Published: March 6, 2013

The roof is in a very difficult operating conditions because it is exposed to atmospheric factors for a long time. Uneven precipitation, temperature deformations, creep phenomena and shrinkage of reinforced concrete floorings have a harmful effect on the strength and water tightness of the roof. In industrial areas, in addition, chemically aggressive substances contained in the atmosphere have a destructive effect on the roof and form weak concentrations of acids and alkalis in the first minutes of rain. In particularly unfavorable operating conditions are the roofs of hot shops, which experience not only excessive heating, but also significant dynamic effects from overhead cranes with a rigid suspension of working equipment (rolling, stripper shops, etc.).

The foregoing allows us to conclude that when choosing the material and construction of the roof, in addition to the physical and chemical properties of the material and the construction area, it is necessary to take into account the specifics and microclimate of production.

The roofing material must be of low weight, be durable, allow the smallest coating slope, be easy to install and repair, and meet the requirements of deformability and fire resistance.

Roofs are divided into rolled, asphalt rollless, asbestos-cement and metal.

Roll roofs meet many of the requirements noted above and allow you to arrange coatings with a zero slope. The materials used for roll roofing include isol, brizol, polyethylene film, roofing material, glassine, roofing felt, hydroisol, tar-bitumen and gudrokamovy materials, roofing fiberglass and fiberglass.

Depending on slope roll roofing industrial buildings may be flat (slope<2,5%) и скатные (уклон ≥ 2,5%). Наибольшие уклоны скатов при рулонных кровлях не должны превышать 25%.

In order to ensure water tightness, roofs are arranged from several layers, the number of which is assigned based on the magnitude of the slope:

at i ≥ 15% - two-layer without a protective layer;
with i ≥ 10% - three-layer without a protective layer;
at 2.5 ≤ i< 10% - трехслойные с защитным слоем;
for 0 ≤ i< 2,5% -четырехслойные (и более) с защитным слоем.

Rolled roofs with more than four layers are used in operated coatings or in those areas of the coating where technological equipment is installed and passages are provided.

The sticker of rolled materials is produced with bituminous, tar and other mastics, depending on the roofing material. When assigning the heat resistance of the mastic, it must be taken into account that on clear summer days the roofing carpet can heat up to 70-80 °, and in the coatings of hot shops up to 100 ° and above. In case of insufficient heat resistance, the mastic softens and flows down the slope. This causes a breakdown of the carpet seams, the formation of folds from the slipping of the panels, changes the physico-chemical properties of the mastic (volatilization of light fractions of mastic oils), clogs the valleys and funnels of the internal drain. Mastics with excessive heat resistance are undesirable, as they have increased brittleness at low temperatures.

Panels of rolled materials with slopes of up to 15% are placed parallel, and with slopes of more than 15%, they are perpendicular to the ridge. The value of overlapping panels on each other is taken: in width - in the lower layers of 50-70 mm. and in the upper 70-100 mm, along the length - in all layers not less than 100 mm.

Experiencing significant heating and large daily (up to 60-70°) and annual (up to 100°) temperature fluctuations, the roof is subjected to significant alternating deformations, which often leads to rupture of the carpet and disruption of its adhesion to the base. In order to reduce the harmful effects of atmospheric influences and protect against direct mechanical damage, a protective (armoring) layer is arranged over rolled roofs with a slope of less than 10%. It is made of light-colored gravel with a grain size of 5-15 mm or mica chips. The connection of the layer with the roof is carried out with the same mastic that is used to stick the waterproofing carpet. Sometimes the protective layer is made of concrete or other slabs laid on a sandy layer.

To reduce the heating of the roof, you can paint it in a light tone (for example, with lime or aluminum paint). However, the color of roofs is short-lived, especially in areas with a polluted atmosphere; more durable and reliable roofing material, covered on the outside with aluminum foil, reflecting most of the sun's rays.

In places where rolled roofs adjoin protruding elements (parapets, gables, lanterns, etc.), as well as in areas and cornices, additional layers of a waterproofing carpet (2-4 layers) are provided.

