Flat roof - device and types. Roofing materials for flat roofs selection and use What are the new technologies for covering flat roofs

There is no bad weather,

Every weather is a blessing.

But when nature is harsh on us,

The roof must be tightly covered!

Few people know that the expression "to have a roof over your head" was not originally identical to the expression "to have housing in general." The fact is that the poor inhabitants of many African countries build their dugouts literally without a roof, so that the building is not considered a house in the full sense of the word, and you would not have to pay tax for it. Extremely rare precipitation in those countries makes it possible to live without a roof over your head, and during periods of rain simply cover the dwellings with tarpaulin or polyethylene. As an option: such an under-house is simply covered with wide leaves, which will protect from the weather, and in fact are not a roof.

The harsh nature of less hot regions does not allow such liberties, and the roof in the house is designed, first of all, to protect residents from precipitation: rain, snow. Its second function is thermal protection. Keeping a building at a comfortable temperature for existence is the task of not only the walls, but also the roof. Both functions are performed not so much by the frame as by the outer covering, called the roof. It is the roof that mainly provides water tightness and thermal protection.

Since ancient times, residents of countries with an unfriendly climate have used various materials for roofing: straw, wood, animal skins. Later - clay and metal.

In Rus', the roof was made mainly of wood (with waxing for better moisture protection) and fastened with a tiled method (nails were prohibitively expensive). Laying "ploughshare" or "male", made without a single nail, served as a good protection for the huts at any time of the year. Wood, both for huts and for roofing, was taken durable, proven for centuries. The best material was Siberian larch. Incredibly strong, very resinous, it is still the backbone of Venice and forms the basis of many old European bridges.

No matter how strong and reliable wood is, it somehow has a short service life compared to metal, concrete, clay.

The roofs used to be completely pitched, therefore they required additional reinforcing structures (beams) and the creation of attics.

Over time, flat roofs, without slopes, firmly came into use. They have a number of disadvantages compared to a pitched roof (there is no drain, the need for cleaning from heavy rainfall, sometimes a drain is needed, which also has problems). But there are also pluses: exploitability (i.e., something can be placed on them), no need to create an attic, lower cost compared to pitched, convenient installation of equipment (antennas, air conditioners, etc.), more convenient exit (no need to use outdoor stairs), more convenient repair.

However, flat roofs must be protected in a special way, because the precipitation from it does not disappear by itself.

The main types of materials for covering flat roofs 2020

• bituminous;
• polymeric membranes;
• bulk mastics.

Bitumen roofing materials for flat roofs

Ruberoid

The most common waterproofing material today. Its composition is cardboard impregnated with bitumen. On one or both sides, the roll is sprinkled with protective sand, talc, asbestos, etc. The service life of the roofing material is on average 5-10 years. Almost does not absorb moisture, resistant to mechanical stress and damage: snowdrifts or heavy hail are not terrible for him. And this material is afraid of temperature. At 50 degrees and above, it will melt, and in severe frost it will crack. But it is easy to operate and install and relatively cheap.

Popular brands of roofing material:

Medium-density roofing felt for roofs where no hard loads are planned.

Filling: powdered talc.

Density: 300 g/sq.m.

Roll size: 1x15 meters.

Average price: 270 rubles per roll.

Advantages:

• low price;
• ease of storage and transportation;
• can be ordered in pallets (each - 40 rolls).

Flaws:

• resistant to extreme temperatures;
• lengthy installation.

Glassine P-250 1×20 m

Thin roofing material without sprinkling - for roofs that are not planned to be used at all or roofs that are not subject to serious loads (heavy snowfalls, hail).

Manufacturer: TechnoNIKOL

Filling: absent.

Thickness: 1.1mm.

Roll size: 1x20 meters.

Roll weight: 3.5 kg.

Average price: 160 rubles per roll.

Glassine P-250 1×20 m

Advantages:

• very low price;
• relatively small weight.

Flaws:

• no protective coating.

Differs in the increased density and greater resistance to tearing. It is used for roofs that are planned to be heavily loaded (machinery, installation of equipment, etc.) or in harsh weather conditions.

Producer: "KRZ", Ryazan.

Filling: powdered talc.

Density: 300 g/sq.m.

Roll size: 1x15 meters.

Average price: 450 rubles per roll.

Advantages:

• high density, tear resistance, durability.

Flaws:

• the price is above average;
• installation will require a number of auxiliary materials that must be purchased separately.

Visually about how to lay roofing material on the roof:

Rubemast

Improved version of ruberoid. It differs only in a thicker layer of bitumen on its underside. Thus, its plasticity, resistance to cracking increases. The service life of such material can reach up to 15 years.

Popular manufacturers of rubemast:

Producer: CJSC "Soft Roof", Samara.

Filling: abrasive crumb (upper side).

Weight: 375gsm

Roll size: 1x10 meters.

Roll weight: 29 kg.

Average price: 565 rubles per roll.

Advantages:

• high density;
• increased tear resistance.

Flaws:

• the price is much higher than that of a conventional roofing material;
• rolls are heavier.

Rubemast RNP-400-1.5

Producer: Korda LLC.

Coating: film + double-sided fine-grained coating.

Density: 400 gr/sq.m.

Roll size: 1x10 meters.

Rubemast RNP-400-1.5

Advantages:

• filling and film on both sides;
• very high resistance to tearing and cracking.

Flaws:

• rolls are heavy, add significant weight to the roof;
• the price of rubemast increases significantly with increasing density.

