Do-it-yourself flat roofing. Flat roofs - their types and designs

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 should be thought out in more detail, but it is 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 flat roof roofing pie should look like:

• Base. As a rule, it is made of reinforced concrete slabs, but some use thick profiled metal. This component of the 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 it will last. flat roof in a private house. It is worth understanding that the failure of at least one of them will certainly lead you to repairs, therefore, take the selection of 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. By 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. A slope of 3 cm per 1 linear meter of the 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.

Flooring bitumen material happens 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.

Constructing a flat roof on temporary structures is generally not a complex job that 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 timber is laid on the installed beams. wooden planks, the thickness of which is about 4-5 centimeters. 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, it is usually laid thermal insulation material. 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

In addition to the well-known methods of constructing a flat roof, a new method of creating a roof has recently appeared in construction. So here you go technological process construction of a concrete roof.

• Concrete is far from light construction material, therefore, it is worth using appropriate products as 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 required amount water
• The base is the same lumber located on the bottom flange of the I-beam. Wooden elements should be protected from the mortar with 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, bulk material - expanded clay - is delivered to the resulting surface. 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 the natural drainage of precipitation from the roofing surface. As a rule, a flat roof is equipped with an internal drain, but there are options where it will be external. Therefore, at the very beginning of construction, builds to think over this moment, and decide which drain will be more beneficial 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 an external drainage system is installed, 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 the required slope using bulk material. Expanded clay or perlite are ideal for this. Having set the required slope, this material is 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 expensive method of tilting is the installation of plastic panels, which differ in thickness from each other. By laying them out in a certain sequence, you can achieve the required slope

A 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.

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

A house with a flat roof is reliably protected from increased wind loads. But, without slopes, it does not have the ability to quickly drain rain and melt water from the roof surface. The situation is complicated by the fact that the surface of the roofing materials has a rough structure, which does not allow moisture and snow to slide freely. Based on this, a do-it-yourself flat roof must meet strict requirements building codes to waterproofing, slope and construction technology.

The structure of the roofing pie

The need for a high level of protection from liquids makes it necessary to place roofing materials flat roof in layers, one above the other, forming a so-called “pie”. If you examine its cross-sectional structure, you will notice the following layers:

1. A flat base made of cement slabs or sheets of profiled metal. It provides rigidity to the structure, bears the weight of the roofing pie, transferring it to the load-bearing partitions and, ultimately, to the foundation. The base of the roof in use must be as solid as possible.
2. Vapor barrier. A layer that is needed to protect a flat roof from the penetration of vapors from internal heated rooms into the thickness of the insulation. When water settles on the thermal insulation in the form of condensation, it will irreversibly reduce its insulating properties by more than half. As a simple vapor barrier, polyethylene film or bitumen-based coatings are used.
3. Insulation. For thermal insulation of a flat roof, backfill materials are used, such as expanded clay, perlite, slag, rolled materials, for example, mineral wool and in the form of slabs, in particular polystyrene foam. By the way, insulation is used not only for regulation temperature regime, but also for bending over at home with flat roof. The main requirements for insulation are thermal conductivity and low hygroscopicity, light weight.
4. Waterproofing. Flat roofing allows the use of rolled materials for coating to protect against liquids: bitumen, polymer and bitumen-polymer. In addition to high waterproofing qualities, they must be resistant to temperature changes, elasticity, and have a long service life.

nuances and types of roofing of their installation

The design of a flat roof determines the nature and design of the application. IN individual species, requiring a special approach during construction, the following are distinguished:

Roof installation for unheated buildings

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

Roofing felt, the most affordable material, is used as a waterproofing agent. It is created and sold in the form of rolls. They cut the waterproofing by cutting strips so as to lay them in the direction of the slope of the flat roof. Strips of roofing felt are laid in stages with an overlap of 10-15 cm and fixed with wood slats or metal strips every 60-70 cm in the direction of the drain, so as not to block the path of the flowing liquid. Flat roof unheated room Easy to install with your own hands and also by one worker without the help of assistants.

Roof installation for heated structures

In case they are building personal home with a flat roof, which is going to be connected to the heating system, then the work takes place in the following sequence:

In order to build a house with a flat roof, the length of which exceeds 6 m, a beam with a cross-section of 150x150 mm or more, or a metal I-beam, is used to make support beams.

