Features of a flat roof: pros and cons of its use. Construction of a flat roof - a budget option for a reliable roof with your own hands How to make a flat roof with your own hands

Many people think that a modern house with a flat roof looks unusual, rich and original. Using such a roof in construction for country cottages and villas, the owners emphasize their wealth, sophistication of taste and unconventional thinking. Country houses with this type of coverage they are an excellent place where you can take a break from routine and gain strength for new achievements. The flat roof is not only original, but also practical.

Building a house with a flat roof is often used in areas with low rainfall. Often the choice of roofing type is influenced not only by the owner’s desire, but also by climatic conditions. Therefore, if you decide to install a flat roof in an area where there is frequent precipitation, then you must:

• take into account maximum loads;
• use beams with a good cross-section in construction;
• use strong fastenings of all elements.

The most common form of building houses with a flat roof is the square shape. Square house with this coating it turns into an original penthouse that meets European style standards. In this article we will tell you how to properly make a flat roof with your own hands and describe all the pros and cons of this roof.

Advantages and disadvantages

Advantages:

1. The use of this type of roof not only expresses originality external form buildings, but also allows you to equip upper platform surfaces for your needs.
2. One of the advantages of such a house is the arrangement of a swimming pool with a place to relax or planting ornamental trees, shrubs and a lawn. In addition, you can save a lot of money on such a roof, because it does not require complex rafter systems and can be easily erected with your own hands.
3. A flat roof is also good because it has a special niche in the cavity, which is an additional insulation that retains heat in the building and significantly reduces heating costs in winter.
4. Repair flat roof It will take a little time and will not be particularly difficult. In addition, if you choose roofing felt or some other budget option as the roofing material, this will help save additional funds.
5. The whole essence of the repair usually comes down not to a complete covering of the roof surface, but only to timely periodic prevention in the form of sealing cracks.

Flaws:

1. The absolute disadvantage is that the process of designing a flat roof and its installation must be very careful. The slightest gaps in the work of builders can result in expensive repair work inside the building.
2. In addition, it should be remembered that a flat roof must be made at a certain slope (usually varies from 3 to 15 degrees depending on the design and the level of annual precipitation). Otherwise, precipitation will remain on the roof covering for a long time, which will create unnecessary load on the structure and reduce the service life of the roof.

A flat roof has its undoubted advantages, and the disadvantages are easily corrected by a careful approach to the very process of its construction.

Device

Flat roof structural system for unheated room consists of the following:

• load-bearing beams;
• rack or metal lathing with small steps (50-70 cm);
• roll coating.

Note! The angle of inclination of such a roof is ensured by the entire structural system, starting with the beams. Therefore, careful attention should be paid during installation to maintain the slope. To do this, you should check it every few meters. If desired, you can make a flat frame for the rafter system (angle of inclination - 10 degrees). To do this, you need to install it along the roof. After which you can attach the sheathing.

The design of a heated room has a slightly different appearance. It includes:

• bitumen primer for screed;
• roll coating;
• cement mortar based screed;
• roofing felt (overlap 15 cm);
• insulation materials such as expanded clay, slag and other similar materials are the main components for creating a roof slope;
• load-bearing beams (step from 0.5 to 1 m, section from 100x100 to 150x200 mm);
• plank sheathing (flooring).

Monolith roof

Instead of wooden beams, I-beams of metal (from 12 to 15 cm) are laid, on the lower shelves of which there is a continuous plank sheathing. Roofing felt is laid on it. Then a frame made of reinforcement (profile with a cross-section of 10-15 mm) is mounted in two rows. It is important to maintain the distance between the reinforcement frame and the roofing felt. At the next stage, the concrete mixture is poured, which needs to be compacted periodically.

Note! If it's worth hot weather, a layer of concrete must be covered protective film made of polyethylene so that it does not harden quickly, but evenly and efficiently. It is advisable to remove the film no earlier than after three or four days.

If such a film is not available, you will have to monitor the concrete hardening process and periodically water it with a small amount of water. After the layer has dried, you should give the roof a certain slope using insulation, and then screed and lay a roll covering. On this device monolithic roof can be considered completed.

Roof base

Iron can be used for flat roofing concrete slab or corrugated sheet.

Corrugated sheeting is used in cases where the upper part of the roof will not be used as an additional platform. This type of base is the most economical, however, it requires additional insulation.
First, a support layer is installed, and a vapor barrier layer is laid on top of it. The latter is used to save warm air in the house and prevent it from escaping into the air. Vapor barrier is mainly made from rolls of a certain length and cut width. The place where the vapor barrier overlaps must be carefully glued, melted and welded. Polyethylene can be used as a vapor barrier material.