Stekloizol

Outwardly, it is very similar to roofing material and rubemast, however, it has significant differences from them. It is based not on cardboard, but on fiberglass (fiberglass). And it is this material that is impregnated with bitumen. On the one hand there is a filling, on the other - a thin fusible film. The installation itself is also carried out by welding.

Fiberglass significantly outperforms the cardboard base, as it does not rot. Also, the dense base does not allow the upper layers to crack. Hence the durability of the coating and the service life of up to 20 years.

Popular manufacturers of glass isol:

Stekloizol R HPP 2.1

Producer: TechnoNIKOL, Russia.

Roll size: 1x9 meters.

Material thickness: 2.1 mm.

Roll weight: 18.9 kg.

Average price: 400 rubles per roll.

Stekloizol R HPP 2.1

Advantages:

• crack resistance, high density;
• with proper laying, it forms a flat, without bumps, surface.

Flaws:

• the price is higher than roofing material and rubemast;
• in a roll only 9 sq.m. material.

Stekloizol U K-3.5

Manufacturer: Russia.

Filling: gray crumb.

Roll size: 1x9 sq.m.

Thickness: 3mm.

Roll weight: 32.5 kg.

Average price: 550 rubles.

Stekloizol U K-3.5

Advantages:

• very high density and durability.

Flaws:

• big weight;
• high price.

Euroruberoid (bitumen-polymer membrane)

It is similar to its predecessors (roofing material, rubemast, stekloizol), but in terms of execution it is at a much higher level. Today, among bituminous coatings, this material is the most modern and highly functional. It is based on fiberglass or polyester.

Impregnation - bitumen with various additives (eg pieces of rubber) and fillers. On both sides of the roll there are polymer films and / or bulk materials (talc, sand, shale). Installation of euroroofing material is carried out either by heating one of the layers, or - if there is a self-adhesive material on one side - by removing the protective film and gluing it.

Popular brands of euroroofing material:

Euroruberoid HKP 2.5 mm

Manufacturer: TechnoNIKOL.

Sheet thickness: 2.5 mm.

Average price: 48r/sq.m.

Euroruberoid HKP 2.5 mm

Advantages:

• domestic manufacturer provides an affordable price;
• available in various thicknesses;
• high quality material.

Flaws:

• The material is rare and hard to find.

How to correctly choose euroroofing material - in the video:

Polymer membranes

Not so long ago, a material that appeared on the market is very popular in roofing. Does such a coating perfectly tolerate mechanical stress? Temperature fluctuations and much more elastic than bituminous materials. In addition, the membranes are supplied in much larger rolls compared to roofing felt: up to 60 meters long and up to 20 meters wide, so much less seams are obtained during installation.

The term of effective operation of such material: 30-50 years.

Membranes are divided (depending on the base material) into PVC, TPO and EPDM.

PVC membranes

You can order rolls in different colors. Only over time the colors fade in the sun.

Popular brands of PVC membranes:

Logikroof V-RP RAL 9001 1.2 mm (2.1 x 25 M). Various color performances.

Manufacturer: TechnoNIKOL.

Sheet thickness: 1.2 mm.

Roll size: 2.1x25 meters.

Average price: 410 rubles per roll.

Logikroof V-RP RAL 9001 1.2 MM (2.1 x 25 M)

Advantages:

• performance in various colors;
• light weight of the material;
• high strength and durability.

Flaws:

• relatively small area of ​​the roll;
• volatile substances are not environmentally friendly.

PVC membrane laying technology - in the video:

Ecoplast V-RP GRAY (T) 1.5 MM (2.1 X 20 M). Color: grey.

Production: TechnoNIKOL.

Sheet thickness: 1.5 mm.

Roll size: 2.1x20 m.

Average price: 390 rubles per roll.

Advantages:

• increased thickness and strength.

Flaws:

• color performance - only gray;
• volatile substances are not environmentally friendly;
• relatively small roll area.

TPO membranes

There are no volatile substances in this membrane, therefore it poses less danger to environment than PVC membranes. In addition, this material can withstand temperatures up to -60 °C. without deformation.

Popular manufacturers of TPO membranes:

Manufacturer: Carlisle, USA.

Sheet thickness: 2.03 mm.

Roll size: 3.05x30.48 m.

Average price: 1300 rubles per roll.

Advantages:

• very high insulating properties;
• great tear resistance;
• ease of installation;
• large roll area.

Flaws:

• high price.

Sheet thickness: 1.83 mm.

Roll size: 2.44x30.5 m.

Average price: 1500 rubles per roll.

Membrane FireStone UltraPly TPO 1.83mm reinforced

Advantages:

• quality and many years of experience of the manufacturer;
• big rolls.

Flaws:

• high price.

Video instruction for laying TPO membrane:

EPDM membranes

It is based on rubber, reinforced with fiberglass or polyester mesh. Compared to other membranes, it has a much higher strength and, oddly enough, a lower price.

Such a material can be made not only on the basis of rubber, but on the one hand have a bitumen-polymer coating. Also, this material can be mounted on old bitumen without dismantling the latter.

More details about this material - in the video:

Popular manufacturers of EPDM membranes.

Manufacturer: Firestone, USA.

Sheet thickness: 0.8 mm.

Roll size: 20 sq.m.

Average price: 370 rubles per roll.

Butyl rubber film "GISCOLENE F"

Advantages:

• maintains temperatures from-70 to +130 gr.S.
• small thickness;
• increased resistance to mechanical damage.

