Flat roof pitched roof. Flat roofs, their types and designs. The use of mastic as an independent roofing material

A flat roof is a common architectural solution in civil, industrial and private construction. The device of a flat roof has its own characteristics, but the main principle is that the waterproofing layer must be a continuous carpet with certain technical characteristics. The design of roof structures must be carried out in accordance with the current SNiP.

The structure of the roofing cake

If you look at the structure in a section, this type of roof is a multilayer structure, which includes:

• flat base;
• vapor barrier layer;
• insulation;
• waterproofing.

The base of a flat roof can be a reinforced concrete floor slab, or a metal profile structure. Depending on the type of base, the material for the remaining components of the roofing pie and the methods of its installation are selected.

The vapor barrier layer is made of rolled or bituminous materials. It prevents the penetration of moisture from the premises into the heat-insulating layer of the roof structure.

A wide range of materials are used as insulation for flat roofs, including:

• mineral wool;
• expanded clay gravel;
• polystyrene boards;
• cement-sand screed.

The waterproofing layer is traditionally made of bitumen-based roll materials. Special mastics or a PVC membrane can also be used.

The waterproofing carpet must have a certain elasticity in order to withstand mechanical deformations of the base and temperature changes.

The structure of the pie depends on the functional features of the roof. The following types of roofing are distinguished:

• traditional;
• ventilated;
• operated;
• inversion.

Flat roof slope

According to SNiP, when installing a flat roof structure, it is necessary to provide for its slope of 1-4 °. This design of flat roofs avoids the accumulation of water on the surface of the coating. For waterproofing, not only prolonged stagnation of water in certain areas is dangerous. Severe deformation and destruction of the outer covering of the roof is the result of repeated repetition of the process of freezing and thawing of accumulated moisture. Various materials can be used for roof slopes. The choice depends on their technical characteristics and installation features.

Lightweight concrete with bulk polymer filler (in particular, extruded polystyrene) is one of the most popular materials. It is quite easy to install, the resulting design has high strength. But the use of this material for leveling should be provided at the design stage of the building, since the significant weight of the concrete used increases the load on the floor, walls and foundation of the building.

Lightweight concrete with a filler of perlite or expanded clay has similar characteristics. This material is cheaper, but its weight is even greater, while the resulting roofing cake is less durable.

The device of a flat roof can be carried out with the use of monolithic heaters, which allow to perform a slope. In this case, sheet material (mineral wool, expanded clay sheets, etc.) is mounted on the prepared surface. Fastening can be carried out on a strong, tenacious glue, which excludes the displacement of sheets over time. Dowels with a plastic spacer can also be used - it is advisable to exclude metal contact with the base of the roof so that the roofing cake does not have cold bridges.

The most time-consuming is the device of the roof with the use of bulk materials for spreading. It is difficult to pour a layer of loose insulation (expanded clay or perlite) with concrete, observing the required angle of inclination of the roof plane, since the granules can move.

An effective, but expensive option for leveling is the laying of foam concrete, followed by the application of a layer of fiber-reinforced concrete. A cake with such a heat-insulating layer is designed for long-term operation. This technology requires the involvement of experienced professionals.

In accordance with SNiP, the slope of the roof is carried out towards the water intake funnels (in the presence of an internal drain), or towards the water intake gutters of the external drainage system, which must be mounted under the roofing carpet or on the outer wall of the building.

Roof knots

In order for the roofing cake to be reliably protected from external influences, special attention should be paid to the places where it adjoins building structures - parapets, walls, pipes, external parts of ventilation systems, etc. There are various nodes of a flat roof, first of all, this is a node:

• adjoining;
• overhang;
• passage through the roof.

The nodes are installed on a reinforced concrete base in places where the roofing pie adjoins the vertical structure with a cut. Manufacturers of roofing materials often develop their own systems, which may have certain design features.

The node must ensure the tightness of the joint and its thermal protection, therefore, the installation of the nodes should be taken very carefully.

The device of an unexploited flat roof

The most common design is the traditional soft roof. In the section, it consists of a bearing base slab, a vapor barrier layer, thermal insulation made of sheet mineral wool and a waterproofing carpet made of rolled bitumen-containing material. The advantages of this design include low cost and easy installation.