At the next stage, thermal insulation is laid, for which special slabs with a certain joint are used. The most commonly used is a two-layer thermal insulation system.

After this comes waterproofing equipment made of polymer film. She protects inner part roofs from external environment. The waterproofing is fused and then laid in several layers.

When the hydro- and vapor barrier is ready, it’s time to apply the final coating. Its role is played by concrete screed and reinforced concrete slabs.

Polycarbonate base

Recently, polycarbonate has often been used in roof construction work.
A roof made of this material may be suitable for you if you do not want to make a room under it. As an option, you can build an indoor greenhouse or gazebo.

Polycarbonate has increased strength and is very lightweight material, which is quick and easy to install. It does not require additional structural reinforcement.

Thus, the flat roof can be made in various forms. In any case, no matter what option you choose, you should always be careful about the installation, because if there are serious errors, you can run into big expenses and a complete redo of the roof from scratch.

Insulation and waterproofing

Waterproofing a flat roof can be done using the following components:

• PVC and EPDM membranes;
• waterproofing film;
• hydrophilic rubber;
• liquid rubber, sprayed waterproofing (polyurea);
• penetrating materials;
• lubricants;
• silicone-based resins, as well as emulsions (injectable substances).

New to the technology market are waterproofing materials such as PVC, PDM and diffuse membranes. Super-diffuse material has become especially popular, which does not require making a gap between thermal and waterproofing, repels moisture efficiently and does not allow it to pass onto the thermal insulation layer. In addition, such membranes have a long service life (up to 25 years), are fireproof and environmentally friendly.

Mastic can be used as waterproofing. It is applied as flat roof, and on a roof with a slight slope.

According to the method of application, they are divided into cold and hot. Cold ones should be applied to the surface at above-zero temperatures, while hot mastics require preheating (160 degrees) before application and can be used at almost any time of the year. The principle of operation of the mastic is based on the fact that it adheres firmly to the base. The validity period of this type of coverage is about 20 years.

In some cases it may be used painting waterproofing. In the process of such insulation, bitumen, emulsions, paints and varnishes are applied to the surface of the coating. The coating occurs in several layers until it is achieved required thickness(5 mm). A layer of fine-grained sand is applied on top of the coating. The service life of waterproofing is 5-6 years.

Note! One of the most reliable and proven types of waterproofing is glued waterproofing. It involves the use of roofing felt, which, after preheating, is glued to the surface of the coating.

After selecting and installing waterproofing, you should start insulating - very important stage construction of a flat roof. There are several types of insulation:

• By location: external and internal.
• According to the number of layers applied: single-layer and two-layer insulation systems.

The two-layer system makes it possible to reduce the load on the floor. The bottom layer plays the role of a heat insulator in this case. The upper one has a distribution function and has a denser structure.

Now you know how to make a flat roof with your own hands. As you can see, this is not difficult at all. You just need to pay attention to the matter, and soon the coating for your home will be ready.

Video

A flat roof in a private house provides many different possibilities. With such a simple design, you can save on roofing materials and labor, and installation is carried out in less than short term. It is also easier to place on its surface various systems: antennas, hoods, solar panels and others. In addition to all this, additional space can be used by arranging a garden, recreation area or greenhouse on it.

However, despite the cheaper installation, many nuances must be taken into account so that such a roof does not become a “headache” for the home owner.

Flat roof design

A flat roof, like any other, must fully perform all its functions: protection from water and its drainage and thermal insulation. In addition, it must have sufficient strength to withstand external loads.

This is what determines the structure of the roofing pie, which consists of the following mandatory elements.

1. Base. This part bears all the main loads. The ceiling must be very durable, but it all depends on whether the roof will be used or not. Most often, the base is a reinforced concrete slab laid on load-bearing walls, less often on non-residential buildings - a layer of profiled sheets.
2. Vapor barrier layer. Performs protective function, which consists in preserving materials from steam penetrating from inside the room.
3. Thermal insulation. Reduces heat consumption from the house.
4. Waterproofing. Flat roof does not completely drain away all the water, like gable analogues, as a result, high-quality protection against penetration of room moisture is needed.

For normal moisture removal, a slope is used. Most often, it is a screed that forms angles of inclination along which water can flow into a prepared system of trays for its removal from the roof plane.

