Construction of flat roofs of various types. Flat roof in a private house Flat roof of a house: pros and cons

Not so long ago, such a fashion as a flat roof in a private house came to the CIS countries. Most developers did not consider this advisable and continued the construction of pitched roofs. They can be understood, because several decades ago, when the quality of materials remained in doubt, the construction of a flat roof was carried out only on temporary structures. But today, when the quality of materials has improved significantly, it is foolish to refuse this type of roofing.

Flat roof roof pie

There is no point in saying once again that a residential building with a flat roof is reliably protected from the wind. As for moisture removal, roofers have also learned how to efficiently solve this problem. They realized that a small slope device would naturally remove excess moisture from the roof plane, but materials whose structure has different roughnesses could hinder this.

That is why installation work needs to be thought through in more detail, but it's worth it. After all, you save significantly on lumber and the time it takes to build a flat roof.

So, in order for all layers to perform their functions efficiently, they should be laid correctly. This is what a roofing pie should look like flat roof:

Base. As a rule, it is made of reinforced concrete slabs, but some use thick profiled metal. This component roofing pie will bear impressive loads, therefore, it should be made as stable as possible. Often flat roofs are made to be used, for example, a lawn is sown on the surface. If you plan to do anything similar with this plane, then check the base calculations several times
Vapor barrier layer. During operation, this component will play an important role. It will serve as protection against moisture vapor coming from the underlying floors. Remember that if moisture gets to the insulation boards, they will have to part with their positive qualities, therefore, this layer will become useless. To install a vapor barrier layer, as a rule, polyethylene film or bitumen is used, but developers who have the finances can afford a unidirectional membrane. It allows you to remove excess moisture from insulation and at the same time serve as protection for them
Thermal insulation layer. A flat roof differs from a pitched roof in that there is the possibility of laying unique materials, for example, backfill. They are perlite, slag, expanded clay, and so on, but in addition to them, this layer also includes slabs of mineral wool or polystyrene foam. By the way, roofers try to lay these materials in such a way as to give the roof some slope. As mentioned above, this allows atmospheric precipitation to be naturally removed from the roof plane. The requirements for this layer are as follows: low weight and low hygroscopicity
The most important component of a flat roof is waterproofing layer. It uses bitumen, polymer or mixed products. You can choose slightly different materials for yourself, but remember that in addition to waterproofing qualities, they must be resistant to sudden temperature changes, good elasticity and a long service life

The quality choice of materials and their installation will significantly influence how long a flat roof will last in a private home. It is worth understanding that the failure of at least one of them will certainly lead you to repair, therefore, be careful when selecting roofing materials as seriously as possible.

Types of flat roofs and the nuances of their installation

Before installing a flat roof for a private house, you should figure out what purpose you will pursue.

If you want to create a non-exploitable roof, then it is best to use profiled metal sheets. This will save you money and significantly affect the speed of the installation process. But if you are in doubt, it is best to immediately think through this option and resolve this issue
Operated roof implies that you will build some additional structure on its surface or arrange a pool or lawn here. This type roofs will be an excellent solution in buildings whose dimensions do not allow creating additional rooms. It is worth understanding that with the arrangement of the roof space, the load that puts pressure on the base will increase, therefore, the quality of it is laid reinforced concrete slabs. According to technical documents, the slope of such a roof should not exceed three degrees
Inversion. This type is a variation of the traditional one. Their difference lies in the fact that the inversion roofing cake is laid somewhat differently. Waterproofing changes with thermal insulation boards. This option is the most common in private construction, which is why architects offer it
Ventilated. Despite the fact that ventilation is more suitable for pitched roofs, flat ventilated roofing exists in construction. To do this, aerators are correctly placed on its surface, which, under a pressure difference, draw polluted air out and thereby circulate it. It is advisable to install them for large roof areas

Before starting construction, carefully consider all the details. As for load calculations, this work is best left to professionals.

Construction of flat roofs on unheated structures

If it is necessary to cover a temporary structure, for example, a barn, gazebo or canopy, a not very difficult structure is created. To regulate the slope, support beams are used. Tilt 3 cm per 1 linear meter slope, which, in fact, will be 3% will be quite enough for precipitation to be removed naturally.

The base for the roofing pie will be a solid wooden sheathing. By the way, for ventilation it is worth leaving a small distance of 1-3 millimeters between the boards. This will allow any condensation that occurs to be removed. Self-tapping screws or long nails are used as fastening elements.

The waterproofing layer on this structure will be a rolled material - roofing felt. This product is a very cheap material and its qualities are quite enough to cover a temporary structure and protect it from moisture for 10 years, and if repairs are required, then it is enough to buy a couple more rolls of roofing material and roll it again, on the old base.