Flaws:

• small roll area.

Manufacturer: Firestone, USA.

Sheet thickness: 1.02 mm.

Roll size: 9.15x30.5 m.

Average price: 600 rubles per roll.

Film butyl rubber EPDM membrane Firestone width 9.15m

Advantages:

• high strength;
• large rolls.

Flaws:

• there are no special ones.

Bulk mastics

Roll materials for roofing have one significant drawback: the presence of seams and joints that need to be very carefully worked out from leaks. Joints are weak points in the resulting roof.

With the help of bulk roofing materials, it is possible to make an integral coating and not resort to complex laying of rolls.

The disadvantage is the short service life of such coatings: only 3-10 years.

Roofing mastics are viscous masses that harden over time when exposed to air. Mastics are also used during the installation of rolled roofing as a fastening material.

Self-leveling roofing mastics come in cold and hot applications. Cold ones are already ready for application, while hot ones must be heated to 160-180 degrees C.

Mastics are divided into:

• bituminous;
• bitumen-rubber (they also contain crumb rubber);
• bitumen-polymer (polymers);
• polymeric (purely from polymers).

Mastic bituminous 18l Izoart

Hot mastic (that is, it must be heated before installation) is a binder bitumen with fillers. It can be made with antiseptics and herbicides.

Manufacturer: Isoart.

Volume: 18l.

Average price: 330 rubles per bucket.

Mastic bituminous 18l Izoart

Advantages:

• affordable price.

Flaws:

• the need for heating.

Mastic Bitumen-rubber AquaMast 3 kg or 18 kg

Cold mastic: bituminous binder with crumb rubber, processing aids, organic solvent and mineral filler.

Manufacturer: AquaMast.

Weight: 3 kg or 18 kg.

Average price: 350 rubles for a bucket of 3 kg and 1370 rubles for a bucket of 18 kg.

Mastic Bitumen-rubber AquaMast

Advantages:

• crumb rubber for better protection and additives for better durability;
• cold mounting.

Flaws:

• no particular ones were found.

Cold mastic, completely ready for installation. Composition: bitumen plus special polymer materials.

Manufacturer: TechnoNIKOL.

Volume: 20l.

Average price: 800 rubles for a 20l bucket.

Advantages:

• cold application;
• excellent insulating properties;
• can be used to insulate pipes and other structures.

Flaws:

• no particular ones were found.

Cold mastic, consisting of an aqueous emulsion of bitumen, artificial rubber, technological fillers and mineral additives. Provides excellent adhesion to the base, strength and durability.

Flat roofs, their types and designs can be classified:

• According to the purpose of the surface. It can be operated and non-operated.
• According to the method of laying the roofing cake. It can be traditional and inversion.
• By type of construction. It can be attic and non-attic.
• Separately, ventilated and non-ventilated structures are distinguished.

exploited roof

The exploitable flat roof can be used as a parking lot, helipad, tennis court, swimming pool, green roof and just a terrace. In any case, it is necessary to calculate the possible load on the roof.

• Load from operation (weight of a person, car, water in the pool, etc.).

IN individual cases, the roof is subjected to a pressure of 20 tons per square meter.

Also, due to the nature of the flat roof device, it is highly exposed to ultraviolet rays.

Together, these factors mean that the choice of building materials for such a roof must be approached with great care.

The device of the roofing pie of the operated roof is as follows:

• Reinforced concrete floor slab.
• Sloping layer. It is made of slag, concrete, expanded clay, wedge-shaped mineral insulation and other similar materials. From above it is fixed with a concrete screed. Slope up to 3%. It is necessary for high-quality water drainage in the required direction. Sloping is always arranged in front of waterproofing to ensure that water flows through it.
• Leveling concrete screed.
• Waterproofing. It is made of bituminous, polymeric, PVC materials and sealants. Roofing material is often used, laying it in two layers, while it is important that the joints of the upper and lower rows do not coincide.
• thermal insulation. Keeps indoors warm in winter and cool in summer. Requires a careful approach to the calculation of thickness. In the event of a mistake, condensation inside the room cannot be ruled out. If not an inversion type of roof is used, but a traditional one, the insulation must be resistant to steam. Otherwise, there must be resistance to water absorption.
• drainage layer. Given the technology of a flat roof, water must flow over the surface into drainage trays. But in other cases, moisture can get into the joints between the tiles used as a finishing paving element, or soak into the ground when using a green roof. So that the elements of the roofing cake do not get wet, they arrange a drainage layer that drains water in the right direction.
• Further, it all depends on the type of roof being used. If it is a green roof, geotextiles are laid, which will prevent plant roots from destroying the roofing pie. If this is a roof-terrace, or a parking lot, a concrete screed under the tile, or other finishing material, goes behind the drainage layer.

Please note that when using a traditional roof, the order of the elements of the roofing cake changes. A vapor barrier is laid along the slope-forming layer, then a heater, and only then waterproofing.

The advantages and disadvantages of this method are discussed below.

Unexploited roof

An unused flat roof is notable for its economy. It is not designed to withstand any load other than snow. This allows less careful approach to the choice of building materials.

The device of a roofing pie of this type of roof is as follows:

• Reinforced concrete floor slab. Instead, it is allowed to use profiled sheets with a large wave height, such as H-153 and H-158.
• Slope layer.
• Vapor barrier.
• Thermal insulation.
• Waterproofing.
• Ballast layer of gravel. The thickness of such a layer should be from 10 to 20 centimeters. It is necessary to protect the waterproofing from UV rays and to prevent fires.