Saving on any parts of a flat roof is unacceptable, otherwise it will lead to leaks, freezing and other negative phenomena of a poorly installed roof pie.

Types of Flat Roofs

Availability, order and sequence individual elements roofing pie determines the type of roof. The following types of flat floor structures are distinguished:

• Unexploited. These designs can be seen at multi-storey buildings. It is believed that their surface is not intended for use and is designed for short-term stay of people. In this option, on non-residential buildings you can use a profiled sheet as a base.
• Exploited. In this case, it is necessary to have a concrete base capable of withstanding heavy loads. The surfaces can be used as a garden, recreation area or even car parking. In addition to a solid base, it is important to observe the angle of inclination, which should not exceed 3 degrees.

• Inversion. The design involves changing the order of layers of the cake. The waterproofing is placed under the insulation, which allows it to be protected from damage. Quite often this type of roofing is used in the construction of private residential buildings.
• Ventilated. These types of roofing have a ventilation system (built-in aerators) that evaporate excess moisture from the thickness of the roofing pie. Can be combined with other types of roofs.

In addition, the type of roof depends on other factors, for example, whether the room is heated or not.

Installation of a flat roof on different types of buildings

Depending on whether the room will have a heating system or not, the technology for assembling the roof may differ during installation.

Roofs on unheated premises

Typically, unheated buildings are garages, sheds, gazebos, and various pavilions.

• The required slope of 3 degrees on such buildings is formed by the load-bearing roof beams. The height difference is about 30 millimeters per 1 meter of beam length.
• After laying the beams, a flooring is made that will serve as a base. These can be boards or profiled sheets. They are secured with self-tapping screws or other suitable fasteners.
• If the room is unheated, you may miss a layer such as thermal insulation. Waterproofing material is laid on the base. Roofing felt is used as a waterproof coating. It is spread in overlapping strips (about 150 mm) and additionally fixed with slats, which are placed along the slope of the roof.

This is the simplest version of a flat roof, which can be mounted on an unheated utility room with your own hands. minimum costs money and time.

Assembling a flat roof on heated buildings

IN residential buildings with heating system roofing pie flat roof will be different. Here you will definitely need a thermal insulation layer, high-quality hydro- and vapor barrier. The presence of the latter is no less important, since water vapor can gradually ruin the entire roofing pie.

• The floor under the base is assembled from wooden beams, which are placed at intervals of 900-1000 mm.
• They are covered with flooring made of boards with a cross-section of 40-50 millimeters. The thickness of the lumber is selected depending on the distance between the beams. The larger it is, the thicker the boards are needed.
• Roofing felt is laid on the flooring, it is cut and straightened in advance. Waterproofing sheets are laid with an overlap of about 100-150 mm.
• The thermal insulation layer can be made using the bulk method. To do this, fill the resulting base with a layer of expanded clay up to 300 mm and level it.
• Next, pour onto the layer of thermal insulation backfill cement-sand screed(minimum thickness 30 mm).
• After the cement has hardened, the surface is covered with bitumen-based soil and covered with a layer of roofing material.

You can also install a more solid roof made of monolithic concrete.

Monolithic concrete flat roof

In this embodiment, a durable concrete base with your own hands.

• An I-beam is used as support beams, which are laid level without forming a slope.
• For pouring, you will need to prepare concrete of a grade not lower than M250; it is prepared in a concrete mixer, maintaining a ratio of 4:1.5:1:1, where the ingredients are crushed stone (20-25mm), cement (m400), water and sand, respectively.
• For pouring, a base is made of boards, which are mounted on the lower shelves I-beams and covered with roofing felt.
• Fine crushed stone is poured on top of the waterproofing, which is filled with the resulting concrete. The filling must be done at one time, otherwise the structure of the roof will not be the same.
• Next, expanded clay is poured in and a slope is made.

Leaning

Sloping is the formation of slight slopes on the surface of a flat roof, which allows water to be removed from its surface. The drainage system is assembled in two versions: external and internal. That is, the trays can be attached to the end of the roof or on its surface.

If the drainage gutters are located internally, the presence of drainage basins is planned in advance, the number of which is calculated as follows - 1 funnel per 25 square meters of roof area.

Construction of a gable or hip roof not always rational and expedient when it comes to outbuildings, industrial and commercial facilities, and sometimes private homes in modern style. High consumption material, complex rafter system make the construction of these structures an economically unprofitable, 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, a do-it-yourself flat roof must meet strict requirements building codes to waterproofing, slope and construction technology.