Monolithic concrete roofing

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

Leaning process

Sloping a flat roof is the arrangement of a small angle of the roof surface to organize drainage. Before building a house with a flat roof, it is better to decide in advance which drain you will install, internal or external, and make a drawing. If an internal drain is provided, the water must flow through a slope into water-collecting funnels, which are located 1 per 25 sq.m or more often. If you make an external drain, moisture must enter the gutter. The slope is formed in the following ways:

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

Video instruction

Do-it-yourself flat roofs have become popular precisely because of their easy-to-build structure. Let's take a closer look at the process of constructing such a roof.

First step: flat roof house designs

Projects of houses with a flat roof and cottages are not popular enough in moderate climatic zone. Even an impeccable project can be spoiled by poor-quality installation work and the use of low-quality materials.

Unfortunately, innovative technologies and materials appear in the post-Soviet space much later than in other countries.

If you decide to build such a shelter, then it is better to entrust the creation of its design, especially on a residential building, to specialists. There are certain subtleties of installation and operation of such roofs that must be taken into account in the project. Thus, the following processes must be justified:

1. Cleaning. Indeed, snow and water can accumulate on the roofing surface of a flat roof. If mistakes were made during its design and construction, then all precipitation will gradually begin to flow into the house, and can even significantly damage the ceiling.

Therefore, if you want to build such a roof with your own hands, you need to remember this at the design stage, especially when calculating the slope of the future roof. Even the smallest, visually invisible slope is enough to ensure effective water drainage. It is more difficult for such a roof to cope with winter snow deposits when roofs with the steepest slope, let alone almost flat ones, cannot cope with them. Snow, as a result of alternating thaws and frosts, turns into an ice crust on the roof.

There are 2 ways out of this situation: mechanical cleaning of the roof and installation of various heating and anti-icing systems, otherwise leaks will appear. Any design developments are calculated and included in the project.

1. Thermal insulation. A roof with a classic structure, with a pitched system at its base, has a layer of air in the attic, which provides insulation of the house building from above. A do-it-yourself flat roof has virtually no attic and, accordingly, no air gap. Therefore, roofs require additional high-quality insulation and the creation of a thermal insulation layer, which is reflected in the project.
2. Easy to install. It is easier to build a flat roof with your own hands than a gable, hip, hip or half-hip roof. She does not have truss structure, no skates or runs. But this roof requires more high-quality installation roofing to prevent leaks.
3. Application. The flat roof of the house can be used as a terrace, recreation area, sports ground or even a swimming pool. It is enough to equip the sides to ensure the safe stay of people. A modern building materials and technology makes it possible to arrange roofing lawn and plant various plants. This use may be especially useful in big cities when it is not possible to create a green area around housing construction. If the shelter is planned to be used not only for its intended purpose, this should be additionally calculated in the project.

Step two: installing a flat roof

Building a flat roof with your own hands is not difficult, so even one builder can handle the roofing of a garage or outbuilding. Technologically, for the construction of such a roof it is assumed that beams made of metal or wood will be used as the main load-bearing element, redistributing the load from the roof structure to the surface of the main walls. The roof must withstand:

• load in the form of the entire roof, all its elements and communications placed on it;
• the weight of the builder carrying out the inspection or restoration work;
• the weight of snow falling on its surface in winter.

When calculating roofing flat design, (especially when calculating its reliability), it is necessary to remember that the load of fallen snow may be too great, since the roof will not have sloped surfaces from which the mass of snow could fall down.

The minimal cost of purchasing building materials makes DIY flat roof construction one of the most inexpensive roofing projects. The basis for arranging such a roof is, as a rule, reinforced concrete. For this, floor slabs or a monolith are used, on top of which all components of the roofing pie are installed. A layer of waterproofing is placed on the concrete, on which, in turn, insulation is laid. The thermal insulation layer is protected by laying another layer of waterproofing on top of it.

Step three: how to make a flat roof with your own hands for different rooms

The technology for constructing a flat roof with your own hands will depend on its further purpose. There are two types of structures for such roofs:

1. Roofs for unheated housing construction.
2. Type of roof used for heated buildings.

Roofs over unheated rooms must be made with a slope. Since even a slight slope of the roof will effectively get rid of moisture resulting from precipitation in the form of snow and rain. The structure of such a roof consists of load-bearing beams, on top of which a continuous plank flooring is placed. Roofing felt (or other flexible roofing building material) is laid on top of the deck in several layers, which serves as waterproofing. Distinctive feature roofs of this type are minimum costs for the purchase of building materials and minimal labor costs, however, the service life of a roof of this design is very short.

Rolled building materials must be fixed with slats with a laying step of 70 cm; the laid slats should not block the flow of precipitation from the roofing surface. The minimum slope of this type of roof should be 3° so that water drains on its own.

