Flat or pitched roof. How to choose between pitched and flat roofs? General arrangement of a flat roof

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

Architects and developers are attracted by these unusual buildings, where you can equip an observation platform or even set up a real hanging garden. Of course, in practice everything turns out to be more complicated than in theory.

Designing a flat roof raises many questions regarding its cost, the choice of materials for insulation and waterproofing, the organization of water flow, maintenance, etc. Finding answers to them is not easy. The fact is that domestic contracting firms working in the field of cottage and are well familiar with the most popular design - pitched, and, as a rule, they do not have experience in erecting flat roofs arranged in a completely different way.

flat roof cost

Immediately noteworthy is the fact that the area of ​​​​a flat roof is smaller than a pitched one, which means that fewer materials will be required, and the work will be cheaper. However, this statement is true only for regions with a warm climate and low snow load, moreover, if we are talking about an unexploited roof. In central Russia, to ensure the reliability and durability of a horizontal roof, rather expensive engineering solutions are required.

beam ceiling

In principle, when erecting a ceiling, a combination of beams (wooden, steel) and a supporting corrugated board can be used. However, experts do not recommend the use of wooden beams (with the exception of those made of LVL beams with a cross section of 200 × 100 mm) in regions where the snow cover pressure exceeds 1.2 kPa (about 120 kgf / m2) - that is, in most of the territory of the Russian Federation. Roofing made of steel I-beams and corrugated board with a wave height of 60 mm and a wall thickness of 0.7 mm makes it possible to cover a span of up to 12 m and withstands a pressure of at least 6 kPa. But in general, it is less durable than concrete, and is relatively rarely used in individual construction. It is more reasonable to use corrugated board as a fixed formwork, which, by the way, does not eliminate the need to build a reinforcing cage.

It turns out that 1 m2 of a flat concrete or steel base, the bearing capacity of which will withstand the weight of the snow cover, costs 2–2.5 times more than the wooden beam structure of a pitched roof. The difference in the volumetric flow rate of the insulation is offset by the fact that a flat roof requires a more expensive high-density material. There is still hope to save on roofing, however, modern polymer membranes - optimal waterproofing for horizontal roofs - are no cheaper (and sometimes much more expensive) than flexible tiles. You won’t need to install snow retainers, but you can’t do without a roof hatch and a drainage system. If you try to reduce the cost of the estimate, then later you will have to pay with the need to repair the roof every 10-15 years.

The durability of a flat roof largely depends on the ability of the supporting base to withstand operating loads without significant deformations.

Finally, it should be noted that flat roofs are appropriate only on houses of modern architecture - with a large glazing area and sophisticated finishing with the latest facade materials. Both of these won't come cheap.

On a solid foundation

As a rule, in low-rise housing construction, flat roofing is a prefabricated or monolithic reinforced concrete slab. Reinforced concrete slabs (PB, hollow core PC, PV, etc.) are able to cover a span up to 9 m long and withstand a pressure of 8, 9 or 12.5 kPa (this value is indicated by the last digit in the product marking). They can serve as a "base" for any roofing pies, including those with a top layer of paving slabs or fertile soil. However, for the installation of the structure, it will be necessary to ensure the arrival of a truck crane site (while steel beams and decking are easy to lift with winches). The depth of support of the ceiling on the wall depends on the material of the latter - for example, for a brick, this parameter should be equal to the thickness of the slab. Before proceeding with the installation of the roof, it is important to seal the joints of the elements with mortar and additionally seal them with an elastic polymer tape.

The main advantage of membranes based on artificial rubber is that they remain elastic at low temperatures, that is, they can be mounted in winter

Flat roof classification

Flat roofs are divided into non-exploited and exploited. The former are visited only for revision, prevention and repair; for this purpose, a roof hatch is equipped, to which an attic staircase leads. The operated roof in cottages most often serves as a terrace, that is, a durable wear-resistant coating must be laid on it, and the supporting base is designed for increased loads. A variety of exploited - a roof with landscaping, lined with a turf layer on top of the main heat and waterproofing cake; usually it is arranged with paths and a recreation area. A convenient exit should be provided for the operated roof, for example, from a vestibule superstructure.

