Construction and installation of a typical flat roof: a thorough overview of technological subtleties. About flat roofing and its operation. Example of a flat roof device

A flat roof is a common architectural solution in civil, industrial and private construction. The construction of a flat roof has its own characteristics, but main principle is that the waterproofing layer must be a continuous carpet with certain technical characteristics. The design of roofing structures must be carried out in accordance with current SNiP.

Roofing pie structure

If you look at the structure in cross-section, this type of roof is a multi-layer structure, which includes:

The base of a flat roof can be reinforced concrete slab ceilings, or metal profile construction. Depending on the type of base, the material for the remaining components of the roofing cake and methods of its installation are selected.

The vapor barrier layer is made of roll or bitumen materials. It prevents the penetration of moisture from the premises into the thermal insulation layer of the roof structure.

A wide range of materials are used as insulation for flat roofs, including:

mineral wool;
expanded clay gravel;
polystyrene foam boards;
cement-sand screed.

The waterproofing layer is traditionally made from roll materials on a bitumen basis. Special mastics or a PVC membrane can also be used.

A waterproofing carpet must have a certain elasticity in order to withstand mechanical deformations of the base and temperature changes.

The structure of the pie depends on functional features roofs. The following types of roofing differ:

Flat roof slope

According to SNiP, when installing a flat roof structure, it is necessary to provide for its slope of 1-4°. This design of flat roofs avoids the accumulation of water on the surface of the covering. It is not only prolonged stagnation of water in certain areas that is dangerous for waterproofing. Severe deformation and destruction outer covering roof damage is a consequence of repeated repetition of the process of freezing and thawing of accumulated moisture. Various materials can be used to pitch the roof. The choice depends on their technical characteristics and installation features.

Lightweight concrete with loose polymer filler (in particular, extruded polystyrene) is one of the popular materials. It is quite easy to install, and the resulting structure is highly durable. But the use of this material for leveling should be considered at the building design stage, since the significant weight of the concrete used increases the load on the floor, walls and foundation of the building.

Has similar characteristics lightweight concrete with perlite or expanded clay filler. This material is cheaper, but its weight is even greater, and the resulting roofing cake is less durable.

The installation of a flat roof can be carried out using monolithic insulation, allowing for slope. In this case, it is mounted on the prepared surface sheet material(mineral wool, expanded clay sheets, etc.). Fastening can be done with strong, tenacious glue, which prevents the sheets from moving over time. Dowels with a plastic spacer can also be used - it is advisable to exclude metal contact with the base of the roof so that the roofing cake does not have cold bridges.

The most labor-intensive is the installation of a roof using bulk materials for deflection. Difficult to pour concrete layer bulk insulation(expanded clay or perlite), observing the required angle of inclination of the roof plane, since the granules can move.

An effective, but expensive option for degrading is laying foam concrete followed by applying a layer of fiber-reinforced concrete. A cake with such a heat-insulating layer is designed for long-term use. This technology requires the involvement of experienced specialists.

In accordance with SNiP, the roof slope is towards the water intake funnels (if there are internal drain), or towards the water intake gutters of the external drainage system, which must be mounted under the roofing carpet or on external wall building.

Roofing units

In order for the roofing pie to be reliably protected from external influences, special attention should be paid to the places where it adjoins building structures– parapets, walls, pipes, external parts ventilation systems etc. There are various nodes of a flat roof, first of all, this is the node:

adjacencies;
overhang;
passage through the roof.

The units are installed on a reinforced concrete base in places where the roofing pie meets the cut side vertical design. Manufacturers of roofing materials often develop their own systems, which may have certain design features.

The unit must ensure the tightness of the joint and its thermal protection, therefore the installation of the units should be treated with the utmost care.

Installation of an unused flat roof

The most common design is the traditional one. soft roof. In cross-section, it consists of a load-bearing base slab, a vapor barrier layer, thermal insulation made of sheet mineral wool and a waterproofing carpet made of rolled bitumen-containing material. The advantages of this design include low cost and simple installation.

More practical non-exploited roofs are made using modern materials. PVC membrane waterproofing is very popular. Its installation can be carried out in any season, since the membrane is resistant to low and high temperatures. In addition, if the thermal insulation layer has managed to accumulate moisture during the installation process, the membrane allows it to evaporate. At the same time, the material has high water-repellent properties. In the process of installing the panels into a single whole, special welding equipment without an open flame is used.

Covering an unused flat roof can be done using mastic. This is a liquid material that is applied on top of a rigid, even thermal insulation layer. The mastic is made on the basis of elastic, hydrophobic polyurethane resins. On outdoors, a certain time after application even layer, it polymerizes to form a continuous rubber-like membrane. The installation of such waterproofing allows you to reliably protect the roofing pie from moisture penetration.

A popular technology is the use of built-up waterproofing. This is an affordable option in terms of price and quality ratio - the durability of such a roof is from 25 years. A bitumen-polymer material based on a fabric that is not subject to rotting creates a super-strong waterproofing layer. Using this material it is possible to install exploited roofs.

Construction of a serviceable roof

This flat roof design is much more expensive to install, but makes it possible to profitably use additional space. Today, this type of roofing is widely in demand for equipping sports grounds, green areas, cafes, parking lots, etc. Installation of a reinforced roof is also necessary if heavy objects, including equipment, are to be installed on the roof. In accordance with SNiP, the roofing structure must withstand uneven high loads, that is, not deform in limited areas. The section of a flat roof in use differs from the usual one in the presence of a rigid base or a special screed on top of the waterproofing layer. This coating prevents pressing of the waterproofing carpet with its subsequent destruction.

Features of inversion coating

The structure of an inversion roof is fundamentally different from other types of roofs. When arranging it, first of all, a waterproofing layer is mounted on the base. In cross-section, the roofing pie looks like this: base slab, waterproofing, insulation, drainage layer, geotextile. This design allows you to protect the waterproofing material from the destructive effects of ultraviolet radiation, temperature changes, and mechanical damage. Geotextiles, in turn, provide protection for the insulation. Used as an outer layer paving slabs. Such a roof can withstand high loads, including use as a parking lot.

It is required to approach the installation of the waterproofing layer as carefully as possible, since in order to correct errors it will be necessary to open the ballast layers.

The installation of a traditional roofing structure can be done independently, but for the installation of flat roofs using modern materials and technologies, it is recommended to involve specialists who have the necessary equipment.

Flat roof installation: design and components

The device of a flat roof and its design. The main components and composition of the roofing pie in section. SNiP for the structure and slope of flat roofs

Flat roof installation

Many people associate a flat roof with urban high-rise buildings. And very few people picture in their imagination a country house with a flat roof, which combines saving precious space and the possibility of creating luxurious places for relaxation on the roof.

Flat roof pie.

In the age of modern building materials and new technologies, it is possible to successfully build private houses with a flat roof, without fear of the surprises of our unpredictable climate. But the full extent of pleasure from a flat roof can only be experienced when the builders and the customer himself listen carefully to the advice of a specialist in installation technology and the selection of the necessary components of the roof structure. Only under such conditions will a flat roof serve for a long time for more than one generation of the inhabitants of the house, without requiring additional costs.

What are the advantages of flat roof designs?

Until recently various designs and the parts for installing a flat roof were either very expensive or not reliable and functional enough, which did not at all benefit the popularization of roofs of this type, especially for private developers.

However life experience proves that, being under the influence of stereotypes, we are too biased towards many problems, as a result of which we do not always judge things objectively. The main thing is from many existing options choose the most adequate and correct one to avoid mistakes.

