Flat roof in a private house cons. Flat roof. What top coat to use

Many people are used to thinking that it is customary to erect flat roofs only on multi-storey buildings and industrial buildings. However, in Lately given view roofs are increasingly used in the construction of private houses. Flat roof in a private house it is easy to build, taking into account modern technologies and a variety of building materials.

They are distinguished by 4 types:

Exploited. The main feature of this type is a fairly strong base, otherwise there is a possibility of damage to the waterproofing layer. Decking or concrete screed, acting as a base, allow you to create the necessary slope for arranging the drain. Thermal insulation on such a roof must be resistant to severe loads. This is all done in order to use the roof of the house in any capacity, whether it be a working 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 variant. And the strength of the insulation also does not play a significant role. This roof is cheaper than the operated one, but it will also last a shorter period.
Traditional. A feature of their design is the frequency of layers - waterproofing goes above thermal insulation. Here, a reinforced concrete slab is located at the base, and an inclined expanded clay concrete screed is used for the drain.
Inversion. The flat roof device in this version has practically no problems with water leaks. Here the insulation is located above the waterproofing, which gives the latter protection from UV rays and the effects of temperature fluctuations. Such a roofing device turns out to be the most durable and functional, which opens up a lot of opportunities for using the roof space.

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

The 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 - and this saves effort and money;
Convenience and safety of work - it is quite difficult to fall from a straight horizontal surface, but all necessary tools are at hand;
Fast construction - as a consequence of the first two advantages, such work is done much faster;
Ease of maintenance and replacement of roofing - the dismantling of worn-out parts is usually not carried out, but a new pie is laid directly on the old one;
The use of additional territory - the arrangement of an exploited 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;
Making your home clear 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 periodically accumulate - sometimes mechanical cleaning of the roof is required;
A more complex structure - the presence of drains suggests their inevitable blockages, especially in bad weather;
Regular control - 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 a similar roof both in Russia and abroad, this type of roof 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 first need to 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 built by hand, then it is enough to install support beams, on which the base is then laid from uncut boards fastened with self-tapping screws or nails. When installing a flat roof on a garage, roofing material is often used as waterproofing due to its cheapness. Strips of roofing material are applied in the direction of the slope of the roof, fixing them with wooden or steel slats. A flat roof with your own hands on an unheated room is created quite easily - here all the work can be done by one person without anyone's help.

When installing a flat roof on private house, which is planned to be heated, is customary next order works:

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

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

Laying waterproofing.
Thermal insulation laying. In this case, the backfill insulation is 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 material is laid and glued.

The structure of the roofing cake

In order to make the roof reliably protected from moisture, it is necessary to place the materials in layers one above the other - this arrangement is extremely important. The standard base is made of concrete slabs or profiled 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 operated roof must have the most solid foundation.

Then there are 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 huge cottage to small cozy house built many years ago - houses with a flat roof will be reliably protected from various influences environment on the long years.

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

A house with a flat roof is reliably protected from increased wind load. But, not having slopes, he is not able to quickly divert 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 slip freely. Based on this, a self-assembled flat roof device must meet strict requirements building codes to waterproofing, slope and construction technology.

The structure of the roofing cake

The need for a high level of liquid protection forces roofing materials a flat roof in layers, one on top of the other, forming the so-called "pie". If you look at its device in section, it is possible to notice the following layers:

Flat base made from cement slabs or profiled metal pages. It provides the rigidity of the structure, carries the weight of the roofing cake, transferring it to the load-bearing partitions and, as a result, to the foundation. In the operating roof, the base should be as solid as possible.
Vapor barrier. The layer that is needed in order to protect the flat roof from the penetration of vapors from the inner heated rooms into the thickness of the insulation. By settling on the thermal insulation in the form of condensate, water will irreversibly reduce its insulating properties by more than half. Used as a simple vapor barrier plastic wrap or coatings based on bitumen.
Insulation. For thermal insulation of a flat roof, filling materials are used, such as expanded clay, perlite, slag, roll materials, for example, mineral wool and in the form of plates, in particular expanded polystyrene. By the way, insulation is used not only for regulation temperature regime, but also for the spreading of a house with a flat roof. The main requirements for insulation are thermal conductivity and low hygroscopicity, light weight.
Waterproofing. A flat roof can be used for covering to protect against liquids roll materials: bituminous, polymer and bitumen-polymer. In addition to high waterproofing qualities, they must be resistant to temperature changes, elasticity, and long service life.

nuances and types of roofing their installation

The flat roof design determines the nature and design of the application. In certain types that require a special approach during construction, the following are distinguished:

Installation of a roof for unheated buildings

If a flat roof is being erected with your own hands for an unheated utility room, for example, a shed, gazebo, shed or annex, the slope is organized by means of support beams. They are installed at an angle of 3 degrees, which forms 30 mm for any linear meter of the beam length. After that, a base is laid on the beams from unedged boards, securing them with nails or self-tapping screws.