The bituminous material is laid in layers. The overlap of the strips should be at least 10 centimeters. The coating is secured to the base by placing wooden or steel slats on its surface. Their installation should be carried out in such a way as not to interfere with the natural flow of water from the surface.

The construction of a flat roof on temporary buildings, as a rule, is not hard work which can be completed by one or two workers.

Construction of roofs on heated buildings

The installation of a flat roof of a private house in which heating is provided will proceed as follows:

First, the floor beams are installed. During this process, it is especially important to monitor the horizontal, so for the convenience and speed of the process, get a laser level.
Unedged wooden boards, the thickness of which is about 4-5 centimeters, are laid on the installed beams. If there is a very large distance between the installed support beams, then the cross-section of the boards must be increased to the required design value.
Strips of roofing material are rolled out onto the created base, but other material can be used as waterproofing. After cutting off unnecessary parts, some developers leave the bitumen product in this state for a day, but further work can be carried out without waiting this period. For a reliable connection, the joints of the strips are laid with a ten-centimeter overlap.
After waterproofing, as a rule, thermal insulation material is laid. You will remember that a backfill product is often used for flat roofs. Its design hides some dangers, because with a small mistake you can end up with huge puddles collecting on the surface of the roof, which will significantly reduce the life of your roof, so I recommend inviting a knowledgeable person to carry out this work.
Next, the plane is filled with a screed thickness, which should be at least 20 millimeters.
After the cement mass has hardened, the entire roofing surface is primed, and then the roofing covering is laid.

If you perform these layers with the highest quality, your roof will last even longer than the manufacturers of roofing products assure you.

Monolithic concrete as a roof

Besides known methods When constructing a flat roof in construction, a new method of creating a roof has recently appeared. So here you go technological process construction of a concrete roof.

Concrete is far from a lightweight building material, therefore, it is worth using appropriate products for floor beams. An I-beam steel beam with a thickness of 120-150 millimeters is ideal for its role. Their installation should be carried out without any slopes, ideally horizontally
Experienced developers recommend using a concrete grade of at least 250. It is best mixed in a concrete mixer installed on site. If you decide to mix the solution by hand, then most likely you will not achieve the desired consistency. Concrete is created in the following proportions: 4 buckets of fine crushed stone, one and a half buckets of cement, a bucket of sand and the required amount of water
The base is the same lumber located on the bottom shelf I-beam. Wooden elements should be protected from the solution with a waterproofing material, for example, roofing felt. After the waterproofing wraps the boards, it is laid on top reinforced mesh with cells 2x2 centimeters
The next layer is fine crushed stone, and then comes the prepared concrete

IMPORTANT: Complete the entire pouring process within one working day, otherwise there is a risk of cracks appearing on the future element.

Allow the screed to harden. She will do this in 1-2 days, in addition, do not forget to take care of the concrete, of course, if quality is important to you. To do this, wrap it with plastic wrap or, after some time, water this element with water.
After complete drying, the resulting surface is delivered bulk material– expanded clay. Next, they make a ramp and lay out a ballast sleeve from paving slabs

In this article, I mentioned the deflection quite a few times and probably not everyone knows what it is, so let me explain.

What is a slope

This process is typical only on flat roofs. It is arranged in order to ensure a natural gathering atmospheric precipitation from the roofing surface. As a rule, a flat roof is arranged with internal drain, but there are options where it will be external. Therefore, at the very beginning of construction, consider this moment and decide which drainage system will be more profitable for you.

If your choice fell on internal system drainage, then the slope is carried out so that water flows into special water-collecting funnels. Their number depends entirely on the dimensions of the roof plane, for example, 1-2 funnels are provided for a roof of 25 square meters.

When equipped external system drain, then using a slope, water is brought to the edges of the slopes, where the gutter is installed.

Deflection can be done in the following ways:

Create required slope using bulk material. Expanded clay or perlite are ideal for this. Having set the required slope, this material covered with a screed, and the roofing covering is laid on it
Thermal insulation boards are also able to set the required slope. But I believe that playing with laying this layer is much more complicated and expensive than purchasing expanded clay
Specially created formwork allows you to pour concrete so that it already has the required slope
The most in an expensive way deviation is considered a device plastic panels, which differ in thickness from each other. By laying them out in a certain sequence, you can achieve the required slope

Flat roof is an excellent solution for creative people. After all, this design will not only serve as an excellent protection for your comfort from bad weather, but will also give you additional square meters that you can use for your own purposes, for example, to equip your workshop for crafts on the roof.

By making special fences on the roof, you can build a rather interesting children's playground right on your roof! And if the options I have proposed do not suit you, then perhaps you will find a use for these square meters on your own.

