Most people associate flat roofs with multi-story buildings. In private housing construction such roofing structures ten years ago they were practically not used. Today they can be seen in many projects country cottages. Therefore, many developers consider a flat roof in a private house as an option and analyze the pros and cons of its operation.

In this article

Types of flat roofs

Any building structures are divided into individual species, subspecies. So, for example, for some flat roofs country houses provided attic space, for others no. Therefore they are classified:

By purpose:

• Exploited roofs - additional objects can be built on their surface, equipment can be installed, and the following can be organized:

1. recreation areas, lawns, flower beds;
2. greenhouse or winter garden;
3. children's and sports ground;
4. parking;
5. pool;

Strength of house floors and load-bearing walls must be suitable for the type of roof use. It is important to note that reliable noise and vibration absorption must be ensured.

The main features of the roof in use. - this is sufficient strength of the floors and protection of the waterproofing layer.

• Unexploited roofing is the exact opposite of the first option. There is nothing superfluous on their surface; only in winter can there be snow.

When the roof is not in use, people climb onto the roof only in case of its maintenance, repair, as well as when it is necessary to service structures located on it, such as ventilation caps, cable lines, antennas, air lines power transmission, etc.

Important! In regions with heavy snow, flat roofs are generally not used due to the relatively large snow loads.

By type of construction:

• No attic space. Such structures require high-quality waterproofing, since they are, in fact, a ceiling last floor buildings. And in winter period snow accumulating on the roof surface will constantly melt due to room heating.
• WITH attic space . Between the ceiling of the last floor and the roof, a free space is formed - an attic. Typically, roofs of this type are made without thermal insulation and do not require special care in winter.

On arrangement roofing pie:

• Traditional- first goes in the roofing pie insulating layer, then waterproofing is installed.
• Inversion- in this design, on the contrary, on waterproofing layer Thermal insulation boards are laid.

Private developers, paying attention to the listed points, end up with a practical, high-quality flat roofing structure.

Advantages, disadvantages of flat roofing

Houses with a flat roof stand out in the private sector among houses with pitched roofs.

When choosing such a roof design for country house the developer receives the following benefits:

• There is no need to arrange a rafter system, which means you can significantly save on building materials.
• On the roofing surface, you can organize additional objects, for example, a swimming pool, a mini-gym, a summer recreation area, etc. But then a flat roof requires an increase in its strength and a waterproofing layer.
• Ease of maintenance, possibility of arrangement electrical system heating, thanks to which ice will not form on the base of the roof in winter.
• Due to the virtually non-existent slope, it is much easier and faster to erect such roofing structures than pitched ones.
• Interior rooms will not have sloped walls.
• Much easier to produce renovation work on a flat roof than on a sloped one.
• It is much more convenient to install and secure on a flat surface additional equipment: solar panels, air conditioners and more.

Important! So that precipitation does not linger on the surface flat roof, minimum angle its inclination should be 5°. This slope can be created by overlapping or using slag or expanded clay.

But a flat roof, like other roofing structures, has, in addition to its advantages, disadvantages, for example:

• In some cases, it is necessary to organize internal drainage system, which often gets clogged, freezes in winter. If it is not cleaned in time, it can lead to adverse consequences.
• It is necessary to constantly check the tightness of the roofing pie and the moisture content of the insulating material.
• During heavy snowfalls, snow has to be removed from the roof (excessive load, which can lead to damage to the structure) manually.
• Also, when a large mass of snow accumulates on the surface of the roof, the snow below begins to melt - accordingly, leaks are possible.

The flat roof structure in a private house is not complicated, so you can easily build it yourself. But you need to take into account some important points:

• In order to carry out work at a high-quality level, you will need to first calculate the expected loads on the roof during its operation. So, for example, in addition to its own weight, the roof will have to withstand elements of communication systems, the weight of several people, wind and snow loads.

Important! Using only high quality building materials.

Construction of a gable or hip roof not always rational and expedient when it comes to outbuildings, industrial and commercial facilities, and from time to time private buildings in modern style. Enormous consumption of material, complex rafter system make the construction of these structures an unprofitable, protracted undertaking. Whereas flat roof projects significantly reduce construction costs, are built quickly and are suitable for virtually any structure.