According to architects, buildings in the spirit of constructivism, which brings a minimum of details and simplicity of design, are now becoming fashionable again. As a consequence, in better side The attitude of customers towards flat roofing is changing. In Europe the design flat covering houses are called fashionable architectural feature project. A house with a roof without slopes looks more modern.

Flat roof installation diagram.

Until recently, a flat roof was a complete taboo for most consumers. According to some, it was simply tasteless, others were afraid of heavy precipitation in the form of snow, and still others believed that a flat roof was an undertaking that required prohibitive financial costs. Nevertheless, experts cite a lot of obvious advantages for buildings with this design:

In most cases, a flat roof is equipped as a green recreation area.
Material savings, because the area of a flat covering is less than the area of a pitched covering with the same architectural basis.
Laying a flat roof is much more convenient than a pitched roof - it is easier to install the covering under your feet rather than in an unsafe position at a high altitude.
Maintaining flat roofs is not an extreme mountaineering activity, but rather a routine procedure.
Plus, the design of flat roofs makes it possible to get additional area without increasing the outline of the structure.

By the way, in developed countries, the possibility of using a flat roof is most relevant in megacities. Here, the problem of ecology has increasingly come to the fore, and therefore raising elements of gardens, parks, vegetable gardens and lawns from the ground to the clouds has become a very popular thing. And most importantly, if you want your flat roof to provide reliable protection, it must be installed correctly using durable modern building materials.

Components of a flat roof

Typically, a flat roof is based on a load-bearing base (it can be a reinforced concrete slab or profiled a metal sheet), on which heat-insulating material is laid over a vapor barrier layer, which is protected from precipitation by a waterproofing layer.

Scheme of an inversion flat roof.

It is characteristic that all components of the roofing “pie” are of equal importance, and if at least one of them is unsuitable, the entire structure will be damaged. The basis for installing a flat roof is A complex approach, which consists in determining the type of coating and implementing the best design solution when considering all operational and technological properties, such as fire resistance, water resistance, ease of maintenance, labor costs during installation, aesthetic qualities, etc.

Specialists pay special attention to sealing seams, choosing fastening methods and elements, arranging technological components of the coating (junctions to parapets and pipes, drains, corners, superstructures, etc.) and performing through holes. And it goes without saying that the operation of the roof will not depend on any damaging factors if the various components of the structure are made of impact-resistant and weather-resistant materials that are resistant to corrosion processes and exposure to UV rays. Excluding even one detail from the overall system is fraught with the most undesirable consequences.

Depending on the type of waterproofing, it can be glued, mechanically secured, or loosely laid. Much attention should be paid to the quality of fasteners and the method of their installation, especially for materials that are laid to the base of the roof with mechanical fastening.

If the rules for laying roofing are neglected, the following undesirable consequences may occur:

Breakdown of waterproofing by strong gusts of wind.
Loss of the bearing capacity of the base due to electrochemical corrosion in the “wrong screw + corrugated sheet” system.
A clogged or frozen funnel, causing the roof to fill with moisture and leaks.

The roofing “pie” consists of the following layers (from bottom to top):

Insulation of a flat roof

Types of flat roof insulation: one, two and three layers.

The base of a flat roof is a load-bearing slab made of monolith, reinforced concrete or corrugated metal sheet. On top it is covered with a vapor barrier material, which protects the insulation from water vapor, thus preventing it from swelling from getting wet and ensuring the preservation of all properties. After this, thermal insulation is installed on the roof, which, in turn, is covered with a waterproofing carpet to protect it from precipitation.

For a flat roof, there are one- and two-layer thermal insulation systems. Nowadays, a two-layer system is more often used in construction. It works like this: the bottom layer, 70-200 mm thick, is assigned the main function of thermal insulation, while the top layer, which is 30-50 mm, is responsible for the redistribution of mechanical loads. Despite the smaller thickness, the second layer is more durable and has more high density. This distribution of flat roof covering layers makes it possible to significantly reduce its weight and, thereby, the load on the floors. The insulation must meet the following requirements:

Low thermal conductivity and water absorption.
Fire safety.
High vapor permeability.
Compressive and peel strength of layers.

Drainage device

Diagram of a drainage system on a flat roof.

When installing roofs, it is very important to ensure the free escape of wet vapors from the roof covering. Necessary elements ventilation accessories are modern roofing accessories. As a result of human activity, water vapor is continuously generated inside the building. Due to the convective process and diffusion, it rises upward and, when cooled, condenses in the space under the roof. This process is especially intense in winter time. It negatively affects roof elements - both wooden and metal. If too much condensation accumulates, wet spots form on the ceiling and mold develops. In addition, moisture accumulating in thermal insulation material, reduces its properties, which leads to increased costs for heating the room. To avoid such situations, you need to take care of the proper removal of moisture from the outside of the building.

With this task the best way This is done by special roofing components - a roof fan, otherwise called an aerator. The aerator consists of pipes different diameters made of plastic or metal, which are covered with umbrella-shaped caps.

The operation of the aerator is based on the pressure difference caused by the flow air masses. Its design allows moisture vapor to be removed from under the roofing without damaging the latter.

On flat roofs, aerators are placed evenly over the entire surface at the highest points of the roof plane at the junction of the thermal insulation boards with each other. It is advisable to install aerators at the same time as the roof itself. Otherwise, the cost of installing ventilation increases significantly.

There are a large number of components for installing a flat roof. The need for their use is determined by the design of the roof. For example, in Western countries, much attention is paid to equipping roofs with natural smoke removal devices, which enable people to safely leave the building in the event of a fire.

The reliability of the roof also depends on its slope. There are no completely flat roofs, because to drain water you need, albeit a very small, slope. For a flat roof it is measured as a percentage.

It is not advisable to install roofs with a slope of less than 2 percent. The most the best option is a slope of 2.5 percent. In this case, the structure is freed from water in a short time, providing more comfortable conditions for the functioning of the roofing material. With a good slope, even a small defect in roofing will be insignificant.

One more important element roofs are gutters that “carry away” moisture and snow along a given route. On a flat roof, an internal drainage system is most often installed. Special located on the roof surface drainage funnels or fittings effectively drain water during heavy rainfalls, eliminating roof flooding. Their location and quantity must be determined taking into account the design rules for these structures and construction requirements for the design of drains and sewerage systems for buildings. The required number of funnels on the roof depends on its operating conditions, architecture and amount of precipitation. The funnel comes with a special filter that protects the drain from foreign objects getting into it. To prevent the water in the drain from freezing, the mouths of the funnels are equipped with special thermal cables, which guarantees rapid drainage of water at any time of the year.

External drainage is more often used as drainage from a flat roof in private houses, because the internal one is more suitable for installing flat roofs of large industrial buildings. External drainage is usually performed using overflow windows, which are installed in the parapet along with roof storm drains. Ideally, self-regulating thermal cables should be used in this case, since the storm inlet and overflow window, by virtue of their design, winter period susceptible to icing.

When choosing a drainage system, due attention should be paid to the choice of structural material. For example, products made of PVC (polyvinyl chloride) are less susceptible to icing than metal ones.

Flat roof design

The flat roof design is a simple and very profitable option for home improvement. It is easy to maintain and opens up a lot of new possibilities.

Design and installation of a typical flat roof: a thorough overview of technological details

The apparent simplicity of a flat roof often misleads novice home builders. The elementary configuration suggests efficiency and low cost of construction. Minimum number structural elements is capable of dulling the vigilance of independent performers who are ignorant of the intricacies of the roofing business. In reality, installing a flat roof requires scrupulous adherence to the rules unique to it, guaranteeing the flawless operation of the structure and long-term operation.