The structure of the roofing pie

Necessity high level protection from moisture makes it necessary to place roofing materials flat roof 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 profiled metal sheets. It provides rigidity to the structure, bears the weight of the roofing pie, transferring it to the load-bearing partitions and, ultimately, to 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 polyethylene 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 for regulation temperature regime, but also for tilting 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 be resistant to temperature changes, elasticity, for a long time operation.

Types of roofing and nuances of their installation

The construction of a flat roof is determined by the design and nature of its use. Some types that require a special approach during construction include the following:

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. A flat roof of an unheated room can be easily installed with your own hands, even by one worker without the help of helpers.

Roof installation for heated structures

If they are building a private house with a flat roof, which they plan to connect to a 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:

Deflection 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 instruction

Flat roofs are in demand in modular construction. Among the advantages of this method are the affordable cost and high speed of construction of housing, as well as the possibility of gradually increasing its area

Architects and developers are attracted to these unusual buildings, where you can equip an observation deck or even set up a real hanging garden. Of course, in practice everything turns out to be more complicated than in theory.

Designing a flat roof raises many questions regarding its cost, choice of materials for insulation and waterproofing, organization of water flow, maintenance, etc. Finding answers to them is not so easy. The fact is that domestic contracting companies working in the field of cottage and rooftops are well familiar with the most popular design - pitched, but, as a rule, they have no experience in constructing flat roofs, which are designed completely differently.

Flat roof cost

What immediately attracts attention is the fact that the area of ​​a flat roof is smaller than a pitched roof, which means that less materials will be required, and the work will be cheaper. However, this statement is only true for regions with warm climates and low snow load, moreover, if we are talking about an unused roof. In central Russia, to ensure the reliability and durability of a horizontal roof, it is necessary to apply rather expensive engineering solutions.

Beam floor

In principle, when constructing a floor, you can use a combination of beams (wooden, steel) and load-bearing corrugated sheeting. However, experts do not recommend using wooden beams (with the exception of those made of LVL beams with a cross-section of 200 × 100 mm) in regions where the snow cover pressure exceeds 1.2 kPa (about 120 kgf/m2) - that is, in most of the territory of the Russian Federation. A roof covering made of steel I-beams and corrugated sheets with a wave height of 60 mm and a wall thickness of 0.7 mm allows you to cover a span of up to 12 m and can withstand a pressure of at least 6 kPa. But in general, it is less durable than concrete, and is relatively rarely used in individual construction. It makes more sense to use corrugated sheets as permanent formwork, which, by the way, does not replace the need to build a reinforcement cage.

It turns out that 1 m2 of flat concrete or steel base, load bearing capacity which will allow you to withstand the weight of the snow cover, costs 2–2.5 times more than a wooden beam structure of a pitched roof. The difference in the volumetric consumption of insulation is leveled due to the fact that a flat roof requires more expensive material high density. There is still hope to save on roofing, however, modern polymer membranes - the optimal waterproofing for horizontal roofs - are no cheaper (and sometimes much more expensive) flexible tiles. There is no need to install snow guards, but you cannot do without a roof hatch and a drainage system. If you try to cut costs according to the estimate, you will subsequently have to pay the price of having to repair the roof every 10–15 years.

The durability of a flat roof largely depends on the ability of the load-bearing base to withstand operational loads without significant deformation

Finally, it should be noted that flat roofs are only suitable for houses modern architecture- With large area glazing and sophisticated finishing with the latest façade materials. Both will not be cheap at all.

On a solid foundation

As a rule, in low-rise housing construction, the flat roofing is a prefabricated or monolithic reinforced concrete slab. Reinforced concrete slabs (PB, hollow PC, PV, etc.) are capable of covering a span of up to 9 m in length and can withstand a pressure of 8, 9 or 12.5 kPa (this value is indicated by the last digit in the product labeling). They can serve as a “base” for any roofing pies, including those with a top layer of paving slabs or fertile soil. However, to install the structure, it will be necessary to ensure that a truck crane can enter the site (while steel beams and flooring can be easily lifted using winches). The depth of support of the ceiling on the wall depends on the material of the latter - for example, for brick this parameter should be equal to the thickness of the slab. Before proceeding with the installation of the roof, it is important to seal the joints of the elements with mortar and additionally seal them with elastic polymer tape.