Roofing material is used as a waterproofing agent - the most affordable material. It is created and sold in the form of rolls. They cut the waterproofing by cutting the strips so as to lay them in the direction of the slope of the flat roof. Roofing material strips 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. A flat roof of an unheated room can be easily assembled with your own hands, in addition, by one worker without the help of helpers.

Installation of roofs for heated buildings

If they are building a private house 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 bar with a section of 150x150 mm or more, or a metal I-beam, is used for the manufacture of support beams.

Monolithic concrete roof

Another option, how to build a flat roof with your own hands - application monolithic concrete... The process looks like this:

The unclassing process

Flat roof slope - device small corner roof surfaces for the organization of the drain. Before building a house with a flat roof, it is better to decide in advance what kind of gutter you will be installing, internal or external, and make a drawing. If an internal drain is provided, the water by means of a slope must drain into the water-catching funnels, which are located at 1 per 25 square meters or more often. If you make an external drain, then the moisture must get into the gutter. The deflection is formed in the following ways:

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

Video instruction

For many, a flat roof is associated with urban multi-storey buildings, faceless and monotonous. But we are ready to surprise you! A flat roof in a private house will be a pleasant discovery for you if there is not too much snow in your area, but the winds are strong enough. The fact is that in winter all snow accumulations from such a roof will simply be blown away. And the main thing is that not a single strong hurricane can blow off the roof, which simply does not exist! And also a whole ocean of possibilities opens up before you, which now you can build over your head: a cafe, a dance floor, a mini-garden and even a whole greenhouse!

The main thing is just to know about all the intricacies of the arrangement of houses with a flat roof, and everything will work out. And we will reveal all the secrets now.

Such a roof is much smaller in area than the flattest pitched roof. And this is saving on materials.
Such a roof is being built much faster than a gable and even more hip.
Comfort and safety of all rafter work. You still need to manage to fall from such a roof!
Convenient subsequent repair and replacement of roofing.
Unlike a gable roof, dismantling the old flat roofing is usually not necessary - this is additional waterproofing and protection. The new cake is made just like the old one, which saves a lot of time and effort.
The ability to use the roof as an additional useful area where you can set up a flower garden, make open terrace and even build a greenhouse.
The ability to install transparent roof elements (with careful waterproofing), and thus make a view of the night sky.
Possibility to build a house with a laconic architectural form. Minimalism is at the height of fashion!

And now - about the cons and disadvantages:

Such a roof generously accumulates snow in itself. After all, he now has nowhere to slide, and the snow itself often becomes the cause of leaks.
On especially generous days, the snow will have to be mechanically removed, which often damages the roofing.
The structure of the roof is becoming more complicated: now gutters are needed, which, in addition to everything, also clog up.
The difference is that water drains off the pitched roof quickly enough (and it happens that it does get into the under-roof space). But on a flat one, it generally stands!
Control of the moisture content of the insulation and the general condition of the roof should be regular.
But, despite the fact that for her arrangement building materials much less is needed than for a pitched roof, a flat roof in terms of installation is much more complicated. Let's just say, there are many more different subtleties and nuances that are important to know about.

That is why many have fair doubts about the reliability of such a roof. But the European and overseas experience of private residential houses with a flat roof is successful, and therefore you can safely get down to business.

Consider only such points:

There is much more snow in Russia than in warmer European countries.
The only thing worse than snow is the big difference between summer and winter temperatures, for which not all foreign roofing materials are designed.

And here technology decides everything!

What is a flat roof?

So, what acts as the supporting base of a flat roof:

Reinforced concrete slab.
Roofing sandwich panels.
Reinforced steel sheet.

And thanks to the fact that they learned to make a flat roof "breathable", i.e. with internal ventilation, now it has become possible to use completely non-breathing waterproofing - roofing material similar to it.