The roofing carpet, lubricated with mastic, is led onto the protruding elements, attached to them with nails or dowels, and the joint is protected with grease or upholstered with galvanized steel roofing. In the areas of the valleys of all pitched coatings, a protective gravel or mica layer is necessarily laid (Fig. 80).

Rolled roofs in foreign industrial construction, with a variety of design solutions, do not fundamentally differ from ours. Most roofs are designed with air gaps connected to the outside air along the overhangs and at the ridge and with a protective layer of sand, gravel and slag. It is used abroad and wooden flooring, although steel and reinforced concrete floorings are predominantly common. Flat roofs in the US are often used to accommodate auxiliary equipment, household add-ons, etc.

Roll-free mastic (asphalt) roofs allow you to save scarce roll materials. They have a simple design, are durable, cheaper than rolled ones by 20-40% and less labor-intensive (1.3-1.6 times). Such roofs are more suitable for roofs that are subject to mechanical stress (during frequent renovations, cleaning) and the risk of ignition from sparks and hot gases.
Mastic roofs are used with the same slopes as rolled ones. In zero slope pavements, mastics may have reduced heat resistance. The roof in this case is “self-healing”, since the bumps, cracks and other damages formed during the cold season are leveled off by filling with softened mastic in hot weather.

For non-rolled roofs, rubber-bitumen, asphalt, emulsion and bitumen-latex mastics are used.

The surfaces of leveling layers for mastic roofs, made of cement-sand mortar, asphalt, asphalt concrete, hard wood-fiber and other boards, are coated with a primer solution of a bituminous binder in a solvent, bitumen-latex emulsion, etc.

A waterproofing carpet with a mastic roof consists of several layers (2-5), depending on the slope of the coating, reinforcing pads (fiberglass, fiberglass, burlap, etc.) and a protective layer made of asphalt concrete or cement slabs, sand, gravel or slag (Fig. 80, e). The thickness of individual mastic layers depends on the waterproofing properties of the mastic used, and it is taken from 2 to 6 mm.

Rice. 80. Details of coatings with rolled (a-d), asphalt (e) and water-filled (e) roofs:
a - adjoining the roof to the parapet; b - middle valley; c - adjoining the roof to the pediment with a flat roof; g - the same, with pitched; e - insulated asphalt roof; e - water-filled roof: 1 - wall; 2 - plate; 3 - main carpet; 4 - additional layers; 5 - protective layer; 6 - funnel; 7 - cement mortar; 8 - galvanized steel; 9 - dowel "through 500; 10 - crutches after 500; 11 - steel strip 40X3; 12 - mastic isol; 13 - mastic layers; 14 - vapor barrier; 15 - insulation; 16 - layer of water

In recent years, mastic roofs made of polymeric synthetic materials have been introduced: polyvinyl chloride, vinyl, neoprene and others with the addition of plasticizers, stabilizers, solvents and other components. These roofs are applied by spraying. They have high waterproofing properties, weather-resistant, frost-resistant and elastic.

Asbestos-cement roofs used in our country have been discussed earlier (see Fig. 73). Here we point out some features of the arrangement of these roofs in foreign construction. Asbestos-cement sheets produced by firms are not divided into industrial and civil. Their length ranges from 1220-3600 mm, the width does not exceed 1000 mm, the thickness is 5.5-8.7 mm, and the wave height is 30-60 mm.

Along with unpainted, asbestos-cement sheets with various colored surfaces are produced. For example, in England they produce brown, red, blue, green sheets (7-8 colors and shades). In the USA, sheets are usually coated with a thin waterproof layer of bituminous emulsion or paraffin, and they are also hydrophobized with organosilicon compounds that provide complete waterproofing of asbestos cement. Semi-wavy and folded sheets are also used, sheets of the "cascade" type, which make it possible to reduce the slope of the coating to 1: 12. In some cases, the sheets are reinforced with steel mesh. Sheets are fastened to the girders mainly with screws and bolts, and their heads, protruding above the surface of the sheets, are closed with anti-corrosion caps.