The main advantage of membranes based on artificial rubber is that they retain elasticity when low temperatures, that is, they can be installed in winter

Classification of flat roofs

Flat roofs are divided into unused and used. The former visit only for inspection, prevention and repair; for this purpose, a roof hatch is installed, to which it leads attic staircase. The roof in use in cottages most often serves as a terrace, that is, a durable roof must be laid on it. wear-resistant coating, and the supporting base is designed for increased loads. A type of exploitation is a roof with landscaping, laid with a turf layer on top of the main heat-waterproofing pie; Usually there are paths and a recreation area on it. A convenient exit to the roof in use should be provided, for example from a vestibule superstructure.

A monolithic reinforced concrete floor is erected from heavy concrete using removable (for example, from OSB boards on jack stands) or permanent (from corrugated sheeting) formwork. It is reinforced with a two- or four-level welded frame made of rods with a diameter of 12 mm. Dimensions monolithic slab are not regulated (unlike prefabricated), which provides the architect with freedom when designing a building; other advantages are the absence of seams, the comparative simplicity of the installation of passage units (chimney, ventilation ducts) and high load-bearing capacity (subject to compliance with technological regulations).

Roof protection from cold and heat

In the low-rise sector, mostly flat roofs without attics are in demand, because the attic requires additional costs and disrupts the architectural proportions of the house. This means that the roof must protect against winter cold and summer heat. A common feature of flat roofs is that the heat-insulating layer is located on top of the supporting structure (in pitched roofs it is usually located between the rafters). If you insulate the room from below, the dew point may shift into the thickness of the ceiling, which will lead to a reduction in the service life of the latter.

Mastics should be used primarily on roofs of complex configurations

As for roofing options, there are dozens of them. Suffice it to say that more than 40 “recipes” are given in SP 17.13330.2011 alone. At the same time, companies producing coatings and insulation materials are offering more and more new engineering solutions. However, they are always based on one of two circuit diagrams- traditional or inversion.

TechnoNIKOL roof installation diagrams

“TN-ROOF Terrace”: 1 - ceiling; 2 - vapor barrier; 3–5 - EPPS (including the slope-forming layer); 6 - fiberglass; 7 - LOGICROOF V-GR membrane; 8 - geotextile; 9 - tiles on supports

Traditional design in general outline is as follows: laid on top of the supporting base vapor barrier film(polypropylene, polyethylene, butumen-polymer), followed by insulation, for example - slabs from mineral wool, having a compressive strength at ten percent deformation of at least 30 kPa, in one or two layers with a total thickness of 200 mm. Above is a separating layer (for example, from polyethylene film), along which a reinforced slope-forming screed is poured (a flat roof must be given a slope of 2–3% towards the center or edges to ensure water drainage). The dried screed serves as the basis for a roll or mastic waterproofing coating.

“TN-ROOF Green”: 1 - overlap; 2 - ramp made of expanded clay; 3 - reinforced screed; 4 - bitumen primer; 5 - “Technoelast EPP”; 6 - “Technoelast Green”; 7 - geotextile; 8 - EPPS; 9 - PLANTER GEO membrane; 10 - fertile layer

Other options are also possible. For example, a slope-forming screed can be located at the very bottom of the pie; in this case roofing waterproofing fixed with gravel ballast, paving slabs on supports or special dowels. Some materials, say the “RUF SLOPE” system (Rockwool) or “TechnoNIKOL Slope”, allow you to do without a screed altogether: the slabs have variable thickness, and with their help it is not difficult to create smooth changes in level to ensure water drainage.

Inversion roofing is designed differently: in it, insulation resistant to constant exposure to water (usually extruded polystyrene foam - EPS) is located on top of the waterproofing. At the same time, the latter is reliably protected from mechanical damage and is located in a zone of positive temperatures (freezing-thawing cycles are destructive for almost any material). Inversion roofing It’s easy to turn it into a usable one, for example, by filling the insulation with a drainage layer of sand and gravel and laying paving slabs. The disadvantages of the design include more complex drainage. However, we need to talk about gutters separately.

Thermal insulation requirements for flat roofs are: special requirements. The material must not only have a low thermal conductivity coefficient, but also have good resistance to mechanical loads - both distributed (pressure from the overlying layers of the roofing pie, equipment, snow) and local ones that arise during installation. In addition, it is important that the material has hydrophobic properties and is non-flammable. On this moment There are several ways to install thermal insulation: using mechanical fasteners, adhesive and free laying. In addition to traditional two-layer insulation, single-layer installation is becoming an increasingly popular solution. Rockwool offers unique dual-density slabs that consist of a rigid top layer and a lightweight bottom layer, which speeds up work and improves its quality.