More practical unexploited roofs are made using modern materials. PVC membrane waterproofing is very popular. Its installation can be performed in any season, as the membrane is resistant to low and high temperatures. In addition, if the thermal insulation layer has managed to accumulate moisture during installation, the membrane allows it to evaporate. At the same time, the material has high water-repellent properties. In the process of mounting the canvases into a single whole, special welding equipment without an open flame is used.

Covering an unused flat roof can be done using mastic. This is a liquid material that is applied over a rigid, even heat-insulating layer. Mastic is made on the basis of flexible, hydrophobic polyurethane resins. In the open air, after a certain time after being applied in an even layer, it polymerizes, forming a continuous rubber-like membrane. The device of such waterproofing allows you to reliably protect the roofing pie from moisture penetration.

A popular technology is the use of built-up waterproofing. This is an affordable option in terms of price and quality ratio - the durability of such a roof is from 25 years. Bitumen-polymer material based on a rot-proof canvas creates a heavy-duty waterproofing layer. Using this material, you can perform.

Operating roof device

This design of a flat roof is much more expensive to install, but allows you to profitably use additional space. Today, this type of roofing is in great demand for equipping sports fields, green areas, cafes, parking lots, etc. Installation of a reinforced roof is also necessary if heavy objects, including equipment, are to be installed on the roof. In accordance with SNiP, the roof structure must withstand an uneven high load, that is, it must not deform in limited areas of the area. The section of a flat exploited roof differs from the usual one by the presence of a rigid base in the pie or a special screed over the waterproofing layer. Such a coating excludes punching of the waterproofing carpet with its subsequent destruction.

Inversion Coating Features

The structure of an inverted roof is fundamentally different from other types of roofs. When it is arranged, first of all, a waterproofing layer is mounted on the base. In the context of a roofing pie, it looks like this: base slab, waterproofing, insulation, drainage layer, geotextile. This design allows you to protect the waterproofing material from the damaging effects of ultraviolet radiation and temperature extremes, mechanical damage. Geotextiles, in turn, provide insulation protection. Paving slabs are used as the outer layer. Such a roof is able to withstand high loads, including being used as a parking lot.

Minimizing costs and increasing the speed of work have long been current trends in the construction industry. The frantic pace of life and production processes forces developers to choose those designs that allow them to deliver the project as quickly as possible, cheaper. Therefore, for multi-storey residential buildings of standard construction, industrial facilities, office buildings, a flat roof based on rolled waterproofing materials is increasingly being chosen.

A flat roof, which replaced the intricate designs of gable, three-slope and hip roofs, is completely utilitarian. Its roofing cake protects the building from moisture penetration and maintains an optimal temperature regime inside.

Technology The use of modern roofing roll materials and installation methods guarantee the highest level of waterproofing and thermal insulation. In what conditions and for what design a flat roof is appropriate, we will tell in this article.

Performance and Benefits

The name "flat" has a figurative meaning, because even though such a flat roofing cake does not have slopes, there is still a slight slope in it. After all, completely flat, even structures will not allow melt water and rain to drain into the designated places.

Without even a small slope of 2-3 degrees, excess moisture accumulates on the roof, forms puddles, and provokes leaks. Unlike other varieties, the technology of mounting a flat roof from rolled materials has the following advantages:

• economy. Comparing the construction costs of even the simplest gable structure and a flat one, it is obvious that the pitched options lose in terms of saving material resources. On this cost item, you can save up to half of the money included in the estimate for the construction of the roof through the use of inexpensive roll materials.
• Speed ​​and ease of installation. Due to the absence of the need for a truss system, flat roofing works are carried out very quickly, despite their large area requiring overlap. In addition, the workers performing the installation may not be highly qualified.
• High degree of protection against wind and precipitation. This point is especially important for the construction of high-rise buildings. Imagine a skyscraper with a gable roof, the picture that pops up in your imagination is sure to cause laughter. But, not taking into account the appearance of such a roof, its installation is impossible due to insecurity. The higher the overlapped structures, the stronger the wind load on it, the more gently sloping their roof should be.
• Rational use of space. The flat multi-layer cake of the exploited roof makes it possible to compensate for the entire area occupied by the building. Since it is possible to equip a parking lot, a swimming pool, a recreation area, a cafe, even a garden or install solar panels on it. While there is a lack of living space in megacities, every square meter of available space must be used as efficiently as possible.