If the room over which you need to build a roof will be heated, you should choose an insulated type of roof.

Roofing pie such a roof consisting of several layers building materials, provides the necessary level of thermal insulation and protection of the insulation itself from moisture.

Construction technologies, insulated flat roofing structures a lot, but to build with your own hands you need to use the most simple options. The base of that roof is made up of beams on which the plank flooring is placed. Roofing material is laid on top of it with an overlap of 15 cm. Insulation made of expanded clay or slag is poured on top of it, and the direction of the slope must be taken into account.

After leveling the insulation, a 2-3 cm screed of Portland cement is made above it. This must be done so as not to inadvertently damage the roof as a result of winter snow removal. After the screed has dried, it is covered with a bitumen primer, and then a roll flexible roofing covering is laid.

It is important to take into account the distance between the support points of the load-bearing beams, since the reliability of the future structure depends on its value. If this value is more than 6 m, then it is better to entrust the construction of the roof professional builders. If the distance between the walls is less than 6 m, a 10x15 cm beam or an I-beam made of steel is used as a beam.

An alternative to timber flat roof construction is reinforced concrete. With such a roof, the main burden falls on the load-bearing steel I-beams.

These roofs do not have a frame. The reinforced concrete slab must be reinforced longitudinally and transversely, thus increasing the concrete's resistance to bending and damage.
If the roof span is less than 5 m, then beams with a height of no more than 15 cm are used to arrange the roof.

When a flat roof is built with your own hands from a cement-concrete mixture, you need to purchase sand, crushed stone and cement, and you will also need water. You can prepare the mixture by hand, but it is better to use a concrete mixer. The ratio of ingredients in the mixture varies and depends on the brand of cement. So for PC-400 grade cement the ratio of parts crushed stone-sand-cement will be 8:4:3 and 2 parts water.

Formwork is made from unedged boards. They are laid end to end along the lower edges of the I-beams, then roofing felt is laid. Next stage work is the laying of a reinforcing structure consisting of reinforcement, which is placed both along and across the beams. For these purposes, steel rods with a diameter of at least 1 cm are used. The pitch for mesh elements made of reinforcement should be 20 cm. The reinforcement is carefully fixed with steel wire or welding to prevent displacement of the elements during the process of pouring the structure.

Concrete is poured different ways, but always until the entire surface of the roof under construction is covered with concrete. The laid mixture is carefully compacted (so as not to damage the structure) with a vibrator. The resulting structure is dried naturally.

During the construction of the roof modern house Thermal insulation must be installed to reduce the overall heat loss of house construction through the roof. Flat roofs can be insulated, unlike other types of roofs, both from the inside and outside. Initially, during construction, insulation is done on the outside, and the interior can be done later, when the structure is in use. Mineral construction wool is used as insulation. Also, another insulation material—expanded polystyrene—is becoming increasingly popular among builders. It is mounted on wooden blocks, which are placed in increments of 30-40 cm. And the slabs are glued to the wood with mastic or special glue.

The construction of a flat roof is completed by laying waterproofing. Usually they use special material sold in rolls.

The flexible roof covering itself is laid with an overlap of 7-10 cm.

Important: each layer of flexible roofing building material is laid in such a way that the bottom seams of the elements of the rolled flexible building material are placed closer to the middle. All coating strips are laid in the same direction.

Video instruction

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Houses with a flat roof - options and projects

Recently, there has been growing interest in projects of low-rise houses with a flat roof. Architects and developers are attracted to these unusual buildings, where you can equip an observation deck or even set up a real hanging garden. Of course, in practice everything turns out to be more complicated than in theory.

Designing a flat roof raises many questions regarding its cost, choice of materials for insulation and waterproofing, organization of water flow, maintenance and operation of the roof. Finding answers to them is not so easy. The fact is that domestic row companies working in the field of cottage and country house construction, the most popular design - pitched - is well known, but, as a rule, they have no experience in constructing flat roofs, which are designed completely differently.

Which roof will be cheaper?

What immediately attracts attention is the fact that the area of ​​a flat roof is smaller than a pitched roof, which means that less materials will be required, and the work will be cheaper. However, this statement is only true for regions with a warm climate and low snow load, especially if we are talking about an unused roof. IN middle lane In Russia, to ensure the reliability and durability of a horizontal roof, it is necessary to apply rather expensive engineering solutions.