Metal roofs in industrial construction are still used to a limited extent. The most promising are roofs made of aluminum sheets, which do not corrode and, due to their high reflectivity, resist temperature changes well, are light in weight (3 times lighter than asbestos-cement and 20 times lighter than reinforced concrete coatings).

Domestic industry produces flat and corrugated aluminum sheets. The flat sheets are 2000 to 4000 mm long, 400 to 2000 mm wide and 0.3 to 10 mm thick. Corrugated sheets are made up to 6000 long, up to 1500 wide, wave height 50-100 and 0.8-1.2 mm thick. Steel sheets have the following dimensions: flat - length 710-4000, width 510-1500 and thickness 0.25-4 mm; wavy - length 1420-2000, width 710-1000 and thickness 1-1.75 mm.

Metal sheets are attached to the girders in the same way as asbestos-cement ones. In order to avoid electrochemical corrosion at the points of contact between aluminum sheets and steel girders, the latter are coated with a special primer or pasted over with a cloth impregnated with this protective material.

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The safety and long service life of any industrial building directly depends on the quality of the roof device. Roofs of industrial buildings must comply with all building codes, as well as withstand internal and external loads. For the construction of an industrial facility, an expensive material is used that can ensure the strength and stability of the entire building. In this article we will tell you what roof structures are used in industrial complexes, as well as analyze their design.

The roofs of industrial buildings are divided into attic and non-attic types. A flat roof, as a rule, is not attic and is performed at a slight slope for unhindered drainage of precipitation. Roofs of the attic type are made in the form of a pitched structure with an inclined angle of 30-70 degrees, as well as using load-bearing trusses, panels and the presence of rafters.

For information! The type of materials and the device of the supporting structure are selected based on the technical requirements of the explosion safety class, fire resistance and the size of the spans of the industrial structure.

Roofs of industrial buildings must provide the following:

• safety for the life of personnel;
• safety of industrial equipment, production processes;
• maintain the original appearance of materials and finished products;
• maintain a constant normal level of temperature and humidity indoors;
• ensure a normal microclimate inside the premises for the performance of all production processes in accordance with the current sanitary norms and rules;
• protect the premises (inside and outside) from the negative effects of external factors.

For the installation of the roof of industrial buildings, special coatings with layers or channels are used that allow air to move freely. When air passes inside the interlayer, the moisture evaporates. This material allows you to use it in completely different wet and temperature conditions.

Roof and pitched roof

The photo shows a pitched metal roof.

The pitched type of roof is considered the most common not only in the industrial complex, but also in low-rise construction. The device of the roof allows you to perform it in one, two and four-slope form, this feature depends on the preference of the customer and the architecture of the complex. The main feature of the roof is the presence of a slope of more than 10 degrees. Her device includes the following:

• truss system of a vertical type, which is fixed to the walls of the building;
• a solid base or the presence of a horizontal crate, its main task is to perform the role of a coating or fastening for a finishing coating.

The main advantages of a pitched roof of an industrial building include:

• for its device, you can use almost all building materials (profiling, metal tiles, bituminous, composite tiles, seam metal roofing);
• provides high protection of the building, and with high-quality insulation and sound insulation, it provides complete silence and retains heat inside the room;
• the presence of an air gap performs the function of additional thermal insulation;
• due to the rapid evaporation of moisture, the performance of a pitched roof increases significantly and allows for a long time not to carry out repairs;
• provides constant and unhindered access to the entire structure;
• due to the attic space, the usable area is significantly increased.

For information! Modern panels for pitched roofing are made of waterproof concrete, it does not need additional waterproofing, so roll-type materials are not used.

Roof and flat roof

Flat roofs are mounted for large storage facilities, fuel and energy complexes, in medical or educational institutions. The functional advantages of this design include the ability to use all the free space on its surface. As a rule, generators, ventilation systems and air conditioning systems are placed on the roof surface. Advantages of a flat roof:

• simple device and low consumption of roofing materials;
• safe movement and repair work;
• ease of installation, it is based on reinforced concrete slabs, on top of which a roofing cake is applied.