Any roof that we call flat, in fact, still has a slight slope: to one side or purposefully towards the drainpipe.

Here is the simplest example of a flat roof for a private house:

Types of flat roofs: unexploited and inverted

Of course, unexploited roofs are cheaper. And the exploited ones, which are correctly called "inversion", include additional materials.

A separate type of flat roof of a residential building is exploited. Those. the one on which people will walk and what objects will stand. This is the same garden, or sports ground, or outdoor cafe. All this creates considerable loads on the roof, and therefore its device is already different from that which is intended only to protect the house from precipitation.

So, the main difference in the structure of traditional and inverted roofing is that in the first layer of thermal insulation is located under the waterproofing, which is quite logical, and in the second - above it. But in the second version, the waterproofing is more protected from ultraviolet rays and temperature extremes. This design is more durable and functional: you can safely arrange a lawn or lay paving slabs on it.

And now in more detail.

Unused roofing: standard pie

But on an unexploited roof, a person can also occasionally climb - for the same repair, for example.

Those. in a traditional flat roof top layer waterproofing serves, and it is she who is subjected to all mechanical and thermal stress.

A separate type of it is a roof with a pressure layer, which is designed for a person to walk on it from time to time:

Inverted roofing: reverse pie

The standard slope of the inverted roof is 5-7%. The inversion method assumes that the layer of thermal insulation is already located on top of the waterproofing, which now also serves as a vapor barrier at the same time.

Moreover, the pie of inversion flat roofs can be very different. It all depends on what you are going to arrange on the roof: a terrace, a mini-pool (and this is not uncommon) or a garden. But the base will still be common: a monolithic screed is made, which levels the entire surface, then waterproofing is laid and all this is covered with insulation. And on top already - cement-sand mixture or rubber cover.

Note that the active operation of the roof is frequent damage to the insulating layer, due to which moisture makes its way to the insulation and freezes in winter. Over time, the whole deteriorates roofing cake, and therefore a flat roof ventilation system is indispensable.

Cement-sand screed is able to even better distribute the layer of pressure on the heat insulator, but it must be additionally reinforced with a grid against cracking.

Subtleties of flat roof insulation

A layer of thermal insulation for a flat roof is required. For comparison: gable roof insulate only when equipped under it residential attic, and in all other cases, the maximum is laid mineral wool on the attic floor. But for a flat roof, insulation is always necessary.

The fact is that without a heat-insulating layer in a flat roof, condensation will constantly appear on the ceiling in the house (such a roof will just be the cold part onto which water vapor will rush). And this is bad not only because repairs will have to be done, but also because the whole structure deteriorates.

You can insulate a flat roof both from the outside and from the inside - the difference is small. More importantly, in how many layers a particular roof needs to be insulated - in one or two.

Thermal insulation materials you need to attach to the base of the roof mechanically, both screws or dowels, and glue. Sometimes the mount is not used at all if the heat insulator is located from the outside, and paving slabs or pebbles are pressing on it.

Why two layers? The fact is that the first layer of thermal insulation on a flat roof performs the function of insulation, it is from 70 to 200 mm thick. And the second, from 40 to 50 mm, is designed to distribute all the loads. And the thickness of both layers is important to calculate accurately, based on the climatic features of the area and the future use of the roof itself.

With two-layer insulation, all joints should be staggered, in a checkerboard pattern, so as not to fall on each other. Moreover, in the places where the plates adjoin the walls and the parapet, it is additionally necessary to make heat-insulating sides. A cement-sand screed is able to even better distribute the pressure layer on the heat insulator, but it must be additionally reinforced with a grid against cracking.

Correct drainage system

But this is already a difficult task. Flat roofs are bad because they are completely open to rain. But everything can be solved! The main thing is to correctly organize the drain, and for convenience, we have opened this issue for you in the following schematic illustrations:

Internal ventilation device

Another important point when arranging flat roofs - ventilation. The fact is that if moisture accidentally enters the insulation, it no longer evaporates - it only accumulates. As a result, the insulating material rots, and the waterproofing swells. And there are many reasons for leaks: broken waterproofing, mechanical damage to the upper layer of the roof, cracks and harm from frozen water.

A damp heat insulator is also bad because of it, bubbles and cracks appear on a flat roof in the summer heat - all due to the active evaporation of water. As a result, the roofing also collapses. And if moisture eventually gets under the old screed, then the entire roof begins to flake off. This is why a flat roof needs to "breathe".

