Flat roof solution. Flat roof in the house: device, materials and technologies. There are two main types of flat roofs

A house with a flat roof, in a row of similar “boxes” with a pitched roof, looks fresh and unusual. Therefore, every year the number of suburban residents who are seriously considering the construction of such a house for permanent residence is increasing. Fans of “cubic” design are captivated by the wow effect and increased attention from neighbors. Someone wants to place it on the roof engineering equipment, or lay out a lawn and arrange seating areas. Still others believe that building a house with a flat roof is cheaper and easier than with a pitched roof. Is it really? Let's consider the main pros and cons of these buildings and draw a conclusion whether they are suitable for our country. To do this, we will answer the following questions:

Why is it difficult to choose a suitable plot for a “cubic” cottage?
Is it true that flat roofs are not suitable for our climate?
Why does a flat roof leak?
A flat roof is simpler and cheaper than a pitched roof - this is a myth
Why is a flat roof difficult to repair?

1. House with a flat roof and domestic realities

Most country residents look at cottages with flat roofs with skepticism, calling these houses “boxes”. Why? Houses with flat roofs came to us from abroad. Traditionally, they were built in countries with a warm climate, where there is practically no winter, heavy snowfall, severe frosts with sudden thaws, prolonged rains, but strong winds blow. For example, somewhere on the Mediterranean coast. These houses then became a "not for everyone" design trend in Western Europe, and from there they already came to us.

Tretin User FORUMHOUSE

I see that we mainly build houses with a pitched roof. But is this really necessary? In Germany and Switzerland, designs for houses with flat roofs have long been offered. What could be the disadvantages of a flat roof, besides the supposed unaesthetic appearance?

Indeed, can anyone be left indifferent by the cottage with panoramic windows in the photo below?

Or this high-tech house with a flat roof in the forest.

Or a cottage with an observation deck on the roof, a lawn and a place to relax.

Now imagine these houses here. Harsh winter. In an ordinary - not elite village, where roads float in spring and autumn, and areas are fenced with corrugated sheets. Most houses are finished with siding or lined with facing bricks. And pitched roofs are covered with slate, metal tiles or, less commonly, a more expensive solution - flexible tiles. The picture doesn't add up. Something's missing, isn't it? I no longer want to sit on the flat roof of a house, as I dreamed of, with a cup of tea or coffee. After all, from there the view opens not to the ocean, sea, mountains or nature untouched by man, but to dense village buildings or, in best case scenario, fields overgrown with grass.

A house with a flat roof, in a high-tech style, looks advantageous only on a spacious isolated area, for example, on a slope, with beautiful view to a forest, lake or river. A cottage with a flat roof is lost without landscape design, and among good-quality, but similar houses, it looks like a “black sheep.”

This is where it lies the first "pitfall" - dreams of stylish home flat roofs break when you realize,how much will the plot cost?, on which the cottage will look just right.

Having conceived the construction of a house with a claim to a non-standard foreign design, select an appropriate site for it.

2. Reliability of a flat roof in our climate

When you look at beautiful houses, which are hundreds of years old, ask yourself why they were built this way and not otherwise. Why do houses built in a coastal area somewhere in Norway, Sweden or Scotland do not have roof overhangs and the usual drainage? They are simply not needed due to strong winds that turn rain into a horizontal stream of water hitting the walls. The same goes for houses with flat roofs. They were built in warm climates, where there is little precipitation but strong wind load.

A flat roof is more wind resistant than a pitched roof.

Dmitrievich-50 User FORUMHOUSE

Our ancestors are smart people. They considered the design of the house from the point of view of practicality, based on the climatic conditions of their residence. Why were flat roofs built in Central Asia? On the Central Russian Upland are they sloped? In the Baltics, not just pitched ones, but with a sharp ridge angle? A pitched roof with a slope of 45 degrees, in the Moscow region or Saratov, will provide reliable protection from rain or snow for 20-25 years, even if covered with cheap corrugated board or slate.

A flat roof, with the right approach to construction and using modern materials, will also provide reliable protection for the house from precipitation and will not leak.

The only question is how much 1 sq. m. will cost. m of such a roof with a guarantee that it will not leak quickly during frequent transitions through 0. Icing. Night freezing and day thawing snow cover. Lingering downpours. And most importantly - how to make a roof so that it lasts a long time in our climate?

The second difficulty in building a cottage with a problem-free flat roof is the harsh Russian operating conditions.