Roll roofing of industrial buildings

Industrial construction of a pitched or low-slope coating involves the use of a rolled roof. If the room is planned to be heated, it is recommended to use rolled or mastic roofing. They are mounted taking into account the slope from 1.5 to 12 percent. The main advantage of roll roofing is:

• providing protection against cracking of the structure;
• providing additional water resistance;
• exclusion of the formation of mechanical and atmospheric influences;
• protect the building from overheating.

For information! A high level of water resistance in the places of funnels is achieved by sticking a waterproofing carpet with reinforced glass mesh, fiberglass and applied mastic layer on the flange of the funnel bowl.

The device of the drainage system

The drainage system is an important element in the installation of an industrial roof. It is internal and external. For example, for a flat structure, an internal drainage system is performed, its device consists of a conventional riser pipe, which is included in the sewer system. At the top of the riser there is a funnel with access to the outside. The roof is mounted taking into account the slope towards the funnel of at least 1 degree. In the pitched roof, gutters are mounted and downpipes are installed.

For information! The device of the funnel involves its removal to the outside through a small hole, the joints and cracks of which are carefully sealed with bituminous mastic.

How to mount a drainage system on industrial buildings can be found in the video

When choosing the type of roofing for an industrial building, one should take into account the architectural features of the future structure, its geographical location and its intended purpose. The installation of roofing systems is recommended to be carried out by attracting specialists, because. Mistakes made can lead to injury to personnel and damage to the industrial complex.

Roofs are hydro- and heat-insulating structures covering buildings and structures and are designed to protect buildings from atmospheric precipitation and maintain the required temperature in the room.

Depending on the slopes of the roof are divided into:

a) flat (with a slope of less than 2.5%);

b) pitched (with a slope of 2.5% or more).

Depending on the thermal requirements for the premises, roofing can be:

a) cold - devoid of insulation; they are suitable for unheated buildings with excessive heat release;

b) semi-warm - they are used for rooms with normal temperature and humidity conditions with internal water drainage;

c) warm - used for heated buildings with normal temperature and humidity conditions with external drainage and for rooms with high humidity, where there is a risk of condensation on the inner surface of the coating.

Depending on the drainage system, two types of roofs of industrial buildings are distinguished:

1) with an internal drain - through the funnels into the storm sewer. This is the main way to remove precipitation from the roofs of industrial buildings. It is used in heated buildings and unheated buildings with excessive heat release (where the temperature in the building is not higher than 0 ºС);

2) with external drainage - it is arranged both in unheated buildings without heat emissions, and in heated buildings up to 10 m high, if the length of the roof slope in one direction does not exceed 36 m.

External drainage can be performed:

a) organized - using a system of wall gutters and downpipes;

b) unorganized - along the entire front of the slope.

The device of cold and insulated coatings.

The cold coating consists of a bearing part, screed and waterproofing, which are often combined in one material (Fig. 3.12.).

In industrial buildings, mainly rolled roofs are arranged, but sometimes - cold coatings and coatings from asbestos-cement sheets laid on wooden crates and girders.

The enclosing part of the insulated coating of the building consists of:

from the supporting structure;

· vapor barrier;

leveling layer (screed);

· waterproofing carpet;

protective layer.

The vapor barrier is laid on reinforced concrete slabs (in buildings with a relative humidity of more than 60% of the internal air). The purpose of the vapor barrier device is to prevent the formation of condensate on the inner surface of the coating and the wetting of the insulation. Water entering the insulation layer fills the pores and cells, as a result of which its thermal conductivity increases sharply, and the insulation does not perform its functions.

As a vapor barrier, rolled waterproofing materials are used - roofing material, roofing felt, waterproofing, glued to the surface of the flooring using mastics. You can also use bituminous mastics as a vapor barrier.