For this purpose, the so-called aerators are used on it. It looks like simple plastic or metal pipes covered with umbrella caps. They should be placed evenly over the entire roof area, preferably at its highest points. The essence of such a mechanism is that different pressures are created inside the roof and the air begins to create flows, simultaneously capturing all excess moisture vapor.

In practice, it looks like this:

In addition, in any living space, water vapor rises up to the ceiling. Moreover, they often successfully overcome this barrier (the water molecule is very small) and get into the insulation, which is bad for him. That is why vapor barrier is required. And not the one that is usually used to insulate the attic, but dense, made of high-quality polypropylene or polyethylene. A bituminous membrane is even more reliable.

Choosing the right roof covering

So what is used as a coating for these roofs?

Option # 1 - bitumen and polymer-bitumen materials

Such roofs are the cheapest for the owners of private houses. Primarily it comes about roofing material and euroruberoid. These are rolled roofing sheets, based on - synthetic fabric, and on the sides - bitumen. As an elastic and frost-resistant material, bitumen serves as an excellent protection and waterproofing.

Moreover, the installation of bituminous roofing on a flat roof is absolutely simple, you only need gas-burner... The rolls are easily fused together.

But such a roof has a significant drawback - fragility. And also the fact that the roofing material does not breathe at all, i.e. it is vapor-tight, and therefore it is imperative to arrange ventilation for such a roof, unless you want the insulation to rot in a year:

Option # 2 - liquid rubber

Such roofs have the huge advantage that they do not contain any seams. As we have already said, the minus of a flat roof is, first of all, that snow accumulates on it, which then causes leaks.

But there are some subtleties here. So, liquid rubber for a flat roof, you only need to take a two-component, preferably the highest quality. And it is extremely important to correctly apply this material to a flat roof: evenly, avoiding unnecessary layers and savings in certain places. So, where the paint was applied unevenly, problems should be expected after 8-10 years.

Option # 3 - PVC, TPO and EPDM membranes

Roofing membranes are valuable as a covering for flat roofs in that they allow steam to escape to the outside. After all, whatever the vapor barrier used, moisture still at least a little, but gets into the insulation, and not only from below, but also from above - after heavy rains, for example.

There are three types of membranes for the device of such a roof: TPO, PVC and EPDM. The most popular is PVC membrane, it is also the most flammable. The EPDM membrane is more durable and affordable, but if mechanical damage occurs in it, nothing can fix it, while the PVC membrane can be melted with a hair dryer. In addition, the joints of the EPDM membrane must be glued with a special tape, which is much less reliable than the welding of PVC sheets.

But the cheapest membrane in its sector is PVC. But it has such significant disadvantages as low resistance to ultraviolet rays and fear of contact with bitumen, various oils and even styrofoam, otherwise the service life is significantly reduced.

Bonding EPDM membranes requires professional skills. TPO membrane, like PVC, is also hot air weldable. It is not afraid of ultraviolet light, it is more chemically resistant and can be stacked directly on polystyrene foam or old bituminous roof without geotextile. But its service life is shorter than that of EPDM, therefore, for the flat roof of a residential private house, we recommend using a PVC membrane.

So, the cake of a flat roof device with a PVC membrane is traditionally made like this:

Step 1. We arrange a monolithic floor slab.
Step 2. We put a tear-resistant vapor barrier film.
Step 3. We make a slope of insulation or screed.
Step 4. We put insulation. In private construction, this is usually 35 density foam, and on top is XPS at 50 mm, which is even stronger.
Step 5. Now geotextile, 300-500 g per square meter.
Step 6. Moving on to waterproofing - this is the PVC membrane. The density of the insulation is enough to walk on such a roof. But, if you plan to make an open terrace on the roof, then the pie needs to be continued further.
Step 7. Again, lay geotextile - now directly on the membrane.
We put rubber tiles or a reinforced screed 5-7 cm, on which we already put the paving slabs. Ballast is required to make a screed.

And also such roofs are made of rubber, polymers or even foil. Unlike bituminous ones, they are durable, fire-resistant and firmly adhered to the base. Reach a slight slope using expanded clay or concrete screed.

How to achieve 100% waterproofing?

