kinds of atmospheric influences.

The most common in Europe and in Russia are various types of inclined or, to put it another way, pitched roofs.

The roof of the building consists of the following elements (see the figure): inclined planes called skates (1), which are based on rafters (2) and lath (3). The lower ends of the rafter legs rest on the Mauerlat (4). Crossing of skates forms inclined (12) and horizontal ribs. The horizontal edges are called the ridge (5). Crossing skates, forming incoming corners, create valleys and valleys (6). The edges of the roof above the walls of the building are called cornice eaves (7) (are located horizontally, protrude beyond the outline of the outer walls) or gable overhangs (11) (located obliquely). The water along the slopes flows down to the wall troughs (8) and is diverted through the water intake funnels (9) into the drain pipes (10) and further into the storm sewer.

Types of roof shapes.

Shed roof is supported by its load-bearing structure (rafter, truss system, etc.) on the outer walls, which are at different levels. One-pitched roofs are used most often in the construction of verandas and terraces, outbuildings, warehouses.

Gable roof is the most common classical construction. It is also called gable. There are variants of roofs with hanging rafters or with inclined rafters. To numerous variants of this type it is necessary to attribute roofs with a uniform or non-uniform angle of inclination of a slope or the size of a cornice overhang.

Tent 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. Used for buildings in the form of a square or an equilateral polygon.

Hip roof . It is four-sloped: two slopes are trapezoids, and the other two, on the side of the end walls, are triangles (they are called hips). A kind of hip roof is semi-royal.

Multi-hood roof . It is arranged on houses with a complex polygonal plan. Such roofs have more end (inner corner) and ribs (protruding corners, which form the intersection of the roof slopes), which requires high qualification when performing roofing works.

Mansard roofs . To increase the volume of a residential attic space (attic), often slopes of various slopes are made: the lower ones are steeper and the upper ones are more flat. This type of roof construction is very popular with modern construction. effective use of the living area of the attic floor is ensured.

Dome and conical Roofs are used to block buildings in a circular outline in plan.

Flat roofs find the widest application in both civil and industrial construction. Unlike pitched roofs, flat roofs do not use sheet and sheet materials as roofing. Here you need materials that allow the construction of a continuous carpet (bitumen, bitumen-polymer and polymer materials, as well as mastics).

1. Attic. Stairs. Construction of the attic. Making stairs: Reference / Comp. IN AND. Ryzhenko. - Moscow: Onyx Publishing House, 2007.

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

3. Attic and attic rooms. J. Coso. - Moscow: Publisher Kontent, 2008.

4. Attic. Eckers. Balconies. V.S. Samoylov, V.S. Levadnyi. - M .: Adelant Publishing House, 2006.

Fire protection requirements

Requirements SNiP to design of attic floors

General instructions Sanitary and hygienic requirements, illumination and insolation 1.1 *. The height of living rooms from floor to ceiling should be at least 2.5 m, for climatic subareas IA, IB, IG, ID, IIA - not less than 2.7 m. The height of floors from floor to floor for residential houses of social purpose is recommended not to take more than 2,8 m, for climatic subareas IA, IB, IG, ID, IIA - no more than 3,0 m. B. The height of intra-apartment corridors should be not less than 2,1 m. Using this norm and the rule of determining the area of the attic floor ( Annex 2, paragraph b), we can obtain a formula for calculating the possible use of an attic for residential purposes: a\u003e b + 0,7хс; where a is the area of the room with a height of more than 2.5 m, b is the area of the room with a height of 1.1 m to 2.5 m, c is the area of the room with a height of 0.8 m to 1.1 m (see Fig. .1).

Figure 1 - Rules for calculating the area of the 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 the light apertures of all living rooms and kitchens of apartments and hostels to the floor area of these premises, as a rule, should not exceed 1: 5.5. The minimum ratio should be at least 1: 8, for mansard floors, when using attic windows it is allowed to take a ratio of 1:10. This paragraph indicates that when using roof windows located in the roof slope, a 25% smaller glazing area is allowed in comparison with the use of vertical windows in the standard floor. Unfortunately, when using loukarene / dormer windows in the attic, the designers use a factor of 1: 8 in calculating the glazing area, which leads to insufficient illumination of the premises. This coefficient is provided for the calculation of translucent structures in a traditional floor with vertical walls. When using vertical windows in the attic, deep slopes form in which up to 2/3 of natural light is delayed compared to the attic window (see Figure 3).

Figure 3 - The principle of calculating the glazing area

Floors and degree of fire resistance1.13 *. It is permitted to build the buildings of I, II and III degrees of fire resistance with a single attic floor with load-bearing elements having a fire resistance rating of at least R45 and a fire hazard class KO, regardless of the height of buildings set forth in Table 1, but not more than 75 m. The attic must meet the requirements imposed on the structures of the superstructure. When using wooden structures, constructive fire protection should be provided to ensure these requirements. There is an opinion that wooden structures in the attic floor are prohibited. In fact, with proper protection of the structure and height of the building to 75 m, this prohibition does not exist. It is proposed to use antiperspirant impregnation for wooden parts of the attic. With existing known impregnation technologies (it is possible that impregnations with better characteristics have already been invented), it is required to repeat this operation three to five years later, which is impossible with constructive solutions that have become widespread in Russia. Therefore in SNiPah there is an instruction to use constructive protection. How to confirm the compliance of the chosen constructive solution with the specified norm? Our company tested a sample of the structure of the covering and overlapping of the attic floor (see Figure 2). This design showed the results (REI75 and K045), exceeding the minimum requirements of SNiPs. A similar design was tested by other firms, and the results were confirmed. There is a simple technique that increases the fire resistance of the roofing structure - it is laying under the wooden rafters 100-millimeter layer of mineral wool. It serves not only as heat and sound insulation, but also for protecting the load-bearing structures from the effects of flame and temperature. The same method is used in the case of load-bearing structures from rolled and cold-bent metal profiles. Another issue that often arises: an indication in the SNIP of "one attic floor". On this issue, we consulted with Gosstroy experts and received the following answer. The requirements specified in clause 1.13 apply to the installation of a single attic floor. If, on the basis of technical and economic indicators or architectural decisions, a multi-level attic is required, then measures should be developed and agreed with firefighting authorities to ensure safety in the building (in the attic). These activities can be summarized as follows: increase the fire resistance of structures; fulfillment of requirements for evacuation, including from two-level apartments;

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