Specifics of flat roofs

Flat roofs- a separate category of roofing structures that do not require the construction of a rafter frame. Purely visually, it is a ceiling that rests directly on the walls of the building. Due to the absence of slopes, a flat roof does not upset the windage that occurs under the influence of gusty winds. However, its configuration does not contribute to the rapid removal of snow deposits from the surface.

The load from the snow is not transferred to the rafters, as in standard pitched systems, but presses directly on the walls of the building. Therefore, it is strongly recommended to equip houses with flat roofs in regions with insignificant amounts of winter precipitation and high wind loads.

In regions and districts of the fatherland located in middle lane and further north, flat roofs are used mainly in industrial construction. Private owners install them over one-story extensions, garages, and household buildings. For an independent craftsman, a flat roof over a shed or shed is an excellent option to practice as a roofer.

Briefly about the design of a flat roof

It is customary to call roofs flat, the only conditional slope of which is located to the horizon at an angle from 0º to 1.5º, or otherwise up to 2.5%. However, a number technical sources calls systems with a slope of up to 5º flat, the percentage value is up to 8.7%. Even roof structures have a slight slope, creating a clearly horizontal impression. It is formed to drain wastewater to drainage points or to an overhang.

Regardless of the steepness, the layers of a flat roof are arranged in a strictly defined order:

Vapor barrier covering the base. It is necessary to protect the insulation from the penetration of household fumes.
Insulation laid in one or two tiers. Required to prevent leakage of heat waves through the upper ceiling, used exclusively in insulated systems.
A screed created when the thermal insulation is insufficiently rigid or when there are no slopes for drainage.
Waterproofing that protects the insulation and ceiling from the destructive effects of atmospheric water. It is laid with a continuous waterproofing carpet.
A finishing coating that gives the structure an aesthetic appearance.

Brands currently on the market waterproofing materials successfully perform the functions of a finishing roof. These include numerous rolled and mastic bitumen, bitumen-polymer, and polymer varieties. Most of them are laid in one layer.

Due to the slight slope of flat roofs, the use of piece materials in the arrangement is contraindicated, because multiple joints between elements create the risk of leaks. It is undesirable to use large sheet metal due to the harmful effects on the material of water stagnating on a flat surface during periods of heavy rain and snowmelt.

When using old, well-known roofing felt types of roll coatings finishing roof arranged in 4 or more layers, the lower of which play the role of waterproofing. A mastic or emulsion self-leveling roof is constructed in a similar way: the emulsion or mastic is applied in five or more layers, alternating pasty or creamy material with layers of fiberglass or polyester.

To lay and fix the above elements of the roofing pie of a flat roof, a rafter structure is not required. They are laid directly on the base, which can be a ceiling, a screed created on top of it, or the upper plane of the attic structure. To fasten PVC-coated systems, adhesive, mechanical or ballast methods are used. Self-leveling roofs are applied according to their name, the descendants of roofing material are fused or glued.

Unlike their stingy counterparts in flat systems there are no lathing creating ventilation ducts for washing the insulation with air currents. Therefore, the selection of design solutions, materials and their sealed installation should be approached with due respect and focused attention. A ventilated flat roof is only possible when lumber is used in the construction of the ceiling and attic. The latter option is most often used in private construction.

Types of floors used

The construction of flat roofs is carried out on floors made of reinforced concrete, wood and profiled sheets. The choice of material for the ceiling depends on the purpose of the roof structure, the size of the span to be covered, possible operation and ease of maintenance.

One of the significant advantages of a flat roof is the possibility of organizing a used area on it: a place for relaxation, a solarium, a green area, a terrace, etc. Of course, the overlap for such objects should be quite powerful. In addition, in the flat family there are roofs that do not involve incidental use, and therefore do not require a thorough covering.

Depending on the operational criteria, flat roofs are equipped with:

Reinforced concrete floors, if it is planned to organize useful space above a long-span brick or concrete box.
Steel profiled flooring metal beams, if an unused roof is being constructed that covers spans of any size between walls made of brick or other artificial stone.
Wood panel made from boards 40-50mm thick, up to 180mm wide. It is used to cover medium and large spans of wooden buildings in the event of planned operation.
Wood chipboards and fibreboards according to wooden beams, used to cover small spans of wooden and stone buildings. They are used if an unused roof is being constructed.

Lumber is a leader in the construction of low-rise residential buildings, because... are ahead of concrete and steel competitors in terms of environmental criteria. Note that wood is inferior in fire resistance. True, fire hazard in low-rise housing construction is not recognized as a decisive factor. In addition, to combat it there are effective means- flame retardants.

Roll coverings in flat systems with wooden base Then they serve only as waterproofing, on top of which plank or parquet flooring is laid. If a flat roof is being erected over a brick or concrete box, it is wiser to lay a reinforced concrete floor for the object in use or corrugated sheet for the one not in use.

The overlap of a flat roof does not always serve as the basis for its construction. In some cases, an attic structure is erected above the ceiling, which can be either a canopy over the base with a roofing pie, or the base itself. Roofing pie structure attic roofs similar, but the layers can be located in different levels.

With or without an attic?

The unconditional inclusion of flat roofs in the category of non-attic structures is fundamentally incorrect, although it has strong technical justifications. They may or may not have attics, although they are not formed by installing rafter legs.

Depending on the presence of an attic, flat roofing systems are divided into:

Without roofs, the elements of which are structurally combined with the ceiling. They are completely devoid of an attic superstructure, which significantly reduces the budget allocated for their construction.
Attics with an attic superstructure above the ceiling. The minimum height of the superstructure is 80cm. The construction of attic structures for flat roofs is more expensive, but by separating the floor from the roof, the service life of the system increases at least three times.

In addition to the budget cost, one of the advantages of atticless systems is the ability to eliminate mechanical cleaning. The snow will melt due to the heat emanating from the room. Due to spontaneous precipitation, it is not advisable to equip flat roofs without an attic with parapets. It is enough to install railings, which further reduces costs. The disadvantage of the absence of an attic will affect when identifying the causes of leaks, because the condition of the thermal insulation and other layers of the cake cannot be controlled.

The attic is an air chamber between the ceiling and the roof. This is a kind of buffer that compensates for the difference in temperatures outside and inside the premises. The presence of an attic reduces the likelihood of condensation forming, and as a result prolongs life cycle structural elements. Elements of the attic system are always available for observation: the simplicity of inspections is difficult to overestimate.

An undeniable advantage is the possibility of installing insulation after construction, which prevents it from getting wet. The disadvantage of flat roofs with attics is their high cost and the need to regularly clear snow.

Despite the mythical cheapness of atticless systems, this is a very complex structure that requires experience from the builder, careful selection of materials and adherence to technologies for their hermetic connection. For an independent master It is better to give preference to roofs with an attic, if their construction is not excluded by the design decision.

Subtleties of water drainage

Flat roofs must be equipped with drainage systems that all year round are obliged to freely drain water at an operational pace. Systems come in external and internal types.

Optimal type drainage system determine the climatic conditions of the construction area:

External drains are constructed when constructing flat roofs in the southern regions, where icing of drains in external pipes is excluded. According to the external type, water is discharged to pipes located outside along the perimeter of the building or to a gutter attached along the lowest overhang. In the middle zone, only flat roofs of non-residential buildings are equipped with external systems.
Internal drainage systems for atmospheric water when installing flat roofs are built in the middle zone and to the north. In accordance with the internal layout, water along slopes or obliquely installed pipes transported to water intake points in the center of the roofs. Drainpipes transporting water to the sewer system are laid inside the building, but isolated from the premises.