It turns out that 1 m 2 of a flat concrete or steel base, the load-bearing capacity of which will allow it to withstand the weight of snow cover, costs 2-2.5 times more than a wooden beam structure pitched roof. The difference in the volumetric consumption of insulation is leveled due to the fact that a flat roof requires more expensive high-density material. There is still hope to save on roofing, but modern polymer membranes - the optimal waterproofing for horizontal roofs - are no cheaper (and sometimes much more expensive) than flexible tiles.

There is no need to install snow guards, but you cannot do without a roof hatch and a drainage system. If you try to cut costs according to the estimate, you will subsequently have to pay the price of having to repair the roof every 10-15 years.

Finally, it should be noted that flat roofs are only suitable for houses modern architecture- with a large glazing area and sophisticated finishing with the latest facade materials. That and the other one won't be cheap at all.

Flat roof covering

As a rule, in low-rise housing construction, the flat roofing is a prefabricated or monolithic reinforced concrete slab.

Reinforced concrete slabs (PB, hollow PC, PV, etc.) are capable of covering a span of up to 9 m in length and can withstand a pressure of 8, 9 or 12.5 kPa (this value is indicated by the last digit in the product labeling). They can serve as a “base” for any roofing pies, including those with a top layer of paving slabs or fertile soil. However, to install the structure, it will be necessary to ensure that a truck crane can enter the site (while steel beams and flooring can be easily lifted using winches). The depth of support of the ceiling on the wall depends on the material of the latter - for example, for brick this parameter should be equal to the thickness of the slab. Before proceeding with the installation of the roof, it is important to seal the joints of the elements with mortar and additionally seal them with elastic polymer tape. A monolithic floor is erected from heavy concrete using removable (for example, from OSB boards on jack stands) or permanent (from corrugated sheeting) formwork. It is reinforced with a two- or four-level welded frame made of rods with a diameter of 12 mm. Dimensions monolithic slab are not regulated (unlike prefabricated), which provides the architect with freedom when designing a building; other advantages are the absence of seams, the comparative simplicity of the installation of passage units (chimney, ventilation ducts) and high load-bearing capacity (subject to compliance with technological regulations).

Beam floor

In principle, when constructing a floor, you can use a combination of beams (wooden, steel) and load-bearing corrugated sheeting. However, experts do not recommend using wooden beams(except for those made of LVL timber with a cross-section of 200 * 100 mm) in regions where the snow cover pressure exceeds 1.2 kPa (about 120 kgf/m2) - that is, in most of the territory of the Russian Federation. A roof covering made of steel I-beams and corrugated sheets with a wave height of 60 mm and a wall thickness of 0.7 mm allows you to cover a span of up to 12 m and can withstand a pressure of at least 6 kPa. But in general, it is less durable than concrete, and is relatively rarely used in individual construction. It makes more sense to use corrugated sheets as permanent formwork, which, by the way, does not replace the need to build a reinforcement cage.

Types of flat roof

In the low-rise sector, mostly flat roofs without attics are in demand, because the attic requires additional costs and disrupts the architectural proportions of the house. This means that the roof must protect against winter cold and summer heat. Wherein general feature flat roofs is that the heat-insulating layer is located on top of the supporting structure (in pitched roofs it is usually located between the rafters). If you insulate the room from below, the dew point may shift into the thickness of the ceiling, which will lead to a reduction in the service life of the latter.

The requirements for thermal insulation for flat roofs are: special requirements. The material must not only have a low thermal conductivity coefficient, but also have good resistance to mechanical loads - both distributed (pressure from the overlying layers of roofing cake, equipment, snow) and local ones that arise during installation. In addition, it is important that the material has hydrophobic properties and is non-flammable. At the moment, there are several ways to install thermal insulation: using mechanical fasteners, adhesive and free laying. In addition to traditional two-layer insulation, single-layer installation is becoming an increasingly popular solution.

As for roofing options, there are dozens of them. Suffice it to say that more than 40 “recipes” are given in SP 17.13330.2011 alone. At the same time, coating and insulation manufacturing companies are offering more and more new engineering solutions. However, they are always based on one of two circuit diagrams- traditional or inversion.

Traditional flat roof design in general terms it is as follows: laid on top of the load-bearing base vapor barrier film(polypropylene, polyethylene, 6-item-polymer), followed by insulation, for example, mineral wool slabs with a compressive strength at ten percent deformation of at least 30 kPa, in one or two layers with a total thickness of 200 mm. Above is a separating layer (for example, from polyethylene film), along which a reinforced slope-forming screed is poured (a flat roof must be given a slope of 2-3% towards the center or edges to ensure water drainage). The dried screed serves as the basis for a roll or mastic waterproofing coating.

