Flat roofs nowadays are undeservedly forgotten and not spoiled by the attention of developers. In private housing construction, they are found mainly in the southern regions, where heavy rains and snowfalls are rare. Hip roofs, on the contrary, have become firmly established in the projects and minds of homeowners.

This state of affairs can be explained simply: until recently, builders did not have reliable and durable waterproofing.

Standard roofing felt - cardboard impregnated with bitumen - cannot resist moisture and temperature changes for long. Even a thick 4-layer coating from it has to be changed after 6-8 years.

Today, interest in flat roofs is beginning to grow.

There are several reasons for this:

• Economic benefit. The cost of arrangement is lower than that of a tent structure (more simple design and smaller area);
• Additional usable space. There is a possibility of its rational use (flower garden, playground, recreation area, swimming pool);
• Availability of maintenance and operation (cleaning drains, installing air conditioners, antennas, inspecting coating, ventilation and smoke ducts);
• A layer of snow acts as additional thermal insulation, reducing heating costs.
• Original appearance buildings.

Types of flat roofs

Strictly speaking, you will not see a completely flat roof on a building. Any of them has minimum slope from 1 to 4% required for precipitation runoff.

There are four types of flat roofs:

• unexploited;
• exploited;
• green (lawn);
• combined.

Unused roofs are found on industrial buildings.

Operated roofs have found application in public and private construction. They are equipped with recreation areas, cafes and restaurants, and used as parking lots and helipads.

Green (lawn) coverings are made to decorate buildings, as well as when there is not enough space on the site. In addition to the aesthetic function, they perform an important practical task. A layer of plant turf is an excellent heat and sound insulator.

Combined roofs with a flat surface are the most common option. Comfortable stay on fresh air surrounded by green grass and flowering plants everyone likes it.

According to the method of drainage, houses with a flat roof are divided into two types:

• With internal drain;
• With external water discharge (along the perimeter of the roof).

Internal drainage is cheaper than external drainage because it does not require a large number of gutters, pipes, funnels and high-altitude work to install them. It is more difficult to execute. Errors when creating a slope, poor-quality sealing of joints lead to leaks and damage to the integrity of the protective layer of waterproofing.

In operation, flat coverings with internal drainage are more profitable. In winter, icicles do not grow on the eaves of such a roof. Drainpipes pass inside the building and therefore do not freeze. Cleaning debris funnels is easier and easier than hanging gutters.

Device Features

According to the method of arrangement and arrangement of structural layers, experts distinguish two types of flat roofs:

• Classic;
• Inversion.

The classic roofing “pie” is equipped using the following technology:

• a slope is made from cement-sand mortar on reinforced concrete floor slabs;
• lay vapor barrier and insulation;
• lay a waterproofing membrane or roofing felt carpet;
• if the coating is to be used, the waterproofing is protected with ceramic tiles.

Classic design flat roof

The main disadvantage of the traditional design is the vulnerability of the outer insulating layer from solar ultraviolet radiation and temperature changes.

Working to solve this problem, engineers came up with the idea of ​​an inversion coating. In it, the main structural elements (insulation and waterproof membrane) are swapped. The waterproofing is hidden under the foam, which is protected from external influences by a ballast layer of gravel or tile trim.

Inversion coating design

The technology of work is changing accordingly. Waterproof carpet made of roofing felt or EPDM membrane glued to the slab or spread on it, fixing it in places adjacent to the parapet.

The slope in this case is created in one of two ways:

• Mortar screed on the slab;
• Insulation, changing the thickness of its installation.

Installing thermal insulation on a flat roof

Water intake funnels and pipes are installed at the lowest points of the slope. In addition to them, ventilation is installed to remove water vapor that accumulates in the area of ​​contact between the vapor barrier and the insulation.

When arranging a covering designed for planting plants, the structure is supplemented top layer waterproofing. Drainage layers of gravel are poured over it, geotextiles are laid and a fertile layer of soil is poured.

In addition to roofing coverings laid on reinforced concrete slabs, designs for houses with a flat roof on wooden beams have been developed.