Despite the impressive cost, the construction of an internal drainage is mandatory for temperate and northern latitudes, and in the south its construction is irrational.

Installation of slopes for drainage

If the slope of the flat roof was not provided for during the construction of the old roof and the construction of the new one, it must be created. The roof must be inclined towards the water intake funnels by at least 1-2%, approximately 1º. Those who want to know how to correctly make a slope on a flat roof and what material is best to use to form slopes should adhere to the following recommendations:

Slopes on reinforced concrete slabs are made mainly using a screed, or a screed is combined with preliminary filling of expanded clay or laying slab insulation. On an unused roof, it is enough to lay wedge-shaped mineral wool slabs, produced specifically for forming slopes.
Slopes on corrugated floorings are formed using metal structures or wedge-shaped insulation.
Slopes by wooden bases are specified structurally, but if they are absent in the project, it is possible to use wedge-shaped mineral wool.

Due to their serious weight, screeds are poured only for exploited roofs erected over a concrete floor. On a concrete slope, the recommended thickness of the screed is 10-15mm, on rigid insulation panels 15-25mm. For backfill thermal insulation, the screed is poured with a layer of 25-40 mm and used metal mesh for reinforcement.

Nuances of organizing ventilation

Normal ventilation can be done in the only way - by installing battens on the floor beams; similar methods are dictated to us by the construction schemes of pitched structures. It is clear that the above method is only valid for wooden options, and for roofs by concrete base or it is unacceptable to the professional sheet.

The ventilation system for roofing pies on concrete and corrugated sheets depends on the type and characteristics of the finishing coating. PVC roofing is capable of spontaneously transmitting excess moisture from the insulation to the outside, so there is no need to install ventilation ducts between it and the insulation.

When using bitumen and bitumen-polymer materials, it is mandatory to install weather vanes over the entire area of the flat roof. The spacing of these devices depends on the thickness of the insulation. Vane aerators ensure the removal of moisture from the under-roof space to the outside.

Algorithm for constructing a flat roof

Let's consider the common case of constructing an unused flat roof over an extension on a suburban site. It will be equipped with an external drain. Insulation of the structure is not expected, because climatic conditions and the purpose of the room below do not require thermal insulation.

The sequence of constructing a cold flat roof on wooden beams:

We mark the installation step of the floor beams, for which we will use a board 40-50mm thick. Installation step from 50 to 70cm: choose it based on the actual length of the walls. There should be equal spaces between the beams.
We place the board on its edge, fasten it with nails or corners. Required slope to the lowest overhang is created spontaneously due to the difference in the height of the walls of the box.
We lay a continuous flooring made of OSB boards, moisture-resistant plywood or other similar material on the beams. There should be a gap of 3-5mm between the plates to compensate for thermal expansion. They are fastened with galvanized self-tapping screws or rough nails.
We install a wind board along the perimeter of the roof, the edge of which rises 5-7 cm above the plane of the future roof so that a small side is formed.
We nail a wooden strip with a triangular cross-section or a regular plinth to the sides. These are fillets necessary to drain water from the edges of the roof.
All wooden elements We treat with antiseptics and fire retardants. After they dry, apply primer.
We lay an additional waterproofing carpet in a strip along the perimeter on top of the fillets. In the case of junctions and pipes passing through the roof, additional waterproofing is applied to the adjacent vertical planes similarly, i.e. on top of the fillets.
We fuse the finishing roofing material selected for installation, heating its back side with a gas burner.

In the case of thermal insulation, a vapor barrier layer is first laid out on the base, the edges of which are placed on the vertical sides. Insulation boards are placed in a kind of pallet formed by the vapor barrier, the thickness of which is calculated in accordance with the requirements of SNiP 02/23/2003. Thermal insulation is attached to the base with self-tapping screws and telescopic devices.

Then waterproofing is laid over the sides and junctions. If one of the latest brands of rolled waterproofing material is chosen for the installation, then it will also be entrusted with the responsibility of the finishing coating.

An impressive range of new polymer-bitumen and polymer coatings laid in one layer, which helps to save the installer’s effort and construction costs. Among them there are materials that are extremely preferable for home craftsmen and do not require the use of gas burner. They are glued to mastics or using the back adhesive side, fixed mechanically, laid loosely and loaded with ballast.

Video for DIYers

A video collection will help you consolidate information about the difficult task of constructing flat roofs:

We hope that the information we presented will help future roofers who decide to practice with their own hands in constructing a not-so-simple design.

There are many conditions for the proper construction of a flat roof, but they must be observed for ideal operation and long service. Information about the intricacies and specifics of constructing a flat roof will help not only determined craftsmen, but also owners of country estates who resort to the services of third-party construction organizations.

Some of the materials for writing this article were taken from here:

But for me, a flat roof is the best option, it is preferable to use a roof slab made of expanded clay concrete grade 100, and also do not forget about thermal and waterproofing. Still, a flat roof is more aesthetically pleasing to me. And the fact that in winter you will need to constantly remove snow, I think that this must be done from any other roof too. But if you consider that the material is concrete and plus protection, then when performing this necessary measure there is no risk of structural damage.

Flat, but still with an insignificant slope of a couple of degrees, or rather. A flat roof to some extent makes it possible to minimize costs. Flat roofing is utilitarian. Temperature insulation and water protection are also excellent. The use of rolled materials creates the possibility of savings, ease and speed of installation, and a good degree of protection from weather conditions.

Installation of a flat roof: design, device, installation, layers, elements

The installation of a flat roof requires strict adherence to the rules for installing elements and a clear arrangement of layers laid when installing rafter-free structures

The apparent simplicity of a flat roof often misleads novice home builders. The elementary configuration suggests efficiency and low cost of construction. The minimum number of structural elements can dull the vigilance of independent performers who are ignorant of the intricacies of the roofing business.

In reality, installing a flat roof requires scrupulous adherence to the rules unique to it, guaranteeing the flawless operation of the structure and long-term operation.

Flat roofs are a separate category of roofing structures that do not require the construction of a rafter frame. Purely visually, it is a ceiling that rests directly on the walls of the building. Due to the absence of slopes, a flat roof does not upset the windage that occurs under the influence of gusty winds. However, its configuration does not contribute to the rapid removal of snow deposits from the surface.

In regions and districts of the country located in the middle zone and to the north, flat roofs are used mainly in industrial construction.

Private owners install them over one-story extensions, garages, and household buildings. For an independent craftsman, a flat roof over a shed or shed is an excellent option to practice as a roofer.

Briefly about the design of a flat roof

It is customary to call roofs flat, the only conditional slope of which is located to the horizon at an angle from 0º to 1.5º, or otherwise up to 2.5%. However, a number of technical sources call systems with a slope of up to 5º flat, a percentage value of up to 8.7%.

Even roof structures have a slight slope, creating a clearly horizontal impression. It is formed to drain wastewater to drainage points or to an overhang.

Regardless of the steepness, the layers of a flat roof are arranged in a strictly defined order:

Vapor barrier covering the base. It is necessary to protect the insulation from the penetration of household fumes.
Insulation laid in one or two tiers. Required to prevent leakage of heat waves through the upper ceiling, used exclusively in insulated systems.
A screed created when the thermal insulation is insufficiently rigid or when there are no slopes for drainage.
Waterproofing that protects the insulation and ceiling from the destructive effects of atmospheric water. It is laid with a continuous waterproofing carpet.
A finishing coating that gives the structure an aesthetic appearance.

