Two fundamentally different types of roofs have been used in Moscow construction: non-attic and attic, and non-attic roofs are used in two constructive varieties - non-ventilated (Fig. 7.1) and ventilated (Fig. 7.2).
Atticless roofs have been widely used in five- and nine-story buildings. large-panel houses. The most typical example is the construction of the combined roof in the houses of the 1605 or I-464 series (see Figure 7.1). The same flat reinforced concrete slabs, as in interfloor ceilings. Under the conditions of construction, a foam glass insulation, cement-fibrolite slabs, etc., are laid along the vapor barrier layer along the supporting slab, cement screed and waterproofing carpet. Drainage from the roof is organized through an internal drain.
This design is highly labor-intensive, since all work is carried out in construction conditions.
Ventilated combined roofs, the design of which consists of paired reinforced concrete slabs with insulation enclosed between them (see Fig. 7.2, a), are manufactured at the factory. The drainage here is also internal (see Fig. 7.2, b). As a heater, mineral wool slabs on a bitumen or phenolic binder, cement fibrolite, etc. are used. required slope top roof panel.
New in this design is the inclusion of a prefabricated valley element in the roof structure, which allows you to clearly organize the drainage of water from the roof to the funnels of the internal drain.
The weight of an integrated panel of this design is approximately 8 tons. It is used for nine-story large panel houses mass series II-57, II-49 and 1605/9. Surveys showed reliable performance such a roof structure, satisfactory waterproofing and heat engineering qualities.
Attic roofs are usually made on buildings elevated number of storeys- more than 9 floors. Their designs are largely determined by the constructive solution of the house as a whole. At panel construction For houses with a narrow pitch of transverse load-bearing walls, the roof is made of often-ribbed vibratory-rolled slabs in combination with a special prefabricated valley element, as is done, for example, on a 17-storey house of vibro-rolled structures built on Prospekt Mira. Insulation in this case is located on the ceiling above the upper residential floor, and the attic, thus, remains cold.
In houses with a wide pitch of transverse walls, the attic roof is supported by panels used in interfloor ceilings, or ribbed roof decks. In houses with longitudinal load-bearing walls, such as the I-515 series or in brick houses, the roofing is carried out on vibro-rolled often ribbed panels, laid on special transverse purlins (Fig. 7.3) or on ribbed long flooring.
Similar solutions for attic roofs have been implemented in all high-rise buildings, both large-panel and frame. The use of attic roofs improves the performance of residential buildings and at the same time is not associated with a significant increase in construction costs.
Consider the features of the roof and compare the existing design solutions for roofs.
The combined roof as an external fence differs from the external walls in the presence of a powerful waterproofing layer (carpet) located with outer side. The waterproofing layer is practically vapor-tight, it creates conditions for the accumulation of moisture directly in the insulation layer under the waterproofing. Due to the diffusion of water vapor penetrating from the room, moisture is retained in the structure and as a result of this (when the building is operated in winter period) there is a sharp deterioration in the heat-shielding qualities of the roof, delamination and violation of the waterproofing carpet, destruction of the insulation. The situation is aggravated by the high initial humidity of heat-insulating materials - fibrolite, mineral wool boards and other porous materials that easily absorb and slowly release moisture. As field observations showed, the actual moisture content of the heat-insulating material after 2.5 years of operation ranged from 12 to 28% instead of the standard 3-10%. Such a high humidity of the heat-insulating layer of combined roofs adversely affects their performance, reducing durability and increasing the thermal conductivity of structures, which causes freezing of the roof or condensation on the ceiling of residential premises.
It is well known that with an increase in the moisture content of materials, their thermal conductivity increases significantly. For example, for foam concrete with a volume weight of 600 kg / m 3, the thermal conductivity coefficient at a weight humidity of about 10% is 0.226 kcal / m 2 ·h · deg, and at a weight humidity of about 20% it is already 0.321 kcal / m 2 ·h · deg. During the heating season, heat loss through 1 m2 of coatings with an increase in the humidity of foam concrete from 10 to 20% increases by almost 30%. This can be compensated by increased heating (and correspondingly increased fuel costs). But with increased heating at roof panels with insufficient resistance to heat transfer (due to high humidity) the sanitary conditions of the premises are deteriorating, despite the increase in operating costs.