A monolithic reinforced concrete floor is erected from heavy concrete using a removable (for example, from OSB boards on jack stands) or fixed (from corrugated board) formwork. It is reinforced with a two- or four-level welded frame made of bars with a diameter of 12 mm or more. The dimensions of a monolithic slab are not regulated (unlike a prefabricated one), which provides the architect with freedom in designing a building; other pluses are the absence of seams, the relative simplicity of the arrangement of passage units (chimney, ventilation ducts) and high bearing capacity (subject to the technological regulations).

Roof protection from cold and heat

In the low-rise sector, mostly non-attic flat roofs are in demand, because the attic requires additional costs and violates the architectural proportions of the house. So, the roof should protect from the winter cold and summer heat. At the same time, a common feature of flat roofs is that the heat-insulating layer is located on top of the supporting structure (in pitched roofs, it is usually located between the rafters). If the room is insulated from below, the dew point may shift into the thickness of the ceiling, which will lead to a reduction in the service life of the latter.

Mastics should be used primarily on roofs of complex configuration

As for the options for the execution of the roof, there are dozens of them. Suffice it to say that only in SP 17.13330.2011 there are more than 40 "recipes". At the same time, companies - manufacturers of coatings and insulation offer more and more new engineering solutions. However, they are always based on one of two fundamental schemes - traditional or inversion.

Schemes of the device of roofs "TechnoNIKOL"

"TN-ROOF Terrace": 1 - ceiling; 2 - vapor barrier; 3–5 - EPS (including slope-forming layer); 6 - fiberglass; 7 - LOGICROOF V-GR membrane; 8 - geotextile; 9 - tiles on supports

The traditional design in general terms is as follows: a vapor barrier film (polypropylene, polyethylene, butum-polymer) is laid on top of the supporting base, then a heater follows, for example, mineral wool boards with a compressive strength at ten percent deformation of at least 30 kPa, in one or two layers with a total thickness of 200 mm. Above is a separating layer (for example, from a polyethylene film), along which a reinforced slope-forming screed is poured (a flat roof must be given a slope of 2-3% to the center or edges to ensure water flow). The dried screed serves as the basis for a rolled or mastic waterproofing coating.

"TN-ROOF Green": 1 - ceiling; 2 - expansion from expanded clay; 3 - reinforced screed; 4 - bituminous primer; 5 - "Technoelast EPP"; 6 - "Technoelast Green"; 7 - geotextile; 8 - EPPS; 9 - PLANTER GEO membrane; 10 - fertile layer

Other options are also possible. For example, a slope-forming screed can be placed at the very bottom of the pie; in this case, the roof waterproofing is fixed with gravel ballast, paving slabs on supports or special dowels. Some materials, for example, the RUF SLOPE system (Rockwool) or TechnoNIKOL Slant, allow you to do without a screed at all: the plates have a variable thickness, and with their help it is easy to create smooth level drops to ensure water flow.

The inversion roof is arranged differently: in it, a heater resistant to constant exposure to water (usually extruded polystyrene foam - EPS) is located on top of the waterproofing. At the same time, the latter is reliably protected from mechanical damage and is located in the zone of positive temperatures (freeze-thaw cycles are destructive for almost any material). It is easy to turn an inverted roof into an exploitable one, for example, by filling the insulation with a drainage layer of sand gravel and laying paving slabs. The disadvantages of the design include a more complex drainage system. However, drains need to be discussed separately.

There are special requirements for thermal insulation for a flat roof. The material must not only have a low coefficient of thermal conductivity, but also resist mechanical loads well - both distributed (pressure of the higher layers of the roofing cake, equipment, snow) and local ones that occur during installation. In addition, it is important that the material has hydrophobic properties and is non-combustible. At the moment, there are several ways to install thermal insulation: using mechanical fasteners, adhesive and free laying. In addition to the traditional two-layer insulation, one-layer laying is becoming an increasingly popular solution. Rockwool offers unique dual-density boards that consist of a rigid top layer and a lightweight bottom layer to speed up and improve quality.