Once again, we draw your attention to the fact that the layers of steam, heat and waterproofing can change places depending on the type of roofing used.

traditional roof

The device of a flat roof according to the traditional type has been used for a very long time. In this case, the roofing pie will look like this:

• Slope layer.
• Vapor barrier. It is necessary to protect the insulation from steam emanating from the room. Otherwise, even in the case of one percent moistening of the heat-insulating layer, a significant increase in thermal conductivity occurs. It is made of specialized vapor barrier membranes and films.
• Thermal insulation. It is allowed to use almost all types of insulation, even with a low percentage of moisture resistance.
• Next, according to the traditional drawing of the roof of a flat roof, a layer of waterproofing should be laid. Please note that it must certainly be of high quality, since it is absolutely not protected from temperature extremes.

The advantages of a traditional roof are that it guarantees the protection of the heat-insulating layer from getting wet. Firstly, it allows you to use the entire range of roofing insulation. Secondly, the insulation will not lose its thermal conductivity characteristics, which means that a comfortable temperature regime will always be maintained in the room.

At the same time, this flat roof design compromises waterproofing. It is most susceptible to temperature differences, which leads to its accelerated aging. Also, the insulation does not protect the waterproofing from external power loads, which again negatively affects its service life. In general, this type of roof is less durable and requires fairly frequent repairs.

inverted roof

It is a more progressive type of flat roof device. Assumes the device of the following roofing pie:

• Reinforced concrete floor slab or corrugated board.
• Slope layer.
• Leveling concrete screed.
• Primer for waterproofing, for a better fit. During this process, the screed is carefully inspected for cracks and water bubbles. Cracks are covered with mortar, water bubbles are removed.
• Waterproofing.
• Thermal insulation.
• Further, either a drainage or ballast layer, depending on whether the roof will be exploited or not.

An inverted roof has the following advantages:

• Protecting the waterproofing film from temperature extremes. As a consequence, this extends the life of the film in particular, and the life of the roof in general.
• The insulation redistributes the power loads on the waterproofing in such a way that it does not affect it.
• Extruded polystyrene foam, which is commonly used as thermal insulation for this type of roof, is cheaper than mineral wool used for traditional roofing.
• The inverted design of a flat roof allows more repairs, if necessary, replacement, or adding insulation.

There are also disadvantages, which include:

• It is permissible to use heaters only with closed cells in order to prevent them from getting too wet.
• The need to install a more complex design of gutters.

attic roof

The technology of a flat roof with an attic implies the possibility of using two types:

1. The attic roof is a light superstructure, and the attic floor acts as the main supporting structure.
2. The attic floor and the attic roof are independent of each other and are able to withstand power loads equally well.

The advantages of a roof with an attic are:

• Possibility of continuous monitoring of the tightness of the waterproofing layer.
• The ability to regularly monitor the condition of the insulation.
• Insulation can be laid after the roof has been installed.
• The attic itself performs the function of thermal insulation.

The disadvantages include:

• The impossibility of mechanical removal of snow, provided that the attic roof is used as a light superstructure. Instead, the attic is blown with hot, dry air, which ensures that the snow melts from above and gradually melts.
• This type of roof is more expensive.

roofless roof

More popular is the bare roof. She:

• It costs less than an attic.
• Easier to install.
• Provides snow melting by conducting heat from the room.

A non-attic flat roof also has a significant drawback:

• There is no way to timely determine the violation of the waterproofing layer. These damages appear as a wet spot on the ceiling, making it impossible to determine the exact location of the leak.

Ventilated and non-ventilated roof

Roof ventilation is arranged between the insulation and the waterproofing layer. Thus, constant air circulation is achieved, which ensures the constant dryness of the insulation. Used in the traditional type of roofing cake.

When installing ventilation, it is important to adhere to the following recommendations:

• The height of the vent is at least 1/30 of the width of the building.
• Hole diameter not less than 1/150 of the total roof area.
• The air inlets must be lower than the outlets.
• The holes are evenly distributed across the width of the entire building.

In turn, a non-ventilated roof does not require the creation of additional roof elements for flat roofs. But this somewhat shortens the service life of the heat-insulating material.

This option for arranging the upper part of the building is used, as a rule, in the construction of "high-rise buildings", as well as various administrative, industrial, warehouse and some other buildings: pavilions, showrooms, and the like. Despite the fact that a flat roof has a number of disadvantages, this does not reduce the popularity of such a design, including in private housing construction.

Benefits of flat roofs

Firstly, the installation of a flat roof can be carried out independently, and not to invite assistants or hire professionals, as, for example, when constructing a roof of complex configuration (, four-pitched, etc.). Consequently, they will not have to pay for their work (we are not talking about large areas where it will be problematic to cope alone).

Secondly, the construction of such a roof provides significant savings both in terms of materials (money) and in time (the coverage area is much smaller than with pitched equipment). You don’t have to make numerous calculations or order a project (which will cost a lot), assemble a complex system of rafters, install jibs, sprigs, and so on. In addition, there are no restrictions on the choice of the type of roofing.

Third, a flat surface is much easier to maintain and repair, which also gives tangible savings in the future.