3. The main problem of building a reliable house with a flat roof in the Russian Federation

link82 Member of FORUMHOUSE

The company built me a house with a flat roof. We made 6 pieces along the edges. heated funnels and led out to the sides, through the parapet, drain pipes. Is it correct? Maybe it was necessary to make a slope to the center and, with a small roof area, install two funnels instead of six? And put the pipe inside the building. Output in the base and further into storm sewer? I am afraid that the knee that is being taken out of the funnel into the street will freeze. Ice has already formed on the pipes. What if the pipe bursts due to frost? How to fix it? Throw in a heating cable? So much money has already been spent on this roof!

The house with a flat roof was built in 2013.

In addition to problems with drainage, another one was added. When link82 I came to check the house and discovered that the roof was leaking in several places. Water came from the second floor to the first. All the drywall floated. Now you have to quarrel with the builders. Trying to take the money and completely redo the roof. According to Mikhail-snabss(a user of the portal is a professional in the construction of flat roofs) this example contains a whole bunch of errors. The main one is builders who simply don’t know how to make flat roofs correctly.

When building a house with a flat roof, do not go cheap. Every step of builders and stage of work needs strict control. More careful than when constructing a pitched one. Mistakes will be costly!

The roof was most likely made of a built-up waterproofing material - glass insulation. The tree played and the fiberglass tore. Repairing this roof with a special roofing membrane will cost from 130 to 200 thousand rubles.

The third factor complicating the construction of a cottage with a flat roof in the Russian Federation - lack of highly qualified builders who know exactly how to build just such houses correctly. How to use and combine materials with each other. What tools are needed for this? Even if the future owner of a house with a flat roof has a detailed design, and he should be, then everything can be ruined by “specialists” who work on the principle: “we always build this way and no one has complained yet!”

Flat roofing should only be done by professionals.

4. Is a flat roof cheaper and simpler than a pitched roof?

Usually, when it comes to the advantages of a flat roof, you can hear the argument that it is cheaper than a pitched roof. Why? Smaller area means lower consumption of materials. It’s easier to make an overlap, because no need for classic rafter system. No need to arrange attic floor etc. And that's true, but as they say, the essence is in the details.

If we take a simplified look at the “pie” of a flat roof, then the following are laid on the base, for example concrete floor slabs:

vapor barrier;
thermal insulation;
waterproofing.

Or the so-called inversion flat roof, where the layers go like this:

waterproofing;
thermal insulation;
finishing layer.

In an inversion flat roof, the waterproofing layer is located under the insulation and “works” in more gentle conditions, because from above, from the negative influence of weather conditions, it is protected by crushed stone, tiles or soil with a lawn. Those. a ballasted flat roof is installed.

But, when building a flat roof it is necessary:

Arrange slopes for water drainage - about 2 cm per 1 linear meter. Slopes are usually made concrete screed or wedge-shaped insulation elements.
Lay several layers of insulation. If stone wool is used and not extruded polystyrene foam, install aerators to remove water vapor from the thermal insulation.
Put water intake funnels with electrically heated , otherwise, due to the ice that has formed, they will not drain water from the roof.

One water intake funnel, with a diameter of 110 mm, drains water from an area of up to 300 square meters. m.

Install a drainpipe with a slope of 3 cm per 1 linear meter.
Make high-quality waterproofing from PVC, TPO or expensive EPDM membranes. TPO membranes are less elastic than PVC membranes, but have higher strength. Welding TPO membranes requires professional installers with special equipment. The advantage of EPDM membranes is their large format, and the fewer welds, the more reliable the flat roof.

When installing a flat roof, you will have to take into account many nuances.

Calculate the snow load depending on your region of residence. For example, Moscow and St. Petersburg belong to the third climatic region. The snow load on a flat roof, with a slope of 2%, in the Moscow region will be 180 kg per 1 sq. m. m. In the fourth climatic region, the snow load is 240 kg per 1 sq. m. m, and in the fifth there are already 320 kg. Do not forget that the weight of 1 m 3 of loose, freshly fallen snow is on average 50 - 100 kg. Already compacted 350 kg. A cube of wet or melting snow weighs approximately 400-600 kg.

There is no need to remove snow from a properly designed flat roof in winter. The excess is blown away by the wind, and the loose snow becomes a heat insulator.

