Recently, flat roofs have been increasingly being erected, which are gradually replacing traditional gable structures. With the help of such a roof, the building can be given a more concise and stylish look.
The device and installation technology have their own characteristics. Before starting work, it is necessary to understand the technology and the procedure. Not so long ago, projects of flat-roof houses were distributed only in Europe and in the West, today more and more Russians prefer this design option.
Device
Classical building standards are becoming a thing of the past, people prefer economical and practical technologies. A flat roof meets these requirements. Its device is different in that the time and financial costs are reduced, which is especially noticeable when compared with a gable roof. Flat roofs can be increasingly found on country houses and presentable cottages; it is not very expensive to implement such an idea. As part of this design, there are several layers, among them should be highlighted:
- base;
- vapor barrier;
- insulation;
- waterproofing.
Do I need a slope
The device of a flat roof necessarily provides for a slope. It should be within 4˚. This will avoid the accumulation of melt and rain water on the surface, reducing the risk of leaks, corrosion and deterioration of materials. The coating will become unusable in a short time after installation is completed if the water freezes and settles for several seasons.
The most common material for these roofs is lightweight concrete mix. It should contain extruded polystyrene. Its installation is quite simple. To do this, you do not need to have professional skills.
After hardening, the material acquires durability and strength. But the use of this composition should be taken into account even at the design stage, since concrete weighs a lot and exerts an impressive load on the ceiling and load-bearing elements. The device of a flat roof may involve the use of a concrete mixture, to the components of which perlite or expanded clay is added. The cost of the roof is reduced, but the weight is increased, so the roofing "pie" is not as strong. The slope in this case is formed using monolithic thermal insulation.
Sheet thermal insulation is laid on the prepared surface and fixed with glue to prevent displacement over time. It is recommended to use not only glue, but also dowels with plastic spacers, which will eliminate the contact of steelbase elements. This need is also due to the fact that the described areas become places where cold bridges are most likely to appear.
Slope problem
A flat roof must necessarily have a slope, but it is most difficult to form it if bulk materials are used, because it will be problematic to fill the expanded clay layer with concrete. But if a positive result can be achieved, then the layer will be durable and strong. The slope can also be formed on foam concrete blocks, which are covered with fiber-reinforced concrete. Such thermal insulation will be ready to serve without major repairs for several decades, but the price of materials is quite high, and installation entails additional financial costs.
Roof knots
A flat roof must be protected from the external environment. To achieve a positive result, special attention must be paid to those areas where docking with pipes, walls, ventilation and other building elements is carried out.
The main functions of the nodes are to ensure the tightness of the joints and insulation. On a reinforced concrete basis, the described nodes are organized in those places where the cut of the roofing pie will adjoin the vertical structures. At large manufacturers, you can find systems that take into account the design features of materials.
Traditional flat roof installation
Ordinary roofing provides for the presencewaterproofing, which is located on top of the insulation layer. It is also a finishing coating, which will be affected by the external environment. This type of roof is the most common, so it can be seen on almost every modern building with a flat roof.
Not so long ago, it was customary to use roofing felt for waterproofing, but today PVC membranes are the most suitable option. An ordinary flat roof cannot be exploited, since it does not have a reinforcing concrete screed. During the installation process, bas alt wool should be used, which will not be able to withstand constant loads.
Preparation
Before starting work, it is necessary to prepare the base by laying floor slabs or organizing a monolithic surface of reinforced concrete slab. Next, a vapor barrier is spread, which can be polyethylene or polypropylene film materials.
You can purchase polymer or bituminous rolled vapor barrier sheets. The latter are built-up and have important advantages when compared with film ones - they are thicker and denser, and during the installation process there is no seam through which moisture could penetrate. At the next stage, when building a house with a flat roof, insulation is laid. It is selected taking into account the characteristics of the climate and construction.
For a bath, it is better to use several layers so that heat is better retained inside. The most popular modern solution is mineral wool, whichis inexpensive and has all the necessary characteristics.
Insulation
The next step is to fix the insulation material. You can use glue or mechanical method for this. In the first case, bituminous glue is used. Thermal insulation is fastened according to a technology that determines the method of fixing waterproofing. If dowels were used, then the waterproofing is laid and attached to them. Experts recommend using bitumen, but the statement is true when it comes to laying on a concrete base.
Vapor barrier
When it is planned to use a polymer-bitumen vapor barrier, it is better to take dowels as mechanical fasteners. The next layer will be waterproofing. For this, rolled material is suitable, which is rolled out over the surface and fastened with an overlap of 20 cm. Then welding is carried out in a fireless or fire way. Installation of a flat roof at the next stage involves laying the top layer of waterproofing. This increases the durability and reliability of the "pie". Rolled material is welded over the entire area of the web.
Features of inverted roof installation
Compared to traditional, inverted roofing has a higher durability. When conventional roofs begin to leak, the inverted structure remains intact. This has been going on for several decades. Having considered the design in section, you can understand what the installation process looks like. Such a roof can be laid on a built building. To do this, you only have to dismantle the upper layers and lay the insulation in the desiredsequences.
Flat roofing technology can provide for further operation of the roof. From above, you can organize corporate meetings or create a summer studio. The design gives a minimum load, because it consists of a light finishing roll material, as well as steam, heat and waterproofing. You can use such a roof in private houses as a summer playground.
For installation, it is necessary to prepare a base, which is a reinforced concrete slab. It is coated with a primer to provide better fixation of the waterproofing. The next step is to do just that. In this case, the first layer is the waterproof material. For this, it is most convenient to use PVC membranes or bituminous roll products.
Insulation of a flat roof is carried out at the next stage. Then you can install a support layer in the form of geotextiles. It is located between the outer finish layer and the inner insulating materials. For light roofs, roll materials deposited on the surface act as the roofing outer layer. An alternative solution is a layer of rubble.
If the roof will be subjected to medium load, paving slabs or insulating materials must be used. For strong inverted roofs, each layer is reinforced with high-strength geotextile. The outer covering can be a monolithic concrete slab.
Features of calculations
Calculation of a flat roof is easier than any otherIt was. You will need to determine the surface area as well as the area of the covering material. It is usually overlapped, so it is important to check the usable area in the instructions.
The first value is divided by the second to get the number of sheets. They are purchased with a margin of 10%. According to the same algorithm, when calculating, it is necessary to proceed in the case of other materials, for example, hydro-, steam- and thermal insulation.
Features of installation of fences
The fencing of a flat roof is installed in the same way as in the case of a pitched roof. First you need to determine the place where the roof barrier will be located. It must be removed from the cornice by 40 cm. Next, a universal bracket is installed into which the support posts will be mounted. They have crossbars attached to them. You need to take care of the presence of plugs. All joints are covered with sealant.
Fences are checked by a specialized company. In order for the structure to last as long as possible, special attention must be paid to the choice of material. The base can be galvanized steel. It is manufactured with high precision rolling. This indicates that the material can be used for various fencing and fastening systems.
Steel structures are coated with a zinc layer during the production process, which protects the metal from corrosion. Flat roof construction may include stainless steel railings. It has excellent corrosion resistance andalloying additives such as molybdenum, chromium, titanium and nickel. The most successful addition is chromium in the amount of 20%. Such steel does not corrode, because a film is formed on its surface, which excludes the influence of atmospheric precipitation.
The most expensive fences are those made of copper. They have excellent anti-corrosion performance, electrical and thermal conductivity. After several years of operation, such fences are covered with an oxidized green layer, which creates a barrier to aggressive external influences, temperature and moisture.