Flat roof device

A structure in the form of layers of rolled materials is called a roofing pie. This cake consists of layers of three types:

1. Base. Depending on how the roof is used, either concrete slabs or profiled metal sheets play this role. The main purpose of this layer is to stiffen the structure. Since one of the features of a flat roof is that it can be used not only for the temporary location of people, but even for parking cars or arranging a pool.
2. Screed. Its task is to set the slope of the roof surface so that melt and rain water can be channeled into it. To do this, use a concrete mixture or a cement-sand mortar. In roofs under construction, it is advised to lay a slope of 2-3 degrees, in restored or repaired - 1 degree.
3. Waterproofing. A layer that prevents the penetration of moisture into the roofing cake. For its manufacture, bitumen, polymer and bitumen-polymer roll materials are used.

Important! The nature of the use makes adjustments to the structure of the roofing pie, adding special layers, but the base, screed and rolled waterproofing materials are present in any type of flat roof device.

Types by nature of use

The design of a flat roof, depending on how it will be used, is significantly different. There are the following types:

Simple operated roof

Roofing cake of an exploited flat roof

If the building project provides for the installation of an operated flat roof, a drawing is drawn up that reflects the sequence of layers of the pie. They are usually placed in the following order:

1. Reinforced concrete base;
2. Concrete screed;
3. Waterproofing film or membrane in the form of a roll material;
4. Drainage metal grate;
5. thermal insulation material;
6. Sand-cement mortar;
7. Terrace cover.

As thermal insulation, extruded polystyrene foam or mineral wool in the form of solid slabs is used. Most often, an exploited flat roof is covered with paving slabs intended for paths and parking lots.

The main disadvantage of this arrangement method is that the insulation is located quite close to the surface, which can cause it to deform, sag, get wet, and therefore lose more than 50% of its peat insulating properties.

Inverted operated roof

Before the invention of membrane elastic materials, builders noted a significant drawback with a simple exploited roof - the rapid wear of the waterproofing layer, which was made from rolled bitumen derivatives based on cardboard.

Since he was at the top of the pie, his condition quickly deteriorates due to exposure to temperature changes, UV rays, and mechanical damage. The way out of this situation was the invention of an inverted flat roof, the arrangement of the layers of which is different.

It looks like someone turned a roofing pie upside down. Waterproofing from rolled materials, bitumen or bitumen-polymer material is laid on concrete slabs.

This is followed by a layer of moisture-resistant insulation, extruded polystyrene foam covered with geotextile is ideal. The top layer necessary for protection is made by pouring gravel. This technology and placement of rolled materials has three advantages:

• The waterproofing layer of the roof, securely hidden in the thickness of the roofing pie, lasts longer, as it is not exposed to external influences.
• Condensation does not form on the insulation located in the upper part of the roof, it does not get wet, it retains high thermal insulation qualities for 20-25 years.
• Close to the surface of the slabs of the thermal insulation layer, it makes it easy to replace them and repair the roof.

green roof

This type of exploitable roof turns the top of the building into a blooming oasis, with lawns, flower beds or small beds with kitchen herbs and vegetables. In conditions of high gas contamination of cities, green roofs are not only decoration, but a means of their recovery and relaxation.

The peculiarity of this type of roof is that a layer of geotextile is laid over the insulation to hold the soil layer and the earth itself, which is subsequently sown with a grassy lawn mixture. It is important to choose high-quality, reliable waterproofing and moisture-resistant insulation, for example, polystyrene foam.

Ventilated roof

The invention of a ventilated roof solves the problems of moisture accumulation in the thickness of the roofing pie. It penetrates there in various ways: it settles in the form of condensate on the insulation, accumulates in a concrete screed, and remains in the layers of the old roof. The breathable roof gives excess water an outlet - aerators, installed at the rate of 1 piece per 50 square meters. m.

Ventilated roof

Advantages of ventilated roofs:

1. Installation does not require the removal of the previous roofing.
2. Aerators guarantee effective evaporation of moisture, and a new layer of screed-decomposer effectively channels it through the drainage system.
3. A method, the application of which is possible both during repair and during the initial installation of the roof

Flat roofs of various types open up many opportunities for the implementation of bold design projects. This is the future of housing construction, modern technology for the careful use of free space, because the arrangement of greenhouses and gardens on the roofs, the placement of solar panels will make the life of urban residents more convenient and comfortable.