The brands of waterproofing materials currently supplied to the market successfully perform the functions of finishing roofing. These include numerous rolled and mastic bitumen, bitumen-polymer, and polymer varieties. Most of them are laid in one layer.

Due to the slight slope of flat roofs, the use of piece materials in the arrangement is contraindicated, because multiple joints between elements create the risk of leaks.

It is undesirable to use large sheet metal due to the harmful effects on the material of water stagnating on a flat surface during periods of heavy rain and snowmelt.

When using old, well-known roofing felt types of roll coverings, the finishing roof is arranged in 4 or more layers, the lower of which plays the role of waterproofing. A mastic or emulsion self-leveling roof is constructed in a similar way: the emulsion or mastic is applied in five or more layers, alternating pasty or creamy material with layers of fiberglass or polyester.

To lay and fix the above elements of the roofing pie of a flat roof, a rafter structure is not required. They are laid directly on the base, which can be a ceiling, a screed created on top of it, or the upper plane of the attic structure. To fasten PVC-coated systems, use adhesive, mechanical or. Self-leveling roofs are applied according to their name, the descendants of roofing material are fused or glued.

Unlike their pitched counterparts, flat systems do not have sheathing that creates ventilation channels for washing the insulation with air currents. Therefore, the selection of design solutions, materials and their sealed installation should be approached with due respect and focused attention.

A ventilated flat roof is only possible when lumber is used in the construction of the ceiling and attic. The latter option is most often used in private construction.

Types of floors used

Depending on the operational criteria, flat roofs are equipped with:

Reinforced concrete floors, if it is planned to organize useful space above a long-span brick or concrete box.
Steel profiled flooring on metal beams, if an unused roof is being constructed that covers spans of any size between walls made of brick or other artificial stone.
Wood panel made from boards 40-50mm thick, up to 180mm wide. It is used to cover medium and large spans of wooden buildings in the event of planned operation.
Particle boards and fibreboards on wooden beams, used to cover small spans of wooden and stone buildings. They are used if an unused roof is being constructed.

Lumber is a leader in the construction of low-rise residential buildings, because... are ahead of concrete and steel competitors in terms of environmental criteria.

Note that wood is inferior in fire resistance. True, fire hazard in low-rise housing construction is not recognized as a decisive factor. In addition, there are effective means to combat it - fire retardants.

Rolled coverings in flat systems with a wooden base then serve only as waterproofing, on top of which plank or parquet flooring is installed.

If a flat roof is being erected over a brick or concrete box, it is wiser to lay a reinforced concrete floor for the object in use or corrugated sheet for the one not in use.

Roofing pie structure attic roofs are similar, but the layers can be located at different levels.

With or without an attic?

Depending on the presence of an attic, flat roofing systems are divided into:

Without roofs, the elements of which are structurally combined with the ceiling. They are completely devoid of an attic superstructure, which significantly reduces the budget allocated for their construction.
Attics with an attic superstructure above the ceiling. The minimum height of the superstructure is 80cm. The construction of attic structures for flat roofs is more expensive, but by separating the floor from the roof, the service life of the system increases at least three times.

It is enough to install railings, which further reduces costs. The disadvantage of the absence of an attic will affect when identifying the causes of leaks, because the condition of the thermal insulation and other layers of the cake cannot be controlled.

The attic is an air chamber between the ceiling and the roof. This is a kind of buffer that compensates for the difference in temperatures outside and inside the premises.

The presence of an attic reduces the likelihood of condensation formation, and as a result extends the life cycle of structural elements. Elements of the attic system are always available for observation: the simplicity of inspections is difficult to overestimate.

Despite the mythical cheapness of atticless systems, this is a very complex structure that requires experience from the builder, careful selection of materials and adherence to technologies for their hermetic connection. It is better for an independent craftsman to give preference to roofs with an attic, if their construction is not excluded by the design decision.

Subtleties of water drainage

Flat roofs are required to be equipped with drainage systems, which are required to freely drain water at an operational pace all year round. Systems come in external and internal types.

The optimal type of drainage system is determined by the climatic conditions of the construction area:

External gutters constructed when constructing flat roofs in southern regions, where icing of drains in external pipes is excluded. According to the external type, water is discharged to pipes located outside along the perimeter of the building or to a gutter attached along the lowest overhang. In the middle zone, only flat roofs of non-residential buildings are equipped with external systems.
Internal drainage systems atmospheric water when installing flat roofs are built in the middle zone and to the north. In accordance with the internal design, water is transported through slopes or inclined pipes to water intake points in the center of the roofs. Drainpipes transporting water to the sewer system are laid inside the building, but isolated from the premises.

Despite the impressive cost, the construction of an internal drainage is mandatory for temperate and northern latitudes, and in the south its construction is irrational.

Installation of slopes for drainage

Those who want to know how to correctly make a slope on a flat roof and what material is best to use to form slopes should adhere to the following recommendations:

Slopes on reinforced concrete slabs are made mainly using a screed, or a screed is combined with preliminary filling of expanded clay or laying slab insulation. On an unused roof, it is enough to lay wedge-shaped mineral wool slabs, produced specifically for forming slopes.
Slopes on corrugated floorings are formed using metal structures or wedge-shaped insulation.
Slopes on wooden bases are specified structurally, but if they are not included in the project, it is possible to use wedge-shaped mineral wool.

Nuances of organizing ventilation

Normal ventilation can be done using the only method - by installing battens on the floor beams, similar methods are dictated to us. It is clear that this method is valid only for wooden options, and for roofs on a concrete base or corrugated sheet it is unacceptable.

Algorithm for constructing a flat roof

The sequence of constructing a cold flat roof on wooden beams:

We mark the installation step of the floor beams, for which we will use a board 40-50mm thick. Installation step from 50 to 70cm: choose it based on the actual length of the walls. There should be equal spaces between the beams.
We place the board on its edge, fasten it with nails or corners. The required slope to the lowest overhang is created spontaneously due to the difference in the height of the box walls.
We lay a continuous flooring made of OSB boards, moisture-resistant plywood or other similar material on the beams. There should be a gap of 3-5mm between the plates to compensate for thermal expansion. They are fastened with galvanized self-tapping screws or rough nails.
We install a wind board along the perimeter of the roof, the edge of which rises 5-7 cm above the plane of the future roof so that a small side is formed.
We nail a wooden strip with a triangular cross-section or a regular plinth to the sides. These are fillets necessary to drain water from the edges of the roof.
We treat all wooden elements with antiseptics and fire retardants. After they dry, apply primer.
We lay an additional waterproofing carpet in a strip along the perimeter on top of the fillets. In the case of junctions and pipes passing through the roof, additional waterproofing is applied to the adjacent vertical planes in the same way, i.e. on top of the fillets.
We fuse the finishing roofing material selected for installation, heating its back side with a gas burner.

An impressive range of new polymer-bitumen and polymer coatings are laid in one layer, which helps to save the paver's effort and construction costs. Among them there are materials that are extremely preferable for home craftsmen and do not require the use of a gas burner. They are glued to mastics or using the back adhesive side, fixed mechanically, laid loosely and loaded with ballast.

Video for DIYers

A video collection will help you consolidate information about the difficult task of constructing flat roofs:

We hope that the information we presented will help future roofers who decide to practice with their own hands in constructing a not-so-simple design.

Flat roofs, their types and designs can be classified:

According to the purpose of the surface. Can be exploited or unexploited.
According to the method of laying the roofing pie. It can be traditional and inversion.
By type of construction. It can be attic or non-attic.
Ventilated and non-ventilated structures are distinguished separately.