The main task when installing a flat roof is to make all joints and abutments as tight as possible. Indeed, such a roof is most affected by moisture, hail, temperature extremes and debris carried by the wind. Therefore, the sealants used for sealing such joints must be of high quality and resistant to any influences. This is also a kind of expense that you have to go to.

For the same purpose of waterproofing, it is recommended to make a flat roof slope of at least 2%. Few? In fact, this is quite enough so that all atmospheric moisture does not linger on the surface, but flows down into funnels and pipes, and from them into a septic tank, soil or sewer. Therefore, even at the design stage, you need to think carefully about the future drainage system.

Moreover, the drainage itself is made both internal and external. So, the internal drainage system consists of fittings - funnels located throughout the roof, which take in the flowing water and direct it into pipes that go through buildings, but are isolated from living quarters. The only disadvantage of such a system is that the pipes are clogged with small debris and leaves, for which it is advisable to equip them with special filters and periodically clean them.

External drainage systems are already fixed along the outer walls of the building. Of course, it is easier to clean these when they get clogged, but in cold weather they often freeze over. For which it is customary to additionally supply them with electric heating in the form of cables.

As for the material for internal and external drainage system flat roof, then PVC or metal is fine. Both options have their pros and cons. So, polyvinyl chloride does not corrode, but it is more fragile than metal.

In order to prevent the gutters from freezing in winter, equip them with roofing thermal cables.

Green area on the roof: fashionable and sustainable

Greenery and recreation areas are often lacking not only for the inhabitants of the "stone jungle", but even for the owners of private houses. The thing is that the same beautiful garden furniture it is not always possible to leave the house in the yard, and beautiful rare flowers in the garden bed are often trampled by pets. Therefore, it is not surprising that the green area on the roof has become fashionable among the owners of cottages. Especially if the exit to it goes directly from the bedroom and no one else can disturb your morning peace with a cup of coffee.

There is also a fashion for some cafes to make the roof flat, and put a small greenhouse on it. All the greens are immediately on the table! And it is beneficial, because bringing fresh dill or onions to the kitchen is not so easy, and it is economically profitable - there is where to send kitchen waste. And it's hard to know who borrowed this idea from whom: the enterprising inhabitants of private houses with flat roofs, or the best minds of public catering. But what is the location closed ground profitable is a fact: rodents will not dig under the beds, insects and pests will not get there (as well as pests in the form of neighbors), and the fact that it is always a little hotter on the roof is only a plus for the same tomatoes. But the main thing is to correctly calculate the loads on such a roof during construction!

And the roofing pie is often standard: waterproofing on the floor, thermal insulation, geotextiles, drainage and again geotextiles. And on top of it, you can already have both the ground and the beds:

Or in this version for more powerful floors:

A flat roof is a huge space for any imagination. Designers and architects love to implement a variety of projects for her: a garden, a greenhouse, a jogging track, a mini-beach with sun loungers, and much more. Some craftsmen even manage to make a parking lot on it!

A house with a flat roof, in a series 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. Admirers of the "cubic" design are captivated by the wow effect and increased attention from the neighbors. Someone wants to place on the roof engineering equipment, or lay out a lawn and equip places to rest. Still others believe that it is cheaper and easier to build a house with a flat roof than with a pitched one. Is it really? Consider the main pros and cons of these buildings and conclude whether they are suitable for our country. And for this we will answer the following questions:

Why is it difficult to choose suitable site under the "cubic" cottage
Is it true that flat roofs are not for our climate
Why is a flat roof leaking?
A flat roof is easier and cheaper than a pitched roof - this is a myth.
Why flat roofs are difficult to repair

1. House with a flat roof and domestic realities

Most of the country dwellers are skeptical about cottages with a flat roof, calling these houses "boxes". Why? Houses with a flat roof came to us from abroad. Traditionally, they were built in countries with warm climates, where there is practically no winter, heavy snowfalls, severe frosts with sudden thaws, prolonged rains, but they blow strong winds... For example, somewhere on the Mediterranean coast. Then these houses turned into fashionable design The erratic trend "not for everyone" in Western Europe, and from there they have already come to us.

Tretin FORUMHOUSE user

I see that we mainly build houses with pitched roofs. But, is it really necessary? In Germany and Switzerland, projects of houses with a flat roof have been proposed for a long time. What are the disadvantages of a flat roof, except for the imaginary unaesthetic look?

Indeed, can anyone leave indifferent a cottage with panoramic windows in the photo below?