Video instruction

There are several types of roofing depending on the shape: single-pitched, gable, complex and flat. The last option is the fastest, but at the same time technologically difficult. Familiarize yourself with the technology of self-construction of a flat roof with your own hands.

The device of a flat roof and the principle of its construction

Flat roof - has a fairly simple configuration, and with the right approach, the process of its construction takes a maximum of two days. First of all, decide on the construction technology, draw up a project, purchase and prepare materials for work.

On load-bearing walls, wooden or steel beams are installed that transfer the load from the roof to the walls and foundation.

In addition, beams perform several other important functions, such as:

• retention of the total weight of the attic and ceilings;
• the weight of people who repair and maintain roof structures;
• wind loads, the weight of precipitation that accumulates on the roof.

For the correct selection of the diameter and size of the beam, consider all the loads that affect them. In addition, for the construction of a high quality flat roof, choose the right finish that is durable and performs well.

One of the most important stages is heat and sound insulation. The flat roof of capital buildings consists of floor slabs, on top of which a heat and waterproofing cake is laid:

1. Initially, a vapor barrier is laid on the surface, preventing the penetration of moisture to the insulation. For the manufacture of vapor barrier, reinforced bitumen film based on fiberglass is most often used. The edge of the film is wound beyond the vertical line of the overlap, and all seams are carefully soldered.

2. Installation of insulation is the next step. It is possible to use expanded clay for surface insulation, initially a concrete screed is installed on it, and with a lightweight version of the roof, solid versions of polymer insulation are used.

3. The most important and final layer is waterproofing. The life of the roof as a whole depends on the quality of its execution. Most often, waterproofing of a flat roof is carried out using polymer-bitumen materials.

There are two options for a flat roof, in relation to the type of room for which it is being built:

• flat roof for a heated room;
• flat roof for unheated premises.

The construction of a flat roof over an outbuilding, a shed, a gazebo does not require special skills. To create a stack, a slight slope to one side is enough.

The process of creating a flat roof for a heated room is divided into stages:

1. A boardwalk is installed on the laid beams, which is covered with roofing felt or roofing felt with a large overlap on top.

2. A heater is laid on the roofing material, which is based on expanded clay or slag. When filling the heater, adhere to a certain slope, in relation to the discharge of melt or rainwater from the roof.

3. A screed based on cement mortar is installed on the insulation, at least two centimeters thick. After it has set, the material is treated with a bitumen-based primer. A rolled carpet is additionally glued onto the screed.

It is recommended to create a flat roof with a minimum span, thus reducing the difficulties in its hydro- and thermal insulation. Roofs with a width exceeding 600 cm are recommended to be erected only with specialists. Incorrect calculation of loads on beams leads to terrible consequences: incorrect load distribution and reduced use of roofing materials.

Installation technology of a flat roof made of monolithic concrete

Double-tee steel beams act as load-bearing structures for a concrete flat roof. If the span of the roof does not exceed 500 cm, then beams with a thickness of 15 cm are used to equip the roof.

• crushed stone, fraction 1-2 cm;
• cement brand 400.

The ingredients are combined in the amount of eight buckets of crushed stone and three buckets of cement, four buckets of sand and two buckets of water.

This is followed by the process of mounting the boards on the lower shelves of the beams, roofing felt and reinforcing mesh are mounted on the boards, with a minimum cell size of 10 mm. To connect the intersections of the grid, use knitting wire or a welding machine. The gap between the grid and the roofing material is about 4-5 cm, for this, crushed stone is placed under the grid. The thickness of the concrete layer in this case is at least fifteen centimeters.

At the same time, the strips are laid evenly, it is not allowed to leave an unfinished strip until the next day. This negatively affects the quality of the roof structure. The best option is to fill the roof for one day. After pouring, the surface is compacted with a concrete vibrator or a hand tool. When compacting the concrete, be careful not to deform the mesh.

Next, a polyethylene film is installed on the roof, which prevents excessively rapid evaporation of moisture and cracking of the top layer. After the roof has completely dried, a slope is constructed with the help of a heater to drain water.

Do-it-yourself thermal insulation of a flat roof

A flat roof differs from standard single-pitched and double-pitched types by the need for both internal and external insulation. First, the roof is insulated from the outside, and if necessary, inside.