Grigory Gromakov

ROCKWOOL Flat Roof Development Specialist

Flat roof drainage

A flat roof is equipped with a parapet (attic) 30–90 cm high, which helps to ensure organized; on the operated roof, it also serves as a safety fence. At the same time, the design of gutters should be approached very responsibly, because in the event of an error, a huge puddle can form above your head, which threatens to damage the supporting structures.

As a rule, the choice is made in favor of an internal drain. Such a system is less exposed to the atmosphere and therefore more durable and reliable than the outdoor one. Let's talk more about its main elements.

Drainage funnels are installed on low sections of the roof. As a rule, two funnels are mounted on roofs up to 150 m2 - the main one, connected to the riser, and the emergency one - with water discharge through a hole in the parapet. With an increase in the number of funnels and risers, the reliability of the system increases, but its cost also increases.

For inverted and green roofs, special funnels with drainage rings have been developed to collect moisture from the intermediate layers. Water intakes must be equipped with electric heating based on a self-regulating cable - then they will properly perform their function during alternating thaws and frosts.

Covering traditional with an external drain 1 - overlap; 2 - slope-forming screed; 3 - vapor barrier; 4, 5 - mineral wool insulation; 6 - waterproofing; 7 - drain

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

The drain riser is made of sewer pipes - polypropylene, PVC, and it makes sense to use noise-absorbing products, such as RAUPIANO Plus (REHAU), or to soundproof the riser, otherwise you will hear the murmur of water for hours. The riser is attached to the funnel using an elastic coupling. When laying pipes, minimize the number of elbows and the length of horizontal sections that reduce the throughput of the system.

A drainage pipe laid in the basement or insulated underground connects the riser to the rain sewer or provides water discharge into the linear drainage tray. In the second case, there is a risk of clogging the outlet with ice, so the riser should be equipped with a “winter” outlet to the domestic sewer (the latter should be equipped with a water seal). The outlet pipe is cleaned through a collapsible connection or revision module.

Image: Vladimir Grigoriev/Burda Media

Roof covering inversion with an internal drain 1 - coupler; 2 - PVC membrane; 3 - EPPS; 4 - funnel with a drainage ring; 5 - drainage membrane; 6 - sand; 7 - paving slabs

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

The external drainage system is more vulnerable than the internal one, and also affects the appearance of the facades, but it does not require holes in the roof and ceilings and does not eat up the usable area of ​​the house. Water is discharged through parapet funnels or branch pipes embedded in the parapet, under which classic funnels are installed (as on a pitched roof) and downpipes attached to the walls with brackets. When calculating, it is assumed that for every square meter of roof area there should be 1–1.5 cm2 of the cross section of drainpipes. Elements of the external system can be made of PVC, steel, copper, zinc-titanium.

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

Dmitry Mikhailidi

Head of the Engineering and Technical Center of the Technical Directorate of the TechnoNIKOL Corporation

Roof greening

Turf-covered roofs have been used since ancient times in countries with a moderately cold and humid climate, and the green carpet performed the main moisture-protective function in them.

As part of the modern concept of a green roof, a layer of fertile soil with plants is needed to give unusual features to the appearance of the building, decorate the terrace roof and extend the life of the coating by covering it from ultraviolet rays. In addition, it absorbs rainwater, unloading gutters, dampens the sound of rain, protects the upper floor from overheating in summer and reduces heat loss in winter. It is believed that landscaping almost doubles the life of a roof. Its disadvantages include an increase in the load on the supporting structures of the building and an increase in the cost of construction. In addition, the green carpet needs care, the intensity of which depends on the selected plant species. If you do not pay due attention to plantings, they will freeze and die from drought.

For landscaping the roof, it is necessary to lay on top of the main waterproofing layer (in the case of an inversion scheme - on top of the insulation) an additional cake of materials that will protect the waterproofing layer from roots, filter and drain rainwater. For these purposes, special films, dense geotextiles, gravel bedding or drainage and moisture-accumulating membranes made of high density polyethylene, such as PLANTER GEO or Delta-Floraxx, are used.