There are many roof design options for a private home. Today, along with tent structures modern technologies and materials allow you to create flat options. It is worth considering in more detail what a house with a flat roof is, its design features, pros and cons.

Description

Traditionally, in temperate and northern latitudes, a hip roof with sloping slopes was erected, which prevented accumulation on the surface. snow cover and allowed heavy rainfall to flow down onto the storm drain system. Houses with a flat roof were common in the southern regions, where there was no heavy rains, and there was no snow at all in winter. But development construction technologies and appearance modern materials, especially waterproofing, made it possible to create a horizontal roof without any problems in any region, even in the Far North.

A flat roof is a ceiling that is located horizontally directly above the residential floors of a private house. Several layers of insulating materials that protect against moisture, cold and steam, as well as a drainage system, make it possible to create reliable upper protection in a one-, two- or three-story private house.

Don't be afraid of what's on the ceiling last floor leaks will appear, since with a competent approach and quality materials they are completely excluded. The main thing is to properly operate such a roof and promptly change the coating in accordance with the warranty period.

For buildings with a straight roof, functionality increases because the roof surface can be used. In many ways, the installation of such buildings is simplified compared to tented options, where it is necessary to erect a rafter system. They also have a lot of other advantages.

Principle and types of design

To begin with, it is worth noting that a flat roof in a private house is not strictly horizontal; in order to prevent water from accumulating and allowing it to drain, a surface slope of approximately 5-7° is provided. The principle here is the same as with spillways pitched roof– they are located at a slight slope, which is invisible from the ground, but allows all the accumulated moisture to flow into the drainpipe. The same is true on a flat roof: water collects in a certain place due to the unevenness of the surface, but the area looks horizontal; you can safely lay out a lawn on it or arrange an area for recreation.

The drainage system on such a roof contains special funnels, into which rainwater flows under the influence of gravity and then, using a system of hoses, goes into the sewer or underground. These devices are made of plastic that is not susceptible to moisture and rot, mounted in layers of insulation on the roof, and equipped with a protective mesh on top so that the neck and drains do not become clogged. One such water intake funnel is designed for approximately 100-150 square meters. m of roof area, from here you can calculate their total number. Usually for a small country house 1-2 pieces are enough.

A flat roof can be used or not. If it is practically not used, that is, it is climbed several times a year to check integrity and routine repairs, then the coating contains the following layers from bottom to top: thermal insulation, vapor barrier and waterproofing. The flooring technology here is almost the same as in residential multi-apartment and industrial buildings.

There are the following common types of unused flat roofs: corrugated and monolithic.

The first option is frame. First on concrete base a sheathing made of metal profiles or wooden beams is mounted, and the insulating materials. Then profiles are attached to the frame metal sheets. It's relative cheap option, easy to install, the design is lightweight. But it is practically impossible to walk on such a roof, because the profiles will sag and deform.

Monolithic coating for a flat roof contains several layers. Directly on concrete slab is laid vapor barrier film from hot bitumen, then comes mineral wool and waterproofing, and a cement-based screed reinforced with reinforced mesh is poured on top. Such an unused roof will have a lot of weight, but it will reliably protect the house from precipitation and cold.

Another option is if the roof is constantly in use, people walk on it, or there are some objects standing on it. Then the insulating layer changes order: first comes the waterproofing, on top of which the thermal insulation is installed. Therefore, such a roof is called inversion.

The order of laying materials is as follows: First, a bitumen-polymer membrane is placed on the floor slab, then a layer of thermal insulation made of penofol, penoplex or expanded polystyrene is laid. If you want to create a green lawn on the roof of your house, then a separating and filtering layer of geotextile is laid on top of these insulators, and then a fertile layer on which natural grass will grow.

Such a roof with a fertile layer can be used freely throughout warm period, with a properly installed drainage system, it is not afraid of rain. On the roof you can place a children's or sports ground, put sun loungers or benches, create flower beds and even have a picnic. Operable roofs with green coating are now common not only in country houses, but also in city houses.

The installation of a flat roof does not end with flooring and pouring insulating layers and laying drainage systems. For correct operation ventilation must be created. Moisture and its vapors can accumulate between the layers of insulation; later, when it freezes, the insulation cake can crack, bubbles appear on it, and peeling occurs. In order to avoid this, aerators are used - plastic or metal tubes with umbrella-shaped caps that are mounted inside the roofing. The air entering through them, due to the pressure difference, evaporates water vapor from the insulation layers, they remain completely dry.