Fourth, a choice of arrangement options. A flat roof can either serve only as a traditional "cover" for the house, or be used (inverted). For example, greenhouses, summer gardens, solariums and the like are mounted on it. There are even heliports. This fully compensates for the inconvenience due to the lack of an attic room.

Flaws

• Increased requirements for waterproofing. Since the roof is located horizontally, water falling in the form of precipitation will stagnate on it. You can use eg.
• Debris will constantly accumulate (for example, fallen leaves), so such a roof will have to be serviced more often.
• Lack of an attic (mansard) space

What to consider

• The maximum load that the roof will experience (for the roof structure). This includes the weight of the frame itself, roofing material, layers of insulation and insulation, as well as possible snow cover. In addition, you need to rely on the fact that the roof must withstand the weight of people who will subsequently walk on it.
• The purpose of the building and the possibility of further use of the surface (for example, terrace equipment). Depending on this, the type of overlap is determined.

Work technology

The simplest version of a flat roof is when reinforced concrete slabs are laid (for example, a garage, a barn). Everything is extremely simple here. A so-called “layer cake” is arranged on the surface: vapor barrier, if necessary - insulation material, a layer of waterproofing. For the equipment of the latter, roll materials are most often used.

Insulation of a reinforced concrete slab can be done by pouring a layer of expanded clay and equipping a cement screed on top. Slag and some other materials are also used.

Traditionally, roofing material is used for waterproofing, which is covered with bituminous mastics on top. It should be noted that this material will last no more than 5 years, and then you will have to deal with repairs. It is more expedient to lay polymeric materials, for example, membranes, as a "waterproofer". Liquid rubber is also great.

Since the installation of plates requires the involvement of special equipment, with an independent device of a flat roof, you can equip the simplest truss system made of wood.

First of all, supports - Mauerlats - are laid on the upper parts of the bearing walls. The most commonly used material is timber. It must be taken into account that these structural elements must be rigidly fixed in order to exclude the possibility of their horizontal displacement.

Therefore, metal pins are immured in their upper end surfaces along the entire length of the walls. Their length is calculated so that after mounting the Mauerlat they rise above the beam by about 5 cm. Threads must be cut at their ends.

If the masonry is old, then a "tape" of concrete mortar is arranged on top of the walls. After that, pre-planned holes are drilled in each wooden blank with a diameter slightly larger than the cross section of the metal "fingers". First, strips of roofing material (or similar waterproofing material) are laid on the tape, and then Mauerlats. They are mounted on pins, and a washer is put on top of each, and with the help of a nut, the beam is securely fixed at the installation site.

Next, floor beams are laid. It should be noted that the roof should protrude beyond the dimensions of the house by 50 - 60 cm (required overhang). This will protect both the walls and the blind area from water flowing from it, as well as from raindrops.
Support frame device. Depending on the type, it can be either solid (boards, slabs) or cellular (battens).

• Vapor barrier.

• Insulation. For flat roofs there is a nuance. The absence of an attic space deprives such a building of an “air cushion” from above. Therefore, insulation is carried out both outside and inside. But at the same time, it is necessary to take into account the weight of such material, since it is an additional load on the truss system.

• Waterproofing.

• Roof covering.

• Overhang finishing.

This is only a general list of necessary activities. The technology for the production of work for each item depends on local conditions and on the selected materials.

• Any "wood" used in construction must be well dried. The moisture in its structure gradually “leaves” (natural shrinkage of the material), which leads to a change not only in the volume of the workpiece, but also to its deformation (for example, twisting).
• Wood has two significant drawbacks - it burns and is prone to decay. Therefore, before using it, all wooden parts of the structure are pre-treated with flame retardants and antiseptics. It is better to spend money on these funds than to suffer with frequent repairs later.
• When installing power plates, you need to constantly monitor their horizontal position using the building level. Otherwise, the roof will turn out to be skewed. If necessary, either the tape is leveled, or a rigid lining is made under the Mauerlat.
• To exclude stagnant water on the roof, it is advisable to make it with a certain slope (approximately 3 0 - 5 0). As a rule, the decrease goes towards the rear side of the building. To do this, the height of the front Mauerlats increases, so the floor beams will fall with a slope.

When building a house, the final, but no less important process is the roofing of the roof, often called by architects the “fifth facade”. Pitched roofs are considered to be a classic option for private houses, but recently their flat counterparts have begun to gain more and more popularity. And the whole secret is that the device of a flat roof has a lot of advantages.

flat roof house

This type of roof is widely applicable in both industrial and private construction. The main difference between flat roofs and pitched "brothers" is the use of piece and sheet roofing materials. The device of a flat roof involves the use of materials that can form a continuous carpet. These include polymer, bitumen and bitumen-polymer materials, as well as mastics. In order for any temperature fluctuations and mechanical deformations to which the roof base is subject to be perceived well enough, such a carpet must be highly elastic. The basis for it can serve as load-bearing plates, screeds, as well as the surface of thermal insulation. All layers stacked on top of each other represent the so-called flat roof pie.

Exploited and non-exploited flat roofs

The use of operated roofs is advisable on those buildings that provide for frequent access to the roof of people or the presence of any heavy objects on it. The design of this type of flat roof has its own peculiarity, consisting in the need to lay a rigid base or a special screed on the waterproofing layer. This is necessary so that the roof structure can withstand any load, often unevenly distributed over the surface. A rigid base in this case will help maintain the integrity of the waterproofing carpet and will not allow it to be pressed through.