But the load on a flat roof must be taken into account with a greater margin than on a pitched roof, taking into account force majeure circumstances. For example, the water inlet funnels became clogged, the heating cable burned out, and the water did not drain from the roof. A month's worth of snow fell in a couple of days, but there was no wind to blow it away and it lies on the roof. Additional weight on the roof puts pressure on the walls, which in turn transfer the load to the foundation, which redistributes it to the soil foundation. The further north you go, the greater the load. Add a lot of crushed stone or soil with grass if you are installing a ballasted flat roof.

From here - the optimal design for a cottage with a flat roof is not a frame or wooden house, and the stone structure, calculated by the designer and built from aerated concrete, brick, warm ceramics, using monolithic technology. Because “Cubic” design involves large unsupported spaces, then it will no longer be possible to block a span of more than 6 m with a tree. Required trusses, I-beam wooden beams, hollow reinforced concrete floor slabs, monolithic floor or prefabricated monolithic floor. Don’t forget to add expensive façade finishing solutions to the cost of a house with a flat roof.

You can't finish a house like this cheap anymore.

Planken, burnt wood, brick are used hand molding, wet facade, combined facades made of wood and stone. And you can’t put it in a house with a flat roof. standard windows. Large or panoramic are required. Add to this additional areas parapets, which also need to be insulated and finished. This increases construction costs.

The fourth factor - a house with a flat roof cannot be called budget construction.

Consider the costs not only for the roof, comparing the final estimate with flat and pitched ones, but for the total cost of the entire “box” with finishing.

5. Low maintainability of a flat roof

sv2321 User FORUMHOUSE

I have a house with a flat roof. Waterproofing - membrane. I'm struggling with the roof. As they say, water will always find a hole. I like the flat roof, but I think I’ll give it up and convert it to a pitched roof, although I’ll have to change the entire architecture of the house. And that's why:

There is no absolute guarantee that all joints of a flat roof will be airtight. Enough microcrack and off we go. If there is a slope, then small defects are not critical;
Snow lingers on a flat roof. He's melting. Water fills microcracks. It was frosty at night. The water is frozen. With frequent daily freeze-thaw cycles, microcracks enlarge and then rupture. They are getting bigger. The pitched roof has no welded areas and there is nothing to tear there. In the worst case scenario, a small temporary leak will appear without progressive consequences. It is easy to find and repair;
The most unpleasant thing. On a flat roof, you will never know exactly where the defect occurred. There is a leak in one place, and water is dripping from the ceiling in another. The craftsmen will come, check the joints and find one of the defects, but the rest will remain. If the roof is inverted or loaded with gravel, then defect detection is an even bigger problem.

According to the user, the optimal roof for our climate is pitched. The angles of the slopes compensate for the crooked hands of the builders and changes in the properties of materials over time, and the overhangs protect the walls and finishing from precipitation.

So, fifth - low maintainability. The quality of a flat roof is greatly influenced by the human factor.

If a pitched roof with a cold attic is leaking, then finding and repairing the defective area is not difficult. As a last resort, you can dismantle the coating and perform local repair or get close to problem area from the inside. In the case of a flat roof, finding a leak and repairing it becomes more difficult due to the complex “pie”. Many layers in the structure, especially in the so-called. "green roof". Presence of concrete screed, etc.

conclusions

Houses with a flat roof certainly look beautiful and stylish. Make a flat, problem-free roof that will serve long years in our climate also possible. The only question is the total cost of all decisions and its feasibility. Anyone who has been involved in roof installation or repair in our climate knows that in summer, a hot roof in the sun - last place where you would like to sit with your family or friends. It's hot and stuffy. I want to quickly go into the shadows. If there are small children in the house, then a used flat roof is an extra headache for parents. You can also organize a shaded private place to relax with barbecue on the site small area. It’s nice to sunbathe in the garden on the grass, throwing in a towel or laying out a sun lounger, and not in full view of all the neighbors and passers-by on the roof. In the countryside, you simply want privacy, and not stick out your private life for everyone to see. Let's add our changeable weather. Rain. The wind, which at altitude is felt completely differently than below. In total, how many days a year will there actually be left to relax on a flat roof? Let's add the need to arrange a place to access the roof directly from the house. Do not climb onto a flat roof using a ladder that is attached to the facade. What's left? Unusual “fashionable” design to attract attention. Therefore, let everyone decide for themselves whether to build a house with a flat roof or not, and FORUMHOUSE offers you proven solutions for this.

how to properly build a house in our climate with a roof without overhangs and a hidden drain, and what are its advantages.

Stone house with a flat roof: a harmonious combination of exterior and interior. The video shows the design features of a monolithic stone house with a flat roof and unusual decoration facade.

