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. The enormous consumption of material and the complex rafter system make the construction of these structures an unprofitable and 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, the installation of a do-it-yourself flat roof must comply with the strict requirements of building codes for waterproofing, slope and construction technology.

The structure of the roofing pie

The need for a high level of protection from liquids makes it necessary 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 from cement slabs or pages 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 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. Flat roof an unheated room can be easily installed with your own hands, in addition, 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

Still an unusual decoration country cottages – flat roof. 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: on beams and those with a base concrete slab.

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

Most often, internal drains are installed on flat roofs: funnels are mounted in the roof, risers from them pass through interior spaces. 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 built solely for the sake of originality and saving 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.

Please note

The design of these roofs differs from simple attics; they cannot be used for use.

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 low, 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 in exploited roofs for various purposes the device will be different:

When constructing a swimming pool, pay special attention to waterproofing;

“Green” roofing also means thorough waterproofing plus soil filling, etc.

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

The disadvantages of rolled materials (and roofing felt in particular) are their 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 allow installation 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 an expensive pitched roof made of 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.

Cons:

• 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: a continuous sheathing of plywood or OSB is nailed onto the beams, a roofing pie is laid (vapor barrier + basalt wool), direct the waterproofing layer and roll roofing.

If you are interested in a flat roof with a more complex structure, please contact us: we will complete roofing of any complexity quickly and efficiently. affordable price.

How quickly time flies! 4 years have already passed since I built an unusual country house. The house uses a lot of non-standard technical solutions, which were previously practically not used in individual construction in Russia. Firstly, the house is heated using, and secondly, the house has a flat roof.

From the very beginning of construction in 2012, I was constantly told that a flat roof is not for our climate (what kind?), that it will definitely leak (why?), and in general, with such a roof, the house looks like a transformer booth (poor Europeans, they have to live in transformer booths).

But most often they tried to prove to me that snow needs to be constantly removed from a flat roof (I wonder why?). Of course, if anyone wants, you can clean it up, no one is stopping you. But on houses with a flat roof there is no need to remove snow. For example, now I have a snow cover more than 80 centimeters thick on my roof! And somewhere there she hid under the snow.

2. Snow on the roof is an additional and completely free insulation.

By the way, as it turns out, many people do not know that a flat roof is not a plane in the direct sense, but a surface with a slope of approximately 2-4 degrees (in fact, a roof is considered flat if its slope angle is from 2 to 20 degrees). And any flat roof must have a drain. It is more correct to make an internal drain for a flat roof, but you can get by with a classic external one. At the time of construction, I did not have sufficient knowledge to design and implement an internal drain, so I made an external one. Advantage internal drain in the absence of pipes on the facade.

3. Summer 2013, just made. A flat roof is significantly cheaper than any pitched roof (at least because its area is on average 1.5 times smaller than that of a pitched roof). With it there is no loss of space and such useless space in the house as the attic. It is simpler and easier to insulate - everything is in the same plane.

Let me remind you of the design of my roof pie (from bottom to top):
1. Prefabricated monolithic floor with filling aerated concrete blocks- 250 mm;
2. Insulation using extruded polystyrene foam - 150 mm;
3. Insulation and creation of a slope using wedge-shaped slabs of extruded polystyrene foam - 0-150 mm;
4. Cement screed- 50 mm;
5. Two-layer built-up waterproofing ( top layer with sprinkles).

4. Another huge plus of a flat roof is that it is not afraid of hurricanes. Look at the chronicles of hurricanes and how easily the coating tears off and breaks rafter system on classic pitched roofs.

5. In the summer of 2016, I finished all the other work on landscaping the surrounding area and decided to do it.

6. By the way, if anyone doesn’t know, then any concrete floor by default has a load-bearing capacity of at least 400 kg per square meter(usually 600-800 kg/m2). While the snow load for the Moscow region is only 180 kg per square meter. This is the maximum calculated snow load, which in reality is rarely achieved, but it is obvious that any ceiling has a huge margin of load-bearing capacity.

7. Another important advantage of a flat roof is that it has completely sealed seams. While the seams on a pitched roof are not airtight, and if the pitched roof is filled with snow and it begins to melt from below (due to insufficient insulation), the pitched roof will leak (especially at the junction of two slopes - valleys). Look at the neighboring houses from pitched roofs- Surprisingly, there is snow on them too!

Why doesn’t a flat roof made using technology leak? It's very simple. Because it is insulated!

It is the insulation that determines the durability of the roof. It is known that the roof accounts for an average of 40% of the heat loss of the entire building. If the roof is not insulated, or is not insulated well enough, then the heat will rise, and the snow lying on the upper roofing carpet will melt. When frost occurs, the melted snow will freeze again, and when it freezes, as is known, water expands in volume. These multiple thaw-freeze cycles will eventually break down the waterproofing (after 2-3 years) and the flat roof will begin to leak.

8. In the last century, when building houses, they did not think about energy efficiency and saving energy resources, so they usually did not insulate the roof. This led to the fact that the roof waterproofing was constantly being destroyed and the roof was leaking.

If the roof is well insulated, then it has only one “enemy” left - the sun and its ultraviolet radiation. But to protect against this, waterproofing is used with a package, or with special additives (in the case of using). And the most effective way protect the waterproofing from damaging ultraviolet radiation - make a lawn on the roof, fill it with pebbles or lay tiles. By the way, a more promising waterproofing solution today is a polymer membrane.