Grigory Gromakov

Specialist in development of the “Flat roofing” direction of the ROCKWOOL company

Water drainage on a flat roof

The flat roof is equipped with a parapet (attic) 30–90 cm high, which helps ensure an organized roof; on a roof in use it also serves as a safety fence. At the same time, the design of gutters should be approached very responsibly, because in case of an error, a huge puddle can form above your head, which can also lead to damage to supporting structures.

As a rule, the choice is made in favor of an internal drain. Such a system is less exposed to the atmosphere and is therefore more durable and reliable than an external one. Let's talk in more detail about its main elements.

Water intake funnels are installed on low areas of the roof. As a rule, on roofs with an area of ​​up to 150 m2, two funnels are installed - the main one, connected to the riser, and the emergency one - with water discharged through a hole in the parapet. With an increase in the number of funnels and risers, the reliability of the system increases, but its cost also increases.

For inversion and green roofs, special funnels with drainage rings have been developed to collect moisture from the intermediate layers. Water intakes must be equipped with electrical heating based on self-regulating cable- then they will begin to properly perform their function during alternating thaws and frosts.

Traditional covering with external drainage 1 - ceiling; 2 - slope-forming screed; 3 - vapor barrier; 4, 5 - mineral wool insulation; 6 - waterproofing; 7 - drain

In a new type of system, the so-called siphon-vacuum system, special funnels are used to prevent air from being sucked into the water flow. Thanks to them, the speed of fluid movement in the pipe (and hence the throughput of the latter) increases, which makes it possible to reduce the diameter of the system elements. However, for low-rise buildings, the savings turn out to be insignificant; moreover, such systems require more accurate calculations than gravity systems.

Gutter riser They are made from sewer pipes - polypropylene, polyvinyl chloride, and it makes sense to use sound-absorbing products, for example RAUPIANO Plus (REHAU), or to soundproof the riser, otherwise you will hear the murmur of water for hours. The riser is connected to the funnel using an elastic coupling. When laying pipes, the number of bends and the length of horizontal sections, which reduce the throughput of the system, should be minimized.

A drainage pipe, laid in a basement or insulated underground, connects the riser to a rain drain or provides water discharge into a tray linear drainage. In the second case, there is a risk of clogging the outlet with ice, so the riser should be equipped with a “winter” outlet to the domestic sewer (the latter should be equipped with a water seal). The outlet pipe is cleaned through a collapsible connection or an inspection module.

Drawing: Vladimir Grigoriev/Burda Media

Inversion roof covering with internal drainage 1 - screed; 2 - PVC membrane; 3 - EPPS; 4 - funnel with drainage ring; 5 - drainage membrane; 6 - sand; 7 - paving slabs

When choosing the standard size of elements of a traditional gravitational system based on the intensity of rain in a given area, focusing on SP 32.13330.2012.

Outdoor drainage system it is more vulnerable than the internal one, and also affects the appearance of the facades, but it does not require holes in the roof and ceilings and does not eat up the usable area of ​​the house. Water is discharged through parapet funnels or pipes embedded in the parapet, under which classic funnels (like on a pitched roof) and down pipes attached to the walls with brackets are installed. When calculating, it is assumed that for each square meter the roof area should be 1–1.5 cm2 of section drainpipes. Elements of the external system can be made of PVC, steel, copper, zinc-titanium.

For roofs in use, as well as roofs installed in regions with harsh climatic conditions, the inversion scheme is ideal. Since the waterproofing layer is located under the thermal insulation layer, it is protected from mechanical influences, as well as from temperature changes and UV radiation, which significantly extends the service life of the roofing system. Waterproofing materials based on modified bitumen, it is necessary to lay at least two layers - this technology is more common, and in addition, it allows you to level out possible errors when fusing the material. One layer is enough for a polymer membrane, and reliability is ensured by automatic welding equipment, which greatly increases the speed of work. In addition, when installing a polymer membrane, an open flame is not used, so the technology is considered safer.

Dmitry Mikhailidi

Head of the Engineering and Technical Center of the Technical Directorate of the TechnoNIKOL Corporation

Roof landscaping

Since ancient times, turf-covered roofs have been used in countries with moderately cold and humid climates, and green carpet performed the main moisture-protective function in them.