Construction technology in this case may include the following operations:

• Beams are mounted on the walls in increments of 50-100 cm, fixing them to the masonry with anchor pins. The cross-section of the beams depends on the span width, the design load and can range from 10x20 cm to 15x25 cm;
• Lay on beams OSB boards, tightly joining them together;
• Spread the waterproofing membrane in 2 layers, carefully gluing the joints of the sheets.
• Thermal insulation is made from durable (extruded) foam, gluing it to the membrane. A slope for water drainage is created by laying insulation in layers of different thicknesses;
• The heat insulator is protected from above with a cement screed, reinforced mesh or tiled.

Examples of private houses

There are many supporters of flat roofs among developers. They are attracted by the ease of construction, low cost of work and the possibility of placing a site for summer recreation.

A thick layer of snow on a flat roof is not a problem, but additional insulation

The design of buildings with such a roof fits perfectly into the style of minimalism, providing project developers with a wide field for creativity.

Spacious, comfortable and nothing superfluous is the motto of everyone who chooses a house with such a roof. Pitched roof visually makes the building heavier, while flat, on the contrary, makes it light and airy.

External view of the facade one-story house with a flat roof compares favorably with the rather boring variations of the “teremkovy” character.

On it, most often you will not see gutters and pipes, the water from which gets on the walls and spoils the appearance of the finish. Internal drainage is efficient, practical and invisible.

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 roof, etc.). Consequently, you will not have to pay for their work (we are not talking about large areas where it would 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 won’t be cheap), assemble a complex system of rafters, install jibs, extensions, and so on. In addition, there are no restrictions on the choice of type of roofing.

Thirdly, 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, summer gardens, solariums and the like are mounted on it. 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.
• Purpose of the building and possibility further use surfaces (for example, terrace equipment). 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: a vapor barrier, if necessary, insulating material, a layer of waterproofing. For the equipment of the latter, roll materials are most often used.

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

Traditionally, roofing felt is used for waterproofing, which is covered with bitumen mastics on top. It should be taken 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 A 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, pre-designed holes with a diameter of slightly larger section metal "fingers". First, strips of roofing material (or similar waterproofing material), 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.
Construction of a supporting frame. Depending on the type, it can be either solid (boards, slabs) or cellular (lathing).

• Vapor barrier.

• Insulation. There is a nuance for flat roofs. Absence attic space deprives such a building " air cushion" 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 shortcomings– burns and is subject 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 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.

The construction of a gable or hip roof is not always rational and advisable if we're talking about about outbuildings, industrial and commercial facilities, and sometimes private homes in modern style. The high consumption of material and the complex rafter system make the construction of these structures an economically unprofitable and protracted undertaking. While flat roofing projects significantly reduce construction costs, are quick to build and suitable for almost any structure.

A house with a flat roof is reliably protected from increased wind loads. However, without slopes, it cannot quickly drain rain and melt water from the roof surface.

The situation is complicated by the fact that the surface of roofing materials has a rough structure, which does not allow moisture and snow to slide off freely. Therefore, the installation of a do-it-yourself flat roof must meet the strict requirements of building codes for waterproofing, slope and construction technology.

The structure of the roofing pie

Necessity high level protection from moisture forces the roofing materials of a flat roof to be placed in layers, one above the other, forming a so-called “pie”. If you look at its cross-sectional structure, you can see the following layers:

1. Flat base made of concrete slabs or sheets of profiled metal. It provides rigidity to the structure and bears the weight roofing pie passing it on load-bearing partitions and, ultimately, the foundation. The base of the roof in use must be as rigid as possible.
2. Vapor barrier. A layer that is necessary to protect a flat roof from the penetration of vapors from internal heated rooms into the thickness of the insulation. When water settles on the thermal insulation in the form of condensation, it irreversibly reduces its insulation properties by more than half. The simplest vapor barrier is used plastic film or bitumen-based coatings.
3. Insulation. For thermal insulation of a flat roof, backfill materials are used, such as expanded clay, perlite, slag, rolled materials, for example, mineral wool and in the form of slabs, in particular polystyrene foam. By the way, insulation is used not only to regulate the temperature, but also to tilt a house with a flat roof. The main requirements for insulation are low hygroscopicity and thermal conductivity, light weight.
4. Waterproofing. A flat roof allows the use of roll materials for covering to protect against moisture: bitumen, polymer and bitumen-polymer. In addition to high waterproofing qualities, they must have resistance to temperature changes, elasticity, and a long service life.