Then a mixture of minerals and fertilizers is poured - the so-called soil substrate. It can be prepared independently by adding fine expanded clay (5–15%), sand (about 20%) and fertilizers to a light soil mixture from neutral peat. As for plants, it is easiest to limit yourself to meadow forbs and drought-resistant ground covers - sedum, carnation-herbal, thyme. They do not need to organize an irrigation system, and the thickness of the soil layer can be only 6-12 cm (the roof of this type is called extensive). If you plan to walk on the roof among ornamental shrubs, you will have to provide watering and increase the thickness of the soil to 20-40 cm. Such a roof is called intensive, it creates a significant additional load on the floor, so it should be provided at the design stage of the building.

The terraced structure provides convenient communication between the living quarters of the cottage and the exploited roof, which serves as a place of rest

Roll materials based on modified bitumen, as a rule, are fused with a gas burner, while it is difficult to prevent small flaws that can cause leakage (if there is no second layer)

Rolled PVC membranes , for example Sikaplan WP, Logicroof, Ecoplast are strong and durable (up to 30 years without repair) and do not support combustion. However, they require a professional approach to installation (the joints of the strips must be carefully welded with hot air) and are relatively expensive - from 320 rubles. for 1 m2. It is important to consider that this material does not tolerate contact with bitumen.

Roll membranes made of ethylene propylene rubber (EPDM) and thermoplastic polyolefins (TPO) , for example Firestone RubberGard, Logicroof P-RP, retain elasticity at low temperatures. Note that EPDM membranes are highly flammable (class G4) and are mainly designed for use in the construction of an exploited roof, where the waterproofing is covered with tiles, gravel or soil. EPDM and TPO membranes cost 1.3–1.5 times more than polyvinyl chloride ones (mostly imported products).

Polymer-bitumen mastics allow you to create a seamless coating, but they can only be applied to a solid, non-cracking base - a floor slab or a carefully reinforced screed, and this process is quite long and laborious. The service life of a two-layer coating 5 mm thick is about 20 years, the price is from 120 rubles. for 1 m2. In practice, mastics are used mainly for repairing roofs and gluing rolled materials.

Polymer and cement-polymer self-leveling waterproofing , say Aquascud, Osmolastic, Osmoflex, high elasticity
and UV resistance. To improve the performance, the materials are used in combination with special primers and lining films, reinforced with mineral fiber (all components are supplied as a single system). Estimated service life of the coating - more than 50 years; price - from 700 rubles. for 1 m2.

Flat roof: pragmatic view

Each of us wants to have our own roof over our heads. Moreover, one that will not only serve reliably for many years, but also give the house an original and unique look, arousing the interest of neighbors and casual passers-by.

The type of roof is chosen at the stage of creating a house project. Flat or pitched, it will define the look of the whole house. When constructing both types of roofing, we can both save and waste building materials.

flat roofs
A flat roof is usually called a roof, the slope of the surface of which ranges from 2 to 20 degrees. A flat roof is also called a non-attic, because, being a ceiling over the last floor, it simultaneously performs the function of a roof.
A flat roof is a flooring of a carrier plate and steam, heat and waterproofing layers. Flat roofs can be ventilated or non-ventilated.

The construction of a ventilated roof is the most effective solution for neutralizing condensate in the under-roof space, which is formed due to temperature differences, as well as atmospheric precipitation. In ventilated roofs, the space between the heat and moisture insulating layers allows air to circulate freely, protecting the insulation from moisture.
Water vapor escapes through ventilation openings, which should be located on the outer walls between the ceiling of the upper floor and the lower part of the roof slope.

A non-ventilated flat roof is easier to build. All its layers are tightly adjacent to each other, there is no space between them. To prevent the formation of moisture in the thickness of the insulation when installing this type of roofing, various technical solutions are used.

One of them is the so-called inverted roof, the difference of which is that the insulation is located not under the waterproofing layer (as in a traditional roof), but above it. In this case, extrusion polystyrene board (XPS) would be the ideal thermal insulation material.

In our climate, flat roofs are especially damaged by regular freeze and thaw cycles. The constructive solution of the inverted roof provides effective protection against the damaging effects of these atmospheric phenomena, as well as from sudden temperature changes.
Flat roofs also provide additional free space. So, the design of the inversion roof allows you to use it as an exploited one - to arrange a garden, terrace, etc. on it.

pitched roofs
The sides of such roofs have an angle of inclination of more than 20 degrees. The design of a pitched roof depends on the type of premises located under it - residential or non-residential.
In the case of a non-residential attic, the principle of roof construction is the same as for ventilated flat roofs, where the thermal insulation layer is located on the ceiling of the last floor of the building.

