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the construction of a warm attic automatically implies insulation of the roof. They insulate it from the inside, while insulating an attic with your own hands is a lot of operations, each of which requires precision. Errors in operation, even minor ones, can subsequently lead to serious damage to roof structures. The danger is that shortcomings may appear too late, when correcting them will be problematic. By using modern materials question, how to make a warm attic, can be solved quite efficiently, and you will learn how to do this on this page.
Choosing insulation for the attic
Almost any insulation material is suitable for roof insulation. For example, the now popular polyurethane foam (PPU), in addition, mineral wool, polystyrene foam (known to most as polystyrene foam). Suitable for covering backfill insulation, in particular expanded clay.
The thickness of the insulating layer is taken depending on the area, based on thermal engineering calculations. When laying mineral wool slabs, or roll insulation, must fit tightly into the space between the beams, and also press well against each other so that the insulation layer is a single whole. The seams between the foam boards are filled with polyurethane foam.
Insulating materials have a certain thermal conductivity; the lower it is, the better the material will conserve heat. Figure 1 shows the thermal conductivity of the most popular insulation materials.
How to insulate an attic with your own hands
The work is carried out as follows:
1. We check the serviceability of all, especially those that will be closed during insulation. The wood is treated with antiseptics and problem areas are repaired.
2. We check the integrity of the vapor barrier (if any). If necessary, we install a vapor barrier. Places of damage to the existing vapor barrier are patched with repair tape.
3. Checking availability ventilation gap 40-50 mm between the roof and the vapor barrier, if we use min. cotton wool for insulation. It is necessary for ventilation of the under-roof space and removal of moisture from the insulation. We also check whether there is a gap on the roof overhang through which air should flow between the roof and the insulation. The air should exit at the ridge of the roof, providing traction; we also check there for gaps. If suddenly this is not the case, it must be ensured. Vent. a gap when using mineral wool for roof insulation is required, otherwise min. the cotton wool will not be ventilated, will become saturated with moisture and will lose its thermal insulation properties over time.
4. The space between the elements is carefully filled thermal insulation material, if the thickness of the layer is insufficient, an additional layer of insulation is placed on top. The joints of the insulation are placed perpendicular to the legs of the rafters, and the joints of the layers should overlap. Bulk insulation is used to insulate the ceiling.
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The attic is the highest building in the house that is not used for housing. To ensure the comfort of housing and maintain a constant temperature, the attic must have good and high-quality ventilation. Good ventilation the attic is also necessary for the owner to preserve the roof of the house, prevent the appearance of types of fungi and mold, which is important for the health of all family members.
Ventilation is important at any time of the year. So in the summer, when there is great heat, ventilation prevents heating of living spaces, and in winter, when frost, condensation, freezing appears, attic ventilation makes it possible to prevent the appearance of dampness in the house. Therefore it is correct done attic ventilation is of great importance for ensuring coziness and comfort in the home.
Attic ventilation in the picture
Attic ventilation depends on its type. There is a difference between a cold attic and a warm one. In a cold attic, only the ceiling is insulated; this type of attic is most common. A warm attic is used if various tanks and pipes are placed on it. It is insulated to prevent these systems from freezing.
The attic is made warm even if it is planned to be used in the future. If all this is missing, then making the attic warm is impractical. In any case, the attic, both cold and warm, should be well ventilated.
Ventilation of cold attics
Cold attics are subject to constant temperature changes depending on the time of year, so their ventilation must be controlled. To do this, during construction you do not need to completely cover the sheathing and rafters of the roof of the house. Another option would be use of stitching with open intervals for air intake.
Of great importance outer covering roofs. If the roof is covered with slate or ondulin, but is not lined with a film for vapor barrier or wind barrier, then in this case ventilation is not needed. This roofing material allows air to pass through very well, in addition, the method of laying the material allows air to freely penetrate into the attic (seams, ridges). Ventilation of such an attic occurs naturally.
Ventilation diagram attic space
If for covering metal tiles are used, it should be taken into account that although it allows air to pass through well, condensation forms under it as a result of evaporation. Therefore, there is a need to use a film underneath. If your house has a gable roof, then we make holes in the gables to ventilate the attic. The second option is to make gaps of the same size when covering the gables and wind overhangs.
What to do if the gables are stone? Everything is very simple - we make holes in the wall at certain intervals to avoid air stagnation, i.e. for normal circulation. To regulate ventilation, it is desirable that the holes can be closed as needed; we install a grille to prevent penetration of foreign objects and small living creatures.
To provide ventilation, they use dormer windows. Moreover, whether or not to glaze them depends on the desire of the owner and the type of roof.
Ventilation of warm attics
When building a house with a warm attic, the roof must be made of ventilated material. If we use flexible tiles or sheet metal, then you need provide space for ventilation. This can be done by nailing an additional counter batten to the rafters. At metal coating use windproof film.
If the covering is made of slate, then the counter batten may not be used, then the air will enter through the sheathing and exit through the ridge on the roof. The owner will ventilate the warm attic in the same way as the room. Air enters through the windows and exits through special ventilation holes. If these are not provided, we will equip the roof special holes(fungi).
It is very good if all this is provided for during the construction of the house. If this is not the case, then the owner can install it all himself.
When planning ventilation system it is necessary to take into account that the ventilation must be reliable, able to withstand any weather changes, the material for the holes is plastic or aluminum (not subject to corrosion). The installation location is of particular importance ventilation holes- This the cleanest area of the attic, the air should not become clogged or blocked. Don't forget about appearance at home, because dormer windows, fungi, etc. can give your home a unique look.