Types of roofing and nuances of their installation

The construction of a flat roof is determined by the design and nature of its use. IN individual species, requiring a special approach during construction, the following are distinguished:

Roof installation for unheated buildings

If a flat roof is being built with your own hands for an unheated utility room, for example, a barn, gazebo, shed or outbuilding, the slope is organized using support beams.

They are installed at an angle of 3 degrees, which is 30 mm for each linear meter beam length. Then a base of unedged boards, securing them with nails or screws.

Roofing felt, the most affordable material, is used as a waterproofing agent. It is produced and sold in roll form. The waterproofing is cut by cutting strips so as to lay them in the direction of the slope of the flat roof.

Strips of roofing felt are laid step by step with an overlap of 10-15 cm and fixed wooden slats or steel strips every 60-70 cm in the direction of the drain, so as not to block the path of flowing moisture. Flat roof unheated room can be easily installed with your own hands, even by one worker without the help of assistants.

Roof installation for heated structures

If they build private house with a flat roof, which they plan to connect to the heating system, then the work takes place in the following order:

To build a house with a flat roof, the length of which exceeds 6 m, a beam with a cross-section of 150x150 mm or more, or a steel I-beam, is used to make support beams.

Monolithic concrete roofing

Another option for building a flat roof with your own hands is to use monolithic concrete. The process looks like this:

Leaning process

– arrangement of a small angle of the roof surface to organize drainage. Before building a house with a flat roof, it is better to decide in advance which drain you will install, internal or external, and make a drawing.

If provided, water should flow into water collection funnels using a slope, which are located 1 per 25 sq.m or more often. If you make an external drain, then moisture should enter the gutter. The slope is formed using the following methods:

A flat roof without proper slope is an unreliable shield between you and bad weather. Moisture that has no outlet will accumulate on the roof surface, causing roof destruction and leaks.

Video instructions

Many people associate a flat roof with urban high-rise buildings. And very few people draw in their imagination country house with a flat roof, which combines saving precious space and the possibility of creating luxurious places to relax 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 the device 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 to choose the most adequate and correct one from the many existing options in order 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 result, the attitude of customers towards flat roofing is changing for the better. In Europe, the design of flat roofing houses is called fashionable architectural feature project. A house with a roof without slopes looks more modern.

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:

1. In most cases, a flat roof is equipped as a green recreation area.
2. Saving material, because the area of ​​​​the flat coating less area pitched with the same architectural basis.
3. 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.
4. Maintaining flat roofs is not an extreme mountaineering activity, but rather a routine procedure.
5. 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 reinforced concrete slab or profiled metal sheet), on which heat-insulating material is laid over a vapor barrier layer, which is protected from precipitation by a waterproofing layer.

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 integrated 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, and installing technological units coverings (junctions to parapets and pipes, drains, corners, superstructures, etc.) and making 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. Exclusion of at least one detail from common 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:

1. Breakdown of waterproofing by strong gusts of wind.
2. Loss bearing capacity foundations due to electrochemical corrosion in the “wrong self-tapping screw + corrugated sheet” system.
3. 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):

1. Vapor barrier.
2. Insulation.
3. Waterproofing.

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 that 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 a higher 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:

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

Drainage device

It is very important to ensure the free escape of wet vapors from the roofing. Necessary elements are ventilation 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. It negatively affects both wood and metal. If too much condensation accumulates, wet spots form on the ceiling and mold develops. In addition, moisture accumulating in the 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.

This task is best accomplished 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 of 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 joints 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.

Components for a flat roof large number. The need for their use is determined. 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 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. Even with a good slope small defect in roofing will be insignificant.

One more important element Roofs are gutters that “carry away” moisture and snow along a given route. This is most often done on a flat roof. Special fittings or fittings located on the roof surface effectively drain water during heavy rainfalls, eliminating flooding of the roof. 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 getting into it. foreign objects. 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.