A house with a flat roof is reliably protected from increased wind loads. But, without slopes, it does not have the ability to quickly drain rain and melt water from the roof surface. The situation is complicated by the fact that the surface of the roofing materials has a rough structure, which does not allow moisture and snow to slide freely. Based on this device flat roof, assembled with your own hands, 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 liquid forces to place roofing materials flat roof in layers, one above the other, forming a so-called “pie”. If you examine its cross-sectional structure, you will notice the following layers:

1. Flat base made of cement slabs or pages of profiled metal. It provides rigidity to the structure, bears the weight of the roofing pie, transferring it load-bearing partitions and, ultimately, the foundation. The foundation of a roof in use must be as solid as possible.
2. Vapor barrier. A layer that is needed 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 will irreversibly reduce its insulating properties by more than half. As a simple vapor barrier, polyethylene film or bitumen-based coatings are used.
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 thermal conductivity and low hygroscopicity, light weight.
4. Waterproofing. Flat roofing can be used as a coating to protect against liquids roll materials: bitumen, polymer and bitumen-polymer. In addition to high waterproofing qualities, they must be resistant to temperature changes, elasticity, and have a long service life.

nuances and types of roofing of their installation

The design of a flat roof determines the nature and design of the application. 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 extension, the slope is organized using support beams. They are installed at an angle of 3 degrees, which forms 30 mm on any linear meter beam length. After this, a base of unedged boards, securing them with nails or self-tapping screws.

Roofing felt, the most affordable material, is used as a waterproofing agent. It is created and sold in the form of rolls. They cut the waterproofing by cutting strips so as to lay them in the direction of the slope of the flat roof. Strips of roofing felt are laid in stages with an overlap of 10-15 cm and fixed with wood slats or metal strips every 60-70 cm in the direction of the drain, so as not to block the path of the flowing liquid. The flat roof of an 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 you are building a private house with a flat roof, which is going to be connected to a heating system, then the work takes place in the following sequence:

In 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 metal I-beam, is used to make support beams.

Monolithic concrete roofing

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

Leaning process

Sloping a flat roof is the 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 an internal drain is provided, the water must flow through a slope into water-collecting funnels, which are located 1 per 25 sq.m or more often. If you make an external drain, moisture must enter the gutter. The slope is formed in the following ways:

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

Video instructions

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 houses in a 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, 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 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. 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 of beam length. Then a base of unedged boards is laid on the beams, secured with nails or self-tapping 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 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

Most people have no idea how to make a flat roof for a house; many people associate the concept of “flat roof” with multi-story buildings. Just a couple of decades ago, flat roofs were rarely used in low-rise construction.

Availability today modern materials and technology makes it possible to make a flat roof both at an affordable price and with high consumer characteristics.

Types of flat roofs:

Operated roofs- need a rigid foundation in the form of a concrete screed or corrugated sheet. On such a roof thermal insulation material experiences static and dynamic loads, so it must be strong when compressed. If the insulation is of low rigidity, a cement screed is needed on top of it.

Unused roofs- do not require a rigid base for installation waterproofing material, as well as in rigid insulation. Such a roof is cheaper to construct, but its service life is shorter than for a used roof.

Traditional roofs have the peculiarity that the waterproofing layer is located above the thermal insulation layer. At the base of the roof there is a reinforced concrete slab; to drain water from the roof, an inclined screed made of expanded clay concrete is laid.

Inversion roofs are deprived of the main disadvantage of flat roofs - water leaks. In such a roof, the thermal insulation layer is located above the waterproofing layer. This feature protects the waterproofing layer from destruction by ultraviolet rays and smoothes out the effects of temperature changes. This type of roof is more durable than other types of roofs. On such a roof you can even lay a lawn or pave it with paving slabs.

Flat roof covering

In accordance with building regulations, the covering of a flat roof at the base must be made of reinforced concrete slabs or corrugated sheets.