Previously, rigid heat-insulating boards were used to insulate flat roofs, but due to their heavy weight, they are practically not used at present. This insulation was replaced by heat-insulating materials based on basalt and mineral wool. The thermal conductivity of this material is much higher, and the weight does not make the structure heavier.

In addition, the insulation perfectly resists mechanical damage and is highly fire resistant. The internal insulation of a flat roof is carried out using refractory structures, 2-3 cm thick. Wooden planks are used to mount the plates on the ceiling, on which the plates are fixed with special glue or mastic. Please note that before insulating the ceiling, all lighting fixtures on the ceiling are dismantled.

In addition, as a heater for a flat roof, materials are used in the form of:

• mineral basalt wool - does not need an additional protective screed;
• extruded polystyrene foam - an excellent option for a roof that is in constant use, does not burn, has good soundproofing characteristics;
• polyurethane foam - does not form butt joints, does not burn and is used as a soft roof insulation;
• ecowool - contains cellulose, has an additional flame retardant coating, therefore it has a high level of safety;
• foam concrete - it has a monolithic structure and a long service life, it is similar in structure to foam, ideal for insulating a flat roof without creating significant loads on the foundation.

Flat roof device and technology for creating a roofing pie

In order to get an ideal roofing with good sound, heat and waterproofing characteristics, you must first create a drawing of a roofing pie, which consists of:

• bearing base - concrete or steel beams;
• vapor barrier layer;
• thermal insulation layer;
• waterproofing.

It is possible to change the sequence of layers and add additional materials, it depends on the individual characteristics of the roof and the building itself. Additionally, after the insulation, a textile layer is laid, then covered with rubble and finishing is performed. Such a roof is called inversion and is used extremely rarely, due to the large weight. It is suitable for buildings with high fire safety requirements.

The device of a flat roof implies compliance with all loads that arise during operation. In relation to this indicator, the thickness of each layer in the roofing pie is calculated.

There are several types of flat roofs in relation to the structural characteristics:

• uninsulated roof;
• insulated roof which has open and closed systems 4
• monolithic roofs;
• inverted roofs.

In relation to the operational load, a flat roof can be:

• exploited;
• not exploited.

Depending on the drain:

• flat roof with internal drainage;
• flat roof with external drainage.

Do-it-yourself inversion flat roof

The inverted flat roof is characterized by good performance and high fire safety. The installation technology for this roof option is as follows:

• laying waterproofing;
• installation of thermal insulation material;
• geotextile component;
• drainage system;
• protective bulk coating.

Among the advantages of a flat roof of this type, we note:

• the complexity of the destruction of waterproofing;
• no condensation on the insulation, as it is located on top of the roofing cake;
• ease of repair and replacement of thermal insulation material.

Excessive moisture that forms in the thermal insulation layer is the reason for the deterioration of the protective characteristics of the roof as a whole. Soon it becomes covered with cracks and bubbles, especially in the summer, when the insulation releases moisture. The complete lack of ventilation leads to peeling of the roof from the base.

In this case, we recommend equipping a breathable roof. For the manufacture of roofing, roll materials are used, with excellent tightness and a long service life. Thermal insulation material is installed between the bituminous mastic, and roofing aerators are used for additional ventilation. Among the advantages of this coverage, we note:

• no need to dismantle the flooring, additional strengthening of hydroprotection;
• laying the second layer with a slope leads to improved moisture removal;
• the possibility of using this method both during the initial installation of the roof, and during repairs.

Instructions for finishing a flat roof with your own hands

Flat roof finishing materials must meet certain requirements, such as:

• high level of strength;
• a light weight;
• heat-insulating and sound-proof characteristics;
• resistance to ultraviolet radiation;
• duration of operation;
• ease of installation and maintenance.

Quite often, roofing material with glassine is laid on a flat roof, however, these materials do not have a long service life, they do not tolerate frost well and are destroyed under the influence of temperature fluctuations. Every 8-10 years of operation, the roof is re-coated with roofing material.

New roll-bitumen coatings are gradually replacing roofing material with glassine. This is due to their following advantages:

• excellent performance characteristics;
• ease of installation;
• complete waterproofing of the roof;
• resistance to chemicals, temperature changes;
• duration of use.