If the attic is to be used as a residential heated space, care should be taken to ensure that the roof is well insulated and that the space underneath is adequately ventilated. Then the sides of the pitched roof are insulated, and a ventilation gap is made between the layer of heat-insulating material and the roofing, which prevents the accumulation of moisture in the under-roof space.

To limit the penetration of water vapor through the roof slope and its accumulation in the insulation, a layer of vapor barrier film is laid. For the vapor barrier of pitched roofs, special membranes are also used, which not only trap steam, but also "control" it. This is the so-called active vapor barrier.

The shape and size of pitched roofs depends on our preferences, capabilities and means. But the fact remains: the construction of roofs of complex shapes brings more worries associated with the arrangement of their insulation, insulation and ventilation.

well, not a dispute, of course ... I just don’t understand the principle of traditionalism without an explanation of its usefulness and profitability and profitability ...

and if my friendline indicates that earlier in antiquity there were few technologies for making non-leaking roofs, and therefore one of the advantages of the pitched “Accelerated flow of water due to the greater slope” that you indicated was important, now how does it affect ???

Let's reiterate what you said:
1. Accelerated water runoff due to a larger slope (ok... but pliz highlight the advantage of this, for example, for a straw roof this is certainly relevant ... but in general ???) do we have tropical monsoons planned in the country?

2. Simple organization of the drain (wow, simple! ... or simple in the sense: the main thing is to drain?)

3. Lack of snow bags (I protest! ... there is no rationale for the occurrence of these)

4. Convenient maintenance of the roof through the attic space or attic
(note ... to look at the gap or observe leaks ... and then a very important addition ... if the roof is made of anything, and by the way, in the case of the attic rooms you specified, doesn’t it make sense?).

5. When designing an attic floor, there is no need to build external walls (it is important to understand that an attic is already a consequence of making a decision about a pitched roof ... at first there were pitched roofs and only then they came up with attics ... not vice versa. let's not interfere in a bunch ....) (at the same time I agree that those who, in the private architecture of instant loan now, have conceived additional meters "a la the second floor" - this solution may turn out to be ... although no. you have to consider.)

I agree with the disadvantages.

For flat:
by cons
3. The risk of clogging or freezing of the internal drain - (if at least somehow you can agree with the first part with a stretch ... then the second is not clear in principle ... in what case can it freeze in the internal?)

4. The need for mechanical cleaning of the roof from snow (I protest!) If pitched roofs with their icicles and other hemorrhoids constantly bring problems and troubles, then in the case of flat ones, I don’t know such cases.

I'm adding to the list. (or just repeat for now)

1. - pitched device is a whole art (rafters, rafters, ridge, beams, battens and many others ...

1.1. - I fell asleep in a flat insulation, put the roof on top and that's it,
- in the pitched way, re-laying, etc.)

2. cleaning ...
- on flat ones, even on a snowplow, ride, and be icicle-free ...
- in pitched insurance, try not to fall, etc. risk))

3.rain water…
- in the flat only a border and a hole, .. hmm. well, in a container or .. as well as a bunch of design and innovation ideas.

- in pitched ... hangers for drains, downpipes, drainage gutters (s) with gratings next to the house and a whole complex ...

4.wind
- for flat fie ...
- for pitched art not sailing, etc.
(it recently stormed in Irkutsk, in the news feeds you can see how many stingrays were on the ground and what damage they caused)

5. for an alternative rudimentary and irrelevant so far, flat energy is better suited ...
also more convenient for flat mounting and engineering equipment, such as antennas, deflectors, air conditioners, etc.

6. according to discovery, a contender for entering the top three projects is the transformation of roofs into beds or flower beds, finally ...

and much, much more... what's the word. I can't come to an opinion

One of the most important parts of the house is the roof - warmth and comfort, noise level and frequency of building repairs depend on its quality.

Naturally, during development planning, the question arises, what type of roof to choose, or which roof is better - cheaper, more expensive, broken or gable, or maybe four-slope?

