The construction of a gable or hip roof not always rational and expedient when it comes to outbuildings, industrial and commercial facilities, and sometimes private houses in modern style. Large consumption of material, complex rafter system make the construction of these structures economically unprofitable, protracted undertaking. While flat roof projects greatly reduce construction costs, build quickly and are suitable for almost any structure.
A house with a flat roof is reliably protected from increased wind load. However, without slopes, it cannot quickly drain rain and melt water from the roof surface.
The situation is complicated by the fact that the surface of roofing materials has a rough structure that does not allow moisture and snow to slide off freely. Therefore, the device flat roof, mounted by oneself, must comply with the stringent requirements of building codes for waterproofing, ramping and construction technology.
The structure of the roofing pie
Necessity high level protection against moisture forces the roofing materials of a flat roof to be arranged in layers, one above the other, forming the so-called "pie". If we consider its device in section, we can see the following layers:
- Flat base made of concrete slabs or profiled metal sheets. It provides structural rigidity, bears the weight of the roofing pie, transferring it to the load-bearing partitions and, as a result, to the foundation. At the exploited roof, the base should be as rigid as possible.
- vapor barrier. A layer that is necessary in order to protect a flat roof from the penetration of vapors from internal heated rooms into the thickness of the insulation. Settling on thermal insulation in the form of condensate, water irrevocably reduces its insulating properties by more than two times. As the simplest vapor barrier, polyethylene film or bitumen-based coatings are used.
- insulation. For thermal insulation of a flat roof, backfill materials are used, such as expanded clay, perlite, slag, rolled, for example, mineral wool and in the form of plates, in particular expanded polystyrene. By the way, insulation is used not only to regulate temperature regime, but also for flat-roofed houses. The main requirements for insulation are low hygroscopicity and thermal conductivity, light weight.
- Waterproofing. flat roof allows the use of roll materials for coating in order to protect against moisture: bitumen, polymer and bitumen-polymer. In addition to high waterproofing qualities, they must be resistant to temperature extremes, elasticity, long term operation.
Types of roofing and the nuances of their installation
The device of a flat roof determines the design and nature of use. The following are distinguished into separate types that require a special approach during construction:
Roof installation for unheated buildings
If a flat roof is erected with your own hands for an unheated utility room, for example, a shed, gazebo, shed or extension, the slope is organized using support beams.
They are installed at an angle of 3 degrees, which is 30 mm per linear meter of the length of the beam. Then a base of unedged boards is laid on the beams, fixing them with nails or self-tapping screws.
Roofing material is used as a waterproofing agent - the most affordable material. It is produced and sold in the form of rolls. Carry out the cutting of the waterproofing, cutting the strips so as to lay them in the direction of the slope of the flat roof.
Strips of roofing material are laid in stages with an overlap of 10-15 cm and fixed wooden slats or steel strips every 60-70 cm in the direction of the drain, so as not to block the path of flowing moisture. The flat roof of an unheated room is easily mounted by one's own hands, even by one worker without the help of helpers.
Roof installation for heated buildings
If they are building a private house with a flat roof, which they plan to connect to the heating system, then the work takes place in the following order:
To build a house with a flat roof, the length of which exceeds 6 m, a bar with a section of 150x150 mm or more, or a steel I-beam, is used for the manufacture of support beams.
Monolithic concrete roof
Another option for building a flat roof with your own hands is to use monolithic concrete. The process looks like this:
Decline process
- the device of a small angle of the roof surface for organizing a drain. Before building a house with a flat roof, it is better to decide in advance which drain you will install, internal or external, and make a drawing.
If provided, water should drain with the help of a ramp into the water-catching funnels, which are located 1 per 25 sq.m or more often. If you make an external drain, then moisture should fall into the gutter. The slope is formed by the following methods:
A flat roof without a proper slope is an unreliable shield between you and the weather. Moisture that has no way out will accumulate on the surface of the roof, provoke the destruction of the roof and leaks.