Another important point After laying the flat roof, this is the construction of lightning protection. It should not be neglected, since, despite the low probability of occurrence, a thunderstorm can lead to the most catastrophic consequences in country house. The lightning protection mesh is installed inside the insulation layers, if they are not flammable, or if they are flammable, on top of them on special holders at a height of 10-12 cm from the surface. All nodes of this grid are connected into one lightning rod made of thick conductive wire, which goes to grounding.

Advantages and disadvantages

Low-rise buildings with a flat roof, built according to various projects, have been in use in our country for several years now. Reviews from owners who have lived in such houses for several years will help highlight all the advantages and disadvantages of such structures.

Their advantages are the following:

saving on materials - there is no need to build a complex rafter system, and roofing work is simplified;
speed of construction compared to gable slopes and even more so hip roofs;

ease of repair and replacement of roofing coverings;
the installation of a flat roof allows you to create a platform on it for various needs: a lawn, a recreation area with a gazebo, a gym, children's Corner etc.;

it is possible to install windows in the ceiling, this is very original project interior plus an additional source of natural light on the ceiling;
roofing work will be much safer than with a hip roof;
in case of strong gusts of wind there is no risk of failure of massive rafter structures and cladding.

Based on reviews from the owners of such houses, one can point out the disadvantages of a flat roof:

unlike tented structures, snow will accumulate on such roofs in winter in large volumes, which must be regularly removed manually;
installation of a drainage system is required;

it will be necessary to constantly monitor the integrity of the roof and the absence of leaks;
Despite the apparent ease of installation, the flooring of a flat roof has many nuances; the insulating layers and gutters must be done as correctly as possible, otherwise leaks cannot be avoided.

Many projects of private houses with a horizontal roof came from Europe, where the climate is milder. Therefore, such decisions must be adjusted in accordance with our more severe weather conditions.

What to make it from?

Flat roofing can be made from various materials, their choice depends on the design of the building itself.

If the house is made of brick, gas silicate or concrete blocks, then a reinforced concrete slab can be used as a roofing. In this case, the roof will be as durable as possible; bulky and heavy objects can be placed on it. This type of flooring material does not protect against moisture, so in any case you will have to make a layer of waterproofing from rolled bitumen or screed with a lower bitumen-polymer membrane.

Wooden roofing slabs similar designs will cost less than concrete ones, they can be made at suburban area yourself. A frame with beams is installed on the walls; planed beams 10x4 cm or others can be used as them, the main thing is that they are able to withstand the weight of future insulation and other objects located on the roof. The wood is treated with an antiseptic and fireproof solution. A timber roof can be covered with wood boards, boards or metal corrugated sheets.

Bitumen is traditionally used as waterproofing for houses with a flat roof. This organic material hydrocarbon-based, which is produced during the distillation of oil. It has excellent waterproofing properties, is not susceptible to moisture, rotting, and is not afraid of frost. The main disadvantage of bitumen is considered to be that it is not environmentally friendly - it contains harmful components and, when heated, emits Strong smell. Nevertheless, bitumen insulation is still in demand, including in the construction of houses with a flat roof.

Bitumen can be rolled or liquid. Typically, a combination of these two types is used for maximum effectiveness. First, the hot solution is poured onto the prepared, cleaned surface, then rolls of solid bitumen are rolled out onto the top. This combination allows you to close any microscopic cracks and cracks and reliably protects the roof from moisture.

There are other modern waterproofing materials that are cleaner and harmless than bitumen. These include, for example, euroruberoid. It is also made on a bitumen basis, but, thanks to the synthetic fabrics and polymers in its composition, it emits fewer harmful substances and odors. Euroroofing felt is produced in rolls; for strength, it is sprinkled with special mineral chips.

There is sprayable waterproofing for roofing in the form of powders and aerosols. It is applied to the surface using special equipment. Such mixtures are produced from plasticizers, cement, synthetic resins and hardeners. Their advantages are that they not only protect from moisture, but also reflect the sun's rays and do not allow steam to pass through.

Coating waterproofing is widely used to protect against precipitation. It, like liquid roofing felt, is applied to the roof surface with a roller or brush. Among such materials, emulsion, rubber, polymer mastics and primers are especially common.

There are options for bulk waterproofing in the form of granules, which absorb moisture well and prevent it from leaking into the living space. Examples include expanded clay and crushed stone. Their advantage is that no complicated installation is required - the granules simply rise to the roof level, scatter and evenly smooth over the surface.

Typically used as a vapor barrier layer plastic film 0.1-0.5 mm thick, which is laid across the entire width of the roof under the thermal insulation layer. To protect against the cold, many effective materials are used: mineral wool, polystyrene foam, penoplex, expanded polystyrene and others.