Operable roof

A usable flat roof can be used as a parking lot, helipad, tennis court, swimming pool, green roof or just a terrace. In any case, it is necessary to calculate the possible load on the roof.

Load from operation (weight of a person, car, water in a swimming pool, etc.).

In some cases, the roof is subjected to a pressure of 20 tons per square meter.

Also, due to the design of a flat roof, it is highly susceptible to ultraviolet rays.

Together, these factors mean that the choice of building materials for such a roof must be approached with particular care.

The structure of the roofing pie of the roof in use is as follows:

Reinforced concrete floor slab.
Sloping layer. It is made of slag, concrete, expanded clay, wedge-shaped mineral insulation and other similar materials. The top is secured with a concrete screed. Slope angle up to 3%. Necessary for high-quality drainage of water in the required direction. Sloping is always installed in front of the waterproofing to ensure water flow through it.
Leveling concrete screed .
Waterproofing. Made from bitumen, polymer, PVC materials and sealants. Roofing felt is often used, laid in two layers, and it is important that the joints of the upper and lower rows do not coincide.
Thermal insulation. Keeps the room warm in winter and cool in summer. Requires a careful approach to calculating thickness. In case of an error, condensation may form inside the room. If not an inversion type of roofing is used, but a traditional one, the insulation must be resistant to steam. If on the contrary, there must be resistance to water absorption.
Drainage layer. Given the flat roof technology, water should flow along the surface into drainage trays. But in other cases, moisture can get into the joints between tiles used as finishing paving elements, or be absorbed into the ground when using a green roof. To prevent the elements of the roofing pie from getting wet, a drainage layer is installed that drains water in the right direction.
Then everything depends on the type of roof being used. If this green roof– lay geotextiles that will prevent plant roots from destroying the roofing pie. If it is a roof terrace, or a parking lot, behind the drainage layer there is a concrete screed under the tiles or other finishing material.

Please note that when using traditional roofing, the order of the elements of the roofing pie changes. A vapor barrier is laid over the slope-forming layer, then insulation, and only then waterproofing.

The advantages and disadvantages of this method are discussed below.

Unused roof

An unused flat roof is distinguished by its efficiency. It is not designed to withstand any loads other than snow. This allows for a less careful approach to the selection of building materials.

The structure of a roofing pie of this type of roof is as follows:

Reinforced concrete floor slab. Instead, it is allowed to use profiled sheets with a high wave height, such as N-153 and N-158.
Slope formation layer.
Vapor barrier.
Thermal insulation.
Waterproofing.
Ballast layer of gravel. The thickness of such a layer should be from 10 to 20 centimeters. Necessary to protect waterproofing from exposure to ultraviolet rays and prevent fires.

Once again, we draw your attention to the fact that the layers of steam, heat and waterproofing can change places depending on the type of roof used.

Traditional roof

The traditional type of flat roofing has been used for a very long time. In this case, the roofing pie will look like this:

Slope formation layer.
Vapor barrier. Necessary to protect the insulation from steam emanating from the room. Otherwise, even in the case of one percent moistening of the thermal insulation layer, a significant increase in thermal conductivity occurs. Made from specialized vapor barrier membranes and films.
Thermal insulation. Almost all types of insulation can be used, even with a low percentage of moisture resistance.
Further on traditional drawing A layer of waterproofing should be laid on a flat roof. Please note that it must be of high quality, since it is absolutely not protected from temperature changes.

The advantages of a traditional roof are that it guarantees protection of the thermal insulation layer from getting wet. Firstly, this allows you to use the entire range of roof insulation materials. Secondly, the insulation will not lose its thermal conductivity characteristics, which means that a comfortable temperature regime will always be maintained in the room.

At the same time, this flat roof design compromises waterproofing. It is maximally susceptible to temperature changes, which leads to its accelerated aging. Also, the insulation does not protect the waterproofing from external force loads, which again negatively affects its service life. In general, this type of roofing is less durable and requires fairly frequent repair work.

Inversion roof

It is a more progressive type of flat roof device. It assumes the installation of the following roofing pie:

Reinforced concrete floor slab or corrugated sheet.
Slope formation layer.
Leveling concrete screed.
Primer for waterproofing, for better adhesion. During this process, the screed is carefully inspected for cracks and water bubbles. The cracks are covered with solution, water bubbles are removed.
Waterproofing.
Thermal insulation.
Next is either a drainage or ballast layer, depending on whether the roof will be used or not.

Inversion roofing has the following advantages:

Protection of waterproofing film from temperature changes. As a result, this extends the service life of the film in particular, and the service life of the roof in general.
The insulation redistributes force loads across the waterproofing in such a way that this does not affect it.
Extruded polystyrene foam, which is usually used as thermal insulation for this type of roofing, is cheaper than mineral wool used for traditional roofing.
The inversion design of a flat roof allows for more repairs, if it is necessary to replace or add insulation.

There are also disadvantages, which include:

It is permissible to use insulation materials only with closed cells to prevent them from getting excessively wet.
The need to install more complex design gutters.

Attic roof

The technology for installing a flat roof with an attic implies the possibility of using two types:

The attic roof is a lightweight superstructure, and the attic floor serves as the main supporting structure.
The attic floor and the attic roof are independent of each other and are able to withstand force loads equally well.

The advantages of a roof with an attic are:

Possibility of constant monitoring of the tightness of the waterproofing layer.
The ability to regularly monitor the condition of the insulation.
The insulation can be laid after the roof has been installed.
The attic itself performs the functions of thermal insulation.

The disadvantages include:

Impossibility mechanical cleaning from snow, provided that the attic roof is used as a light superstructure. Instead, the attic is blown with hot, dry air, which ensures that the snow from above melts and gradually melts away.
This type of roof is more expensive.

Roofless roof

More popular is the roofless roof. She:

It costs less than an attic.
Easier to install.
Provides snow melting by conducting heat from the room.

A roofless flat roof also has a significant disadvantage:

There is no way to timely detect a violation of the waterproofing layer. This damage appears as a wet spot on the ceiling, making it impossible to determine the exact location of the leak.

Ventilated and non-ventilated roof

Roof ventilation is arranged between the insulation and the waterproofing layer. Thus, constant air circulation is achieved, which ensures constant dryness of the insulation. Used for traditional type roofing pie.

When installing ventilation, it is important to adhere to the following recommendations:

Height vent at least 1/30 of the width of the building.
The diameter of the hole is at least 1/150 of the total roof area.
Air inlets should be located lower than the outlets.
The holes are evenly distributed across the width of the entire building.

In turn, a non-ventilated roof does not require the creation additional elements roofs of flat roofs. But this somewhat shortens the service life of the thermal insulation material.

This option for arranging the upper part of a building is used, as a rule, in the construction of “high-rise buildings”, as well as various administrative, industrial, warehouse and some other buildings: pavilions, showrooms and the like. Despite the fact that a flat roof has a number of disadvantages, this does not reduce the popularity of such a design, including in private housing construction.

Advantages of flat roofs

Firstly, the installation of a flat roof can be carried out independently, rather than inviting assistants or hiring professionals, as, for example, when constructing a roof with a complex configuration (hipped, etc.). Consequently, they will not have to be paid for their work (we are not talking about large areas, where it will be problematic to cope alone).

Secondly, the construction of such a roof provides significant savings both in materials (money) and in time (the covering area is much smaller than with a pitched roof). You won’t have to make numerous calculations or order a project (which will be expensive), assemble complex system rafters, installing jibs, spigots, and so on. In addition, there are no restrictions on the choice of type of roofing.