All roofs can be divided into two types according to their design characteristics: combined roofless roofs and attic roofs. Combined roofs, in turn, are divided into ventilated (with drainage layers or grooves) and non-ventilated. In the cavities of the layers of ventilated roofs, air exchange must occur with the help of wind and heat pressure. All attic roofs are divided into three types: cold attic, warm attic and open attic. Let's look at each type in detail.
Roofs with a cold attic
Roofs with a cold attic began to be erected in Moscow in the mid-fifties of the twentieth century. Roofs of this type were then erected over many residential and public buildings, since this type provided a guarantee (in comparison with bitumen) of many years of operation. Also at the same time, roofs with a semi-through attic appeared in Moscow. The design of roofs with a cold attic allows air to enter from ventilation ducts directly into the atmosphere. Why channels within sections using ventilation ducts combined to reduce the number of intersections between the roof and the rolled carpet. Thus, a certain temperature is maintained in the attic through natural ventilation, preventing condensation and the formation of frost on the lower surface roofing panels. Such ventilation significantly limits heat loss from the premises of the building.
The advantage of a roof with a cold attic:
Roofs with a warm attic
In this roofing system, the attic floor is not thermally insulated - the closed volume of the attic independently performs the duties of a prefabricated ventilation chamber static pressure. Ventilation air entering the warm attic from the premises is removed into the atmosphere through the general exhaust. The entire volume of the attic is heated by warm ventilation air from the premises, which is why the enclosing structures of such an attic must have increased thermal protection and be carefully sealed.
Advantages of roofs with a warm attic:
Important! According to sanitary and hygienic requirements, sewer and garbage chute exhaust pipes and channels from the technical underground are not led into the attic. The exhaust parts of the sewer risers should be combined within the attic with cast iron pipes and discharged with one pipe through an exhaust shaft. An exhaust shaft for releasing air into the atmosphere is installed in the middle at equal distances from the ventilation units.
Roofs with open attic
In a roof design with an open attic, the attic floor is thermally insulated, and outside air enters it through openings measuring 700x300 mm, located along the perimeter of the attic in 1 m increments. This air is removed through exhaust vents. The principle of operation of an open attic is that a mass of dry outside air enters the attic space and removes moisture from the premises. The peculiarity of the open attic is the combination of warm and cold attic systems.
Advantages of roofs with an open attic:
But a roof with an open attic, unfortunately, has a number of significant disadvantages, such as:
Such inconsistency in properties shows that roofs with an open attic are best used in southern regions. Intensive ventilation of the attic space reduces overheating of the upper floors from solar radiation, when the reinforced concrete coating acts as a continuous sun screen.
A separate type of roofing can be identified as a roll-free reinforced concrete roof - this structure has a non-passable, semi-passable or walk-through attic and a covering of special reinforced concrete elements. The design of the roll-free floor does not have an attic; it is replaced by a covering of reinforced concrete elements, which perform enclosing and heat-insulating functions and protect the premises from atmospheric influences. In roll-free roofs, waterproofing compounds only protect the concrete surface of the coating from premature destruction by the atmosphere, and the waterproofness of the joints of the roofing panels and their interface with the enclosing structures is solved by constructive methods. Roll-free reinforced concrete covering consists of supporting elements - trusses, frames, pitched beams, etc. and reinforced concrete slabs under mastic waterproofing insulation. Roll-free reinforced concrete roofs are divided into:
By drainage method- with a central drainage tray made of separate trough-shaped panels, three-sided panels and a funnel tray with a drainage funnel; with drainage trays located near the parapet walls; with external unorganized drainage.
By type of mating of roofing slabs- with sides located above the roof panel flange; with gutters along the edges of the roof panels.
According to the method of joining roofing slabs to frieze panels- using additional elements; with extension along the edges of the building onto fascia panels.
According to the design of roofing panels- single-layer of heavy or light concrete; multilayer or with heat-insulating liners; with conventional reinforcement.
An uninsulated roof (cold attic) is usually an acceptable solution for those who have no plans to use the attic. This solution is perfect for people who have enough living space below. The advantages of a cold attic are as follows:
- saving money and effort (it is either not necessary to insulate a cold attic at all, or it is much easier and cheaper than a warm one);
- using an uninsulated attic space as a cold warehouse for storing things that have no place in living rooms Oh.
The warm attic is suitable option for those who need to organize additional under the roof living space. In particular, attics are equipped as children's rooms and recreation rooms. IN in this case you can get a full-fledged second floor without the incredible financial costs of its special construction. To make it pleasant to live in an insulated under-roof space, it will be enough to properly insulate it. An insulated attic will become no less comfortable for living than ordinary living rooms.
Arrangement of the attic using insulation laying
In structures located in a cold under-roof space, the insulation should be placed directly into the ceiling “pie” or laid on top of the ceiling. Wherein rafter system remains uninsulated. This arrangement technology is relevant for unused attic spaces. Therefore, in this case, it does not matter at all what will be laid on top of the rafters - hard or soft roofing.
Arranging a cold-type attic allows you to significantly save money, because... insulation is installed only on wooden floor, the area of which is significantly smaller than the area of large under-roof slopes that are thermally insulated in the case of a warm attic, which is described below.
The scheme for arranging a warm attic space involves financial costs that are many times more expensive than arranging a cold attic, since the thermal insulation of the roof slopes will require quite a lot of insulation and waterproofing material. If the under-roof space is used wisely, then along with the thermal insulation of the slopes, its ceiling is also insulated. In this case, the insulation will also become a sound insulator.