The thickness of the thermal insulation depends on the physical parameters of the material and its operating conditions and is determined by calculation. As a heater, materials with a bulk density are used γ 0 = 300 ÷ 500 kg / m: foam and aerated concrete, expanded clay concrete, gas and foam silicates, foam glass, polystyrene, as well as mineral wool in the form of slabs or blocks. The thermal insulation material must have sufficient compressive strength to ensure the rigidity of the base under the roll carpet. Therefore, in construction, mainly slab heaters are used. However, the insulation may be in the form of a backfill of expanded clay, slag or tuff. In these cases, bulk materials are laid in layers of 10 cm and carefully compacted. Such a heater (in the form of backfills) has rarely been used in recent years - only with small amounts of work.

The leveling layer, or screed, serves as the basis for a rolled roof. It is made from cement mortar grades M 50 - 100 or fine-grained asphalt concrete. The thickness of the screed layer laid on a rigid slab insulation is taken 15 ÷ 25 mm, and on a loose and not having sufficient strength - 25 ÷ 30 mm; the screed is reinforced with welded meshes. Cement screeds are coated with a cold bituminous primer immediately after the installation, which prevents them from cracking and provides better adhesion to the glued rolled carpet.

Asphalt concrete screeds are arranged with temperature-shrinkage joints to prevent asphalt cracking in winter. Asphalt screeds on non-rigid and loose materials are not recommended.

The waterproofing carpet is made of rolled roofing materials, the number of layers of which is chosen depending on the slope of the coating:

with a slope of at least 1.5%, the roof is made of four layers of rolled materials - 2 layers of roofing and 2 layers of hydroisol or 4 layers of roofing;

with a slope of at least 2.5% - three layers of roofing material or hydroisol, or one layer of roofing material and 2 layers of hydroisol;

with a slope of at least 12% - 2 layers of roofing material.

Waterproofing carpets are glued using tar or bituminous mastics (roofing material, waterproofing - on bituminous, roofing - on tar).

In the conditions of Kharkiv, on hot summer days, under the influence of solar radiation, the temperature of the roof made of rolled material, which has a black color, reaches 70 ÷ 85 ° C. Therefore, in order to prevent the destruction of the rolled carpet during drying from mechanical damage, as well as to improve the sanitary and hygienic regime inside the premises, a protective layer is arranged, which helps to reduce the temperature of the upper surface of the roof; the rolled carpet is covered with one or two layers of fine light gravel embedded in the mastic.

The main purpose of the roof is to protect the building from above from atmospheric influences (rain, snow, fluctuations in outdoor temperature, solar radiation and wind). The penetration of water and cold into the building, as well as overheating of the roofs by the sun's rays, lead to their destruction.

The shape of the roof is divided into pitched and flat. The shape of the roof is determined by the architecture of the building and its plan configuration.

According to the design of the roof, attic and non-attic roofs are distinguished.

Depending on the temperature and humidity conditions of the upper building envelope, non-attic (combined) roofs are divided into non-ventilated and ventilated.

By purpose, exploited (tanning beds, sports grounds, cafes, etc.) and non-exploited roofs are distinguished.

pitched roofs there are attic and non-attic.

Attic roofs are made with a cold or warm attic. Non-attic roofs can be cold (over unheated buildings) and warm (over heated buildings). Atticless roofs are arranged both in residential and public, and in industrial buildings for industrial and agricultural purposes. In industrial buildings, light-aeration lamps are often arranged on the coatings.

A shed roof (Fig. 1, a) rests with a slope on the outer walls located at different levels.

A gable roof (Fig. 1, b) consists of two planes resting on walls located on the same level. The triangular parts of the end walls between the slopes are called tongs.

The hip roof (Fig. 1, c) has four triangular slopes, the tops of which converge at one point.

The hip (four-pitched) roof (Fig. 1, d) is formed from the connection of two trapezoidal slopes and two triangular end slopes, called hips.

The semi-hipped (gable) roof (Fig. 1, e) has cut tops above the end walls in the form of triangles (hips).