Third, a flat surface is much easier to maintain and repair, which also provides significant savings in the long term.

Fourth, the ability to choose arrangement options. A flat roof can either serve only as a traditional “cover” for a house, or be used (inverted). For example, greenhouses are mounted on it, summer gardens, solariums and the like. Even helipads are being built. This fully compensates for the inconvenience due to the lack of attic space.

Flaws

Increased requirements for waterproofing. Since the roof is located horizontally, water falling in the form of precipitation will stagnate on it. You can use , for example.
Debris will constantly accumulate (for example, fallen leaves), so such a roof will have to be serviced more often.
Lack of attic (attic) space

What to consider

The maximum load that the roof will experience (for a rafter structure). This means the weight of the frame itself, roofing material, layers of insulation and insulation, as well as possible snow cover. In addition, you need to count on the fact that the roof must withstand the weight of people who will subsequently walk on it.
The purpose of the building and the possibility of further use of the surface (for example, equipping a terrace). Depending on this, the type of overlap is determined.

Work technology

The simplest version of a flat roof is when reinforced concrete slabs are laid (for example, a garage, shed). Everything here is extremely simple. A so-called “layer cake” is arranged on the surface: vapor barrier, if necessary - insulation material, waterproofing layer. For the latter equipment they are most often used roll materials.

Insulation of a reinforced concrete slab can be done by pouring a layer of expanded clay and arranging it on top cement screed. Slag and some other materials are also used.

Traditionally, roofing material is used for waterproofing, which is covered with bitumen mastics. It is necessary to take into account that this material will last no more than 5 years, and then you will have to do repairs. It is more expedient to lay it as a “waterproofing” polymer materials eg membranes. Liquid rubber is also great.

Since the installation of slabs requires the use of special equipment, when independent device flat roof can be equipped with a simple rafter system made of wood.

First of all on the upper parts load-bearing walls supports are laid - Mauerlats. The most commonly used material is timber. It must be taken into account that these structural elements must be rigidly fixed to prevent the possibility of their horizontal displacement.

Therefore, metal pins are first embedded along the entire length of the walls into their upper end surfaces. Their length is calculated so that after installing the mauerlats they rise above the beam by about 5 cm. Threads must be cut at their ends.

If the masonry is old, then a “ribbon” of concrete mortar. After this, in each wooden blank Pre-designed holes with a diameter slightly larger than the cross-section of the metal “fingers” are drilled. First, strips of roofing felt (or similar waterproofing material) are laid on the tape, and then Mauerlats. They are mounted on pins, and a washer is put on top of each and with the help of a nut the beam is securely fixed at the installation site.

Next, the floor beams are laid. It is necessary to take into account that the roof should protrude beyond the dimensions of the house by 50 - 60 cm (the required overhang). This will protect both the walls and the blind area from water flowing from it, as well as from raindrops.
Device load-bearing frame. Depending on the type, it can be either solid (boards, slabs) or cellular (lathing).

Vapor barrier.

Insulation. For flat roofs there is a nuance. Absence attic space deprives such a building of an “air cushion” from above. Therefore, insulation is carried out both outside and inside. But at the same time, you need to take into account the weight of such material, since it is an additional load on the rafter system.

Waterproofing.

Roofing covering.

Finishing of overhangs.

This is only a general list of necessary activities. The technology for performing work on each item depends on both local conditions and the selected materials.

Any “wood” used in construction must be well dried. The moisture in its structure gradually “leaves” (natural shrinkage of the material), which leads to a change not only in the volume of the workpiece, but also in its deformation (for example, twisting).
Wood has two significant drawbacks: it burns and is susceptible to rotting. Therefore, before using it, all wooden parts of the structure are pre-treated with fire retardants and antiseptics. It is better to spend money on these products than to suffer from frequent repairs later.
When installing mauerlats, you need to constantly monitor their horizontalness using a building level. Otherwise, the roof will be skewed. If necessary, either the tape is leveled or a rigid lining is made under the Mauerlat.
To prevent stagnation of water on the roof, it is advisable to make it with a certain slope (approximately 3 0 - 5 0). As a rule, the decline goes towards the rear side of the building. To do this, the height of the front mauerlats increases, so the floor beams will lie with a slope.

Ratings 0

The popularity of flat roofs in suburban housing construction is growing from year to year. Setting up a flat crawl is not like that simple task, as it seems; the design has advantages and disadvantages, and the construction of flat roofs is a multilayer structure. The article compares the most common flat roofs, from traditional and inversion, to ventilated, green and usable. Knowing the differences will help you choose suitable model and confidently navigate the component materials and construction nuances.

The purpose and design of a flat roof varies from project to project.

About flat roofing and its operation

Unlike a pitched roof, this roof is a single plane, the slope of which can vary from 2 to 15-20° (the minimum slope is needed for water drainage). This design is often called roofless; at the stage of housing design, they choose its type, which is easier to determine by the method of use:

Exploited. This implies its practical (often year-round) use. The roof is connected to the living quarters by an entrance, on it there is a recreation area, a flower garden, a solarium, playground. The structure is laid and erected taking into account high loads.

Not in use. The owner appears here only when necessary, for inspection or repairs.

Flat roofs are traditionally common in southern regions with little snowy winters, but there are no direct prohibitions on the construction of such a structure in the northern regions. Contrary to popular belief, their operation is not significantly affected by wind strength or the amount of precipitation in winter.

Operable roof

About the advantages and disadvantages

A flat roof has the following attractive qualities:

Economical construction. With the same area of the house, the area of the flat surface is less than that of the pitched surface; this means reduced costs for materials and components.

Simple and quick installation. To equip a flat roof pie, you do not need to first purchase lumber and install sheathing. Extreme installation work on a flat surface is reduced to a minimum; insurance is not needed here, so the labor intensity and time of installation work is reduced.

Use for technical needs. Flat surface – convenient place for installation solar panels or climate control equipment. The facade of the house will not be damaged by external air conditioning units.

Long service life. The flat roof is designed to last a long time and does not require expensive annual maintenance. Its reliability is guaranteed by compliance building codes and competent organization of drainage.

Solar panels on a flat roof

Simplified Maintenance. In order to inspect the chimney or ventilation duct, or clean the drain, you (or the specialist you invite) will not need the skills of a climber.

Design possibilities. Flat roofing is necessary part for many modern style house projects, giving them a complete, exclusive look.

Additional effective area . The usable roof included in the project allows you to equip a terrace, sauna or swimming pool, create a lawn or a small garden.

There are circumstances in which a flat roof may be inferior to a pitched roof. For example, a roof built without taking into account local climatic conditions may suffer from snow loads for which it was not designed. Most of the disadvantages of flat roofing are related to construction problems. Incorrect installation, violation of construction regulations, errors in drainage arrangement lead to a violation of the integrity of the structure and leaks. A well-equipped flat roof is, in many respects, a more profitable and functional option when compared with other structures.

Rest zone

Varieties and distinctive features of different types of roofs

In modern private housing construction, there are several ways to arrange a flat roof, which have some differences in the order of layers and the composition of the roofing pie.

Traditional roof

The composition of a traditional flat roof (also called soft), regardless of the slope, includes several layers:

Base. Usually this is a reinforced concrete slab or metal profile structure.

Vapor barrier. It is laid directly on the base and protects the overlying layer from diffuse moisture penetrating from below. The layer is made of roll or bitumen materials.