Arrangement of the attic using ventilation
The ventilation scheme in the cold under-roof space assumes the presence of ventilation ducts in the roof eaves. It works like this: when warm air exits through special aerators and dormer windows located in the upper part of the roof, it is replaced by cold air that enters through the lower vents. So in the attic you get a complete forced ventilation, the principle of which is the difference in the levels of the location of the ventilation holes.
The ventilation scheme in a warm under-roof space involves the installation of a ventilation duct located over the entire area of the under-roof slopes. For this purpose, under roofing The sheathing and counter-lattice are installed. Then warm air will begin to enter the attic at the level of the eaves, then rise to the top and exit through the aerator formed by the roofing strip.
Insulation of cold attic floors
There can be no talk of a warm attic here, since all the insulation materials described below are the prerogative of the ceilings of cold attic spaces. The technology for insulating a cold under-roof space, as a rule, involves the use of mineral wool, which is the basis of thermal insulation. So, the work is carried out according to the following scheme.
- Vapor barrier. First, the cold attic should be sealed from steam. This is a mandatory step if mineral wool is subsequently used as insulation. The purpose of vapor barrier is to prevent steam from below from penetrating through the ceiling into the mineral wool fibers. Wet cotton wool acquires additional thermal conductivity, which makes insulation useless. To install a vapor barrier you need a top ceiling lay a vapor barrier membrane.
- Laying mineral wool. Mineral wool slabs should be laid in 2-3 layers between the joists. The cotton wool is placed in such a way that upper layer covered the gaps between the slabs in the bottom layer, and the total thickness of the insulation was at least 10 cm. In addition, plank or plywood flooring should be placed on the insulation laid flush with the top of the joists.
The technology for insulating the floors of a cold attic can be done not only with mineral wool, but also with expanded clay backfill with a fraction of 1.5 cm or more. Work on this type of insulation is carried out as follows.
- Vapor barrier. Since expanded clay, like mineral wool, absorbs moisture well, the spaces between the joists should be lined with a vapor barrier membrane in advance.
- Expanded clay backfill. Only after installing the vapor barrier should the expanded clay be filled in and leveled at intervals.
- Flooring. Next you need to lay plywood sheets(or other sheet material). This is done for two reasons: firstly, in this case the expanded clay backfill will not pull moisture from the air, and secondly, it will be possible to move freely along the ceiling.
Other insulation for a cold attic
- Expanded polystyrene boards. Polystyrene foam should be placed in the gaps between the logs in 2-3 layers to eliminate cold bridges. No waterproofing is needed.
- Polyurethane foam. The foam material is sprayed onto the ceiling. Interacting with air, it gains volume and polymerizes, after which it hardens.
- Ecowool. It is a cellulose product that can be used to fill gaps between joists or pour over the ceiling.
- Sawdust. Like cellulose, it is an excellent eco-friendly material, but as humidity increases, the thermal conductivity of sawdust increases, which is not good. In addition, sawdust is a favorite haven for rodents.
Central Order of the Red Banner of Labor
research and design institute
standard and experimental housing design
(TsNIIEP housing) State Civil Engineering
M Moscow Stroyizdat 1986
Thermal engineering calculation of a roof with a warm attic is presented; the areas and conditions of its application are indicated; technical and economic indicators of the design and operating requirements are given.
For engineering and technical workers of design and research institutes.
Developed by TsNIIEP housing of Gosgrazhdanstroy (candidate of technical sciences A.N. Mazalov). Materials from the TsNIIEP housing of the Gosgrazhdanstroy and the results of research from the MNIITEP (candidate of technical sciences I.I. Staroverova, engineer I.S. Svidersky) were used.
1. GENERAL PROVISIONS
1.1. A fundamentally new solution for a reinforced concrete roof - the so-called “warm attic” * - was first used in Moscow on residential buildings built according to MNIITEP designs. The attic space of the roof is used as a prefabricated static pressure ventilation chamber into which all ventilation ducts of the residential premises open and the air from which is removed through a common exhaust shaft. The advantages of a roof with a warm attic are: improved ventilation of the upper floors; increasing the reliability of the roof; reduction of heat loss top floor; simplification of the coating design; accessibility for inspection and repair.
* Auto. date No. 460365 - “Discoveries, inventions, industrial designs, trademarks”, No. 6, 1975
1.2. These Recommendations apply to the design of reinforced concrete roofs with a warm attic for residential buildings from 5 to 16 floors inclusive, built in all climatic regions, using roll or non-roll roofing.
1.3. The work contains recommendations for the construction of a warm attic and the design of its enclosing structures. Design of other structures and engineering equipment, including roofing and ventilation, must be carried out in accordance with current building codes. When calculating the ventilation system, it is advisable to use the recommendations of MNIITEP.
1.4. The attic space of the roof with a warm attic is used as a prefabricated ventilation chamber, heated by air exhaust ventilation, therefore, its enclosing structures are subject to requirements for thermal protection and sealing.
The warm attic room should be used to accommodate and Maintenance elements of the building's engineering equipment, as well as for roof repairs.
1.5. The enclosing and load-bearing structures of a roof with a warm attic must correspond to the main structures of the building in terms of the materials used, design solutions, manufacturing and installation technology.
The internal surfaces of the walls and attic coverings, according to sanitary requirements, painted with white mineral dyes.
1.6. Application technical solutions and roof structures that differ significantly from those adopted in these Recommendations are allowed after additional research and only for experimental construction.
2. CONSTRUCTION OF A WARM ATTIC
2.1. A roof with a warm attic consists of an interior space and enclosing structures: attic covering, external walls and attic floor. As a rule, the covering is performed with insulation, the ceiling - without it. Schematic diagram roofs with different covering solutions, see fig. .