It is not enough that the roof is just strong and attractive. It must also have a number of important properties: provide good protection from rain and snow, protect from heat and cold, and be fireproof. Let's look at the main types of roofs and their characteristic features, because the choice of material for the roof depends on the type of roof.

Main types of roofs

1. flat roofs. They are usually erected over outbuildings and outbuildings, garages, bathhouses, sheds, as well as houses with a terrace on the roof.
2. pitched roofs. This type of roof is more common, and there are several classifications of pitched roofs, one of which we will give below. Among other things, pitched roofs can be divided into warm and cold, with and without an attic.

We list the main structural varieties of pitched roofs.

• Shed roofs
  Their surface is a plane resting on opposite walls of different heights, i.e. is at an angle to the horizon.


• gable roofs
  They consist of two angled planes and rest on opposite walls of the same height. Perhaps this is the most common type of pitched roofs.


• broken roofs
  A type of gable roof, in which each of the slopes consists of two rectangles located at an obtuse angle.


• cruciform roofs
  They are a combination of several ordinary gable roofs, as if cut into each other at a right angle.


• hip roofs
  These are hipped roofs with two long trapezoidal slopes and two short triangular ones.


• Half hip roofs
  A type of hip roof, sometimes called a Dutch one, in which the end slopes do not reach the eaves. Thanks to this design, the house can withstand the wind better, and its gables are less exposed to precipitation.


• hipped roofs
  A kind of 4-pitched roof, consisting of four equal slopes of a triangular shape.

When choosing the type of roof, one should take into account not only its intended operational properties, but also decorative qualities. In low-rise buildings, the roof has a large relative volume and its appearance largely determines the architectural solution.

In private houses, mainly roofs of high structures are erected. This allows you to build an attic, and the house takes on a more presentable appearance. Also, steep slopes do not allow water and snow to linger on the roof. In areas with strong winds, it is preferable to build low roofs or high ones, with additionally reinforced truss systems.

You should also consider what kind of roof the developer can afford. Naturally, roofs of simpler structures are cheaper, and the most economical options are flat and pitched roofs. An additional convenience of a shed roof is that it allows you to increase the internal volume of the building, and at the same time serve as a ceiling in outbuildings.

If the attic space will be used for household needs, it is better to build a gable roof. In areas with strong winds, a type of hip roof is the best choice, but its construction will be expensive. In addition, the construction of hip roofs requires high professionalism, and should only be trusted by experienced craftsmen.

In houses of complex shape, as a rule, cruciform roofs are used. This is a rather complex structure, consisting of many intersecting slopes. The complexity of the device of the cruciform roof is to ensure the tightness of the inner corners of the roof. Such roofs are expensive, they must be built by experienced craftsmen and always from high-quality materials.

Roof construction elements

After choosing the type of roof, you can begin the selection of materials. Therefore, we will get acquainted with the main structural elements of roofs:

• Basic structure. Its type depends on the type of roof. Usually it is constructed from wooden beams and rafters.
• Roof base. It can be built in the form of a lattice or be solid.
• Hydro- and heat-insulating layers.
• Roofing material.

Rafters and their types

Rafters perform an important function in roof construction. This is a support for the crate, which takes on not only the weight of the roof, but also the wind load, as well as the pressure of snow.

• hanging used for long spans;
• oblique, used for spans up to 6.5 m. With additional support, the spans can be extended up to 12 m.

The design and construction of truss systems is work that requires great skill. Its quality determines the bearing capacity and, consequently, the strength of the roof.

Foundations for roofing

The type of base under the roof is selected depending on the intended roofing material.

There are two main types of base under the roof:

• crate(used for roofing made of metal tiles, slate or metal profile)
• continuous flooring(when using roll media)

Solid flooring is constructed from two layers of boards. The first layer is called working, and the second - protective. The latter is located at an angle of 45 degrees with respect to the worker and is constructed from narrow boards. Between these layers, a windproof material is placed, usually roofing material RRP-300 or 350.

When installing the crate, a number of rules are observed:

• all elements of the crate are securely fastened to the rafters;
• their joints are located on the rafters in a run;
• the distances between them must be maintained over the entire surface of the roof being constructed.