There are several varieties of bituminous materials for a flat roof:

1. Fiberglass, fiberglass - is characterized by high strength, resistance to mechanical damage and absolute moisture resistance.

2. Bituminous materials based on polyester or polypropylene. They are used as the bottom layer of protective coatings, have a high density, good waterproofing performance and are used on reinforced concrete floors.

Polymer membrane materials are based on reinforced plastic mesh, rubber and polymer resins. The cost of such materials is much higher than bitumen, however, compared to the latter, they have certain advantages:

• light weight, so they do not load the foundation and foundation of the building;
• elasticity and tendency to stretch;
• duration of operation, which exceeds 50 years;
• do not need to use open flame for installation, in comparison with bituminous materials;
• hot air is used to connect the joints.

Mastic-based materials are ideal for flat roofs. Roll materials, although they have certain advantages, they all create seams that, under increased load, allow moisture to pass through. Seamless mastic roofing does not create butt joints and is characterized by perfect smoothness. Such a roof is called "bulk". This roofing is easy to apply, forming a single sheet, a brush or brush is enough to level the material. Previously, the roof is treated with soil or primer.

Do-it-yourself flat roof video:

For many people, a flat roof is certainly associated with urban high-rise buildings. And very few imagine a country house with a flat roof, which combines the saving of precious space and the possibility of arranging luxurious places to relax on the roof.

Flat roof cake.

In the age of modern building materials and new technologies, it is possible to successfully build private houses with a flat roof, without being afraid of the surprises of our unpredictable climate. But to feel the full scope of pleasure from a flat roof is possible only when the builders and the customer himself will carefully listen to the advice of a specialist in installation technology and the choice of the necessary components of the roof structure. Only under such conditions will a flat roof serve more than one generation of the inhabitants of the house for a long time, without requiring additional costs.

What are the benefits of flat roof structures?

Until recently, various designs and parts for the device were either very expensive or not sufficiently reliable and functional, which did not at all benefit the popularization of roofs of this type, especially for private developers.

However, life experience proves that, being under the influence of stereotypes, we are too biased towards many problems, as a result of which we do not always judge things objectively. The main thing is to choose the most adequate and correct from the many existing options in order to avoid mistakes.

According to the architects, buildings in the spirit of constructivism, which have a minimum of details and simplicity of construction, are now becoming fashionable again. As a result, the attitude of customers towards a flat roof is changing for the better. In Europe, the design of a flat roof of houses is called a fashionable architectural feature of the project. A house with a roof without slopes looks more modern.

Until recently, for most consumers, a flat roof was a complete taboo. According to some, it was simply tasteless, others were afraid of heavy precipitation in the form of snow, and others believed that a flat roof was an event that required prohibitive financial costs. Nevertheless, experts call a lot of obvious advantages for buildings with this design:

1. A flat roof in most cases is equipped as a green recreation area.
2. Saving material, because the area of ​​a flat coating is less than the area of ​​a pitched one with the same architectural basis.
3. Laying a flat roof is much more convenient than a pitched one - it is easier to mount the cover under your feet than in an unsafe position at high altitude.
4. Maintenance of flat roofs is not an extreme climbing activity, but an ordinary procedure.
5. Plus, the design of flat roofs makes it possible to obtain additional space without increasing the contour of the structure.

By the way, in developed countries, the possibility of operating a flat roof is most relevant in megacities. Here, more and more often, the problem of ecology began to come to the fore, and therefore raising the elements of gardens, parks, kitchen gardens and lawns from the ground to the clouds has become a very popular thing. And most importantly, if you want your flat roof to be reliable protection, it must be properly installed using durable modern building materials.

Components of a flat roof

Usually, a flat roof is based on a bearing base (it can be a reinforced concrete slab or a profiled metal sheet), on which heat-insulating material is laid along a vapor barrier layer, which is protected from precipitation by a waterproofing layer.

It is characteristic that all the components of the roofing “pie” are of equal importance, and if at least one of them is unsuitable, the entire structure will be damaged. The basis of flat roof installation work is an integrated approach, which consists in determining the type of coating and implementing the best design solution, considering all operational and technological properties, such as fire resistance, water resistance, ease of maintenance, labor costs during arrangement, aesthetic qualities, etc.