Thermal insulation. The insulation is often one or two layers of mineral wool or polystyrene foam boards. It is acceptable to use expanded clay gravel or install a cement screed.

Waterproofing. Protects underlying layers from atmospheric moisture. To organize it, bitumen-based materials are used: various rolled materials, as well as mastics or PVC membranes.

Installation of traditional roofing

Finish coating. Its role is successfully fulfilled by modern brands of waterproofing materials. The use of sheet and piece materials is not recommended - a small slope and many joints create a high risk of leaks.

On our website you can find contacts construction companies that offer. You can communicate directly with representatives by visiting the “Low-Rise Country” exhibition of houses.

Operated roof

The main advantage of this design is the ability to obtain and profitably use extra space, in the form of a cozy relaxation corner or a place for sports. The design is a multilayer structure, the characteristics of which are prescribed in SNiP. The rules describe the procedure for arranging a roof in use; A cross-section of the pie with dimensions can be studied there. The operating coating has the following differences from the traditional design:

Above the reinforced concrete foundation is laid slope-forming layer.

Between the layer of insulation and waterproofing performed screed(under right angle) or fiberglass is laid.

Tiled Pie

Between the layer of waterproofing and the final (finish) coating additional protective separator layer(geotextile layer).

Taking into account the peculiarities of use, the layers of the roofing cake are arranged in accordance with the following conditions:

Base. It must be rigid and capable of maintaining the integrity of the waterproofing.

Insulation. The thermal insulation layer in such a roof is under constant load, both dynamic and static, therefore, the main requirement for this layer is to have sufficient compressive strength. If the material is not rigid enough, it is reinforced with a layer of cement screed.

Finishing . The most popular option for finishing material is paving slabs, which are installed on special stands or a sand cushion, which allows the pressure to be distributed more evenly. If it is expected that the operation will be significant, experts recommend installing an inversion-type flat roofing pie.

Video description

About flat roofing in use in the following video:

Inversion roofing

The main problem with a traditionally installed structure is the regular freezing and thawing cycles that are common in our climate. Vulnerability of the outer layer to seasonal temperature fluctuations and solar radiation disappears after installation of the inversion coating.

Unlike a traditional roof, here the thermal insulation is laid not under, but above the waterproofing. The insulating layer on top is protected by a ballast layer from mechanical pressure, temperature changes and sunlight with its destructive ultraviolet radiation. The roofing pie looks like this:

Lay on concrete waterproofing layer. Euroroofing felt, PVC membrane or bitumen mastics cope with this role.

Thermal insulation is being laid. With assigned function in the best possible way extruded polystyrene foam copes - a synthetic material characterized by high compressive strength and extremely low water and vapor permeability.

Laying a geotextile covering, drainage is being installed.

Flat inversion roof design

Upper (ballast) layer, which plays a protective role, is made of gravel (bulk version), with tiles laid on top. On such a surface you can not only lay out a lawn and flower garden, but also without fear create a terrace, place chairs, a tea table or sun loungers.

Non-operational design

If paths, flower beds or a recreation area are not intended to be placed on the roof, it will be much easier (and cheaper) to equip it. Such a surface is not demanding on the parameters of the insulating layer and the overall strength of the base. At the same time, such simplification of requirements means a reduction in the service life of the surface.

Video description

About the intricacies of a flat roof in the following video:

Breathable (ventilated) roof

The reason why roofing structures lose their properties over time is due to waterlogging of the heat-insulating layer. Undesirable changes are especially accelerated in summer period when the temperature rises and increased evaporation of moisture from the insulation begins. The consequences are visible to the naked eye - swellings and tears form on the roof surface, and cracks form. Sooner or later, the destructive process ends with a violation of the integrity of the roofing pie and peeling of the coating from the base.

To prevent destruction, the roof structure is made breathable (ventilated); this neutralizes the formation of condensation and ensures high-quality removal of water vapor. The flat roof structure is undergoing significant changes; The roofing carpet of the ventilated covering consists of the following elements:

Floor slab, on which they stack layers of vapor barrier and insulation.

Cement-sand screed.

Bottom layer of multi-layer waterproofing. Usually this is a layer of euroroofing material (Uniflex VENT), which prevents swelling.

Flat roof ventilation diagram

Waterproofing layer. Polymer-bitumen (SBS) binder, providing additional sealing.

Upper layer multi-layer waterproofing. Uniflex EKP (TKP).

Roof fans(aerators).

TOexpanded clay gravel.

Final roll covering.

Given constructive solution can be used both in the construction of a new roof and in the repair of an old one. In the latter case, the installation of a ventilated covering can be carried out without removing the old fused roofing carpet, which will serve as an additional layer of waterproofing. If a new layer is created with a slope, this will ensure high-quality outflow of water and extend the service life of the structure.

Green roof

The habit of sowing the roof with grass arose in Scandinavian countries several centuries ago. Since then, the technology has spread throughout the world, becoming one of the signs environmental attitude to life. Such designs reduce heat loss at home (and, therefore, heating costs), improve sound insulation of the home and, undoubtedly, give country house unusual, memorable look.

Video description

About green roofs in the following video:

The decision to install a green roof is made at the design stage of the house. This is due to the fact that the layer of soil necessary for plants creates a significant load on the floors and load-bearing structure; this is taken into account in the calculations. It is also necessary to take care of quality protection from water. Installation of a green type flat roof proceeds according to the following plan:

Placed on a reinforced concrete base expanded clay layer(to create a slope).

Performed cement-sand screed, which is treated with a bitumen primer.

Held waterproofing. She receives increased attention. High-quality EPDM membranes are used, as well as varieties of Technoelast (polymer membrane) and geotextiles.

Green roof design diagram

Stacked insulation layer; It is appropriate to use extruded materials here.

Stacked geotextiles(or better yet, two layers, with a profiled membrane between them, which will allow soil pressure to be distributed more evenly).

Drainage layer. Gravel or crushed stone is used.

Filter layer, protecting in parallel root system plants.

Soil and green spaces.

Green roofs, depending on the nature of operation and the amount of landscaping, are divided into two types:

Extensive. Not designed for constant human presence. The soil layer is laid thin in thickness (up to 15 cm); only sown lawn grass, and flowers and ornamental shrub planted in pots or special containers.

Extensive green roof

Intensive. If the design of the house allows you to lay a layer of soil 0.3-0.6 m thick (the total thickness of the roofing carpet reaches 1.2 m), you can set up a full-fledged garden with trees and lush flower beds on the roof. The installation of such a structure should be entrusted to professionals; Repairing a green roof made by hand is a time-consuming, problematic and expensive task.

Rules for using a flat roof

Operating a flat roof is no more difficult than a conventional gable roof. There are a number of rules, compliance with which during installation and further use will help extend the service life of the roofing:

The roofing carpet should protect from contact with organic solvents, gasoline or technical oil.

Roof must be clean. Any debris, nails, forgotten pieces of reinforcement and wire left on the surface of the coating can compromise its integrity.

It should be remembered that the bitumen-polymer materials included in the cake cannot tolerate steam and temperatures above 45°.

Regular inspection. During the melting snow cover and autumn leaf fall, it is necessary to inspect gutters and funnels (at least twice a month).

Modern flat roof project

Conclusion

A country house with a flat roof fits into any landscape, and sometimes acquires additional advantages that are unattainable for buildings with pitched roofs. In order for the roof to last for many years, its installation, repair and maintenance work should be entrusted to specialized professionals. Knowledge of the intricacies of the design and construction of a roofing structure will help you competently control the work of the craftsmen at every stage.

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