Other options are also possible.

For example, a slope-forming screed can be located at the very bottom of the pie; in this case, the roof waterproofing is fixed with gravel ballast, paving slabs on supports or special dowels. Some materials, say the “RUF SLOPE” system (Rockwool) or “TechnoNIKOL Slope” allow you to do without a screed altogether: the slabs have variable thickness, and with their help it is not difficult to create smooth changes in level to ensure water drainage.

Flat roofs are divided into unexploited and exploited. The former visit only for inspection, prevention and repair; for this purpose they equip roof hatch to which it leads attic staircase. The roof in use in cottages most often serves as a terrace, that is, a durable wear-resistant coating must be laid on it, and the load-bearing base is designed for increased loads. A type of exploitation is a roof with landscaping, laid with a turf layer on top of the main thermal-hydro-insulating pie; Usually there are paths and a recreation area on it. A convenient exit to the roof in use should be provided, for example from a vestibule superstructure.

Inversion roof it is designed differently: in it, insulation resistant to constant exposure to water (usually extruded polystyrene foam - EPPS) is located on top of the waterproofing. At the same time, the latter is reliably protected from mechanical damage and is located in the positive temperature zone (freezing-thawing cycles are destructive for almost any material). It is easy to turn an inversion roof into a usable one, for example, by covering the insulation with a drainage layer of sand-gravel and laying paving slabs. The disadvantages of the design include more complex drainage. However, we need to talk about gutters separately.

For roofs in use, as well as roofs installed in regions with harsh climatic conditions, the inversion scheme is ideal. Since the waterproofing layer is located under the thermal insulation layer, it is protected from mechanical stress, as well as from temperature changes and UV radiation, which significantly extends its service life roofing system. Waterproofing materials based on modified bitumen must be laid in at least two layers - this technology is more common, and in addition, it allows you to level out possible errors when fusing the material. One layer is enough for a polymer membrane, and reliability is ensured by automatic welding equipment, which greatly increases the speed of work. In addition, when installing a polymer membrane, it is not used open flame, therefore the technology is considered safer.

Rolled materials based on modified bitumen are usually fused gas burner(a), while it is difficult to prevent minor flaws that could cause leakage (if the second layer is missing). The quality of welding of PVC coating strips (6) is much easier to control

Flat roof drainage and waterproofing system

The flat roof is equipped with a parapet (attic) 30-90 cm high, which helps ensure organized drainage of water; on a roof in use it also serves as a safety fence. At the same time, the design of gutters should be approached very responsibly, because if you make a mistake, a huge puddle can form above your head, which can lead to leaks and damage to supporting structures.

As a rule, the choice is made in favor of an internal drain. Such a system is less exposed to the atmosphere and is therefore more durable and reliable than an external one. Let's talk in more detail about its main elements. Water intake funnels are installed on low areas of the roof. As a rule, on roofs with an area of ​​up to 150 m2, two funnels are installed - the main one, connected to the riser, and the emergency one, with water discharged through a hole in the parapet. With an increase in the number of funnels and risers, the reliability of the system increases, but its cost also increases.

Flat roofs are in demand in modular construction. Among the advantages of this method are the affordable cost and high speed of construction of housing, as well as the possibility of gradually increasing its area

For inversion and green roofs, special funnels with drainage rings have been developed to collect moisture from the intermediate layers. Additional receivers must be equipped with electrical heating on the base self-regulating cable- then they will begin to properly perform their function during alternating thaws and frosts.

In a new type of system, the so-called siphon-vacuum system, special funnels are used to prevent air from being sucked into the water flow. Thanks to them, the speed of fluid movement in the pipe (and hence the throughput of the latter) increases, which makes it possible to reduce the diameter of the system elements. However, for low-rise buildings, the savings turn out to be insignificant; moreover, such systems require more accurate calculations than gravity systems.

The drain riser is made from sewer pipes- polypropylene, polyvinyl chloride, and it makes sense to use sound-absorbing products, for example RAUPIANO Plus (REHAU), or soundproof the riser, otherwise you will hear the murmur of water for hours. The riser is connected to the funnel using an elastic coupling. When laying pipes, the number of bends and the length of horizontal sections, which reduce the throughput of the system, should be minimized. A drainage pipe laid in the basement or insulated underground connects the riser to the rainwater drainage system or ensures the discharge of water into a linear drainage tray.