Within modern concept A green roof layer of fertile soil with plants is needed to give unusual features to the appearance of the building, decorate the terrace roof and extend the service life of the coating by protecting it from ultraviolet rays. In addition, it absorbs rainwater, unloading gutters, dampens the sound of rain, protects premises top floor from overheating in summer and reduces heat loss in winter. It is believed that landscaping almost doubles the life of a roof. Its disadvantages include increased load on bearing structures buildings and increasing construction costs. In addition, a green carpet needs care, the intensity of which depends on the selected plant species. If you do not pay due attention to the plants, they will freeze and die from drought.

To green the roof, you should lay on top of the main waterproofing layer (in an inversion scheme - on top of the insulation) an additional cake made of materials that will ensure protection of the waterproofing layer from roots, filtration and drainage of rainwater. For these purposes, special films, dense geotextiles, gravel bedding or drainage and moisture storage membranes made of high-density polyethylene, for example PLANTER GEO or Delta-Floraxx, are used.

Then a mixture of minerals and fertilizers is poured - the so-called soil substrate. You can prepare it yourself by adding it to a light soil mixture of neutral peat. fine expanded clay(5–15%), sand (about 20%) and fertilizers. As for plants, the easiest way is to limit yourself to meadow herbs and drought-resistant ground covers - sedum, herbaceous carnation, thyme. They do not need to organize an irrigation system, and the thickness of the soil layer can be only 6–12 cm (this type of roof is called extensive). If you plan to walk on the roof among ornamental shrubs, you will have to provide irrigation and increase the soil thickness to 20–40 cm. Such a roof is called intensive, it creates a significant additional load on the ceiling, therefore it must be provided for at the design stage of the building.

The terrace design provides convenient communication between the living quarters of the cottage and the operated roof, which serves as a resting place

Rolled materials based on modified bitumen are usually fused gas burner, while it is difficult to prevent minor flaws that can cause leakage (if the second layer is missing)

Rolled PVC membranes , for example, Sikaplan WP, Logicroof, Ecoplast are strong and durable (up to 30 years without repair) and do not support combustion. However, they require professional approach for installation (the joints of the strips must be carefully welded with hot air) and are relatively expensive - from 320 rubles. for 1 m2. It is important to consider that this material does not tolerate contact with bitumen.

Rolled membranes made of ethylene-propylene rubber (EPDM) and thermoplastic polyolefins (TPO) , for example Firestone RubberGard, Logicroof P-RP, retain elasticity when negative temperatures. Note that EPDM membranes are highly flammable (class G4) and are designed mainly for use in the construction of an in-use roof, where the waterproofing is covered with tiles, gravel or soil. EPDM and TPO membranes cost 1.3–1.5 times more than polyvinyl chloride membranes (mostly imported products).

Polymer-bitumen mastics They allow you to create a seamless coating, but they can only be applied to a strong, non-cracking base - a floor slab or a carefully reinforced screed, and this process is quite long and labor-intensive. The service life of a two-layer coating with a thickness of 5 mm is about 20 years, the price is from 120 rubles. for 1 m2. In practice, mastics are used mainly for roof repair and gluing roll materials.

Polymer and cement-polymer self-leveling waterproofing , say Aquascud, Osmolastic, Osmoflex, is highly elastic
and UV resistance. To improve performance, the materials are used in combination with special primers and lining films, and reinforced with mineral fiber (all components are supplied as a single system). Settlement period coating service - more than 50 years; price - from 700 rub. for 1 m2.

Flat roof: a pragmatist's view

A flat roof is still an unusual decoration for country cottages. It is believed that flat roofs are intended only for urban development or industrial buildings. But that's not true. The roofs of houses in historical neighborhoods are often pitched. And a private house can have a flat roof.

Now we will look at what it is, what are the advantages/cons and how to make a flat roof with your own hands.

Types of flat roof

Structurally, flat roofs are divided into two main types: those on beams and those with a concrete slab at the base.

Flat roofs are never completely flat; there is still a slight angle (within a few degrees). This is necessary for water drainage. Otherwise it will stagnate on the roof.

Most often, internal gutters are installed on flat roofs: funnels are mounted in the roof, and risers from them pass through the interior. Funnels are placed on the lower part of the roof, at the rate of one riser per 150-200 square meters.

The waterproofing around the funnels is reinforced; cable heating is also recommended (so that the water in the riser does not freeze). If the roof is flat without a parapet, and the angle is decent (from 6 degrees), the drainage system can be a standard external one, as for pitched roofs: gutter and pipes.