Video instruction
If earlier flat roofs were made only on urban high-rise buildings and were associated with constant leaks, today the situation has changed radically. These structures are used not only during construction multi-storey buildings, but also in the construction of prestigious private houses on exclusive projects. Such changes were made possible by the emergence of completely new building materials and technologies.
Flat roofs - one of the many types of roofing, has both positive and negative sides. The advantages of such roofs include the following characteristics.
- Saving building materials and speed of construction. The effect is achieved due to physical savings - the area of \u200b\u200ba flat roof is much less than a gable roof. In addition, for this design there is no need to make a complex truss system with various girders, props, crossbars, mauerlats, etc. A small number of roof elements makes it possible to build flat roofs on their own without involving expensive professional specialists.
True, for this you should have the initial skills of performing roofing works, to understand modern technologies and materials. Otherwise, attempts to reduce the estimated cost of the structure can lead to large additional costs for unplanned repairs. And not only the roof itself, but also interior spaces buildings. - The ability to use the roof as exploited. On flat roofs, you can equip winter gardens, places for recreation, flower beds, small playgrounds for sports, etc. But in these cases, the roofs have very complex structure and require a professional approach to the implementation of all construction works.
- Flat roofs facilitate installation and periodic Maintenance various engineering equipment: air conditioning and ventilation systems, solar panels, antennas, etc.
Unfortunately, such architectural structures also have disadvantages.
We have listed real benefits and shortcomings, each developer must carefully analyze them before making a final decision.
Varieties of flat roofs in private houses
Thanks to new materials and technologies, designers have been able to create several types of flat roofs with unique performance characteristics.
flat roof type | Brief description of technical and operational characteristics |
---|---|
The most commonly used, simplest and cheapest type of roof. It is most often found on utility buildings, it is rarely mounted on private houses. | |
Very prestigious roof, allows you to use the area to increase the comfort of living in the building. The arrangement of such roofs requires quality materials and special technologies. The operated roof is often inverted. | |
It differs from the usual arrangement of layers of the roofing cake. Waterproofing is done directly on the bearing base, this feature protects the coating from mechanical damage. Geotextiles, extruded polystyrene foam, another layer of geotextiles and a ballast layer are laid on top of the hydroprotection. Geotextiles allow water to pass through drain system, and the ballast prevents the layers from being undermined by strong gusts of wind. |
Important. The cost of flat roofs varies widely, some options for the price can be several times higher than gable structures.
Roofing pie device
All flat roofs in residential buildings must be insulated, the structures consist of several layers. Each of them performs its function and is critical for the roof.
Base
It can be reinforced concrete or wood.
Professional builders prefer reinforced concrete slabs, but not all houses can use them. Plates are mounted only on brick or concrete facade walls, for wooden or frame buildings such elements do not apply.
vapor barrier
Prices for material for vapor barrier
Vapor barrier material
It is used only in two cases: the base of the flat roof is wooden and mineral wool is used as insulation.
But such options are rare, most often the base is made of a concrete slab, and durable extruded polystyrene is used for insulation. Both of these materials are not only not afraid of steam, but also do not react to direct contact with water. Accordingly, when arranging roofs from such materials, vapor protection is not required.
insulation
There are two types of insulation that can be used in the construction of flat roofs.
Heaters can be installed in two ways.
Currently, architects in most cases prefer the second option for flat roof insulation, keep this in mind. But practitioners advise installing heaters from inside the premises. Each builder must make their own decision.
Prices for thermal insulation materials
Thermal insulation materials
Practical recommendations for arranging a flat roof on a frame house
For example, we will take the option of arranging a flat roof on a wooden frame house. These buildings are very popular with many developers, they are quickly assembled, relatively inexpensive and provide residents with a modern level of comfort.
How to make overlays
For the ceiling, you need to use I-beams, ordinary beams will not work because of very high loads. If the linear dimensions of ordinary beams are significantly increased, then their own weight will play a significant role in calculating the acting forces, and this is highly undesirable for all structural loaded elements.
Important. If the size of the house is large, then it is much more profitable to order short beams and splice them on the spot. Due to this method, the process of transportation and installation of structures is simplified. During installation ceiling beams you need to make a slight slope for the descent of water.