Or such a high-tech flat-roofed house in a forest.

Or a cottage, on the roof of which an observation deck is made, a lawn is laid out and a place for rest is equipped.

Now imagine these houses with us. Harsh winter. In an ordinary - not an elite village, where roads float in spring and autumn, and areas are fenced with a professional sheet. Houses are en masse with siding or cladding facing brick... And pitched roofs are covered with slate, metal tiles or, less often, a more expensive solution - flexible tiles. The picture does not add up. Something's missing, isn't it? I no longer want to sit on the flat roof of the house, as I dreamed, with a cup of tea or coffee. After all, from there you can see not the ocean, sea, mountains or nature untouched by man, but the dense village buildings or, at best, fields overgrown with grass.

A house with a flat roof, in high-tech style, looks advantageous only on a spacious, isolated area, for example, on a slope, with beautiful view on a forest, lake or river. A flat-roofed cottage is lost without landscape design, and among solid, but similar houses, it looks like a "white crow".

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

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

2. Reliability of a flat roof in our climate

When you look at beautiful houses that are more than one hundred years old, ask yourself why they were built this way and not otherwise. Why do houses built in the coastal zone somewhere in Norway, Sweden or Scotland have no overhangs and the usual drainage system? They are simply not needed because of the strong winds that turn rain into a horizontal stream of water hitting the walls. Likewise with flat-roofed houses. They were built in a warm climate, where there is little rainfall, but a strong wind load.

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

dmitrievich-50 FORUMHOUSE user

Our ancestors - smart people... They considered the construction of the house from the point of view of practicality, based on the climatic conditions of residence. Why were flat roofs built in Central Asia? Are they pitched on the Central Russian Upland? In the Baltics, not just pitched, but with an acute ridge angle? A pitched roof with a slope of 45 degrees, in the Moscow region or in 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 of the house from precipitation and will not leak.

The only question is how much will cost 1 sq. m of such a roof with a guarantee that it will not flow quickly with frequent transitions through 0. Icing. Nighttime freezing and daytime thawing of snow cover. Lingering showers. And most importantly - how to make such a roof so that it will serve for 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 FORUMHOUSE Member

The firm built a flat-roofed house for me. 6 pieces were made around the edges. heated funnels and brought out to the sides, through the parapet, drain pipes... Is it correct? Maybe it was necessary to make a slope to the center and, when small area roofs, put two funnels instead of six? And put the pipe inside the building. Withdraw in the plinth and further into storm sewer? I am afraid that the knee, which is brought out of the funnel into the street, will freeze. The ice on the pipes has already formed. What if the pipe bursts due to frost? How to fix it? Throw 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 water disposal, another one was added. When link82 I came to check the house and found that the roof was leaking in several places. Water went from the second floor to the first. All the drywall swam. Now you have to argue with the builders. Try to take the money, and completely redo the roof. According to Michael-snabss(the user of the portal is professionally engaged in the construction of flat roofs) in this example it is assembled whole bouquet mistakes. The main one is builders who simply do not know how to make flat roofs correctly.

When building a house with a flat roof, do not pursue cheapness. Each step of the builders and the stage of work needs strict control. More careful than when erecting a pitched one. Mistakes are costly!

The roof was most likely made of hardfaced waterproofing material- glass insulation. The tree played and the fiberglass tore. Repair of 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. How to use and combine materials with each other. What tools are needed for this. Even if the future owner of a flat roof house has a detailed project, and he should be, then everything can be spoiled by "specialists" who work according to the principle: "we always build this way and no one has ever complained!"

Flat roofing should only be done by professionals.

4. Is a flat roof cheaper and easier 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? Less floor space means less material wasted. It is easier to make the overlap, because the classic rafter system is not needed. No need to equip attic floor etc. And it's true, but as they say, the point is in the little things.

If we simply consider the "pie" of a flat roof, then on the base, for example concrete floor slabs, are laid:

vapor barrier;
thermal insulation;
waterproofing.

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

waterproofing;
thermal insulation;
finishing layer.

In an inverted flat roof, the waterproofing layer is located under the insulation and "works" in more gentle conditions, because from above, from negative impact weather conditions, it is protected by gravel, tiles or soil with a lawn. Those. a ballast flat roof is arranged.