In addition, the high humidity of the materials under the roofing drape dramatically reduces its durability. Due to the intensive heating of the carpet in summer, the pressure of water vapor sharply increases in the pores of the material located under it, as a result of which easily bursting swellings are formed in the carpet, the height of which reaches 20-30 mm. This phenomenon becomes even more intense due to the occurrence of cracks in the wet screed of cement mortar which repeatedly freezes and thaws in winter.
A large initial moisture content is especially characteristic of non-industrial combined roofs, insulated by laying heat-insulating material on the carrier plate, followed by a screed and a carpet sticker (as, for example, in the houses of the 1605 series). Structures of this type are difficult to protect from soaking by atmospheric precipitation during the construction process.
As surveys have shown, ventilated roofs dry out quickly: after a year of operation, the humidity decreases from 13% to the standard - 3%. Observations have shown that the movement of air in ventilated roofs occurs constantly; the speed of this movement, depending on the speed and direction of the wind, ranges from 0.08 to 1 m/s or more.
In the process of developing and improving the structures of combined roofs, many different solutions have been developed, but so far the roofs are still busy and have insufficiently reliable performance.
Among the heavy, non-industrial and at the same time expensive solutions for non-attic roofs is the roof construction in the 1605 series houses. It is no coincidence that it turned out to be 18% more expensive and 2.5 times more labor-intensive than the construction of a combined roof from twin reinforced concrete shells (Table 7.1), in which a normal temperature and humidity regime is ensured. In the latest solution, the design of reinforced concrete rolling elements has been significantly improved, which have become more crack-resistant and rigid; successfully solved the element of the tray, through which atmospheric water is diverted to the internal drains. All the main work on the installation and assembly of the roof is carried out at the factory, and at the building they only close up the seams between the plates and stick the last layers of the waterproofing carpet.
Drains from roofs are internal, since both organized and unorganized external drainage is unacceptable in the Moscow climate, especially in high-rise buildings.
A reliable and rational design of the internal drain has been worked out, which can be recommended for wide application(Fig. 7.4). The internal drain is made of cast iron or, more rationally, of asbestos-cement pipes with a diameter of 150 mm, connected by couplings. Its main feature is the organization of open releases to the surface of the earth. Gutters with such open outlets have been operating flawlessly for more than 10 years.
Measurements of the temperature of melt water in the drain during the winter period showed that it does not fall below -2 ° C, and therefore the possibility of ice plugs is excluded. Thus, traditional solutions with a descent turned out to be completely optional. atmospheric waters from internal drains to systems storm sewer, which are far from being available everywhere and also lead to a sharp rise in the cost of drains (Table 7.2).
In order to avoid the formation of frost on the ground under the open outlet, it is advisable to switch over to the winter period the descent of essentially a very small amount of melt water into the city sewer.
The analysis shows (see Table 7.2) that the cost of arranging internal drains with open system the release of water, which has immeasurably higher performance, is approximately equal to or lower than the cost of outdoor organized drains.
Drainage funnels are usually located along the longitudinal axis of the building and one for each residential section. The maximum catchment area for one drain funnel should be taken no more than 400 m 2. The transverse slopes of the roof, directed towards the axis of the building, along which the drain funnels are located, are usually 1.5-3%. Between the funnels, triangular sloping roof slopes are formed, called envelopes, through which water flows into the funnels. In ventilated roofs, it is most rational to arrange straight gutters with a slight longitudinal slope of 1-1.5% (see Fig. 7.2, b). A waterproofing carpet of four layers of roofing felt on one layer of glassine is laid on envelopes or in a gutter.