Unlike operated roofs, for non-operated roofs there is no need to lay a rigid base on the waterproofing. In this case, soft insulation is used. The use of such roofs is appropriate when maintenance during the operational period is not required, that is, there is no pressure on the roof surface. But even if there is a need to maintain such a roof, the issue can be resolved with the help of special ladders or walkways that will help to evenly distribute the pressure exerted on the roof surface.

The device of a flat roof of an unexploited type will cost an order of magnitude cheaper than in operation, but its service life will also be much lower. Therefore, the choice of roofing should be approached carefully after weighing all the pros and cons.

Other types of flat roofs

Depending on the design features, there are the following types flat roofs:

• classical;
• inversion;
• ventilated.

The traditional option is considered to be a classic flat roof, which has another name - a soft roof. Its base is a carrier plate, on the vapor barrier layer of which a heat-insulating material is applied (in most cases, mineral wool plates are used). Thermal insulation, in turn, is protected from the effects of precipitation by a waterproofing carpet, which is based on rolled bitumen-containing materials.

The device of a flat roof of an inversion type differs from the previous one in that the insulating layer is located above the waterproofing carpet, and not below it. This feature makes it possible to protect the waterproofing from the harmful effects of ultraviolet radiation, freeze and thaw cycles, sudden changes in temperature, as well as mechanical damage, which can greatly increase the life of the inverted roof. This design can be used as an operated flat roof. For example, you can plant grass on it and break flower beds, put a small amount of furniture, or just sunbathe.

Moisture that accumulates in floor slabs and insulation is the main reason for the formation of "bubbles", which subsequently lead to leaks and even ruptures of the roofing carpet. And, unfortunately, removing this cause completely is almost impossible. In the West, this issue is easily solved using the so-called "ventilated roofs". Flat roof units of this type provide for partial fixing of the first layer of the carpet to the roof with glue, or laying on mechanical fasteners. As a result, an air gap is formed between the base and the roof, which eliminates excessive water vapor pressure. It communicates with the outside air through the junctions along the contour of the roof, or through special exhaust deflectors.

Foundation preparation

In order for the end result to be a high-quality and durable roof, it is initially necessary to think over a flat roof plan, the drawing will also be an excellent help in installation work. In most cases, the following main nodes of a flat roof are distinguished: a supporting structure, which can be a monolith, a supporting concrete slab or a corrugated floor, layers of steam, heat and waterproofing and a slope-forming layer designed to drain water.

The first step in flat roofing is the preparation of the foundation. Reinforced concrete slab, corrugated steel sheet, or a solid wood covering most often act as a bearing covering for this type of roof.

If the reinforced concrete base has an uneven surface, it is necessary to create a leveling screed of sandy asphalt concrete or cement-sand mortar. The thickness of the screed will depend on the type of base: for concrete - 10-15 mm; on rigid insulation boards -15-25 mm; on soft insulation boards - 25-30 mm.

If the roof slope is less than 15%, then first the screed is placed on the grooves and only then on the slopes. In the case of a slope of more than 15%, the actions are performed in the reverse order: first, the slopes are leveled, then they proceed to work with grooves and valleys.

Any elements protruding above the roof, whether chimneys or parapet walls, are treated with plaster to a height of 25 cm. Special rails are installed on top of the plastered surface, which serve to fix the roll-type carpet. The roof screed is primed with roofing mastics in order to increase the quality of adhesion of the base to the rolled carpet.

Before priming the base, it must be thoroughly cleaned of contaminants and dried well.

Preparation of roofing soft materials

The roof plan of a flat roof must necessarily include the preparatory work of roofing materials for their further use.

When using rolled materials, they must first be carefully examined for the presence of various kinds of defects: bumps, cracks, oil stains. And then during the day they are kept rolled out or turned inside out.

Mastic for a roof can perform two functions at once. It can be used as a stand-alone seamless coating material for repair work. And also it is applicable as an adhesive agent for connecting rolled materials with the base. Bituminous mastics can be used both hot and cold.

The use of mastic as an independent roofing material

The composition of a flat roof may not include rolled materials; it can be made with just the use of mastic. It is a liquid material based on pure elastic, hydrophobic polyurethane resins. And as a result of its application to a flat roof, when exposed to air humidity, it polymerizes and turns into a rubber-like continuous membrane, which has excellent protective and waterproofing properties.

For a flat roof, mastic as a roofing material has a lot of obvious advantages: it is safe and reliable, has high resistance to ultraviolet rays, precipitation and various microorganisms, has high adhesion to any building surface, and besides, it does not change its volume during polymerization . The ease of use of this material is also captivating - it can be applied either manually, with a brush or roller, or by airless spraying.

Roof covering with roll materials

Thinking through the plan of the roof of a flat roof, an important point is the choice of the roofing material itself. Roll materials can be called the most suitable in their properties. Laying of rolled panels for soft roofing is carried out on overlapping slopes. If the roof slope is more than 5%, the overlap should be 70 mm in the inner layers of the carpet, and 100 mm in the outer layers. In the case of a slope of less than 5%, the width of the overlap in any layer is 100 mm or more. Laying of roll strips is carried out strictly in one direction.

If, during gluing, the panel deflected to the side, you should try to move it without peeling it off. If the result turns out to be ineffective, then the glued part of the panel should be cut off and pasted with an overlap of 100 mm.

Roll sheets are laid in layers, and in case of their fastening on cold mastic, it is necessary to observe a 12-hour interval between the sticker of each layer.