Continuous glass roofs are very impressive and impressive to look at. A transparent ceiling in a house visually enlarges the space, creates a unique airy atmosphere, and the rooms are always as bright as possible. It is not very difficult to install such ceilings; it is enough to create a frame from metal profiles or wooden frames and glaze it. But the operation of a glass roof becomes more complicated; in winter it is necessary to constantly clear it of snow cover. Therefore, it is best to make a continuous ceiling with small ceiling windows.

Design options

A flat roof can be installed either in a one or two-story house with a small area, or in a spacious cottage. In a large building, you can combine a pitched hipped roof with a horizontal one, for example, using it for an outbuilding or veranda. The shape of the roof can also be different: square, rectangular and more complex. The main thing with a non-standard project is to correctly calculate the slopes and drainage system so that moisture does not accumulate on the surface.

Air conditioners, ventilation systems, television antennas, communication boxes and other equipment can be located on the inversion flat roof. If the roof will be used as a platform for recreation or other active pastime, then it is necessary to install a fence along its edges.

Also, when installing such a roof, you should immediately take care of a convenient climb to the top with railings. There are many designs for inversion roofing with drawings that you can use as a guide when building your home.

Installation Instructions

Before constructing and arranging a flat roof, it is worth breaking down a step-by-step plan for all the work.

It starts with choosing the shape, type and materials for the ceiling. It is worth considering that the load on such a structure is always more intense than on tent options. Based on this, you need to make a drawing of the frame system with beams and floors. The sketch indicates geometric shapes, sizes, color, materials, necessary communications. It's best to have it right away visual representation about what the future roof for your home will look like.

For many, flat roofing 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 much snow in your area, but the winds are quite strong. 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 tear off a roof that simply does not exist! And a whole ocean of possibilities opens up before you, which you can now build above your head: a cafe, a dance floor, a mini-garden and even a whole greenhouse!

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

Such a roof is much smaller in area than the most gently sloping roof. And this means savings on materials.
Such a roof is built much faster than a gable roof, and even more so a hip roof.
Comfort and safety of all rafter work. You still have to manage to fall from such a roof!
Convenient subsequent repairs and replacement of roofing.
Unlike two pitched roof, dismantling the old flat covering is usually not necessary - this is additional waterproofing and protection. The new pie is made directly from 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 plant a flower garden, make open terrace and even build a greenhouse.
The ability to install transparent roof elements (with careful waterproofing), and thus create a view of the night sky.
Opportunity to build a house with a laconic architectural form. Minimalism is at the height of fashion!

And now – about the pros and cons:

Such a roof generously accumulates snow. After all, he now has nowhere to slide, and the snow itself often becomes the cause of leaks.
In particular generous days the snow will have to be removed mechanically, which often damages the roofing.
The structure of the roof becomes more complicated: now we need gutters, which also become clogged.
The difference is that water drains from a pitched roof quite quickly (and sometimes it does get into the under-roof space). But on a flat one it actually stands!
Monitoring the moisture content of the insulation and the general condition of the roof should be regular.
But, despite the fact that for its arrangement building materials you need much less than for a pitched roof; a flat roof is much more complex in terms of installation. Let's just say that 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 buildings with a flat roof is successful, and therefore you can safely get down to business.

Just consider these points:

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

And here technology decides everything!

What is a flat roof?

So, what acts as the load-bearing base of a flat roof:

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

And thanks to the fact that they learned to make a flat roof “breathable”, i.e. With internal ventilation, it has now become possible to use completely non-breathable waterproofing - roofing felt similar to it.

Any roof that we call flat actually still has a slight slope: to one side or specifically towards the drainpipe.

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

Types of flat roofing: non-exploitable and inverted

Of course, unused 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 exploitable. Those. the one on which people will walk and what objects will stand. This is the same garden, or sports ground, or summer cafe. All this creates considerable loads on the roof, and therefore its design is already different from that which is intended only to protect the house from precipitation.

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

And now in more detail.

Unused roof: standard pie

But a person can also occasionally climb onto an unused roof - for the same repairs, for example.

Those. in a traditional flat roof, the top layer is waterproofing, and it is this that is exposed to all mechanical and temperature loads.

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

Inversion roofing: reverse pie

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

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 the whole thing is covered with insulation. And on top is a cement-sand mixture or rubber coating.

Note that active use of the roof means frequent damage to the insulating layer, which is why moisture makes its way to the insulation and freezes in winter. Over time, the entire roofing pie deteriorates, and therefore a flat roof cannot do without a ventilation system.

A cement-sand screed can even better distribute the pressure layer on the heat insulator, but it must be additionally reinforced with a mesh to prevent cracking.

Subtleties of flat roof insulation

A layer of thermal insulation for a flat roof is mandatory. For comparison: a gable roof is insulated only when a residential attic is installed underneath it, and in all other cases, a maximum of mineral wool is laid 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 turn out to be the cold part on which water vapor will rush). And this is bad not only because repairs will have to be made, but also because the entire structure deteriorates.