The gable roof of an industrial building with a longitudinal lantern (Fig. \, e) differs from the gable roof of a residential building by a smaller slope of the slopes and a greater width and length.

A vaulted roof (Fig. 1, g) in cross section can be outlined by an arc of a circle or another geometric curve.

A folded roof (Fig. 1, h) is formed from the connection of individual trapezoidal elements - folds.

The domed roof (Fig. 1, i) is a half-ball in shape with a continuous support along the ring on a cylindrical wall.

The cross vault (Fig. 1, j) consists of four closed arched vaults.

A multi-gable roof (Fig. 1, l) is formed from the connection of the slopes of the planes. The ends of the walls under the gable planes are called tongs.

The spire-shaped roof (Fig. 1, l) consists of several steeply dipping triangular slopes, closed to the top.

The spherical shell (Fig. I, l) is similar in outline to a dome, but rests on the base at separate points. The space between the supports is usually arranged translucent.

The roof of oblique surfaces (Fig. 1, o) consists of several gentle planes resting on the walls.

A roof with an internal drain (Fig. 1, p) is widespread in modern industrial and civil construction.

flat roofs(Fig. 1, p) have a slope of up to 2.5%. They are arranged in the form of playgrounds and used for dispensaries, open cafes and other purposes. Although flat roofs are more expensive than pitched roofs, the savings in operating costs make up for this disadvantage. Recently, new roof structures made of reinforced concrete prefabricated panels have become widespread.

Roof structures

The main structural elements of roofs include load-bearing structures, vapor barrier, thermal insulation and roofing.

Bearing structures perceive the load from their own weight, snow mass, wind pressure and transfer these loads to the walls or individual supports. The load-bearing structures are prefabricated reinforced concrete panels, complex prefabricated roof panels (with heat and waterproofing layers or only with a waterproofing layer), monolithic reinforced concrete, steel profiled decking, wooden rafters and trusses, asbestos-cement slabs.

Vapor barrier is arranged from rolled bituminous, polymeric film or coating materials.

Thermal insulation is arranged from lightweight concrete, bitumen perlite, expanded clay, mineral wool, perlitoplast concrete, perlitobitumen, perlitofosfogel plates, etc.

The roof is made of rolled, mastic and piece (tiles, asbestos-cement slabs, steel and wooden flooring) materials.

Roofs from precast concrete panels there are unexploited and exploited, non-attic (Fig. 2, a) and attic (Fig. 2, b).

Precast concrete roofs suit six types:

• I - attic with waterproofing with mastic or paint compositions (rollless roofing);
• II - attic with a roof made of rolled materials;
• III - non-attic from single-layer panels made of lightweight or cellular concrete;
• IV - non-attic of multi-layer complex panels, consisting of two reinforced concrete panels, between which an effective heat-insulating material is laid;
• V - non-attic with load-bearing panels made of heavy concrete; on which slabs of effective insulating materials are laid;
• VI - non-attic building execution of a multilayer structure with filling insulation and a screed under the roof from rolled materials.

In accordance with the Instruction for the Design of Prefabricated Reinforced Concrete Roofs of Residential and Public Buildings (VSN 35-77) Gosgrazhdanstroy adopted the following definitions for all roofs.

Attic- the volume limited by the coating, frieze walls and attic floor.

Coating- the upper enclosing structure, which simultaneously performs load-bearing, waterproofing, and with non-attic (combined) roofs and with warm attics, also heat-insulating functions.

Roof- the top element of a covering made of waterproof materials and protecting the building from an atmospheric precipitation.

protective layer- a roofing element that protects the waterproofing carpet from mechanical damage, direct exposure to solar radiation.

Otter- a furrow under the ledge formed by the overlap of the masonry or the protruding side.

Attic roofs suit with a cold or warm attic.