For permanent buildings, lightweight floor slabs are usually used, on top of which several layers of insulating materials are laid:

1. A vapor barrier is installed to prevent moisture from entering the insulation from inside the room. For vapor barrier covering of a flat roof it is used fiberglass reinforced polymer-bitumen film, which is glued to concrete screed. The edges of the film are inserted behind the vertical ceiling, the seams are carefully soldered.
2. Insulation is being installed. When using expanded clay for insulation, it is first covered with a concrete screed. If you are making a lightweight version of the roof, then the polymer insulation is glued directly to the vapor barrier layer.
3. Most important stage coatings - waterproofing, usually made from polymer-bitumen or membrane materials.

There are differences in the design of a flat roof for heated and unheated premises:

• for unheated rooms (barn, gazebo...) a slope is created by the roof surface to drain precipitation. Support beams in this case, they are installed at an angle, and a shield made of boards is placed on top of them. It is covered with a roll of roofing material on top. Roofing felt is attached to the board panel using metal strips or slats nailed along the slope. The distance between the slats is 60-70 cm, and the slope should be at least 3%.
• For a heated room, covering a flat roof occurs in several stages:

1. The beams are covered with planks, and roofing felt or roofing felt is placed on top with an overlap of at least 15 centimeters.
2. Expanded clay insulation is poured while maintaining a slope towards the water discharge.
3. A cement screed is laid on top of the insulation; its thickness should be at least 2 cm. Then we treat the screed with a bitumen primer.
4. We glue the rolled roofing felt carpet.

When constructing a roof made of monolithic concrete load-bearing structures are I-beam metal beams. If the roof span is 4-5 meters, then beams with a height of 12-15 centimeters are used.

For monolithic ceiling It is better to use ready-made concrete 250 grade, and if you make concrete yourself, then use a concrete mixer. It is difficult to achieve the required degree of concrete mixing by hand.

The best quality is to lay concrete over the entire roof surface in one day. It is advisable to compact the concrete after pouring, use a vibrator for this, or compact it manually.

To prevent concrete from cracking, it is covered plastic film for 3 days. After the concrete has completely dried, slopes are made using insulation, then a screed and a rolled carpet.

One of important features flat roof - the possibility of insulating it from the outside during the operation of the house, and not just from the inside. In this case, first the external insulation of the flat roof is carried out, and then, if it turns out to be insufficient, the internal insulation is carried out.

Until recently, the main way to insulate a flat roof was to insulate it with rigid insulation boards, but the disadvantage of this method is that the load on the roof increases.

Nowadays, the most well-proven insulation of basalt mineral wool, quite light and having better thermal conductivity and waterproofing. Its advantages include the fact that it does not ignite and is not subject to mechanical stress.

If insulation is necessary inner surface For roofs, it is better to use fireproof polystyrene foam boards with a thickness of 25-30 mm. To do this, wooden strips are attached to the roof ceiling at a distance of 40 cm. Expanded polystyrene boards are glued onto the planks using mastic.

Flat roof waterproofing

Proper waterproofing of a flat roof is very important. A flat roof, regardless of the materials used, should have a slope of 3-5% for water drainage. The drainage and waterproofing system should be thought out at the design stage of a building with a flat roof.

Whatever roofing material you choose, it is important that the joints and junctions of the various roof elements are waterproof. A high-quality sealant is an important component of good waterproofing.

During operation, the roof is exposed to aggressive environmental influences (temperature changes, moisture, etc.). Therefore, when choosing a sealant, pay attention to the characteristics of its resistance to temperature and mechanical influences.

Most often, mastic is used as a sealant; it is based on elastic polyurethane resins. After application to the roof, the mastic polymerizes, after which a continuous rubber-like membrane is formed. It has waterproofing properties and protects the roof from mechanical damage. Mastic is ideal for flat roofs; it is safe, highly resistant to ultraviolet radiation, precipitation, and microorganisms. Apply it with a brush or roller.

In conclusion, it should be noted that, from the point of view of many modern designers, a flat roof is a sign of minimalism in the construction of a house as a whole. For example, in Greece this type of roof is mainly used. If, from a design point of view, the proportions of the house are observed correctly, then this type of roof is beautiful and original.

A flat roof of a house is appropriate for those houses that have simple design with a minimum of components and decorative elements.