For many people, the name “flat roof” is associated primarily with multi-storey buildings. A flat roof - the pros and cons of which we will consider in this article - was practically not used in low-rise construction a dozen years ago. However, today the creation of such a roof in country house is not a problem: modern materials and technologies make it possible to create a flat roof with appropriate consumer characteristics and at an affordable price.

A flat roof is significantly smaller in area than a pitched roof, which allows you to save on materials and construction work.
Thanks to the relatively smaller area of the flat roof, it is possible to optimize costs.
The construction of a flat roof is carried out easier and in a shorter period of time compared to pitched roof, since the necessary materials for installation are located right at the feet of the workers on a flat surface. The same can be said about the repair and maintenance of a flat roof - working on an almost horizontal roof is incomparably more comfortable than on a sloping one.
Installation and subsequent installation are more convenient on a flat roof. service works with all kinds of equipment (air conditioning systems, solar panels, antennas, etc.).
The use of a flat roof is an opportunity to obtain additional useful territory, which can be used as a place where you can relax on fresh air, play sports, create a garden, flower garden, etc. Today, there are technologies that make it possible to cover the roof even with paving slabs or paving stones. A roof paved with beautiful tiles, combined with a green lawn, garden furniture, a gazebo and a fireplace, can become a place for a comfortable family holiday.

Houses with flat roofs are very popular now

A flat roof, in addition to its advantages, has a number of disadvantages:

As a result of heavy snowfalls, a lot of snow accumulates on flat roofs, which, when melted, often causes leaks.
Sometimes the use of internal drains is required.
There is a risk of the internal drain becoming clogged or freezing.
There is a need for mechanical cleaning roofs from too large accumulations of snow.
Regular monitoring of the moisture content of the insulation and the tightness of the roof is necessary.

Types of flat roofs

There are four types of flat roofs:

Flat roof base

In accordance with building codes, a flat roof, the pros and cons of which we discussed above, must have an iron base concrete slabs ceilings or corrugated sheets.

Subtleties of waterproofing

The durability of the roofing structure and its resistance to various negative influences depends on the use of special mixtures and technological processes production of roofing materials. Depending on the roofing materials, they are usually divided into three categories:

Bitumen roofs, as well as polymer-bitumen based on roofing felt. These materials are available due to their low cost. Fused bitumen-polymer compositions are rolled waterproofing and roofing sheets based on synthetics, on both sides of which a special bitumen is used that retains elasticity even at extremely low temperatures (down to -50 degrees Celsius). During the installation of waterproofing, carried out using gas burners, the rolls are fused together. Roof waterproofing can also be carried out with self-adhesive materials based on polymers and bitumen. In this case, the mastic is applied to the bottom surface of the roll and, when treated with a solvent, acquires the properties of glue. Flaw bitumen roofing- fragility.
Membrane roofs with a base made of foil, rubber or polymers. This material has solid strength and is resistant to fire and other negative environmental influences. The membranes are glued to the screed or simply lie on the base, being loaded with ballast, or are attached mechanically or using glue. To connect the membrane sheets, special welding machines are used that hold the material together with hot air.
Roofs based on liquid polymers, which after cooling do not form seams. Such materials are especially often used for structures with complex geometries.

It is very important to properly waterproof your flat roof.

Whatever material is chosen, the joints between the rolls and the junctions with various roof elements must be waterproof. One of the main components of a successful waterproofing device is a high-quality sealant. During the period of operation, the roof is subject to negative influences external environment(moisture, hail, stones, strong temperature changes, etc.). Therefore, a high-quality sealant must be resistant to mechanical and temperature influences.

Mastic is usually used as a sealant - putty, which is based on elastic polyurethane resins. After application to the roof, the mastic polymerizes, resulting in the formation of a continuous rubber-like membrane that has waterproofing properties and protects the roofing from mechanical damage.

Mastic is ideal for flat roofing, it is safe, has high adhesion to building surfaces, and is highly resistant to ultraviolet radiation, precipitation and all kinds of microorganisms. It is applied by brush, roller or airless spray- two multi-colored layers, which allows you to control the quality, layer thickness and uniformity of sealant distribution.

How to arrange water drainage

Regardless of the materials used, a flat roof must have a certain slope to drain water (usually within 3-5%) that appears on the roof as a result atmospheric precipitation. The drainage system should be thought out at the building design stage. Gutters determine how effectively moisture will be removed from the roof surface. To prevent gutters from freezing in winter, they are equipped with special thermal cables.