2.2. To ensure air exchange, the attic space is constructed as a single volume within the planning section of the house. Inside a warm attic, it is not allowed to install insulated compartments with temperature and humidity conditions that differ from the conditions of a warm attic. When using solid internal structures dividing the room (support panels, high purlins, etc.), their total area should be no more than 30% of the area cross section attic.
Rice. 1. Roof diagram with a warm attic
a - coating c roll roofing; b - covering with roll-free roofing;
1 - lightweight concrete covering panel under the roll roofing; 2 - exhaust ventilation shaft;
3 - protective umbrella; 4, 5 - tray panels; 6 - two-layer covering panel with roll-free roofing;
7 - external walls of the attic; 8 - head of the ventilation unit; 9 - internal drain;
10 - support panel; 11 - attic floor; 12 - drain pan
2.3. Adjacent sections of the warm attic are separated by solid fireproof walls, in which a sealed door measuring 1.5 x 0.8 m or a hatch measuring 0.8 x 0.8 m is installed.
In the area of built-in loggias, it is advisable to install the outer walls of the attic in a plane façade walls at home, and above the loggias at the attic floor level, lay floor slabs with a layer of thermal insulation.
2.5. The entrance to the attic and exit to the roof should be made only from the staircase through a fireproof door 1.5 × 0.8 m, installed with sealing gaskets. The entrance to the warm attic is provided in each section of the house, and access to the roof - in accordance with SNiP II-2-80 "Fire safety standards for the design of buildings and structures" - in the end sections and for every 1000 m 2 of coverage. It is not allowed to establish access to the roof directly from the warm attic through a hatch in the roof or through a door in the exhaust shaft.
For access to the attic and roof, it is recommended that flights of stairs be brought up to the attic level. In buildings with an elevator, access to the roof is through a door in the wall of the staircase and elevator unit. In buildings without an elevator (and with a lowered machine room), access to the roof is provided through a separate superstructure with a door and hatch.
All doors and hatches in a warm attic must be equipped with special locking devices.
2.6. The exhaust parts of the house's sewer risers are combined within the attic section and discharged through the exhaust shaft. The prefabricated ventilation riser pipe is installed in the corner of the shaft and brought to the level of the wall.
Pipelines for engineering equipment are laid near the structures of a warm attic at a distance of no more than 0.4 m from the surface of the coating, floor or walls and taking into account convenient access to them.
2.7. The water intake funnel of the internal drain is installed in the middle part of the drainage tray or valley and is connected to the drain riser by outlet pipes. Internal drainage pipes within a warm attic are not insulated and are painted with anti-corrosion compounds.
Drainage trays are placed along the average longitudinal axis of the coating, usually at the same level. For all solutions for trays, a minimum height must be ensured underneath them (see paragraph). The slope of the roof towards the tray is ensured by the inclined laying of the covering panels.
2.8. It is advisable to illuminate a warm attic room with natural light through openings in the upper half outer wall. Light openings are filled with glass hollow blocks, installed, as a rule, in two rows (layers) in the plane of the wall. With a single-layer filling, the heat loss of light openings is taken into account in the thermal engineering calculation. The area of the openings is assumed to be 1 - 2% of the floor area. It is not allowed to use window frames to fill light openings.
2.9. Consoles and mechanisms for hanging repair cradles are not allowed inside a warm attic. It is recommended to install them on the attic covering, which is designed for additional load.
3. VENTILATION SYSTEM CONSTRUCTION
3.1. In panel buildings with a warm attic, unified ventilation units with prefabricated main ducts to the height of the building and bypass ducts to the height of the floor should be used. Ventilation ducts in brick and block houses are made according to a similar scheme.
The dimensions of the ventilation ducts in the blocks must be such that the maximum air flow on one floor exceeds the minimum flow on the other by no more than 1.3 times. In this case, exhaust fans for kitchens on upper floors are not installed.
To release air from the ducts into a warm attic on ventilation units On the upper floor, special heads are installed that act as an air flow diffuser. Separate channels from the upper floor should be left in the heads.
3.3. Air is released from a warm attic into the atmosphere through a common exhaust shaft, one for all apartments in each section of the house or an isolated part of the attic. The construction of a combined exhaust shaft for apartments in different sections of the house is not allowed. The exhaust shaft is located in the central part of each section of the attic, at approximately equal distances from the ventilation units. The shaft is installed, as a rule, on the attic covering, outside the drainage tray, and the shaft inlet is located at the level of the lower surface of the covering. It is not allowed to lower the walls of the shaft to attic floor with side holes installed in them.
At rectangular section holes in the plan, the ratio of the long side to the short side for a free-standing shaft should not exceed 1.5, and for an attached shaft - 2.
Rice. 2. Head of the ventilation unit for a paired installation
a - cross section; b - top view; 1 - concrete head;
2 - ventilation ducts of the upper floor; 3 - prefabricated channels from kitchens and bathrooms;
4 - attic floor panel; 5 - ventilation block
4.4. Domestic support structures roofs are usually made of flat concrete panels installed above the internal load-bearing walls building. The support panels are made with holes of such dimensions that the opening of the structure is at least 50%.
4.5. It is recommended to attach the exhaust shaft to the wall machine room elevator, and the shaft should be 0.5 m higher than the covering of this room. When installing a free-standing shaft, its stability in the wind must be ensured. The exhaust shaft rests on the load-bearing structures of the roof or the supporting elements of the attic.