You can insulate a flat roof both from the outside and from the inside - the difference is small. What is more important is how many layers of insulation a particular roof needs – one or two.

Thermal insulation materials need to be attached to the base of the roof mechanically, both screws or dowels, and glue. Sometimes the fastening is not used at all if the heat insulator is located outside and paving slabs or pebbles press on it.

Why two layers? The fact is that the first layer of thermal insulation on a flat roof acts as 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 it is important to calculate the thickness of both layers accurately, based on the climatic characteristics of the area and the future use of the roof itself.

With double-layer insulation, all joints should be spaced apart, in a checkerboard pattern, so as not to overlap each other. Moreover, in the places where the slabs adjoin the walls and parapet, it is additionally necessary to make heat-insulating sides. A cement-sand screed can even better distribute the pressure layer on the heat insulator, but it must be additionally reinforced with a mesh to prevent cracking.

Proper drainage system

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

Internal ventilation device

Another important point when arranging flat roofs is ventilation. The fact is that if moisture accidentally gets into the insulation, it no longer evaporates - it only accumulates. Eventually heat insulating material rots and the waterproofing swells. And there are many reasons for leaks: damaged waterproofing, mechanical damage to the top layer of the roof, cracks and damage from frozen water.

A wet thermal insulator is also bad because it causes summer heat Bubbles and cracks appear - all due to the active evaporation of water. As a result, the roof covering also collapses. And if moisture gets under the old screed over time, then the entire roof begins to peel off. This is why a flat roof must “breathe”.

For this purpose, so-called aerators are used. They look like simple plastic or metal pipes covered with umbrella caps. They should be located evenly over the entire roof area, preferably at its highest points. The essence of this mechanism is that different pressures are created inside the roof and the air begins to create currents, simultaneously taking with it all the 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 end up in the insulation, which is bad for it. This is why vapor barrier is required. And not the kind that is usually used for attic insulation, but a dense one, made of high-quality polypropylene or polyethylene. The bitumen membrane is even more reliable.

Choosing a suitable roofing covering

So, what is used as a coating for such roofs?

Option #1 – bitumen and polymer-bitumen materials

Such roofs are the least expensive for owners of private houses. Mostly we're talking about about roofing felt and euroroofing felt. These are rolled roofing sheets, the base of which is synthetic fabric, and the sides are bitumen. As an elastic and frost-resistant material, bitumen serves as excellent protection and waterproofing.

Moreover, laying bitumen 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 another thing is that roofing felt does not breathe at all, i.e. It is vapor-tight, and therefore it is necessary to arrange ventilation for such a roof, unless you want the insulation to rot within a year:

Option #2 – liquid rubber

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

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

Option #3 – PVC, TPO and EPDM membranes

Roofing membranes are valuable as a covering for flat roofs because they allow steam to escape. After all, no matter what kind of vapor barrier is used, moisture still, at least a little, gets into the insulation, not only from below, but also from above - after heavy rains, for example.

There are three types of membranes for installing such a roof: TPO, PVC and EPDM. The most popular is PVC membrane, which is also the most flammable. An EPDM membrane is more durable and affordable, but if mechanical damage occurs in it, nothing can be done to fix it, whereas a PVC membrane can only be melted with a hairdryer. In addition, the joints of the EPDM membrane must be glued with a special tape, which is much less reliable than soldering 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 polystyrene foam, otherwise the service life will be significantly reduced.

Gluing EPDM membranes requires professional skills. TPO membrane, like PVC, is also welded with hot air. The best is not afraid of ultraviolet radiation, is more chemically resistant and can be laid directly on polystyrene foam or an old bitumen roof without geotextiles. But its service life is shorter than that of EPDM, so for installing a flat roof on a residential private house, we recommend using a PVC membrane.

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

Step 1. We arrange a monolithic floor slab.
Step 2. Place a tear-resistant vapor barrier film.
Step 3. We make a bend from insulation or screed.
Step 4. Place insulation. In private construction this is usually 35 density foam, and on top is 50 mm XPS, which is even stronger.
Step 5. Now geotextiles, 300-500 g per square meter.
Step 6. Let's move on to waterproofing - this is a PVC membrane. The insulation density is enough to allow walking on such a roof. But, if you plan to make an open terrace on the roof, then you need to continue the pie further.
Step 7. Lay the geotextile again - now directly on the membrane.
We lay rubber tiles or reinforced screed 5-7 cm, on which we already lay paving slabs. To make a screed, you need ballast.

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

How to achieve 100% waterproofing?