It is more often used in private homes, because the internal one is more suitable for constructing flat roofs of large industrial buildings. External drain 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.

The final and one of the most important stages construction is the construction of the roof. Classic solution pitched structures are considered, but in recent years There has been a clear trend towards flat roofs. The secret of their popularity lies in a lot of advantages. Previously, flat, or, as they are also called, combined roofs were erected on administrative, civil, medical, and sports buildings. Today, the scope of their application has expanded significantly and includes residential and suburban construction.

Features of a flat roof

The main difference between this type of roof is the use of sheet and piece materials, which form a continuous carpet when laid. These include materials of bitumen and bitumen-polymer type, mastics. To increase resistance to temperature fluctuations and mechanical deformations, such carpets must have increased elasticity. The function of the base for the carpet is performed by load-bearing slabs, the surface of the thermal insulation layer and screeds. Layers laid one on top of the other result in a roofing pie.

Pros of flat designs

Until recently, many people avoided installing roofs flat type, not being sure of the feasibility of such a decision. However, in reality these designs have a number of obvious advantages:

• Flat roofs allow you to get additional usable area, which can be used as a relaxation area, turned into a swimming pool, garden, etc.
• An important advantage is the opportunity to save on material, since with the same architectural base in area, a flat covering is much smaller than a pitched one.
• Laying flat roofs is incomparably more convenient than pitched roofs: all materials can be placed side by side and worked in a safe position.
• The maintenance of flat roofs and repair work is greatly simplified.
• Additional area is added without increasing or changing the contours of the structure, which is very important in large cities, where lack of territory and the environment are on the list of the most pressing problems.

Flaws

• One of the disadvantages of flat roofs without attics is the need to regularly monitor the degree of moisture content of the insulation and the preservation of the tightness of the waterproofing coating.
• With frequent and heavy snowfalls, a large snow mass accumulates on a flat roof, increasing the load on the structure and often leading to leaks.
• There is a certain risk of blockages in the internal drainage system or its freezing.
• To avoid damage to the roofing, it is necessary to clear the surface from snow accumulations from time to time.

Roofing units

For reliable protection protecting the roofing pie from external influences, special care must be taken in the areas adjacent to such building structures as parapets, walls, pipes, external parts of ventilation systems, etc.

The main components of a flat roof are:

• junction unit;
• overhang unit;
• roof passage unit.

Installation of units is carried out on a reinforced concrete base in those areas where the cut of the roofing pie is adjacent to vertical structures. Often, manufacturers of roofing materials develop their own systems: each of them may have certain design features.

The main requirement for the units is to ensure the tightness of the joint and its thermal protection.

The main components of different types of flat roofs

Operated and non-operated roofs

The construction of roofs of a serviceable type is justified on buildings that provide for periodic access of people to the roof or the placement of heavy objects on it.

A design feature of such roofs is the need to create a rigid base or a special screed on top of the waterproofing layer. This measure is necessary to increase the strength of the structure and distribute the load evenly over it. Increased rigidity of the base will preserve the integrity of the waterproofing layer and prevent it from being pressed through.

A distinctive feature of unused roofs is that there is no need to lay a rigid base on top of the waterproofing. In this case, soft insulation is used. The creation of this type of roof is advisable in cases where there is no need to maintain the structure, since there is no pressure on the roofing surface. In cases where there is a need to care for such a roof or carry out certain work, the issue is resolved by installing special walkways or ladders, thanks to which there is a uniform distribution of pressure over the surface.

When installing a roof that is not in use, you can spend much less money than when installing a roof that is in use, but it should be taken into account that it will last much less.

Other types of flat roofs

The design features of flat roofs formed the basis for their division into the following types:

• classic;
• inversion;
• ventilated.

The traditional solution is classic variety flat designs. In another way they are called soft.

IN classic version The functions of the base are performed by the load-bearing slab. Laying is carried out over its vapor barrier coating thermal insulation material– in many cases, slabs based on mineral wool. Since the thermal insulation layer also needs protection (in particular, from the effects of precipitation), a waterproofing carpet is installed, the basis for which is bitumen-containing roll materials.