The exhaust shaft is made in the form of a prefabricated spatial box, rectangular or round shape(see Fig.), with insulated or non-insulated walls. If there is no drainage pan under the shaft (see paragraph), its walls must have a thermal protection of at least 0.7 of the calculated thermal resistance of the coating, for which it is recommended to make them from expanded clay concrete panels with a concrete layer. If there is a pallet, the walls of the shaft can be made uninsulated, but made of dense frost-resistant concrete (see item) with a minimum wall thickness of 60 mm.
Rice. 3. Diagram of the exhaust ventilation shaft
a - with roll roofing; b - with a roll-free roof; 1 - covering panel with roll roofing;
2 - junction of the rolled roof; 3 - concrete wall of the shaft; 4 - roll-free coating panel;
5 - waterproofing; 6 - protective metal apron; 7 - pallet supports;
8 - exhaust from sewer risers; 9 - drain pan;
10 - twist for condensate drainage; 11 - attic floor
It is allowed to use exhaust shafts with a metal frame lined with asbestos-cement sheets on one side (not insulated) or on both sides (with internal filling with heat-insulating material).
Protective umbrella made of reinforced concrete slab or asbestos cement sheet is installed on metal racks above the shaft at a distance equal to 0.7 of the hole width, with an overlap in each direction beyond the edge of the shaft by 0.4 of the hole width. If necessary, additional protection of the shaft can be provided with louvered grilles or wind deflectors.
Drain pan welded from metal sheets and painted with anti-corrosion compounds, it is installed with a gap on the ceiling along the waterproofing layer (Fig.). The depth of the pan is taken to be 0.15 - 0.3 m (depending on the intensity of rainfall in the area), the size in plan corresponds to the size of the shaft opening, increased by 0.3 m in each free direction. It is possible to use pallets from other durable materials, including dense waterproof concrete. The drain pan is usually not connected to drainage system buildings and water is removed from it by evaporation.
In areas with particularly unfavorable climatic conditions, it is permissible to install a drainage pan in combination with a protective umbrella.
5. LOFT STRUCTURES
5.1. The covering of a warm attic consists of highly prefabricated panels that combine load-bearing, heat-protective and waterproofing functions and are made in the form of a single structural and installation element. The covering panels are made non-ventilated, and their normal wet state is ensured by the arrangement of protective layers and limiting the initial moisture content of the insulation (see paragraphs; and).
It is prohibited to use construction coatings (with backfill and monolithic layers), which have low performance properties and are highly labor intensive.
5.2. By functional purpose the coating differs: covering panels (roofing panels), forming inclined surfaces (slopes) for water drainage, and tray panels (trays) for collecting and draining atmospheric water into the internal drainage system.
The attic covering should usually be solved along the longitudinal design diagram, with the roofing panels resting on the drainage tray and the outer walls of the attic, with the panels symmetrically positioned relative to the tray.
The design of the attic covering must ensure freedom of temperature deformations in the joints of the panels and in the support units.
In this case, rigid connections are not placed at the top of the panels.
Panels and covering trays are designed, as a rule, to be bent according to a beam pattern, with a relative deflection of no more than 1/200 of the span. The use of continuous structures in prefabricated roofing is not recommended.
The covering panels have a constant thickness along the entire length and are usually reinforced with conventional reinforcement.
5.3. Depending on the type and method of waterproofing, the attic covering is performed:
with roll roofing - from layers of rolled roofing material (roofing felt), sequentially glued at the construction site;
with mastic roofing - made from layers of waterproofing mastic (including reinforced) with protective properties not inferior to roofing made from standard roofing material;
with roll-free roofing - made of mastic and painted waterproofing materials that perform protective functions together with waterproof and frost-resistant concrete panels;
with a concrete roof - made of weather-resistant concrete that performs all protective functions without additional surface waterproofing.
Rice. 4. Covering structures with roll roofing
a - from single-layer solid panels; b - from single-layer panels with thermal liners;
insulation; d - using ribbed roofing slabs; g - using multi-hollow
flooring; 1 - panel made of load-bearing lightweight concrete; 2 - roll roofing; 3 - sealing gasket;
4 - concrete key; 5 - rigid slabs of effective insulation; 6 - layers of dense concrete;
7 - lightweight concrete low density; 8 - layers of heavy concrete; 9 - poured thermal insulation;
10 - thermal insert of the joint; 11 - hollow-core flooring; 12 - protective layer of concrete;
13 - ribbed roofing panel
In some cases, it is advisable instead of factory production special panels(Fig., a - d) produce panels based on existing standard designs industrial-type ribbed roofing slabs (Fig. , e) or hollow-core flooring (Fig. , g), on top of which, in field conditions, thermal insulation and protective layers with the above characteristics are laid. When the thickness of the concrete flange of the load-bearing roofing slab (Fig. , e) is less than 40 mm, a layer of vapor barrier made of roofing material or film is glued under the insulation.
Rice. 5. Covering structures with roll-free roofing
a - from two-layer solid panels; b - from panels with thermal liners;
c - from three-layer panels with low-density concrete; g - made of three-layer panels with efficient
insulation; d - from multi-hollow panels with various thermal insulation; 1 - roofing layer of concrete;
2 - layer of load-bearing lightweight concrete; 3 - concrete cover; 4 - sealing gasket;
5 - rigid slabs of effective insulation; 6 - layer of dense concrete;
7 - lightweight concrete of low density; 8 - layer of heavy concrete; 9 - transverse voids;
10 - poured thermal insulation
At the joints of panels for roll roofing (Fig.), it is recommended to make a concrete key in the lower third of the panel thickness and install a sealing gasket on the mastic at the mouth of the joint, filling the middle part of the joint with a heat-insulating liner.