Drains can be organized, when both external and internal water supply is created, and unorganized. When creating an internal water supply system, the roof surface is divided into approximately equal parts of 150-200 square meters each. In places with a slope, drainage funnels are installed, equipped with baskets for catching debris. Typically, funnels are located in the center of the roof, and the pipes are located inside the building.

Rules for insulation and vapor barrier of a flat roof

A flat roof needs insulation. In the absence of a layer of thermal insulation, condensation forms on the roof surface as a result of the contact of warm air masses and the cold surface of the roof. Condensation appears as water stains on the ceilings of the house, and the roof structure gradually collapses.

The roof design involves a base on which a layer of vapor barrier material is laid. The function of a vapor barrier is to protect the insulation from diffuse moisture coming from the premises of the building. The vapor barrier layer includes a glass fiber reinforced membrane (based on bitumen and polymers) or a vapor barrier film. The layer is laid on top of the screed, and along the edges of the roofing structure it is placed vertically to a height exceeding the height of the insulating material. The seams are sealed.

Insulation is placed above the vapor barrier layer, and a bitumen-based waterproofing carpet is placed on top of it. If expanded clay is used as insulation, then it is necessary to make a cement screed over it, then laying a couple of layers of waterproofing. If the roof is planned to be light (in the case where significant loads are not expected on it), then the waterproofing is simply glued along the entire perimeter of the roof.

For roofs without attics, both external and internal insulation methods are used. External method is used more often, so its execution is easier. There are two options for thermal insulation: double-layer and single-layer. The decision about which option to use in practice depends on heat engineering calculations and roof strength requirements. Thermal insulation slabs are placed on the roof structure based on the principle of “staggered seams”. With a two-layer coating of thermal insulation, the joints of the lower and upper slabs are also separated. In the area where the slabs adjoin the parapet, lanterns and walls, thermal insulating edges are created. Thermal insulation materials are attached to the base mechanically (screws, dowels), ballast (pebbles, paving slabs) or glue.

Features of roof ventilation

The roof structure must be equipped ventilation system. As a result of a violation of the tightness of the vapor barrier layer, moisture enters the insulating layer. A thick layer of waterproofing prevents evaporation from occurring, and moisture accumulates in the insulation. As a result, the material loses its insulation characteristics, and moisture appears on the ceilings of the building in the form of spots. In addition, water causes waterproofing to swell, and at low temperatures, freezing water tears off waterproofing material from the base. Temperature changes and mechanical damage contribute to the formation of cracks in the roof, which results in roof leaks.

To avoid these problems, the roof must “breathe”. For this purpose, aerators are used - special devices in the form of plastic or metal pipes. They are covered with umbrella caps and are evenly distributed throughout the entire roof area, gravitating towards its highest points. The aeration mechanism works based on the principle of different pressures, which are created by air flows, removing excess moisture vapor from under the roof and preventing water bubbles from forming.

The installation of a roof is a responsible technological operation. Any, even minor, mistake in the design or construction of a roof can cause it to leak in the future. Therefore, when creating a roof, you need to pay attention Special attention the correct selection of hydro- and thermal insulation materials, accurately calculate the upcoming loads on the roof structure, and also select a team of competent builders.

When constructing urban high-rise buildings and industrial facilities, the basis of a flat roof usually becomes reinforced concrete slab. But for private houses, especially frame and wooden ones, such a choice is most often unacceptable. In this case, a flat roof is built on wooden beams. Its main advantage is its light weight, which reduces the load on the walls and foundation.

The installation of such a roof is simpler and cheaper than using heavy reinforced concrete slabs. But the functionality is the same. Therefore, this option of a flat roof is often chosen by those who want to build it with their own hands.

The main share of such roofs falls on private houses and cottages, whose owners value futuristic style, convenience and practicality. Also - for covering verandas, terraces, balconies, garages. As a rule, all these buildings are wooden or frame, requiring a lightweight roof structure. But this is not a mandatory rule. The wall material can be anything - brick, aerated concrete, foam concrete, etc. In this case, wooden beams often crash into the mauerlat - wooden beam, running along the perimeter of the walls and connected to them using anchor bolts or studs.

Flat roofing is especially attractive to developers because its horizontal surface can be used as usable area. Moreover, this is possible even for a roof with wooden beams at its base.