Thermal insulation in soft roofs

Considering the device of a flat roof, its insulation can be performed in one of the following ways: external or internal. The ease of installation of external thermal insulation makes this method more common. In addition, with the help of this method, both a building under construction and one already in operation can be insulated.

Flat roof - thermal insulation

Flat roofs have a design that provides for two options for thermal insulation, depending on the number of layers: single-layer and two-layer. The choice of thermal insulation is influenced by thermal calculation and strength requirements for the roof structure. For laying on the top of the supporting structure of heat-insulating boards, the principle of "seams apart" is used. With a two-layer coating, the joints of the lower and upper plates must also run "in a row". In those places where the plates of thermal insulation are adjacent to walls, parapets and lanterns, thermal insulating transitional ledges are created. To fix the thermal insulation, use one of the following methods:

• mechanical. The corrugated board is fastened with self-tapping screws, the reinforced concrete base - with plastic dowels with a core;
• adhesive;
• with the help of ballast, which is used as pebbles or paving slabs;
• based.

The main mistakes of installing a flat roof

Installation errors can lead to the formation of so-called "cold bridges", which can be window and door openings, concrete building elements or dowels, with which the plates are attached to the wall. Such "cold bridges" can create heat loss of up to 50%, in addition, they can cause condensation and subsequently mold.

The most common reason for the formation of "cold bridges" is the use of fixing dowels with a metal nail. To avoid this phenomenon, the use of stone wool flat roofs during roofing work will help. This is due to the fact that there will be enough glue for its fastening, but the use of dowels in this case is also possible, since a plastic rod is provided for the cotton wool.

Heat loss can also be avoided when using a two-layer insulation. But in this case, the top layer must be laid in such a way that the joints between the bottom plates are covered by the top insulation.

Use large format slabs - this will reduce the total number of joints.

In addition, errors can be identified initially, you just need to draw up a competent and clear plan for a flat roof.

Do you want the roof of your house to perform not only its main function of protection from atmospheric precipitation? Would you like to turn it into a beautiful garden, recreation area or outdoor sports ground? Then flat roofing is the perfect option for you!

The choice of a particular design largely determines the possibility of using the attic as an additional living space, resolves the issue of the need for insulation and determines the type of roofing.

A flat roof is a specific option that does not allow you to equip the attic as a living space (due to its absence).

But it offers a lot of opportunities for using the territory as an auxiliary site, a place for placing equipment or as a private recreation area, isolated from the external space.

In this regard, a flat roof can provide many interesting possibilities, but its use has its limitations.

The main feature of a flat roof is an almost horizontal surface. such surfaces is low - up to 8 degrees, it is needed only to drain rain or melt water.

According to the conditions of the plane location, there is practically zero wind load (with the correct device without hanging edges) with maximum snow load.

Wherein, roof structure has a complex multilayer structure, which ensures the tightness of the coating and the working condition of the insulation.

The most favorable operating conditions for flat roofs:

• Small amount of snow in winter. The most successful use is in regions with warm or little snowy winters, when removing snow from the roof is not difficult.
• The strength of the wind does not have a significant effect on the roof, therefore, it is permissible to build such roofs in areas with strong or heavy winds.

For areas with cold and snowy winters, the use of flat roofs is only recommended. for small commercial buildings with a relatively small area.

The use of flat roofs on residential buildings is more common in southern regions, where the problem of high snow pressure in winter is absent.

Flat roof

The structure of the roofing pie

There is no specific, classic composition of a flat roof roofing pie. The structure of the layers most often based on the following factors:

• The purpose of the roof;
• Cover type;
• Roofing material.

The decisive factor determining the composition of the roof from the very beginning of construction is the purpose of the roof. It depends on it what material is needed for the construction of the ceiling, how exactly it will be insulated, what is the optimal coating material in this case.

Warming of a flat roof from a soft roof is made from the outside, since this method is much more convenient and reliable in terms of the tightness of the cake.

The general technology of insulation looks like this:

• Base (concrete, wooden floor);
• vapor barrier film;
• layer of insulation;
• The top layer of waterproofing;
• Roofing.

This is a general plan, in practice it is often supplemented or complicated in order to more reliably protect against water penetration or the formation of cold bridges.

roofing cake

One of the flat roof options is inverted roof. This is a relatively new kind of pie construction that takes into account the shortcomings of conventional options.

The fact is that a common problem with flat roofs is the seepage of water through the insulation into the ceiling and the appearance of stains and stains.

To eliminate this phenomenon, an inverted roof is used when a reliable waterproofing carpet (often multilayer) is installed between the ceiling and the insulation.

The composition of the pie is built like this:

• overlap;
• Waterproofing preparation layer - usually a building primer;
• Waterproofing carpet;
• Geotextile layer;
• Insulation (optimally - extruded polystyrene foam);
• The top layer of geotextile;
• Ballast bulk layer of gravel.

On top of the ballast layer, if necessary, a hard coating can be laid to maintain a uniform thickness of the ballast and ease of movement.

Inverted roofing cake

Roof base - wood or concrete?

Wood or concrete can be used as the basis for a flat roof. Both options are acceptable, but not interchangeable.

So, wooden base is used for small buildings, most often for economic purposes.

If there is no heating, then such a roof is not insulated, a simple truss system is made and the roofing is laid on top. However, wooden floors are also used for residential buildings.

This is due to the desire to lighten the roof, remove excess load from the walls (for example, with the frame method of construction).