In the second case, there is a risk of clogging the outlet with ice, so the riser should be equipped with a “winter” outlet to the domestic sewer (the latter should be equipped with a water seal). The outlet pipe is cleaned through a collapsible connection or an inspection module.

When choosing the standard size of elements of a traditional gravity system, they proceed from the intensity of rain in a given area, focusing on SP 32.13330.2012.

Outdoor drainage system more vulnerable than the internal one, and also affects the appearance of the facades, but does not require the construction of holes in the roof and ceilings and does not eat usable area Houses. Water is discharged through parapet funnels or pipes embedded in the parapet, under which classic funnels are installed (as on pitched roof) and down pipes attached to the walls with brackets. When calculating, it is assumed that for each square meter The roof area should be 1-1.5 cm of the cross-section of the drainpipes. Elements of the external system can be made of PVC, steel, copper, zinc-titanium.

Flat roof landscaping

Since ancient times, turf-covered roofs have been used in countries with moderately cold and humid climates, and the green carpet performed the main moisture-protective function in them.

As part of the modern concept of a green roof, a layer of fertile soil with plants is needed to give unusual features to the appearance of the building, decorate the terrace roof and extend the life of the coating by protecting it from ultraviolet rays. In addition, it absorbs rainwater, unloading the gutters, dampens the sound of rain, protects the rooms on the upper floor from overheating in the summer and reduces heat loss in the winter. It is believed that landscaping almost doubles the life of a roof. Its disadvantages include increased load on bearing structures buildings and increasing construction costs.

In addition, a green carpet needs care, the intensity of which depends on the selected plant species. If you do not pay due attention to the plants, they will freeze and die from drought.

To green the roof, you should lay on top of the main waterproofing layer (in an inversion scheme - on top of the insulation) an additional cake made of materials that will ensure protection of the waterproofing layer from roots, filtration and drainage of rainwater. For these purposes, special films, dense geotextiles, gravel bedding or drainage and moisture storage membranes made of high-density polyethylene, for example PLANTER GEO or Delta-Floraxx, are used.

Then a mixture of minerals and fertilizers is poured - the so-called soil substrate. You can prepare it yourself by adding fine expanded clay (5-15%), sand (about 20 96) and fertilizers to a light soil mixture of neutral peat. As for plants, the easiest way is to limit yourself to meadow forbs and drought-resistant ground covers - sedum, herbaceous carnation, thyme.

They do not need to organize an irrigation system, and the thickness of the soil layer can be only 6-12 cm (this type of roof is called extensive). If you plan to walk along the roof among ornamental shrubs, you will have to provide watering and increase the soil thickness to 20-40 cm. Such a roof is called intensive; it creates a significant additional load on the floor, so it must be provided for at the design stage of the building.

Which coating is better to choose for a flat roof?

Sheet and piece coverings are unsuitable for flat roofs: water will inevitably seep through the joints of the elements. Therefore, roll materials and mastics are used. Let us give a brief description of them.

ROLL REINFORCED POLYMER-BITUMEN ROOF.

The mechanical strength of these materials is several times higher than that of roofing cardboard (roofing felt, roofing felt). And modifying additives increase resistance to moisture, air and ultraviolet radiation. The material is glued to the base with mastic, fixed mechanically or (most often) fused. There are coatings for the lower layers of the roof (Tekhnoelast EPP, Uniflex EPP, Bireplast TPP, etc.) and for the upper ones (Tekhnoelast EKP, Uniflex EKP, Gidrostekloizol TKP, etc.). The latter are sprinkled with mineral chips, which reduce the risk of fire and additionally protect against mechanical damage and UV exposure. The cost of waterproofing of both types is low - from 65 and from 150 rubles, respectively. for 1 m 2 a average term roofing carpet service life is 15-30 years.

ROLL PVC MEMBRANES, for example, Sikaplan WP, Logicroof, Ecoplast are strong and durable (up to 30 years without repair) and do not support combustion. However, they require professional approach for installation (the joints of the strips must be carefully welded with hot air) and are relatively expensive - from 320 rubles. for 1 m 2. It is important to consider that this material does not tolerate contact with bitumen.

ROOF COVERING OPTIONS

Traditional with external drain
1 - overlap; 2 - slope-forming screed; 3 - vapor barrier; D, 5 - mineral wool insulation; 6 - waterproofing; 7 - drain
Inversion
with internal drain
1 - screed; 2 - PVC membrane; 3 - EPPS; 4 - funnel with drainage ring; 5 - drainage membrane; 6 - sand; 7 - paving slabs