Of course, you shouldn’t use the freed up meters for a parking lot, swimming pool or tennis court. Still for similar projects a more monumental foundation is required. And here open terrace, observation deck, home greenhouse wooden beams will easily withstand. The main thing is to make the calculation correctly and not skimp on the thickness of the lumber.

Types of flat roofs on beams

On wooden floors You can build the following types of flat roofs:

unexploited;
exploited;
inversion

That is everything possible types- no limits.

Unused roof– ordinary, completed with a waterproofing finishing coating. It is intended solely to protect the premises from conditions environment and does not set itself other goals. It is forbidden to use it as a place of rest, move in large groups, or install terrace furniture and flowerpots. The covering of such a roof is designed for the fact that 1-2 people will periodically climb onto it, solely for maintenance of the structure.

Operable roof- already more interesting and more complex. In addition to its direct protective functions, such a roof plays the role of additional usable space for the homeowner. The design pie ends not with waterproofing (prone to damage), but protective coating– paving stones, decking, wooden flooring, paving slabs, turf layer, crushed stone or gravel.

Inversion roof– inverted roofing, a qualitatively different option. It can be either exploited or unexploited. Its peculiarity is the inverted order of placing layers in the pie. If in a conventional roof the waterproofing is laid on top of the insulation, then in an inversion roof the opposite is true. The waterproofing lies under the insulation, and the vapor barrier is completely excluded from the structure of the cake. Due to this, the waterproofing is protected from the street environment and its service life is increased.

However, under the influence of unfavorable street conditions turns out to be insulation, so the choice of this type of insulation in inversion roofs is limited. Only EPS (extruded polystyrene foam) and nothing more! This material has virtually zero water absorption, high density and strength. On top of the EPS in inversion roofs is loaded with washed gravel, paving stones, paving slabs or a turf layer.

An interesting option for exploited roofs (including inversion ones) is green roof . It can also be supported on wooden beams. The pie of such a roof ends with a soil layer on which plants are planted. There are other elements that are not used for other types of roofs: a drainage layer (gravel, expanded clay, crushed pumice or geomats), a filtration layer (geotextile).

Flat roof frame on a wooden base

The frame of the described roofs is made of wooden beams laid like an interfloor ceiling. Full-size timber lumber or composite lumber (laminated veneer lumber) can be used. Often beams are made from boards with a section of 100x150 mm.

The beams are laid with support on the walls, similar to interfloor ceilings. If the building is wooden or frame, then the beams rest on the upper crown of logs or the upper frame. If it is brick or block, then on a pre-fixed Mauerlat. A timber with a cross section of 150x150 mm or 150x100 mm is usually used as a Mauerlat. It is mounted on the upper chord of the walls using anchors or studs. To protect the wooden Mauerlat from the wall material, 1-2 layers of waterproofing (roofing felt) are laid between them.

Cuts are made on the beams under the Mauerlat, they are laid and secured with metal corners or nails. The pitch between the beams is maintained at 50-120 mm (depending on the calculated load).

When installing beams, it is important to ensure a roof slope of 1-6°. Despite the fact that the roof is called flat, it is not absolutely horizontal. Slight slope necessary to ensure the movement of water to the drain and thus prevent it from stagnation.

You can create the required slope in the following ways:

Immediately lay the beams with the desired slope. Then, if a horizontal ceiling is supposed to be installed under the roof in the room, it is made suspended or sewn onto a horizontal sheathing.
Lay the beams horizontally, and nail wooden plates of different heights to them to maintain the required angle.
Lay the beams horizontally, and form the angle using different thicknesses of thermal insulation laid on top of the frame.
Use beams with unequal allowance in height.

Most often, the first option is used, that is, the beams are immediately laid with a slope. The easiest way to do this is to fasten along the top load-bearing wall a strong purlin made of timber or boards that will lift the frame (beams) on one side. Instead of a transverse purlin, you can also install short radial beams extending from the central double diagonal beam.

Flat roof pie: what's inside?

A flat roof pie on a wooden frame can have a different structure. There are many design options, many of them are posted on the Internet. And they will all work!

Option 1. Roof with insulation over beams

Flat roof insulation layers can be laid on top of the beams. For example, a proven working option (classic roofing with insulation):

floor beams;
vapor barrier;
waterproofing material – polymer membrane.

When using EPPS insulation and PVC membranes simultaneously in the structure, it is necessary to lay separation layer(geotextile, fiberglass). The fact is that these two materials are incompatible and when they come into direct contact, the PVC is destroyed.