Video - Wooden floor
What to make waterproofing
Prices for PVC membranes for roofing
PVC membrane for roofing
For sealing, it is recommended to use a modern high-quality membrane that has protection from the harmful effects of ultraviolet rays. The membrane thickness is not less than 1.5 mm, the service life of such coatings is more than thirty years. The membranes must retain their original properties at temperatures of -30°C and below. It must be borne in mind that situations may arise when it is necessary to remove snow from the roof in winter, the hydroprotection must withstand mechanical stress and not be damaged.
How to install a funnel for receiving water
The diameter of the funnel must correspond to the area of the roof and the maximum debit of water. The data are available in comparative tables and are attached to the instructions for using the elements. If for some reason there is no such instruction, then you should consult with the seller.
The funnel is installed at the lowest point of the roof. The roof plane is divided into several sectors and each has a slight slope towards the drain. To prevent ice from accumulating in the funnel in winter, it is recommended to connect the system electric heating. Heating functions temporarily and only during the period when the temperature several times a day changes from positive to negative.
How to properly lay a waterproof membrane
The joints are welded with a building dryer and additionally filled with a special two-component adhesive. You should start from the lowest edge, the width of the overlaps is at least 10 cm. To increase the strength of the fastening, each strip of the membrane is separately fixed special mounts, wide washers then close.
Along the perimeter of the parapet, the membrane is also screwed with washers of large diameter, the distance between them is about 20–30 cm.
How to drain water from a roof
Experienced builders do not recommend trying to install external gutters and pipes on flat roofs to drain water to the ground. The best option- let plastic pipes through interior spaces. Installation of the system should be done immediately after assembling the frame of the house, during sheathing internal walls pipes are hidden. Due to such an installation location, the possibility of freezing is completely excluded, the reliability of the system is significantly increased.
The better to process OSB boards
There are many options, the effectiveness depends not only on the materials used, but also on the professionalism of the master. But practice shows that, under all equal conditions, the greatest reliability for bituminous mastics. Surfaces must be lubricated at least twice, this guarantees the tightness of the coating for a long period of time. Of course, the top membrane must also be of good quality and correctly installed.
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In European countries, flat-roofed houses, which can be seen in the photo, are not uncommon; they are often built in the resort towns of the Mediterranean, since precipitation is infrequent there. In domestic open spaces, buildings with such a roof are still rare, they mainly have an industrial or economic purpose - workshops, garages, repair shops, etc. The reason lies in the fact that property owners prefer classic projects construction of private cottages.
flat roof houses
The most common form of their construction is considered to be square houses with a flat roof, they are luxurious penthouses that attract the views of passers-by with their appearance.
Disadvantages and advantages of flat roofs
The advantages of flat roofs are obvious:
- it is possible to use the roof surface for your own needs, you can arrange a place for recreation or sports there, plant ornamental garden, green lawn;
- building a house with a flat roof is profitable, since it saves a significant amount needed to create roof structure;
- snow that accumulates on the roof surface in winter acts as an additional insulating layer (experts call this circumstance controversial);
- for the operation of the top coating in winter time you can install a heating system;
- if inexpensive roofing materials were used to create the roof, then a significant amount of money will not be required for the repair and it will be possible to complete it on their own. Besides repair work, if the roof is made, for example, of roofing material, it is not done on the entire surface, but only partially in case of detection of overlapping defects.
The disadvantages include following points:
- in case of negligence or unprofessional construction work when creating a house with a flat roof, it may be necessary to repair the interior of the building, which will cost a lot of money. To reduce the likelihood of leaks, you must not forget about observing a slight slope of the roof, otherwise the precipitation will not drain, but will remain on it.
Taking into account the disadvantages and advantages of choosing flat roofs, we can conclude that this type of roofing is currently relevant and is a promising and reasonable solution, since it becomes possible not only to build an original building, but also save a significant amount of money.
Features of a flat roof device
The construction of houses with a flat roof has a number of nuances that should not be forgotten at the design stage. Most often, the basis for are corrugated board and reinforced concrete slabs, less often use lumber.