The main task when installing a flat roof is to make all joints and junctions as airtight as possible. After all, such a roof is most affected by moisture, hail, temperature changes and wind-blown debris. Therefore, the sealants used to seal such joints must be of high quality and resistant to any influences. This is also a kind of expense that has to be incurred.

For the same purpose of waterproofing, it is recommended to make the slope of a flat roof 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 the septic tank, soil or sewerage system. Therefore, even at the design stage, you need to carefully think through the future drainage system.

Moreover, the drainage system itself is made both internal and external. Thus, internal drainage is made up of fittings - funnels located throughout the roof, which receive the flowing water and direct it into pipes that go through the buildings, but are isolated from the living quarters. The only disadvantage of such a system is that the pipes become 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 attached to the outer walls of the building. These are, of course, easier to clean when they become clogged, but in cold weather they often freeze over. For this reason, it is customary to additionally supply them with electrical heating in the form of cables.

As for the material for the internal and external drainage system of a flat roof, PVC or metal is quite suitable. Both options have their pros and cons. Thus, polyvinyl chloride does not corrode, but is more brittle than metal.

To prevent gutters from freezing in winter, equip them with roofing thermal cables.

Green area on the roof: fashionable and environmentally friendly

Greenery and recreation areas are often lacking not only for residents of the “concrete jungle”, but even for owners of private houses. The whole point is that the same beautiful garden furniture It’s not always possible to leave it in the yard of the house, and beautiful rare flowers in the garden flower bed are often trampled by pets. Therefore, it is not surprising that the green area on the roof has become fashionable among cottage owners. Especially if the access to it comes directly from the bedroom and no one else can disturb your morning peace with a cup of coffee.

There has also become a fashion for some cafes to make the roof flat and place small greenhouse. All the greens go straight to the table! And it’s profitable, because it’s not so easy to bring fresh dill or onions to the kitchen, and it’s economically profitable - there’s somewhere to send kitchen waste. And it’s difficult to understand who borrowed this idea from whom: enterprising residents of private houses with a flat roof, or the best minds Catering. But the fact that such an arrangement of closed ground is beneficial is a fact: rodents will not dig under the beds, insects and pests will not reach (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 for the ceiling, thermal insulation, geotextiles, drainage and geotextiles again. And on top you can use both soil and beds:

Or in this version for more powerful floors:

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

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A do-it-yourself flat roof is most often located on private low-rise buildings, as well as on garage buildings. This type of roofing device is ahead of its competitors. In our article we will tell you why.

Before we talk about how to make a flat roof, we note that the term “roof” and the term “roof” are not the same thing. The term “roof” refers to those elements that are located above the living space of the house. And the roof is a component of the roof, its upper layer. It is this that protects the entire building from the effects of atmospheric influences. In these conditions, it is very important to create a reliable roof for a country house.

Having become familiar with the difference between the terms, we can state that a flat roof is perfect option for home with small area. If the roofing area is large, it is recommended to work as a whole team.

Flat roof and its features

When working on a small house with a small roof area, you can easily do without assistants.

At the beginning of work, secure wooden beams or steel beams to the supporting frames. With their help, you can reduce most of the roof's mass, directing it towards the main walls and foundation.

So, we found out that the main load on the beams is the weight of the roof. But besides this, there are other loads, such as:

Total weight roofing and communication elements. As a rule, they are located in the attic or attached to the roof.
The weight of the person who is repairing the roof or roof. It can also install optional equipment.
Volume and mass of snow + cold winter wind pressure.

Read the advice of experts on forums, look at photos on the Internet - then you will be able to make the right choice of load-bearing beams and avoid critical mistakes. Surely you will be interested in the article flat roof - pros and cons.

If you want to get a reliable and safe flat roof, then choose only a suitable roofing covering (more details: " "). It is also important to select accompanying materials that can withstand heavy physical activity, as well as the impact of natural disasters.

Don't forget to check everyone technical characteristics materials. To prevent negative consequences– carry out thorough hydro- and vapor barrier.

Place a “pie” of several materials on the slabs (they should have different properties).
The first layer is a vapor barrier. Its function is to protect the insulating layer from moisture. Polymer-bitumen film is used as a vapor barrier material. At the same time, it is often reinforced with fiberglass, and then a flat roof is installed. Place the edges of the film on the verticals of the floors. It is very important to carefully and accurately seal the seams, and also to understand.
Lay insulation on top of the vapor barrier. If expanded clay is used, fill it with a mass of concrete. When constructing a lightweight roof, the polymer insulation must be attached directly to the vapor barrier.
Moisture insulation is the main layer for a roof without slopes. To construct this element you will need membrane or polymer-bitumen materials.