The polymer membrane is fixed to the insulation mechanical method or loaded with ballast. Crushed stone or gravel (for all types of roofs), paving stones (for maintained roofs), and soil (for green maintained roofs) are used as ballast. However, when choosing ballast, you should soberly assess the reliability wooden frame, its maximum load.

If as finishing coating It is assumed that a built-up waterproofing or EPDM membrane with adhesive fixation will be used; a change is made to the scheme discussed above. It consists in laying sheets of plywood, OSB or DSP between the insulation and waterproofing.

This results in the following diagram:

floor beams;
lathing (if necessary);
continuous cladding made of plywood, CBPB, OSB;
vapor barrier;
insulation – EPPS, mineral wool;
plywood sheets, OSB, DSP;
waterproofing material.

Installation of a built-up roof traditionally requires the use of a gas burner, therefore, according to existing fire standards, it is not allowed wooden structures. Therefore, they act as follows. The first layer of waterproofing is nailed or glued to a wooden base, and the second layer is fused, as it should be. It is also convenient to use euroroofing felt with a special adhesive base, for which cold installation without heating with a torch is recommended.

The installation of a membrane roof on a wooden base is shown in the video:

Option #2. Roof with interbeam insulation

Another principle of assembling a flat roof pie is associated with laying insulation in the space between the beams. This option is more convenient than the first if EPDM membranes with adhesive fixation or fused roofing are used as waterproofing.

This scheme is often used roofing pie:

floor beams;
vapor barrier (between beams);
insulation (between beams);
lathing (if necessary);
continuous cladding made of plywood, CBPB, OSB;
waterproofing.

In principle, a similar system is used in the formation of classic pitched roofs.

Option #3. Roof with internal insulation

In this case, on load-bearing structure(beams) are sewn on sheets of plywood, OSB or DSP, and waterproofing is laid on them. The remaining insulating layers of the roofing pie are sewn on the side of the room.

A rough ceiling (made of boards or sheet materials) is fixed to the beams, perpendicular to it load-bearing beams, screw the planks in increments of 40 cm. Polystyrene foam boards are placed between the planks, gluing them to mastic or glue. Hemmed to the insulating layer vapor barrier film. Cover the insulation cake with a finished ceiling.

Or you can go against all “traditional” solutions and build an inversion roof on beams. Due to the fact that the waterproofing will be covered with insulation, that is, protected from loads, exposure to oxygen, UV rays and precipitation, its service life is significantly increased.

When constructing an inversion roof, you can use the following diagram (from bottom to top):

beams;
continuous sheathing;
waterproofing;
separating layer (when using PVC membrane as waterproofing);
EPPS insulation;
separating layer – geotextile;
ballast, paving slabs, decking, etc.

The principle of inversion roofing is often used to install green roofs. For example, you can do this:

What topcoat should I use?

The wooden base of a flat roof, along with its advantages, also has features with a minus sign. This is an increased fire hazard and low load bearing capacity(compared to reinforced concrete slabs).

To waterproof such a roof, it is advisable to use materials that do not require hot installation. Ideally, polymer membranes. When choosing built-up bitumen-polymer coatings (from the Euroroofing felt series), the first layer of material is installed mechanically, and the second - by fusing. In order to minimize the possibility of fire in structures during installation, it is recommended to use non-combustible CBPB boards as continuous cladding (on which the waterproofing is laid).

When constructing serviceable and ballasted roofs, it should also be remembered that excessive load for wooden base can be fatal. Therefore, if the load-bearing capacity of the beams used is small, lightweight materials should be selected for the finishing coating - decking, deck board, rubber paving slabs(rubber mats), etc.

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, a do-it-yourself flat roof must meet strict requirements building codes to 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:

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.
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. Used as a simple vapor barrier plastic film or bitumen-based coatings.
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 thermal conductivity and low hygroscopicity, light weight.
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 for any linear meter of 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

In case they are building personal home with a flat roof, which is going to be connected to the 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 provided internal drain, the water must flow through the slope into water-collecting funnels, which are located 1 per 25 square meters 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 roof surface, causing leaks and destruction of the roof.

Video instruction

Many people are accustomed to thinking that flat roofs are usually erected only on multi-storey buildings and industrial buildings. However, recently this type of roofing has increasingly become used in the construction of private houses. A flat roof in a private house can be constructed without difficulty, taking into account modern technologies and a variety of building materials.