Specialists pay special attention to the sealing of seams, the choice of methods and elements of fasteners, the installation of technological units of the coating (junctions to parapets and pipes, drains, corners, superstructures, etc.) and the execution of through holes. And it goes without saying that the operation of the roof will not depend on any damaging factors if the various components of the structure are made of impact-resistant and weather-resistant materials that are resistant to corrosion processes and UV rays. The exclusion of at least one detail from the overall system is fraught with the most undesirable consequences.

Depending on the type of waterproofing, it can be glued, mechanically fixed or loosely laid. Great attention should be paid to the quality of fasteners and the method of their installation, especially for materials that are laid to the base of the roof with mechanical fastening.

If the rules for laying roofing are neglected, the following undesirable consequences may occur:

1. Breakdown of waterproofing by strong gusts of wind.
2. Loss of the bearing capacity of the base due to electrochemical corrosion in the “wrong self-tapping screw + corrugated sheet” system.
3. Clogged or frozen funnel, which caused the roof to fill with moisture and leaks.

The roofing “pie” consists of the following layers (from bottom to top):

1. Vapor barrier.
2. Insulation.
3. Waterproofing.

flat roof insulation

Types of flat roof insulation: in one, two and three layers.

The basis of a flat roof is a bearing slab made of monolith, reinforced concrete or metal profiled sheet. From above, it is covered with a vapor barrier material that protects the insulation from water vapor, thus preventing it from swelling from getting wet and ensuring the preservation of all properties. After that, thermal insulation is installed on the roof, which, in turn, is covered with a waterproofing carpet to protect it from atmospheric precipitation.

For a flat roof, one- and two-layer thermal insulation systems are distinguished. Now in construction, a two-layer system is more often used. It works like this: the lower layer, 70-200 mm thick, is assigned the main function of thermal insulation, while the upper one, which is 30-50 mm, is responsible for the redistribution of mechanical loads. Despite being thinner, the second layer is stronger and has a higher density. Such a distribution of flat roof coating layers makes it possible to significantly reduce its weight and, thereby, the load on the floors. The heater must meet the following requirements:

1. Low thermal conductivity and water absorption.
2. Fire safety.
3. High vapor permeability.
4. Compressive and tear strength of layers.

Drainage device

In it is very important to ensure the free exit of wet vapors from the roofing. Ventilation accessories are essential elements. As a result of human activity, water vapor is continuously generated inside the building. Due to the convective process and diffusion, it rises and, when cooled, condenses in the space under the roof. This process is especially intense in winter. It negatively affects both wood and metal. If too much condensation accumulates, then wet spots form on the ceiling and mold develops. In addition, moisture accumulating in the heat-insulating material reduces its properties, which leads to an increase in the cost of heating the room. To avoid such situations, you need to take care of the proper removal of moisture outside the building.

This task is best handled by special roofing components - a roof fan, otherwise it is called an aerator. The aerator is pipes of different diameters made of plastic or metal, which are covered with caps in the form of umbrellas.

The operation of the aerator is based on the pressure difference caused by the flow of air masses. Its design allows you to remove moisture vapor from under the roofing without damaging the latter.

On flat roofs, aerators are placed evenly over the entire surface at the highest points of the roof plane at the junctions of heat-insulating plates with each other. It is advisable to install aerators at the same time as the roof itself. Otherwise, the cost of installing ventilation increases significantly.

There are a large number of accessories for a flat roof device. The need for their use is due. For example, in Western countries, much attention is paid to equipping roofs with natural smoke removal devices that enable people to safely leave the building in case of fire.

The reliability of the roof depends on its slope. There are no completely flat roofs, because to drain water, you need a very small, but a slope. For a flat roof, it is measured as a percentage.

It is undesirable to equip roofs with a slope of less than 2 percent. The best option is a slope of 2.5 percent. In this case, the structure is freed from water in a short time, providing more comfortable conditions for the functioning of the roofing material. With a good slope, even a small defect in the roofing will be insignificant.

Another important element of the roof is gutters, which “carry away” moisture and snow along a given route. Most often done on a flat roof. Special or fittings located on the roof surface effectively drain water in heavy rains, eliminating roof flooding. Their location and number must be determined taking into account the design rules for these structures and the construction requirements for the design of drains and sewerage of buildings. The required number of funnels on the roof depends on its operating conditions, architecture and rainfall. A special filter is included with the funnel, which protects the drain from foreign objects entering it. So that the water in the drain does not freeze, the mouths of the funnels are equipped with special thermal cables, which guarantees a quick drainage of water at any time of the year.