Roofing materials and works

The top part of the roof is called the roof. It is in direct contact with the external environment, taking on all the power of wind and precipitation. Therefore, the main qualities that it must possess are strength and water resistance.

There are many materials for roofing, and choosing one of them, you should take into account its performance characteristics, as well as a number of other factors:

• climate;
• functional purpose of the building;
• material durability;
• material cost;
• its soundproofing and heat-saving properties;
• the complexity and cost of roof maintenance;
• external attractiveness of the material.

It is difficult to give unambiguous and exhaustive advice on the choice of roofing material, which will be better, since all of the above factors influence it, and, as you know, ideal building materials do not exist. In addition, the determining criteria may differ, for example, with insufficient funding, the price becomes the main one, and all other factors are considered less captiously. On the contrary, if consumer properties come to the fore, then the price, as a rule, does not have a decisive value. For someone, perhaps, beauty or color will be the main factor, since according to the owners' plan, the house should not be like the rest.

The choice of material should be made at the stage of creating a house project, since the type of roof construction depends on it, and it will be difficult and expensive to make changes to the finished project.

findings

The selection of a roof structure and roofing material is an important stage in the construction of a house. Finding the best solution can only be done by taking into account a number of factors:

• purpose of the building;
• noise-insulating and heat-saving characteristics of the roof;
• construction budget;
• climate features;
• aesthetic impression.

Only by taking into account the listed factors and weighing each of them, you can choose the best roof option and type of roofing material.

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

This state of affairs is explained simply: until recently, builders did not have reliable and durable waterproofing.

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

Today, interest in flat roofs is starting to grow.

There are several reasons for this:

• Economic benefit. The cost of arrangement is lower than that of a hipped roof (simpler design and smaller area);
• Additional usable area. There is the possibility of its rational use (flower garden, playground, recreation area, swimming pool);
• Availability for maintenance and operation (cleaning drains, installation of air conditioners, antennas, inspection of coatings, ventilation and smoke channels);
• The layer of snow plays the role of additional thermal insulation, reducing heating costs.
• The original appearance of the building.

Types of flat roofs

Strictly speaking, you will not see a completely flat roof on a building. Any of them has a minimum slope of 1 to 4%, which is necessary for the runoff of precipitation.

There are four types of flat roofs:

• unexploited;
• exploited;
• green (lawn);
• combined.

Unexploited roofs are found on industrial buildings.

Exploited roofs have found application in public and private construction. They equip recreation areas, place cafes and restaurants, use them as parking lots and helipads.

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

Combined roofs with a flat surface are the most common option. Everyone likes a comfortable outdoor recreation surrounded by green grass and flowering plants.

According to the method of drainage, houses with a flat roof are divided into two types:

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

Internal drainage is cheaper than external drainage, since it does not require a large number of gutters, pipes, funnels and high-altitude installation work. In execution it is more difficult. Errors in creating a slope, poor-quality sealing of joints lead to leaks and a violation of the integrity of the protective layer of waterproofing.

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

Device Features

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

• Classic;
• Inversion.

The classic roofing "pie" is equipped according to the following technology:

• on reinforced concrete floor slabs, they make a ramp out of a cement-sand mortar;
• lay vapor barrier and insulation;
• lay a waterproofing membrane or roofing felt carpet;
• if the coating is to be used, then the waterproofing is protected with ceramic tiles.

Classic flat roof structure

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

Working on a solution to this problem, engineers came up with the idea of ​​inversion coating. In it, the main structural elements (insulation and waterproof membrane) are interchanged. Waterproofing is hidden under the foam, which is protected from external influences by a ballast layer of gravel or tile trim.

Inversion coating design

Accordingly, the technology of work is changing. A waterproof carpet made of roofing felt or an EPDM membrane is glued onto the slab or spread on it, fixing it at the junction with the parapet.

The slope in this case is created in one of two ways:

• Mortar screed on the plate;
• Insulation, changing the thickness of its installation.

Installation of thermal insulation on a flat roof

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

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

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

Construction technology in this case may include the following operations:

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

Examples of private houses

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

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

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

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

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

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