There are 4 types of them:

Exploited. Main feature of this type, the base is sufficiently powerful, otherwise there is a risk of damage to the waterproofing layer. Corrugated sheeting or concrete screed acting as a base allows you to create required slope for arranging a drainage system. Thermal insulation on such a roof must be resistant to serious loads. This is all done in order to use the roof of the house in some capacity, be it a work platform or a recreation area.
Unexploited. Here, the rigidity of the base of the flat roof structure is not as important as in the above option. And the strength of the insulation also does not play a significant role. This roof is cheaper than the one in use, but it will also last a shorter period of time.
Traditional. A feature of their design is the periodicity of layers - waterproofing goes above thermal insulation. Here there is a reinforced concrete slab at the base, and an inclined expanded clay concrete screed is used for drainage.
Inversion. Flat roof installation this option has virtually no problems with water leaks. Here the thermal insulation is located above the waterproofing, which gives the latter protection from ultraviolet rays and the effects of temperature fluctuations. This roofing arrangement turns out to be the most durable and functional, which opens up a lot of possibilities for using the roof space.

Important! Angles in the range from 3 to 5 degrees are considered optimal for the slope of an inversion type of flat roof.

Advantages and disadvantages of this design

A flat roof in a private house, like other types of roofs, has a number of pros and cons. It is worth considering the advantages that determine its popularity in modern construction:

Smaller area than other types of roofing – which saves effort and money;
Convenience and safety of work - it is quite difficult to fall from a straight horizontal surface, and all the necessary tools are at hand;
Fast construction - as a consequence of the first two advantages, such work is done much faster;
Easy to maintain and replace roofing– dismantling of worn parts is usually not carried out, but a new cake is laid directly on the old one;
The use of additional territory - the arrangement of an exploitable roof opens up great prospects;
It is possible to install transparent roof elements - the view of the open sky on the ceiling is extremely tempting for many;
Giving your home a clear look geometric shapes– if the drawing of the house allows, then you can give it a unique look with the help of such a design, especially considering that minimalism is now extremely popular.

It is also worth mentioning the disadvantages of this design:

Snow and leaves accumulate periodically - sometimes mechanical cleaning of the roof is required;
A more complex structure - the presence of drains implies their inevitable blockages, especially in bad weather;
Regular monitoring - the moisture content of the insulation and the general condition of the roof must be constantly checked;

It is not surprising that some people may have doubts about the reliability of this type of structure. But judging by the experience of owners of private houses with similar roofing both in Russia and abroad, this type of roofing successfully functions and pleases its owners.

DIY flat roof installation

Now on the Internet you can find many photos of houses with flat roofs of a wide variety of designs. Interested in the question of how to make a flat roof with your own hands? Before you build a roof, you must first familiarize yourself with the drawing of the house and make sure of its technical characteristics.

The design features of a flat roof depend on many factors. If this is an unheated room and the roof is being erected with your own hands, then it is enough to install support beams, on which a base of uncut boards fastened with screws or nails is then laid. When installing a flat roof on a garage, roofing felt is often used as waterproofing due to its low cost. Apply strips of roofing material in the direction of the roof slope, securing them with wooden or steel slats. Creating a do-it-yourself flat roof for an unheated room is quite easy - here all the work can be done by one person without any help.

When installing a flat roof on a private house that is planned to be heated, the following procedure is customary:

Installation of floor beams. Strict adherence to horizontal alignment is necessary. Here and in subsequent stages, the participation of several workers will be required.
Flooring installation. Usually an uncut board with a thickness of no more than 5 cm is taken.

Important! The size of the lumber cross-section increases in proportion to the distance between the support beams.

Laying waterproofing.
Laying thermal insulation. In this case backfill insulation reinforced with a concrete screed, which dries for a couple of days.
After the screed has dried, a bitumen-based primer is applied to it, then roofing felt is laid and glued.

The structure of the roofing pie

In order to make the roof reliably protected from moisture, it is necessary to place materials in layers one above the other - this arrangement is extremely important. The standard base is made of concrete slabs or professional metal. It is able to withstand the weight of the entire structure above, transferring it to the load-bearing partitions, which, in turn, transfer it to the foundation of the house.

Important! The roof in use must have the strongest possible foundation.

Then come the standard layers: vapor barrier, thermal insulation and waterproofing. When choosing a flat roof roof, you should be guided by the preferences of the owner and the capabilities of the building itself. From a huge cottage to a small cozy house built many years ago, houses with a flat roof will be reliably protected from various environmental influences for many years.