A flat roof is even easier to use than a pitched roof. From a flat roof, snow will never fall on your head or tear off your gutters. There is no need to clear the snow, and if you have a lawn, there is no need to keep the gutters clean (all water is filtered through geotextiles and they will not become clogged with fallen leaves).

Therefore, a flat roof is the most reasonable roofing option, especially for a house made of. The main thing is not to violate technology and not to skimp on insulation.

And cleaning snow from a flat roof is not only useless, but also harmful - you can accidentally tear the waterproofing with the sharp edge of a shovel and the roof will begin to leak.

With all reports dedicated to construction country house with your own hands in chronological order you can familiarize yourself.

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 laying waterproofing material, nor do they require 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 waterproofing layer located above the thermal insulation layer. At the base of the roof there is a slab of reinforced concrete; 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

According to building codes the covering of a flat roof at the base should 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 placed 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 rooms:

• for unheated rooms (barn, gazebo...) a slope is created by the roof surface to drain precipitation. In this case, the load-bearing beams 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. Paste roll carpet from roofing felt.

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

For monolithic floors it is better to use ready-mixed concrete 250 marks, 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 influences external environment(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 a simple structure with a minimum of components and decorative elements.

When building your home, building a roof is one of the most important tasks. We propose to discuss how to make a flat roof in a private house with your own hands from corrugated sheets, its structure, insulation and drainage, as well as the advantages and disadvantages of this type of roofing.

Design features of a flat roof

Modern private builders rarely use flat roofs to cover private buildings and homes; these are mainly surfaces that can be used to cover a gazebo, the surface of a garage, a bathhouse, etc. utility rooms. The flat roof is mainly used for multi-storey residential buildings, where design features You cannot build a gable roof.

Photo - Flat roof roofing pie

Projects of houses and cottages with a flat roof are distinguished by their originality and eclecticism. In addition, you can arrange a special roofing pie, thanks to which the lack of attic (inter-roof) space will play into your hands. There are such types of flat roofs:

Photo - Flat roof waterproofing

There is also a flat combined roof - when the roof combines several of the listed types. For example, inversion and traditional.

Pros flat roof:

1. Very simple design, there are no special principles for installing rafters, frames and other beams;
2. Easy calculation of roofing materials;
3. You can use the surface of such a roof as a foundation for installing various systems directly on the roof: satellite dishes, winter gardens, solar panels etc.;
4. Smaller area, unlike a lean-to or attic (no need for wide overhangs).

But cons flat roofless roof are more significant:

1. Due to the lack of an angle of inclination, it often leaks. Single-pitch, gable and other sloping types of roofs do an excellent job of draining water independently, but for a flat roof you need to build a special drain;
2. Several times a year, a country house will need to be cleaned of the accumulation of leaves and snow on the roof;
3. Often the interior drainage funnels freeze due to the lack of an attic.

But still, in view of economy, the disadvantages that a flat roof has are not very significant compared to its advantages.

Video: flat exploitable roof

How to choose a material for a flat roof

Properly selected roofing materials for a flat roof are half the success of the entire house construction. Of course, you can choose a profiled sheet, but it is worth noting that in this case you need to think through how snow removal and drainage will be carried out. The fact is that from constant exposure to precipitation metal coating may rust and go out of service earlier than the period stated by the manufacturers.

The roofing covering must have excellent resistance to moisture. The following will serve you well here:

1. Corrugated sheeting with polymer coating;
2. Polycarbonate;
3. Slate;
4. Mastics.

Let's consider what material is most often used for flat roofing. Construction mastics most often used on residential buildings. These are special liquid coatings that are applied to the roof surface with a brush, and then harden, forming an airtight solid substance that looks like rolled materials. They are highly resistant to impact high temperature- up to 70 degrees, but can crack at low temperatures - up to 25.

Photo - Flat roof

Polycarbonate is more reliable and beautiful than mastics, but it is an order of magnitude more expensive. Its main advantage is its external similarity to glass, so with its help you can create a stylish roof that will highlight your financial condition. In addition, polycarbonate is chosen for design design residential buildings.

Slate previously used for any type of roof, regardless of its slopes. It is very heavy, so to install it you need to carefully consider the frame and foundation of the building so that the house does not “sink”. The load that slate puts on the rafters is perfectly compensated by its durability indicators: it can last up to 50 years in moderately aggressive environments with strong changes in pressure and temperature. Now it can be replaced by aerated concrete, which is lighter.

Corrugated sheet with a polymer coating - it's almost perfect material for covering a flat roof. A dacha, a greenhouse and a house with such a surface may not be afraid of temperature changes or ultra-low degrees, but a snow cushion is destructive for them. It is necessary to ensure that the metal is periodically cleaned from atmospheric precipitation, so work on natural cleaning systems.

Photo - Flat roof made of corrugated sheets

More rarely, but still, a wooden flat roof is used. Its durability indicators are relatively low, but wood will help protect roofing felt or the same mastics. Timber roofs are mainly used in complex design projects.

Flat roof installation

Let's look at how a flat exploitable roof is installed on square houses, as well as how to insulate this type of coating.

A flat roof is universal type design, it has an excellent price-quality ratio, but there are significant drawbacks in the form of a complex drainage system. When choosing such a roof, carefully weigh all the advantages and disadvantages.