CAREFULLY!

This option imposes certain restrictions on the functionality of the roof, excluding the presence of heavy equipment on it, a large number of people, etc.

More often, for the roofs of residential buildings used, a concrete slab is used as the basis. Such an overlap has a number of significant advantages:

• Reliability;
• No noticeable deformation from loads;
• The penetration of moisture into the material will not cause decay;
• Finishing a concrete floor is easier than wood.

Since it is produced outside, the lower surface of the concrete floor (the ceiling of the upper floor) will be open, which allows the use of any available type of finish - from simple painting to the installation of a stretch ceiling.

If the ceiling is made of wood (beams), then the finishing should be done taking into account possible deformation - “sagging” of the ceiling from existing loads.

Photo of the foundations of the roof in section:

wooden base

concrete base

Flat roofs: arrangement of private houses

The composition of a roofing cake is never chosen at random. The main selection criterion is the general purpose of the roof:

• Lightweight. A roof that serves only as protection from rain. It is mainly used for auxiliary buildings for household purposes;
• Operated. Such a roof serves as a platform for accommodating various equipment, for arranging recreation areas, small greenhouses, swimming pools, etc.;
• Green. On such a roof there is a lawn with grass, plants, etc. Serves as a mini-square for recreation.

Depending on the purpose of the roof, the type of overlap is selected, which, in turn, largely determines the optimal type of roofing material. Therefore, the composition of the roofing cake may have its own individual characteristics.

So, for a flat roof of an outbuilding it will be enough:

• Rafter;
• crate;
• Roofing (, metal profile, etc.).

Lightweight roof

For a used roof, which is used as a platform for installing solar panels, satellite TV dishes or other equipment, composition is much more complex.:

• Concrete floor slab;
• Cement screed forming a slope for water flow;
• waterproofing layer;
• Drainage material that removes water from under the upper layers;
• insulation layer;
• Geotextile layer;
• Sand preparation layer;
• Paving slabs.

In this case, paving slabs serve as an external coating, as a durable and cheap material.

ATTENTION!

At the same time, rain or melt water can quite easily penetrate into the insulation layer, so it must be resistant to moisture, impervious to water, or, alternatively, pass water painlessly for drainage through the drainage layer to the drain.

exploited roof

Green roof pie chart:

• Concrete floor slab;
• Layer ;
• Multilayer waterproofing carpet;
• insulation;
• . It consists of a separating layer of reinforced screed, a double layer of technoplastic (EPP and Green), and a geodrainage rolled layer;
• Soil layer with plantings.

In this case, there is a multi-stage hydroprotection that reliably cuts off the insulation material from the upper soil layer. Such a cut-off, at first glance, is too complicated, necessary to guarantee the creation of a reliable barrier to water.

The soil is an active accumulator of moisture, which will surely seep into the lower layers, so the complexity of the composition of the cake is fully justified.

green roof

How to cover a flat roof

The material for covering a flat roof is selected based on its purpose.

Unused surfaces are most often covered with roofing felt with sealing joints with liquid bitumen..

Recently, a large number of similar materials with improved characteristics have appeared, which make it possible to more reliably protect the roofing pie.

Operating surfaces require a more rigid and durable coating. At the same time, the task of hermetic cut-off of the insulation from external influences is not removed, therefore, most often a sand-cement cushion and a working layer - paving slabs are laid on top of the soft roof.

Coating

Installation of an operated flat roof

How to make a flat roof First of all, you need to decide on the main parameters - the type of roof, device, etc. Consider the option of installing an operated flat roof with a concrete floor and external drainage using gutters:

1. The surface of the overlap is covered with a layer of sloping concrete screed (decrease). To save concrete, a layer of gravel is first poured with a slope, after which a screed is laid on top. Since this stage refers to "wet" work, then it is recommended to cover the overlay surface with a layer of primer or similar material.
2. Laying vapor and waterproofing. As a material, various deposited films or rolled membranes can be used. Laying with an overlap, glue the joints with adhesive tape.
3. insulation layer. Either stone mineral wool or extruded polystyrene foam is used. Insulation is laid in several layers, at least 2 layers. This requirement is due to the need to exclude the penetration of cold through the cracks in the joints of the insulation.
4. over the insulating layer laying a layer of waterproofing.
5. Backfilling of the ballast layer - gravel, sand, etc.. The role of this layer is twofold: protection of the film coating and removal of water from melting snow or precipitation in the summer.
6. over the ballast layer if necessary, a layer of paving slabs can be laid for ease of walking on the surface. In this case, you will need an additional sandy preparatory layer, a direct substrate for tiles.

The specified sequence is one of the options; there are many similar methods that are equivalent in result, but differ in details.

The device of a flat roof, traditionally considered an accessory of auxiliary buildings, can be carried out in such a way that the roof surface turns into an additional platform that can be used for various needs.

Depending on the climatic conditions of the area, the surface of a flat roof is turned into a green lawn, into a technical area for placing equipment, into a recreation area.

All variants of the operated roof require careful arrangement and expensive materials.. A qualitative result directly depends on the qualifications of the people doing the work and on the financial capabilities of the owner of the house.

But do not forget that you can build a flat roof with your own hands.

Investments in an equipped used flat roof will be justified only in regions with short mild winters and low average monthly rainfall. All other issues are solvable and do not cause serious problems.

Waterproofing

Warming

Useful video

In this video you will learn what is the device of a flat roof made of welded materials:

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