Non-attic (combined) roofs perform the functions of load-bearing and enclosing structures of the upper floor of buildings. The structure of a non-attic roof consists of the following elements (Fig. 3): supporting structure 2, which must meet the necessary conditions of strength, rigidity and crack resistance during installation and in operating conditions; vapor barrier layer 3, which prevents the penetration of water vapor from the premises into the thickness of the roof structure (arrange if necessary); heat-insulating layer 4, providing the required resistance to heat transfer; roofing carpet 6, which is arranged on a base of cement or asphalt screeds 5 or on the surface of composite panels.

Rollless roofs of residential buildings with more than five floors are arranged with an internal drainage system (Fig. 4).

A non-ventilated non-attic roof consists of a row of reinforced concrete slabs 2 laid in the coating (see Fig. 3).

The ventilated non-attic roof is a covering of lightweight box-shaped panels - asbestos-cement slabs. At the same time, supply and exhaust air ducts are provided in the design of the plates for ventilation of the internal cavity.

Complete prefabricated coating panels(Fig. 5) combine load-bearing, steam and thermal insulation functions. They consist of two-layer slabs, the lower layer (bearing base) of which is made of heavy reinforced concrete, the upper one is made of cellular concrete or expanded clay concrete, foam plastic, fiberboard. Complex panels can be of various designs. As a bearing base, a precast prestressed slab is sometimes used. The vapor barrier is RPP brand roofing material. The use of complex panels of coatings of increased factory readiness makes it possible to exclude, under construction conditions, operations for the installation of vapor and thermal insulation, cement-sand screed, base priming and waterproofing layers.

Roofs from monolithic reinforced concrete are carried out mainly in buildings with increased seismic resistance, as well as those subject to large dynamic loads.

Roofs from profiled steel decking widely used in industrial construction. The cover panel (Fig. 6, a) is made of load-bearing profiled flooring and complex polystyrene foam or fiberglass and mineral wool boards of increased rigidity. Galvanized steel profiles are used as load-bearing flooring for panels (Fig. 6.6). The seams between the panels are sealed with inserts (Fig. 6, c). Coating panels based on a metal profiled sheet of increased prefabrication are widespread. In such panels, called metal two-layer panels (sometimes monopanels), polyurethane or phenolic foam is used as a heater, which is foamed at the factory between a metal sheet and a layer of rolled waterproofing material.

rafters by design, they are divided into two types: layered, resting with their ends and middle part (at one or several points) on the walls of the building, and hanging, resting only with their ends on the walls of the building (without intermediate supports).

According to the material, wooden and reinforced concrete rafters are distinguished. Wooden rafters are used as load-bearing structures in the construction of temporary buildings, agricultural buildings, in the construction of wooden or brick buildings in rural areas. Reinforced concrete rafters are used in the construction of buildings with large spans (industrial buildings).

Rafters (Fig. 7, a) are arranged when the distance between the supports (span) does not exceed 6.5 m. With one additional support, the width covered by the layered rafters can be increased to 10 ... 12 m, and with two supports - up to 15 m. The lower ends of the rafter legs 3 rest in wooden chopped or cobbled buildings on the upper crowns, in wooden frame buildings - on the upper trim, in stone ones - on support bars 1 (Mauerlats). The location of the rafters depends on the size of the contour of the building in the plan and the presence of internal supports in it in the form of walls or columns.

Hanging rafters (Fig. 7, b) are two rafter legs 3, connected from below by a puff 11, which perceives the thrust. To reduce the deflection of the rafter legs for spans up to 8 m, a crossbar is cut parallel to the puff (between the puff and the top of the rafters), and for spans of more than 8 m, a headstock 9 is installed. staples, bolts and nails.

Farms used in industrial construction at distances between walls and supports of 12 ... 36 m.

The truss consists of lower and upper chords and a grid of struts and braces enclosed between them.

vapor barrier, performed under thermal insulation on load-bearing structures, protects the insulation from moisture penetrating water vapor from the room. Vapor barrier can be painted or glued in one or two layers, depending on the degree of humidity in the room.

Hot bitumen mastic or cold asphalt or bitumen-cooker-salt mastic is used as a paint vapor barrier.