But, when building a flat roof, it is necessary:

Organize slopes for water drainage - about 2 cm per 1 running meter. Slopes are usually made with a concrete screed or wedge-shaped insulation elements.
Lay several layers of insulation. If used stone wool rather than extruded polystyrene foam, supply aerators to remove water vapor from the thermal insulation.
Put electrically heated water inlets otherwise, due to the formed ice, they will not drain the water from the roof.

One water intake funnel, 110 mm in diameter, removes water from an area of up to 300 square meters. m.

Mount the downpipe with a slope of 3 cm per 1 running meter.
High-quality waterproofing made of PVC, TPO or expensive EPDM membranes. TPO membranes are less elastic than PVC membranes, but at the same time they have higher strength. Welding TPO membranes requires professional fitters with special equipment... The advantage of EPDM membranes is the 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 the region of residence. For example, Moscow and St. Petersburg belong to the third climatic region. Snow load on a flat roof, with a slope of 2%, in the Moscow region will be 180 kg per 1 sq. m. In the fourth climatic region snow load 240 kg per 1 sq. m, and in the fifth 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 packed 350 kg. A cube of wet or melting snow weighs approximately 400-600 kg.

It is not necessary to clean off snow from a correctly calculated flat roof in winter. The excess is blown away by the wind, and loose snow becomes a heat insulator.

But, the load on a flat roof must be considered with a greater margin than on a pitched roof, taking into account force majeure. For example, the water intake funnels are clogged, the heating cable burned out, and the water did not leave the roof. In a couple of days, the monthly norm of snow fell, but there was no wind to blow it off and it lies on the roof. The additional weight on the roof puts pressure on the walls, which in turn transfer the load to the foundation, which redistributes it to the subgrade. The farther north, the greater the load. Add a mass of crushed stone or soil with grass if a ballast flat roof is arranged.

Hence - the optimal construction of a cottage with a flat roof is not a frame or a wooden house, but a stone structure, calculated by the designer and built of aerated concrete, bricks, warm ceramics, using monolithic technology. Because "Cubic" design allows for large unsupported spaces, then blocking the span of more than 6 m with a tree will no longer work. Truss required, I-beams wooden beams, hollow reinforced concrete floor slabs, monolithic floor or precast-monolithic floor... Do not forget to add expensive facade finishing solutions to the cost of a flat-roofed house.

You can't do a house like that cheaply.

Planken, burnt wood, hand-molded bricks are used, wet facade, combined facades 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 of the parapets, which also need to be insulated and trimmed. This increases the cost of construction.

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

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

5. Low maintainability of a flat roof

sv2321 FORUMHOUSE user

I have a flat roofed house. Waterproofing - with a membrane. I'm suffering with the roof. As they say, water will always find a hole. I like the flat roof, but I think I will abandon it and convert it to a pitched one, although I will 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 microcracks and gone. If there is a bias, then small defects not critical;
Snow lingers on a flat roof. It melts. Water fills in microcracks. Frost hit at night. The water is frozen. With frequent daily freeze-thaw cycles, microcracks increase, then break. They are getting bigger. The pitched roof has no welded areas and there is nothing to tear. 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 never know exactly where the defect is. There is a leak in one place, and water from the ceiling is dripping in a completely different place. The craftsmen will come, check the joints and find one of the defects, and the rest will remain. If the roof is inverted or laden with gravel, then troubleshooting is an even bigger problem.

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

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

If leaks pitched roof with a cold attic, it is not difficult to find and repair the defective area. In extreme cases, you can dismantle the coating and perform local repairs or get to the problem area from the inside. In the case of a flat roof, leak detection and repair is complicated by a complex “pie”. Many layers in the structure, especially in the so-called. "Green roof". The presence of a concrete screed, etc.

conclusions

Houses with a flat roof certainly look beautiful and stylish. Make a flat, problem-free roof that will last for many years in our climate also possible... The only question is the total cost of all decisions and its feasibility. Anyone who, in our climate, has been engaged in the installation or repair of a roof knows that in the summer, a roof hot in the sun - last place where I would like to sit with my family or friends. Hot and stuffy. I would like to quickly go into the shadows. If there are small children in the house, then an exploited flat roof is unnecessary. headache for parents. You can also organize a shaded private place to relax with barbecue on the site small area... It is pleasant to sunbathe in the garden on the grass, throwing a towel or spreading out a chaise longue, and not in full view of all neighbors and passers-by on the roof. Out of town corny wants solitude, and not stick out your private life for everyone to see. Let's add our changeable weather. Rain. The wind, which is felt at high altitude, is not at all the same as below. So, how many days in a year really will be left to relax on a flat roof? Let's add the need to arrange a place to go to the roof directly from the house. Do not climb the stairs on the flat roof, which is fixed to the facade. What remains? Unusual "fashionable" design to attract attention. Therefore, it is up to everyone to decide whether to build a house with a flat roof or not, and FORUMHOUSE offers you proven solutions for this.

how to properly build in our climate a house with a roof without overhangs with 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 structural features of a monolithic stone house with a flat roof and an unusual facade finish.