As in private houses, they are more often used, because the internal one is more suitable for the construction of flat roofs of large industrial buildings. External drainage is usually carried out using overflow windows, which are installed in the parapet along with roof storm water inlets. Ideally, self-regulating thermal cables should be used in this case, since the storm inlet and overflow window, due to their design, are subject to icing in winter.

When choosing a drainage system, due attention should be paid to the choice of construction material. For example, PVC (polyvinyl chloride) products are less susceptible to icing than metal products.

The construction of a gable or hip roof is not always rational and expedient when it comes to outbuildings, industrial and commercial facilities, and sometimes private houses in a modern style. High material consumption, a complex truss system make the construction of these structures an economically unprofitable, protracted undertaking. While flat roof projects greatly reduce construction costs, build quickly and are suitable for almost any structure.

A house with a flat roof is reliably protected from increased wind load. However, without slopes, it cannot quickly drain rain and melt water from the roof surface.

The situation is complicated by the fact that the surface of roofing materials has a rough structure that does not allow moisture and snow to slide off freely. Therefore, a do-it-yourself flat roof device must comply with the stringent requirements of building codes for waterproofing, ramping and construction technology.

The structure of the roofing pie

The need for a high level of protection against moisture makes it necessary to arrange flat roof roofing materials in layers, one above the other, forming the so-called "pie". If we consider its device in section, we can see the following layers:

1. Flat base made of concrete slabs or profiled metal sheets. It provides structural rigidity, bears the weight of the roofing pie, transferring it to the load-bearing partitions and, as a result, to the foundation. At the exploited roof, the base should be as rigid as possible.
2. vapor barrier. A layer that is necessary in order to protect a flat roof from the penetration of vapors from internal heated rooms into the thickness of the insulation. Settling on thermal insulation in the form of condensate, water irrevocably reduces its insulating properties by more than two times. As the simplest 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, for example, mineral wool and in the form of plates, in particular expanded polystyrene. By the way, insulation is used not only to regulate the temperature regime, but also to flatten a house with a flat roof. The main requirements for insulation are low hygroscopicity and thermal conductivity, light weight.
4. Waterproofing. A flat roof allows the use of rolled materials for protection from moisture: bitumen, polymer and bitumen-polymer. In addition to high waterproofing qualities, they must be resistant to temperature extremes, elasticity, and long service life.

Types of roofing and the nuances of their installation

The device of a flat roof determines the design and nature of use. The following are distinguished into separate types that require a special approach during construction:

Roof installation for unheated buildings

If a flat roof is erected with your own hands for an unheated utility room, for example, a shed, gazebo, shed or extension, the slope is organized using support beams.

They are installed at an angle of 3 degrees, which is 30 mm per linear meter of the length of the beam. Then a base of unedged boards is laid on the beams, fixing them with nails or self-tapping screws.

Roofing material is used as a waterproofing agent - the most affordable material. It is produced and sold in the form of rolls. Carry out the cutting of the waterproofing, cutting the strips so as to lay them in the direction of the slope of the flat roof.

Roofing material strips are gradually laid with an overlap of 10-15 cm and fixed with wooden slats or steel slats every 60-70 cm in the direction of the drain, so as not to block the path of flowing moisture. The flat roof of an unheated room is easily mounted by one's own hands, even by one worker without the help of helpers.

Roof installation for heated buildings

If they are building a private house with a flat roof, which they plan to connect to the heating system, then the work takes place in the following order:

To build a house with a flat roof, the length of which exceeds 6 m, a beam with a section of 150x150 mm or more, or a steel I-beam, is used for the manufacture of support beams.

Monolithic concrete roof

Another option, how to build a flat roof with your own hands, is the use of monolithic concrete. The process looks like this:

Decline process

- the device of a small angle of the roof surface for organizing a drain. Before building a house with a flat roof, it is better to decide in advance which drain you will install, internal or external, and make a drawing.

If provided, water should drain with the help of a ramp into the water-catching funnels, which are located 1 per 25 sq.m or more often. If you make an external drain, then moisture should fall into the gutter. The slope is formed by the following methods:

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

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