Roofs are divided according to functionality, roofing structure and type of coating. Here are a few main varieties:

• The unused roof is flat. It is erected solely for the sake of originality and economy of material. Does not require structural reinforcement.

• Operable flat roof. It can be used for any purpose, from placing an outdoor swimming pool to constructing a parking lot.

The type of floor depends on the intended purpose: it is obvious that for high expected loads, the base should be a concrete slab. But this does not mean that the entire building must be brick or concrete. For example, a flat roof in wooden house can also be exploited. Of course, it cannot be used as a helipad, but setting up a solarium, laying out a garden or putting up a gazebo for tea drinking is fine. Of course, you can’t make a sparse crate, only a continuous one.

• Traditional roofing. The classic design of the roofing pie: a waterproofing layer on top of the insulation, the base is concrete, for the outflow of water - expanded clay concrete (inclined screed).

• Inversion roofing. Here the insulation lies on top of the waterproofing and protects it from damage. The floor can be finished with paving or ceramic tiles, you can also plant a lawn here. Mandatory requirement to the inversion design - an angle of 3-5 degrees.

Roofs can be attic or non-attic. Both types have their advantages: the presence of an attic allows you to place all the necessary communications on it (ventilation pipes, expansion tank heating, etc.), a roofless roof can be made usable.

One of the options for a roofless design is a flat combined roof: attic floor combined with the roof, the lower side is the ceiling in the living room.

note

When the height of the house is ten meters or higher, as well as on roofs in use, a parapet must be installed. For those in use - no less than 1.2 meters.

If the roof is not in use and the cottage is not high, you can make a flat roof without a parapet or install fencing bars instead, or even do without them.

General structure of a flat roof

It is obvious that roofs used for different purposes will have different structures:

The most common covering is flat roofing. It is cheap, simple and high speed installation, excellent waterproofing. The cheapest material that can be used to cover a flat roof is roofing felt.

The disadvantages of rolled materials (and roofing felt in particular) are low durability and low mechanical strength. For “high traffic” roofs, tiles are preferable.

A flat roof made of and a flat roof made of corrugated sheets can only be made in a non-operational version and with the required slope. When choosing a material, you need to read the instructions for the model: some types of corrugated sheets and metal tiles can be installed on roofs with a slope of less than 11 degrees.

Some brands of corrugated sheets can also be used as a base for an unused roof, instead of plywood or a concrete slab.

There are other coating materials for unused roofs:

• Polycarbonate;

Pros and cons of flat roofs

Advantages:

• Original look. Flat roofs on cottages are rare.
• Possibility of operation.
• Flat roof – easy installation and savings on materials. But it depends on how you plan to use the roof. Otherwise, construction will cost even more than the expensive pitched roof from ceramic tiles.
• Laying covering, maintenance, and repairs on a flat roof are easier to perform than on a slope.
• Flat roofs are wind-resistant, pitched roofs have windage.

Minuses:

• A flat roof leaks more often than a pitched roof. Constant monitoring of the condition of the waterproofing layer is necessary.
• The need to clear the roof of snow.
• Rolled flat roofing requires more frequent repairs and changing the coating than metal profiles, tiles and other pitched ones.

So which roof is better, flat or pitched? Purely a matter of taste.

Building a flat roof

Let's consider the option when a corrugated sheet is used as the base of the roof:

1. Sheets are laid on the beams (rafters). The pitch between the rafters depends on the profile. For example, for load-bearing profiles with a corrugation height of 6-7.5 centimeters (H60, H75), the step between the beams is 3-4 meters.

2. Laying a vapor barrier film. The film is laid with an overlap, the joints must be sealed with mounting tape.

3. Thermal insulation. Mineral wool slabs are usually used for this purpose. Please note that the depressions of the corrugation also need to be filled with insulation.

4. Waterproofing. Polymer film is suitable for this purpose. If the insulation is mineral wool, you can also use built-up waterproofing, because cotton wool is a non-flammable material.

5. Finish coating. You can also use a welded one. The roll is slowly rolled out on the roof, heating it with a burner along its entire length. The deposited coating is pressed against the roof and smoothed.

6. On flat roofs, a fused roofing can be laid in several layers.

In other cases, a flat roof wooden beams is arranged more traditionally: they nail it onto the beams continuous sheathing made of plywood or OSB, lay a roofing pie (vapor barrier + basalt wool), apply a waterproofing layer and roll roofing.

If you are interested in a flat roof with more complex device, contact us: we will carry out roofing of any complexity quickly and at an affordable price.