Flat structure inversion roofs fundamentally different from the classic type: in this case, the insulation layer is located above the waterproofing membrane, and not under it. This specificity allows you to protect waterproofing from the negative effects of ultraviolet rays and from loss quality characteristics as a result of freezing and subsequent thawing, with a sharp change in temperature. This arrangement also warns mechanical damage waterproofing membrane, due to which the service life of the roof is significantly increased.

Inversion structures are very convenient to use as operational ones. You can plant plants, grass, light furniture, etc. on them.

The installation of ventilated roofs allows us to solve the problem of moisture accumulation in insulation and ceiling slabs, which often causes the formation of bubbles, leading to subsequent leaks and rupture of the roofing carpet. The specificity of ventilated type flat roofing units is that the first layer of carpet is partially secured to the roof with glue or laid on mechanical fasteners. This feature allows you to create an air gap between the roof and the base, eliminating significant water vapor pressure. Communication with outside air is carried out through connections along the roof contour or through the installation of special exhaust deflectors.

The base is one of the significant components of flat structures

To obtain a high-quality, functional and durable roof, it is necessary to think in detail about the plan of the flat structure in advance. This measure will greatly simplify the installation process itself. In many cases, the main components of a flat roof are:

• load-bearing structure - its functions can be performed by a monolith, a ceiling with a corrugated sheet, or a load-bearing concrete slab;
• thermal insulation layer;
• waterproofing layer;
• slope-forming layer, the function of which is to drain water;

The initial step in creating a flat structure is preparing the base. In most cases, the load-bearing covering of such a roof is profiled steel sheets or solid wood-based coverings.

In the case of an uneven surface of a reinforced concrete base, it is necessary to create a leveling screed from sand-cement mortar or sand asphalt concrete. The thickness of the screed is determined by the type of base:

• By concrete base– from 10 to 15 mm;
• on rigid insulating boards - from 15 to 25 mm;
• on soft insulating boards - from 25 to 30 mm.

If the roof slope is less than 15%, the screed is first placed on the valleys, and then on the slopes.

If the indicator is more than 15%, the actions must be carried out in the reverse order: first of all, level the slopes, and then proceed to work with valleys and grooves.

All elements protruding above the roofing surface (parapet walls, chimneys, etc.) are treated with plaster to a height of at least 25 cm. Special slats are installed above the plastered surface. Their function is to secure the rolled type of carpet.

To improve the quality of adhesion between the base and the rolled carpet, the roof screed is primed with roof mastics. Before starting work, the surface is thoroughly cleaned.

Soft roofing materials

When installing flat roofs, at the initial stage it is necessary to prepare all roofing materials for further use.

If roll materials are used, they are carefully inspected for the presence of different types defects: cracks, unevenness, oil stains. After this, they are rolled out and kept in this form or turned inside out for 24 hours.

Roofing mastic performs two functions simultaneously:

• Used as independent material to ensure a seamless coating and for carrying out repair work.
• Used as an adhesive for joining roll-type materials to the base. Bitumen mastics used both cold and hot.

Mastic as an independent roofing material

Flat structures do not always include rolled materials: they can be constructed using only mastic.

Mastic is essentially a liquid material made from pure elastic hydrophobic polyurethane resins. After application to the surface of a flat roof, under the influence of moisture contained in the air, the process of its polymerization begins, as a result of which the material is transformed into a rubber-like continuous membrane with excellent waterproofing and protective properties.

Due to a number of features, mastic is almost ideal material for the construction of flat structures. Its main advantages:

• reliability;
• safety;
• resistance to ultraviolet irradiation;
• resistance to precipitation and the development of microorganisms;
• excellent adhesion to any type of building surface;
• maintaining the original volume (it does not change even as a result of polymerization);
• ease of use: liquid mastic can be applied manually– using a roller or brush, or a special method of airless spraying.