For gluing vapor barrier, roll materials are used - roofing felt or glassine, glued on hot bitumen, cold bitumen or bitumen-cookersalt mastics.

thermal insulation serves to protect the building from cold and overheating by the sun. Thermal insulation can be monolithic, prefabricated and made of bulk materials.

Monolithic thermal insulation is made from lightweight concrete mixtures, such as perlite concrete, expanded clay concrete, bitumen-perlite.

Prefabricated thermal insulation is made from prefabricated slabs. Such slabs are produced from lightweight cellular concrete mixtures, foams based on polyurethane foam, expanded polystyrene, mineral wool rigid and semi-rigid slabs, perlite concrete, etc.

Thermal insulation from bulk materials is made of expanded clay, shungizite, perlite, vermiculite, etc. Such thermal insulation is used in the absence of prefabricated heaters, as well as in prefabricated complex panels.

Rice. 39. Structural elements of the building: a - roof; b - coating

The covering includes the roof, the attic floor and the space between them (the attic). The roof, in turn, consists of load-bearing structures (rafters, support beams, racks, struts, etc.) and a roof (the main waterproofing layer).

The roof surfaces of a building are called slopes.

To drain atmospheric and melt water from roofs, slopes are made with a slope.

Coating classification

building coverings are classified according to the following criteria:

1) by type of drainage system:

a) coatings with external drainage, which is carried out with the help of gutters and drainpipes (external organized drainage). Coatings with external drainage may be used for buildings with a height of no more than 5 floors;

b) coatings with internal drainage, which is carried out using a storm sewer system consisting of water intake funnels and vertical sewer risers located inside the building.

Rice. 40. Drainage: a - external; b - internal: 1 - slope; 2 - skate; 3 - rib; 4 - valley (groove); 5 - drainage tray; 6 - water intake funnel; 7 - parapet

2) according to the slope of the slopes:

a) pitched coatings with a slope of 3 to 90 °. This type of pavement is divided into two subtypes - gentle pavements (slope from 3 to 45°) and steep pavements (slope from 45° to 90°). The number of roof slopes can be different and depends on the space-planning and architectural and artistic solutions of the building, its geometric dimensions, attic space filling and other requirements.

The supporting structures of pitched roofs are made of wood impregnated with flame retardants or metal.

b) flat pavements with a slope of slopes from 0.6 to 3 °. The slope of the slopes is indicated in degrees, percent, in fractions and as a fraction. In table. 1 shows the ratio of these values ​​for various slopes.

									Table 1
			The slopes of the slopes of the coatings
						The slope of the slopes of the coating
Coating type									In the form of a fraction
			In degrees		In percentages				(height ratio
The main types of roofs
Shed			gable			Chetyrekhskatnaya			Shatrovaya
	Half hip						Multi-slope
Dome			vaulted			Pyramidal			conical
Rice. 41. The main types of pitched roofs

shed roof relies with its supporting structure (rafter system, truss, etc.) on the outer walls located at different levels.

Gable (gable) roof consists of two planes based on walls located on the same level. The triangular parts of the end walls between the slopes are called gables or tongs.

The hipped roof has four triangular slopes, the tops of which converge at one point.

Hip (four-pitched) roof It is formed from the connection of two trapezoidal slopes and two triangular end slopes, called hips.

Semi-hip (gable) the roof has cut tops above the end walls in the form of triangles (hips).

A vaulted roof in cross section can be outlined by an arc of a circle or other geometric curve.

The folded roof is formed from the connection of individual trapezoidal elements - folds.

Rice. 42. Roof shapes: 1 - tent; 2 - half hip; 3 - conical; 4 - attic with a half-hip; 5 - multi-forceps (four-forceps); 6 - domed; 7 - pyramidal (spire-shaped)

Domed (dome) the roof in outline is a half ball with a continuous support along the ring on a cylindrical wall.

The cross vault consists of four closed arched vaults. A multi-gable roof is formed from the connection of the slopes of the planes.

The ends of the walls under the gable planes are called tongs.