Important for ensuring high performance of roofs is the correct design solution for various types of superstructures on roofs: ventilation ducts, hatches, etc. At present, industrial solutions for superstructures have been developed that simultaneously provide for reliable winding and fastening of the waterproofing carpet, in particular, combining ventilation ducts, sewer hoods and radio and television antennas in one block. Thanks to this, it is possible to significantly reduce the number of intersections between the roof and superstructures and eliminate possible damage to the rolled waterproofing that occurs in areas near intersections.
Generalization of construction practice makes it possible to recommend an attic roof type as the main solution for residential buildings with a height of more than 9 floors (with a warm attic) with an internal drain from asbestos-cement pipes and the release of water from the drain at ground level.
Five-storey panel houses series 1-464
Large-panel 4-5-story residential buildings of the 1-464 series of standard projects are the most common first-generation prefabricated buildings. The solution of the houses of the considered series is based on the cross-wall structural system.
The main load-bearing skeleton of the buildings are transverse reinforced concrete walls located at intervals of 3.2 and 2.6 m, due to which this type of house was called houses with a "narrow" pitch of transverse load-bearing walls. Reinforced concrete floor slabs of the size “per room” are supported on them. They also rest on the outer and inner longitudinal walls, which take part of the vertical load, while at the same time providing the longitudinal rigidity of the building.
The floor slabs laid at 3.2m spacing are calculated and operate as supported along the contour. Since all interior walls separating rooms are loaded by floors and floors above, it is not possible to move these walls and thereby change the width of the rooms. For the same reason, the removal of the outer walls at a step of 3.2 m is excluded, without ensuring the support of the floor slab along the short outer wall.
The outer walls are made of panels - three-layer, consisting of two reinforced concrete shells and a layer of insulation between them, or single-layer panels (made of lightweight concrete). Internal bearing walls 12 cm thick and floor slabs 10 cm thick are reinforced concrete floorings of solid section. Roof - combined with a rolled soft roof or attic rafter with a roof of corrugated asbestos cement.
When redeveloping houses of the 1-464 series, it becomes necessary to install new or expand existing openings in the transverse walls. This is possible to a limited extent, but requires confirmation by calculations.
When modernizing a building, floor slabs cannot be dismantled. However, during the superstructure of the building, the floor slabs above the existing fifth floor can be partially dismantled. The arrangement of new openings in them is possible, but with large sizes of such openings, reinforcement of the overlap may be required.
In the series under consideration, balconies are placed at a step of 3.2 m. Balcony reinforced concrete slabs 10 cm thick and 90 cm wide were mounted according to two schemes. AT initial period construction, they relied on outer wall and were held in the project position by two metal rods, which, passing through the joint between the outer walls, were attached to the end of the inner wall panel. In later projects, such a solution was abandoned and, counting balcony slab as a console, supported on the outer wall, it was connected to the floor slab with the help of welded embedded elements.
Five-storey panel houses series 1-468
Typical projects of residential buildings of the 1-468 series were originally developed at the Gostroyproekt Institute, since 1961 - at TsNIIEPzhilishcha.
The load-bearing skeleton of the houses of this series are transverse load-bearing walls located in the plan with a step of 3 and 6 m, due to which, unlike the houses of the 1-464 series, the houses of this constructive system are called houses with a "mixed" step of the transverse load-bearing walls.
The most common representative of houses in this series is a five-story, four-section residential building. In it, the outer wall panels are made of autoclaved cellular concrete or lightweight concrete, and hollow-core reinforced concrete floors rest on transverse load-bearing reinforced concrete walls. The longitudinal walls of the building are self-supporting. The roofs of such houses were erected in two versions: combined with roll coating and an attic truss with a roof of corrugated asbestos-cement sheets.