Flat roofs in our time are undeservedly forgotten and not spoiled by the attention of developers. In private housing construction, they are found mainly in the southern regions, where heavy rains and snowfalls are rare. Hipped roofs on the contrary, they are firmly entrenched in the designs and minds of homeowners.

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

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

Today, interest in flat roofs is starting to grow.

There are several reasons for this:

Economic benefit. The cost of the arrangement is lower than that of the tent (more simple construction and smaller area);
Additional effective area... There is a possibility of its rational use (flower garden, playground, recreation area, pool);
Accessibility in service and operation (cleaning of gutters, installation of air conditioners, antennas, inspection of the coating, ventilation and smoke channels);
The snow layer acts as additional thermal insulation, reducing heating costs.
Original appearance building.

Types of flat roofs

Strictly speaking, you will not see an absolutely flat roof on a building. Any of them has a minimum slope of 1 to 4%, necessary for the flow of atmospheric precipitation.

There are four types of flat roofs:

unexploited;
operated;
green (lawn);
combined.

Unexploited roofs are found on industrial buildings.

The exploited roofs have found application in public and private construction. They are used to equip recreation areas, place cafes and restaurants, and use them for parking lots and helipads.

Green (lawn) coatings are made to decorate buildings, as well as when there is a lack of space on the site. In addition to the aesthetic function, they perform an important practical task. The turf layer is an excellent heat and sound insulator.

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

By the way of drainage, houses with a flat roof are divided into two types:

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

An internal drainage system is cheaper than an external one, since it does not require a large number of gutters, pipes, funnels and high-rise works on their installation. It is more difficult to perform. Errors when creating a slope, poor-quality sealing of joints lead to leaks and a violation of the integrity of the protective layer of waterproofing.

In operation, flat coatings with internal drainage are more profitable. In winter, icicles do not grow on the overhangs near such a roof. Downpipes pass inside the building and therefore do not freeze. It is easier and easier to clean debris from funnels than hanging gutters.

Features of the device

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

Classic;
Inversion.

The classic roofing "pie" is equipped with the following technology:

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

Constructive of a classic flat roof

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

While working to solve this problem, engineers came up with the idea of inversion coverage. In it, the main structural elements (insulation and waterproof membrane) are interchanged. The waterproofing is hidden under the foam, which is protected from external influences by a gravel ballast or tile finish.

Inversion cover design

The technology of work is changing accordingly. A waterproof carpet made of roofing material or EPDM membrane is glued to the slab or spread on it, fixing it at the points of abutment to the parapet.

In this case, the slope is created in one of two ways:

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

Installation of thermal insulation on a flat roof

Inlet funnels and pipes are installed at the lowest points of the slope. In addition to them, ventilation is installed to remove water vapor that accumulates in the contact zone of the vapor barrier with the insulation.

When arranging a coating designed for planting, the construct is supplemented with an upper layer of waterproofing. Drainage layers of gravel are poured over it, geotextiles are laid and a fertile layer of earth is poured.

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

Construction technology in this case may include the following operations:

Beams are mounted on the walls with a pitch of 50-100 cm, fixing them to the masonry with anchor pins. The cross-section of the beams depends on the width of the span, the design load and can range from 10x20 cm to 15x25 cm;
OSB slabs are laid along the beams, tightly joining them together;
Spread the waterproofing membrane in 2 layers, gluing the joints of the canvases with high quality.
They make thermal insulation from durable (extruded) foam, gluing it to the membrane. The slope for water drainage is created by laying insulation in layers of different thicknesses;
From above, the heat insulator is protected cement screed reinforced with mesh or tiled.

Examples of private houses

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

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

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

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

The appearance of the facade of a one-story house with a flat roof compares favorably with the rather boring variations of the "terem" character.

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