In a three-layer panel with porous expanded clay concrete (Fig. , c), its density is assumed to be 800 - 900 kg/m 3, and the strength of the lower layer should be at least B-15.
The concrete of the bottom layer and load-bearing ribs of a three-layer panel with effective insulation(Fig. , d). To reduce thermal inhomogeneity, the thickness of the insulation in the panel (Fig. , d) is taken to be at least 100 mm when using materials of the type (Fig. , b).
For the future, a coating solution made of multi-hollow panels is proposed (Fig. , e), which, with a unified design solution, can have different amounts of thermal protection. The latter is provided by internal air voids, filled, if necessary, with monolithic thermal insulation made of effective materials (foaming foam). The voids are placed in the expanded clay concrete layer of a two-layer panel according to (Fig. , a).
A reliable solution for the joint of roll-free panels is to cover it with a U-shaped reinforced concrete cover over the entire length of the panel (Fig.) Sealing gaskets are installed in the lower and upper parts of the joint, the middle part of the joint is filled with soft insulation. Other joint protection and sealing solutions must undergo manufacturing and performance testing.
5.7. Drainage trays, which are an integral part of the non-roll covering, are usually designed in the form of trough-shaped panels, in which the bottom slope is towards drainage funnel is formed by a variable thickness (60 - 150 mm) of the roofing layer of concrete. The side longitudinal ribs carry the load from the roofing panels, and the end ones serve to form a joint and organize an overflow, for which the middle part of the end rib is lowered or a recess is made in it. The upper part of the tray (bottom and ribs) is made of concrete roofing layer, and the lower part repeats the solution of the type of covering panel in which the tray is used.
Solutions for drainage trays that overlap each other (“cascade” trays) do not provide maximum dimensions for the attic and increase the range of products.
The minimum width of the tray is determined by its width open area(between the drain ribs at least 900 mm) and with the decisions made for the tray assembly (see paragraph) is 1800 mm.
The minimum value of the indicator (brand) at
rollless roofing ( painting waterproofing)
concrete roof (without surface waterproofing)
Compressive strength class
Tensile strength class
Waterproof grade
Water absorption by mass
Frost resistance grade above -15 °C:
in the external range from -15° to -35 °C
five-day temperatures below -35 °C
In addition, concrete of the roofing layer without surface waterproofing must have increased crack resistance (shrinkage and temperature); moisture resistance (wetting - drying cycles) in hot and humid areas; heat resistance (heating - cooling cycles) in hot, dry areas, as well as corrosion resistance in the atmosphere of industrial cities.
Waterproofing applied at the factory to the top surface of non-roll panels must meet the following requirements:
compressive strength of at least 0.5 MPa;
adhesion to concrete with shear not lower than 1.0 MPa;
frost resistance of at least 100 cycles;
waterproof at a pressure of at least 8 atm;
heat resistance (on a vertical surface) not less than 90 ° C;
relative elongation at 20 °C is not less than 200%.
Rice. 6. Solutions for cornice and tray assembly in roll-free covering
a - cornice unit; b - tray assembly; 1 - end rib; 2 - concrete cover;
3 - sealing gasket; 4 - panel drain rib; 5 - drainage tray;
6 - tray support console; 7 - covering panel; 8 - outer wall;
9 - trimming the panel (with the same wall height)
It is also recommended to carry out the cornice assembly with the covering panel overlapping the outer wall, with the end of the panel protected by a cantilever extension of the roofing layer with an increase in the end rib (Fig.). If necessary, the cornice assembly is made with a parapet 200 - 600 mm high, which is formed by extending wall panel, covered on top with reinforced concrete L-shaped stone.
To maintain a constant level of support areas on the walls in the eaves assembly and a uniform slope of the coating when changing the width of the body, it is recommended to trim the bottom layer on the support section of the covering panels, which for existing projects does not exceed 90 mm.
5.10. Roll-free covering of a warm attic can be designed based on other constructive solutions and insulating materials, in compliance with proven design principles (see paragraphs; ; ). Such coating structures must undergo production and operational testing in experimental construction.
The main direction of subsequent improvement of the attic covering should be the maximum lightweighting of structures through the use of effective structural and thermal insulation materials. Coating solutions with single-layer panels of concrete on porous aggregates, which have increased strength, thermal insulation and waterproofing properties, including panels on prestressing cement, are appropriate. Promising designs can be considered panels with internal voids filled with monolithic thermal insulation, including panels made of extruded asbestos cement, as well as reinforced cement sheets.
6. THERMAL CALCULATION OF A WARM ATTIC
6.1. The thermal engineering diagram of a warm attic is a movable interconnected system, the calculation of which is carried out according to winter conditions to determine minimal heat loss building or minimal thermal protection of the coating.
Thermal engineering calculations are based on ensuring sanitary and hygienic conditions of the living space, maintaining the thermal balance of the unheated attic space and preventing condensation from forming in the attic. inner surface its external fences.
Heated air from the exhaust ventilation of the house and heat entering through the attic floor should be taken as heat sources. If necessary, heat release from heating and hot water supply pipelines is also taken into account. Heat loss in the attic is calculated through the covering and external walls.
according to the condition of ensuring the sanitary and hygienic condition of the premises of the upper floor, the minimum permissible air temperature in the attic is
If the temperature of the inner surface of the coating is low, the air temperature in the attic should be determined based on the condition that condensation is not allowed:
The following notations are used in the calculation formulas () - ():
Heat transfer resistance of the attic floor and the outer wall of the attic, m 2 °C/W;
- heat transfer coefficient of the internal surface of the floor and coating, W/(m °C);
D t n - standard temperature difference at the inner surface of the attic floor, °C;
t V ; t n - temperature of internal and external air, °C;
t veins - temperature of the air entering the attic from the ventilation ducts, °C;
q veins - specific heat input into the attic with ventilation air, W/m 2 °C;
F st - reduced area of the external walls of the attic.