The main advantage of the houses in this series is that the floor panels do not rest on the longitudinal walls of the building. Therefore, these walls, except for individual sections inner wall adjacent to the stairwells and ensure the longitudinal stability of the building, can be in separate places dismantled. It is this circumstance that opens up when modernizing such buildings wide opportunities to eliminate design flaws existing apartments by adding additional volumes to the building. The device of new and expansion of existing openings in the bearing transverse walls is possible only if the calculation confirms and strengthens the "contours" of the openings.
Five-storey panel houses series 1-335
Five-story residential buildings of the 1-335 series of standard projects are representatives of the frame-panel structural system. Typical designs of this series were originally developed by the author's team of the Leningrad Design Bureau, and then continued at the LenZNIIEP Institute.
The structural scheme of the house is a so-called "incomplete" frame, which consists of one row of reinforced concrete columns located on the middle longitudinal axis of the building with a step of 3.2 and 2.6 m and reinforced concrete crossbars located across the building and resting on one side of the reinforced concrete columns , and on the other hand, on metal support tables embedded in the body of the bearing external wall panels. Reinforced concrete floor slabs "per room" in size are laid on the crossbars, designed to be supported by two long sides. The columns are interconnected by girders that provide longitudinal rigidity of the building.
In the houses of the system under consideration, load-bearing external walls were used mainly layered. They have an outer layer in the form of a reinforced concrete ribbed "shell" and an inner (insulating) layer of foam concrete 26 cm thick, the surface of which is plastered from the side of the premises. There are no internal load-bearing walls in these houses, with the exception of stiffening diaphragms, which are the intersection walls of the stairwells.
With the same dimensions and steps of houses of different series in the houses of the frame-panel system, the principle of "free planning" can be fully implemented. The presence of crossbars under the floor slabs can be considered as a certain drawback that prevents the traditional formation of the interior of living rooms.
A modification of this constructive system was the introduction of two more rows of columns into it - at the outer walls of the building to support crossbars on them. Such houses are called "full frame houses". In them, the outer walls are self-supporting and can be dismantled during reconstruction.
Five-storey brick houses series 1-447
The 1-447 series includes standard projects 4-5 storey brick residential buildings with three longitudinal load-bearing walls. The load-bearing frame of the houses in this series are three longitudinal load-bearing walls and transverse brick walls- external end and internal, between which are located stairwells. Transverse brick walls act as stiffening diaphragms. All other walls (internal and inter-apartment) are non-bearing.
The floors are made in the form of reinforced concrete multi-hollow slabs, supported by short sides on longitudinal brick walls. The most loaded is the middle wall, on which the floor panels rest on both sides. Openings in the outer longitudinal walls can only be enlarged by eliminating the window sill while maintaining the existing piers. Lintels above windows should also be preserved. AT end walls buildings during reconstruction, the device of openings is possible.
Possible dismantling of partitions in series 1-447
To significant shortcomings panel construction can be attributed to insufficient thermal insulation of the structure. And especially this question concerns the device of the roof. Waterproofing and insulation of the roof is an issue that periodically worries all residents. panel house especially those who live on last floor. The appearance of gaps and cracks in the roofing, its insufficient insulation and a thin layer lead to large heat losses in the cold season, the appearance of leaks and drafts, and a decrease performance characteristics the entire building. Therefore, the insulation of the roof of the house must be carried out in a timely manner to avoid deformation. truss system which could cause the roof to collapse. In the case of a flat roof, which has a base in the form of a concrete slab, insufficient heat and waterproofing of the roof can lead not only to high heat losses, but also to the appearance of dampness and fungus in the rooms of the upper floors.
Types of roofs of modern panel houses
During the construction of panel houses, flat types of roofs with various types roofing or attic roofs with a slight slope to prevent accumulation of snow and moisture on the roofing.
by the most popular species roofs for modern panel houses is roll roofing, multilayer shingles, soft roof and flexible tile. Depending on the type of roofing and the type of roof, the technology of roof insulation and the type of heat insulator are selected. For insulation of panel houses, the following types of heat-insulating materials are used:
- polystyrene boards;
- mineral wool insulation;
- rigid polyurethane foam.