Roll materials for roofing

An important part of a flat roof is the roofing material. Rolled materials are most suitable for flat structures. They are laid over the surface with an overlap. If the roof slope is greater than 5%, the overlap in the internal carpet layers should be 70 mm, in the external layers - 100 mm. With a slope of less than 5%, the overlap width in all layers is 100 millimeters or more. Roll strips are laid in a certain (one) direction.

If during the gluing process the panel deviates to the side, you must try to move it without peeling it off. If there is no result or its insufficiency, the glued part is cut off and glued with a 100 mm overlap.

Laying of roll sheets is carried out layer by layer. When attaching them to cold mastic A 12-hour interval must be observed between gluing layers.

Thermal insulation in soft flat roofs

The layer of thermal insulation material can be installed in two ways: external or internal.

The external (external) method is easier, as a result of which it has become more widespread. In addition, it can be used to insulate a building both at the construction stage and after its completion, in operating condition.

Depending on the number of installed layers, flat structures provide two types of thermal insulation:

• single-layer;
• two-layer.

The choice of a specific type is determined thermotechnical calculation and strength requirements that apply to the roof. When laying on top load-bearing structure The so-called “staggered seams” principle is used for thermal insulation slabs.

In the case of a two-layer coating, the joints of the upper and lower plates are also “staggered”. In areas where heat-insulating slabs adjoin walls, lanterns and parapets, transitional heat-insulating edges are installed. Thermal insulation is fixed in the following ways:

• mechanical, in which the corrugated sheet is fastened using self-tapping screws, and the reinforced concrete base is fastened using plastic dowels with a core;
• adhesive;
• using ballast: it can serve as paving slabs or pebbles;
• on the base.

Horizontal ventilation

During the operation of the roof, damage to the vapor barrier layer may occur, as a result of which moisture enters the insulation, which leads to its freezing in the cold season. All this significantly reduces the thermal insulation characteristics of the material. For this reason, the installation of a ventilated roof is of great importance.

Ventilation of flat structures is a system of aerators (plastic or metal tubes), which are located above the roof membrane. The system extends to the roof surface in the form of umbrellas protected by nets. They should be located at the highest points of the roof.

Drainage system

Very important in the drainage process the quantity plays a role roof slope– it must be at least 2%. Even a slight slope prevents moisture from penetrating inside.

In the case of flat structures, the drainage system is very important.

Its components are receiving funnels, pipes (through which water flows into the sewer system, special storage tanks or into the ground).

Drainage is carried out in two ways:

1. According to the internal system - in this case, fittings (funnels) located on the roof surface collect water flows, and then direct them into pipes: they are mounted inside the building and completely isolated from living quarters.
2. By external drainage - the pipes are fastened along the outer surface of the walls of the house, thanks to which they can be easily cleaned of accumulated dirt.

The downside of the external system is the frequent freezing of pipes in winter.

The specific number of funnels, their diameter, and location areas are calculated taking into account the architectural features of the building, operating conditions of the roof and the maximum amount of precipitation in a given region. As a rule, funnels are equipped with filters to prevent leaves, small birds, etc. from entering the system.

The materials for the drainage system are polyvinyl chloride or metal funnels. The former are more popular because they do not corrode.

CONCLUSIONS:

• The main difference between flat roofs is the use of sheet and piece materials.
• The structure of a flat roof resembles a multi-layer cake.
• Such designs allow you to obtain additional usable space that can be used at your discretion.
• The main units of a flat roof are: the junction unit, the overhang unit, and the roof passage unit.
• A design feature of roofs in use is the need to create a rigid base or a special screed on top of the waterproofing layer.
• A distinctive feature of unused roofs is that there is no need to lay a rigid base on top of the waterproofing.
• The design features of flat roofs became the basis for their division into classic, inversion, and ventilated.
• The initial step in creating a flat structure is preparing the base.
• Flat roofs can be installed using rolled materials or only mastic.
• The most suitable roofing covering for flat structures is rolled materials.
• Thermal insulation is laid in a single layer or in two layers.
• Ventilation of flat structures is a system of aerators above the roofing membrane.
• Flat roofs can have internal and external system drainage

What are the requirements for a flat roof covering? roll materials you can find out from the video.