The installation of corrugated board is considered the most economical and financially advantageous, but it can be used when the upper surface of the roof will not be used, in addition, it will be required additional insulation. Concrete is considered reliable and durable, since on top of it it is possible to install not only a gazebo for relaxation, but also a small swimming pool, which is used in summer.
Natural wood base is usually constructed when building frame houses with a flat roof.
Flat roof decking
If a house with a flat roof is being built using corrugated board, then after installing the support, a vapor barrier layer is laid on top of it. It is necessary to prevent heat loss from the interior of the building. Vapor barrier material is produced in rolls having a certain width and length. Places of overlapping vapor barrier, which can be used as polyethylene film must be carefully connected.
Then a heat-insulating layer is mounted using plates for insulation, which are joined together. For reliability, a two-layer laying system is often used. There are bulges on the sheets of corrugated board, which must be tightly filled with heat-insulating material.
After that comes the stage of creation using a polymer film. When all the insulating layers are laid, reinforced concrete slabs are mounted or a sand-concrete screed is poured.
When is being erected Vacation home with a flat roof, regardless of what the base is made of, it is always necessary to make a slight slope - at least 5 degrees, otherwise water will remain on its surface.
Even a minor oversight made during the construction of a house with a flat roof can cause a major overhaul in the very near future.
Flat roof waterproofing and insulation
brick or wooden houses with a flat roof require high-quality waterproofing of the roof, which is performed using:
- films to create a protective waterproofing barrier against moisture;
- EPDM membranes, PVC membranes;
- hydrophilic rubber;
- liquid rubber- sprayed waterproofing;
- injection materials (silicone resins);
- lubricating compounds that are used to connect waterproofing sheets;
- penetrating materials.
Membrane insulation. Counts advanced technology, allowing to provide high-quality waterproofing when built frame house with a flat roof.
Diffusion membranes are in the greatest demand, they are:
- with microperforation;
- superdiffusion;
- anti-condensate.
Environmentally friendly and fireproof superdiffusion materials are especially in demand, since during their installation it is not necessary to leave a gap between the layers of waterproofing and thermal insulation, they repel moisture, preventing its penetration into the thermal insulation layer. The service life of such membranes is about 25 years. They are often used when building wooden house with a flat roof.
There is another way - old and well-tested - this is adhesive waterproofing. It involves the use of roofing material, which is glued to the surface by heating.
flat roof insulation
Insulation of flat roofs is one of the very important types of work associated with. You can do it from the outside or from the inside in one or two layers. The easiest and cheapest way is to insulate the roof from the outside. The two-layer thermal insulation system makes it possible to reduce the load on the floors. The first layer is a heat insulator. The second layer is denser; the distribution function is assigned to it.
It is not difficult to create a flat roof with your own hands - the main thing is to follow the technology.
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(at correct device without hanging edges) at maximum snow.
Wherein, roof structure has a complex multilayer structure, which ensures the tightness of the coating and the working condition of the insulation.
Most favorable conditions operation of 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 buildings economic purpose 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 him what material is needed for the construction of the floor, how exactly it will be insulated, what is in this case optimum material coatings.
flat roof insulation soft roof produced 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;
- Upper layer waterproofing;
- Roofing.
This is a general plan, in practice it is often supplemented or complicated with a view to more reliable protection from water penetration or the formation of cold bridges.
roofing cake
One of the flat roof options is inverted roof. This is relatively the new kind cake design, taking 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 rafter system is made and laid on top roofing . Nevertheless, wooden floors 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 used roofs of residential buildings, use as a basis concrete slab . 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 you to use any accessible view finishes - 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 general purpose roofs:
- 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 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, impermeable 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..
IN Lately appeared a large number similar materials with improved characteristics, allowing more reliable protection of 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 concrete floor and external drainage using gutters:
- The surface of the overlap is covered with a layer of slope-forming concrete screed(decline). 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.
- 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.
- 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.
- over the insulating layer laying a layer of waterproofing.
- 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.
- over the ballast layer if necessary, a layer can be laid paving slabs 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.. The 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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