Panel house roof insulation technology
Most in a simple way Insulation of a flat roof is considered to be spraying one or more layers of rigid polyurethane foam. This method allows you to create a durable and moisture-resistant roof covering with good frost-resistant characteristics. The main advantage of polyurethane foam roof insulation is the quick application of a heat-insulating coating with excellent mechanical strength and low thermal conductivity. Sprayed polyurethane foam is suitable for insulating soft roofs and roofs with large quantity architectural elements. In addition to insulating the roof with polyurethane foam, there are several other ways to use the insulator, for example, for sealing seams and joints and repairing worn roofing.
Another popular method of thermal insulation is the insulation of the roof with polystyrene foam, which is laid on the concrete floor of the roof in one or more layers to create a waterproofing that protects the heat insulator from moisture penetration and condensation. Extruded polystyrene foam is suitable as insulation for any type of roof, this moisture-resistant and lightweight thermal insulation material for roof insulation, it has high mechanical strength and frost resistance and is included in the composition of the roofing cake when insulating pitched roofs. Its cheaper counterpart is foam, which is used for internal insulation roofs in attic roof structures. Since some types of foam are considered a combustible material, mineral wool boards are used to insulate the roof from the inside, which are attached to the crate and covered with a vapor barrier material that prevents condensate from entering the surface of the insulation.
The technology of roof insulation with mineral wool on flat and sloping roofs panel houses is carried out in two ways, using a single-layer or two-layer roofing pie. In the first case, a roll or mastic waterproofing is laid on the concrete floor, then a heater is attached: polystyrene foam or mineral wool slabs, after which a protective membrane is laid and roofing, for example, a soft roof. The second way is to create double thermal insulation from different types insulation, which allows you to create a high roof insulation cake, which prevents dampness concrete floor, and, consequently, retains heat in the rooms of the last floors.
Reconstruction of the roof of multi-apartment residential complexes differs significantly from similar work in a private house. Therefore, residents of high-rise buildings have to perform a whole algorithm of actions.
To do this, applications are collected from residents, submitted to the management organization, which, as a rule, is not particularly keen to delve into the problems of ward citizens. As a result, the repair of the roof of such houses, taking into account the cost and scale, can be delayed for several years.
But if you don't intend to wait for a long time and endure constant drops from the ceiling, you should contact our Moscow roofers. Our specialists are ready to arrive as soon as possible to inspect the roof, identify the cause of the leaks and draw up a detailed defect list.
Based on this document, an estimate and terms of reference for employees are formed. Therefore, residents are already initial stage will know the real fixed cost of roof repairs and will be able to fully assess the competence of the contractor.
It should be noted right away that the cost installation work during major repairs is quite high due to the need serious investments. If a partial repair is made, the costs, of course, decrease, but there can be no guarantees that repairs will not be required again in the near future.
Usually partial roofing repair performed in the following situations:
- damage to roof elements;
- reduction of soundproofing and heat-insulating properties;
- the appearance of minor leaks;
Partial repairs can improve the appearance of the roof, which is also of interest to many residents. In its turn, overhaul the roof is necessary for more serious damage and dilapidation. In this case, the specialists of the Moscow Roofers company perform complete replacement the entire roofing pie, load-bearing structures, drainage systems, the processing of the wooden frame is carried out.
In order to make a final decision on the need for capital or partial renovation roofing, it is worth getting the opinion of our competent specialist. We are ready to go to the site at a convenient time for you, make a detailed shift and explain all the points of interest regarding the repair and maintenance of the roof of an apartment building.
Where to go and what to do if the roof of a multi-storey residential building is leaking? The easiest way is not to wait for help from local officials, but it is better to call our roofing masters for help!
"Moscow Roofers" objectively assess the condition of the object and make a conclusion about necessary work for consideration by the customer.
Turning to Moscow specialists, you can count on a competent solution of problematic issues in a short time!
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