1. SNiP II-L.1-71*. Residential buildings;
It is recommended to take the heat transfer coefficient of the inner surface of the coating when calculating according to the condition of inadmissibility of condensation according to the experimental values given in Table. .
table 2
|
Inner surface of the coating |
Number of floors of the house |
||||
|
Ribbed |
|||||
|
With partitions |
|||||
When installing a drainage tray, the coefficient values should be taken according to clause 3 of the table. .
Rice. 7. Estimated internal surface temperature
t until- main coating; t cold- cold area
The average temperature of the coldest five-day period with a probability of 0.92 is taken as the calculated outside air temperature (SNiP 2.01.01-82. Construction climatology and geophysics). When calculating a warm attic for residential buildings of 12 floors or more, subject to the condition of inadmissibility of condensation, the calculated external temperature can be taken based on the average temperature of the coldest period (SNiP 2.01.01-82. Construction climatology and geophysics). In this case, the required temperature regime is ensured due to the large thermal inertia of the roof with a warm attic.
The temperature of the inner surface of the coating is determined from the condition of inadmissibility of condensation at the calculated outside temperature and depending on the moisture content of the air in the attic (see paragraph). It is recommended to take the permissible minimum temperature value according to the graph in Fig. .
It is recommended to increase the temperature of the air coming from the ventilation ducts by 1 °C relative to the calculated air temperature of living rooms according to (SNiP II-L.1.-71*. Residential buildings).
Specific heat inputs from ventilation air are determined as the ratio of the product of air flow (according to the standards for exhaust from residential premises SNiP II-L.1.-71 *. Residential buildings), (m 3 / h) by its heat capacity 1 kJ/(kg °C ) and density (1.21 kg/m 3) to the area of the attic covering (m 2). For preliminary and general calculations, it is recommended to take the value from the table. (with security 0.8)
The area of the external walls of a warm attic is determined according to design data and is reduced to 1 m2 of coverage. For preliminary and general calculations, you can take the value of the reduced area equal to 0.4, which corresponds to the end section with a wall height of 1.75 m.
Table 3
|
Specific heat inputs from ventilation air in houses (W/m 2 °C) |
|||
|
gasified |
electrified |
||
|
Thermal resistance of the snow layer, m 2 °C/W |
|||
Intermediate values are interpolated and, taking them into account, the actual heat transfer resistance of the cold section is determined, against which the temperature of the inner surface of the coating is checked. When there is snow cover, condensation on the surface of the cold area is excluded.
The calculation of enclosing structures for this case is carried out according to the condition of inadmissibility of condensation in the following sequence:
in accordance with the established procedure (see paragraph) using formulas () and (), the heat transfer resistance of the coating is found, for which the minimum air temperature in the attic is calculated using formula () according to the condition of inadmissibility of condensation; in this case, the outside temperature is entered with a value that cannot be lower than the initial value by more than 10 °C;
at minimum temperature in the attic, the specified heat transfer resistance of the insulated attic floor is determined
(7)
When installing additional insulation on the ceiling, the thickness of the layer of a given material is determined by the formula
(8)
where l ut - coefficient of thermal conductivity of the insulation material (according to condition “A”), W/m °C.
The calculation is completed by checking the actual air temperatures in the attic and outside using formulas () and () and performing, if necessary, repeated clarifying calculations.
The thermal capabilities of a 5-storey building make it possible by insulating the attic floor to reduce the calculated external temperature by 10 - 15 °C, which on average does not reach the required temperature level for the attic of a 9-storey building by 3 °C. Therefore, the use of a unified coating panel is not always possible.
6.7. The thermal efficiency of a roof with a warm attic is expressed by a decrease in heat loss from the attic floor relative to the standardized (SNiP II-L.1-71*. Residential buildings) value of 35 W/m2 (30 kcal/m2 h).
If it is necessary to reduce the total heat loss of the building to the control values (Gosgrazhdanstroy. Control indicators specific consumption heat for heating residential buildings - Order No. 419 of December 28, 1983) or specified indicators, the thermal engineering calculation of the roof is carried out with minimal heat loss, for which a reduced value is determined heat flow through the ceiling:
(9)
where Δ q F - specified value for reducing specific heat consumption relative to the control indicator, W/m 2 of total area;k- the coefficient for converting the attic floor area to the total area of the house is assumed to be 0.27 for a 5-story building and 0.16 for a 9-story building.
The heat flow value is entered in formula () instead of the equivalent expression D t n α in . The resulting air temperature in the attic cannot be equal to or higher than the internal temperature, therefore, in further calculations, a value lower than the internal temperature by at least 2 ° C is used. The corresponding increase in thermal protection of the coating caused by a decrease in heat loss should be checked in accordance with SNiP II-3-79. Construction heating engineering, etc., using economic calculations based on reduced costs.