Do-it-yourself flat roofing for cold rooms

There are buildings that do not have heating. These include sheds and gazebos. It is supposed to create a slope on them to drain water from the roof. To do this, you just need to equip the roof at the smallest angle.

When constructing a sloping flat roof, its support beams should be positioned at a slight angle. Boards will be attached to the beams. This will be a kind of basis for rolled roofing felt (more details: "").

To install a rolled roofing felt carpet, you will need a frame made of boards. For this, it is best to use thin wooden planks or steel strips. Secure them along the slope. In this case, the step should be 70 cm. But you should not block the path of water flowing from the roof. The slope percentage of such a roof is no more than 3%. In other words, this is 3 cm per linear meter of length.

Construction of flat roofs for warm rooms

Let's consider the nuances when equipping a flat roof for heated houses:

First of all, lay a layer of boards on load-bearing beams, having previously completed . After this, the roofing felt or roofing material should be laid. Their canvases should be arranged using the overlapping method. In this case, the length should be 15 cm.
Expanded clay is laid on top of the roofing felt (you can use slag or other material). Before filling in the insulation, check that the slope is directed towards the drainage direction.
The third stage is pouring the insulating layer with cement. After preparing the screed, treat it with a bitumen primer.
Only a completely finished screed will be ready to accept rolled roofing felt.

As you study the construction of a flat roof, you will see for yourself that roofs with large pitches between support beams require the participation of several people. It is advisable to invite professional craftsmen who as soon as possible will carry out all the necessary work.

When attaching support beams, the distance between them should be maintained. It should be no more than 1 m.

Installation of a flat roof made of monolithic concrete

The first step is to calculate the roof span. If it is 5 m, then 15 cm beams are used. Speaking in professional construction language, this is the “fifteenth I-beam”.

To create a monolithic roof, it is recommended to use concrete grade 250. When creating concrete mortar on site construction work, it is advisable to use a concrete mixer. Otherwise, you are unlikely to achieve the correct consistency of the solution. To obtain concrete for a flat roof, you need to mix crushed stone with 20 mm particles and cement, grade PTs-400.

When calculating the components, adhere to the following rules: for eight buckets of crushed stone - three buckets of cement, 4 buckets of sand, and two buckets of water. If there is not enough water, you can add more, this is not critical.

Insulating a flat roof with foam concrete, watch the video:

Next, the boards are fastened to the lower beam shelves. Roofing felt is laid on the dry surface of the boards. Then, a reinforced mesh of a periodic profile is laid on top. The diameter of this element should not be less than 1 cm. The size of the cells is 20x20 cm.

In order not to carry out repairs to the flat roof, the places where the mesh rods are overlayed are secured using binding wire. An option using glue is possible. Ultimately, the mesh should not slide off when pouring the screed.

For complete coverage with concrete mortar, small pieces of crushed stone are usually laid out at the bottom of the mesh. Thanks to this, a gap of 4 cm is left. It is necessary to differentiate the mesh and the roofing material layer. Pouring is done into the openings between the beams. Let us remind you that their thickness must be at least 15 cm.

After all the steps, the concrete is covered with a polyethylene film. This is especially true if work is carried out at high temperatures. By covering the surface, you will prevent moisture from evaporating from the concrete solution. This in turn will protect the top layer from cracking.

The concrete should remain under the film for at least three days. After the concrete mass has completely dried, add a layer of insulation. Don't forget about slopes. The next step is to create a screed and install the rolled carpet.

Insulating a flat roof

Today, a common phenomenon is the replacement of a flat roof with a pitched one. However, a flat roof is favored by the fact that it can be insulated both from the outside and from the inside. And after it is completed.

Previously, solid insulation boards were used for insulation. However, with this option the roofing weight increased significantly. Having studied past experience, modern construction moved away from this method of insulation. Today, flat roofs are most often insulated using basalt mineral wool. It's pretty lightweight material. In addition, it boasts good thermal conductivity and moisture resistance.

Note that basalt mineral wool is not subject to combustion processes. In addition, it fully tolerates even the most negative influences of nature.

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

In this article

Types of flat roofs

Any building construction are divided into separate types and subspecies. So, for example, for some flat roofs country houses provided attic space, for others no. Therefore they are classified:

By purpose:

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

recreation areas, lawns, flower beds;
greenhouse or winter garden;
children's and sports ground;
parking;
pool;

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

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

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

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

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

By type of construction:

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

For arranging the roofing pie:

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

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

Advantages, disadvantages of flat roofing

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

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

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

Important! To prevent precipitation from remaining on the surface of the flat roof, minimum angle its inclination should be 5°. This slope can be created by overlapping or using slag or expanded clay.

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

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

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

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

Important! Using only high quality building materials.