I climatic region
II - III climatic regions
IV climatic region
Number of floors of buildings
Roof with roll roofing over an attic covering made of panels:
single-layer solid (load-bearing expanded clay concrete)
single-layer with effective thermal inserts
using ribbed roofing slabs
using hollow-core flooring
Roof with roll-free roofing and attic covering made of panels:
two-layer (heavy concrete and load-bearing expanded clay concrete)
double-layer with effective thermal inserts
three-layer (with low-density expanded clay concrete)
three-layer (heavy concrete and effective insulation)
Note. The following symbols are used in the table: P - preferential use is recommended; D - may be used for justification; N - not allowed to be used.
Table 6
|
Given costs, rub. |
Operating costs, rub. |
Labor intensity, person-hours |
Material consumption, kg |
||||||
|
Total |
estimated cost |
capital investments |
Total |
including heating |
general |
at the construction site |
cement |
steel |
|
|
Roofs with roll roofing |
|||||||||
|
Single-layer 250 mm of expanded clay concrete 1100 kg/m 3 |
|||||||||
|
Single layer 250 mm with thermal inserts made of foam 50 mm |
|||||||||
|
Roofs with non-roll roofing |
|||||||||
|
Two-layer 250 mm with expanded clay concrete 1100 kg/m 3 |
|||||||||
|
Double-layer 250 mm with 100 mm foam inserts |
|||||||||
|
Three-layer 250 mm with expanded clay concrete 800 kg/m 3 inside 150 mm |
|||||||||
|
Three-layer 250 mm with 150 mm foam insulation in reinforced concrete |
|||||||||
|
Multi-hollow 250 mm with poured foam (100 mm) |
|||||||||
7.4. When choosing a design for a preliminary assessment of various solutions, it is recommended to use technical and economic indicators various designs coverings of a warm attic, per 1 m of the total area of a 9-story building, given in table. . The types of roofs and panels adopted in it correspond to Table. and rice 5v
By cost
By labor intensity
7.5. To ensure the design conditions for the operation of the ventilation system of the house and the enclosing structures of the warm attic, the roof must be operated in compliance mandatory rules technical maintenance and service. In matters of technical operation of roofs, one should be guided by the instructions of these Recommendations, for which purpose the main conditions for their proper operation should be briefly outlined in the explanatory note to the project.
7.6. To avoid disruptions in the operation of the ventilation system of buildings, all doors and hatches of entrances and exits to the attic, as well as in intersection partitions, must be securely closed during ventilation operation. To do this, they are provided with the installation of special locking devices that prevent them from being opened by unauthorized persons.
Lighting of the attic must be provided at any time of the day, for which the electrical wiring of the scoop is connected to the emergency electrical lighting network.
7.7. When accepting houses for operation, the correct installation and connection of ventilation units and ducts, as well as the cleanliness of the ducts and heads, must be checked. During operation, you should constantly monitor the condition of the channels and heads, preventing them from becoming clogged with debris and dust. It is allowed to install protective nets and gratings on the ends, with cells measuring at least 50 mm.
7.8. Cleaning of a warm attic room should be carried out in the event of a noticeable accumulation of dust deposits on the floor from waste ventilation air. The frequency of cleaning is determined by the intensity of dust. Cleaning is done dry - using vacuum cleaners or wet - using moistened brushes and rags. Wet cleaning of a warm attic by washing the floor and walls with jets of water is not allowed, due to the lack of waterproofing and drainage devices in the ceiling.
During operation, the attic covering should be regularly cleaned of dirt, especially drainage trays and water inlet funnels.
Snow removal may be carried out in certain areas only in the event and location of leaks. When cleaning the coating, it is prohibited to use crowbars, steel shovels and scrapers.
7.9. Monitoring the technical condition of the roof should be carried out through scheduled, general and partial inspections, and, if necessary, extraordinary ones. Periodic general inspections are carried out in the fall and spring, inside the attic and outside the roof. Extraordinary inspections are carried out after particularly strong winds, heavy rains and snowfalls, as well as periods of extreme natural temperatures.
When inspecting roofs, the main points to pay attention to are:
safety of the roof (roll and non-roll) on the coating;
condition of the surface of roofing reinforced concrete elements (with roll-free roofing);
tightness of connections of roofing elements;
condition of parts and components of the coating (drain, cornice, etc.);
condition of drainage devices.
7.10. To eliminate concrete defects that have arisen during the operation of roll-free roofing elements, partial repair of the surface is carried out by clearing the peeling section of concrete, treating with a polyvinyl acetate PVA suspension and applying a layer of polymer cement mortar to restore the damaged panel profile. Cracks that appear in the concrete are also sealed with a polymer-cement mortar, while a crack with an opening of more than 0.2 mm is preliminarily cleared. To seal cracks in drainage gutters, it is advisable to use epoxy compositions.
Restoration of paint waterproofing should be carried out periodically and according to the technology provided technical specifications for relevant materials.
BIBLIOGRAPHY
1. Guide to the design and installation of reinforced concrete roofs with roll-free roofing for residential and public buildings / SibZNIIEP. - M.: Stroyizdat, 1979. - 39 p.
2. Guidelines for calculating the humidity conditions of building envelopes / NIISF Gosstroy USSR. - M.: Stroyizdat, 1984. - 168 p.
3. Guidelines for determining the estimated cost and labor intensity of prefabricated production reinforced concrete structures at the design stage. Constructions of residential and public buildings/ NIIES, NIIZHB, TsNIIEP housing. - M.: Stroyizdat, 1977. - 81 p.
4. Rules and standards for the technical operation of the housing stock / Ministry of Housing and Communal Services of the RSFSR. - M.: Stroyizdat, 1977. - 260 p.
5. Reinforced concrete roofs multi-storey residential buildings: Review / CSTI. - M., 1982. - Issue. 8. Designs of residential and public buildings. - 64 s.
