Very often, owners of houses with a flat roof are faced with the problem that heat is lost through the roof. It happens that it deteriorates due to accumulated condensate. She may collapse one day. In order not to aggravate these problems, it is urgent to start roof insulation. We’ll talk about this today.
What features of flat roof insulation are found?
As a rule, the roof consists of several layers that form a flat surface. It consists of the main floor slab and fixed insulation. There is a separate layer of vapor and waterproofing. An important point is also additional insulation.
Insulation of flat roofs is often found in the construction of residential buildings. This is less common in industry. Usually, roofs of multi-storey buildings should be insulated.
A flat roof in a private house often refers to an inverse type of roof. It is equipped as follows:
- Gravel is initially laid. Its layer on a flat roof in a private house should be at least 50 millimeters.
- The next step is laying the filter material.
- Passes a layer of insulation. Reviews recommend choosing styrofoam.
- The flat roof insulation cake is supplemented with waterproofing and screed.
- After the screed dries, a floor slab is installed.
An interesting feature of this design is that the insulation is installed on top of the waterproofing. The waterproofing layer is protected from ultraviolet radiation. This increases the life of the roof.
The advantage of this coating is that on such a roof you can create an area where you can relax.
What should be the thermal insulation?
Insulation of flat roofs should be done only on suitable boards. There are several types that differ in composition. The slab, which is intended for coating, must be made of reinforced concrete. A variant is possible when a professional sheet is used.
It is necessary to create a special slope for the roof. It can be made using reinforced concrete screeds. An alternative option will be backfill with expanded clay.
All components of a flat roof are subject to special requirements. The material for thermal insulation must be chosen so that it is resistant to various loads. It must withstand snow as well as gusty winds. The roof can be operated in different ways, so the coating should be of high quality.
Single layer thermal insulation system
A feature of a single-layer system of warming flat roofs is the choice of insulation for a roof of the same density. What's the Difference? Concrete screed is made over a layer of insulation.
This method is often used when repairing old housing. Single-layer thermal insulation is widely used when building warehouses and other utility rooms. Another method is used in the construction of garages.
Distinctive features of a two-layer system
It is fundamentally different from a single layer. A very strong material is used as the top layer. It must have increased density. All the load goes to this layer. It should have an appropriate thickness, from about 30 to 50 millimeters.
The bottom layer should be no more than 170 millimeters. It is the main heat insulator. This method of warming flat roofs is perfect for repairing and warming old buildings. It helps to reduce the weight of the roof - say reviews.
It is important to remember that it is not recommended to make a completely flat roof surface. Typically, the slope goes from 2 to 4 degrees.
Distinctive features of materials
Nowadays, many new products are used in the building materials market. They combine all the qualities of each layer. The edge located on top is stiffer than the bottom. Installation is easy and fast.
Depending on the installation method, a material suitable for the particular case is selected. In municipal construction, they still use the option of backfilling with expanded clay, less often with perlite sand. This method is inexpensive. When working, it is revealed that it is difficult to achieve the desired bias. The thickness of the screed will also differ markedly. Additional costs will be required. Nowadays, you can use newer materials that will improve thermal insulation. Each material has its own heat transfer properties.
The most popular methods of insulation
Often used:
- Prefabricated screed. It is made from flat slate sheets or asbestos. This design is expensive. Work on its construction is also not cheaply priced.
- Wet screed. Wet screed is usually called a solution of cement and sand. This option is suitable for people who want to save money. The main disadvantage of this type of insulation is the ability of the solution to make the structure heavier. Before screeding in this case, it is better to put a layer of special strong paper. The solution dries for a long time. If the layer is not dry, but began to make waterproofing, then the likelihood of bubbles. This method increases the load on the coating, so it is necessary to purchase slabs for thermal insulation based on rocks (for example, basalt).
- Mineral wool insulation. It is rarely used, as it has low strength. It needs to be strengthened, so a screed is placed on a layer of mineral wool. Insulation of a flat roof with mineral wool is a rather laborious process. After the work done, the loads on the base will be evenly distributed, and you can start laying the waterproofing carpet.
Why are basalt slabs good?
In the market of building materials, basalt-based slabs are very popular. They have increased rigidity and other advantages. This material is simply laid and has the properties necessary for thermal insulation. The main advantage of basalt based boards is fire resistance. Fire safety is one of the main rules of construction, and this material is fully consistent with it.
The required plates have their drawbacks. They are made on the basis of fiber, so they are hygroscopic. If moisture has got into the stove during use, the thermal insulation properties are gradually lost. The quality and service life of such material is reduced.
The use of expanded polystyrene in the roof
One of the newest materials is extruded polystyrene foam. An interesting feature of polystyrene foam is its design of closed small cells. In this material, they are evenly distributed in the structure. The technology of warming a flat roof with polystyrene foam is quite simple. But you need to know its stages and perform them in the correct sequence. In the manufacture of the material using high temperatures and pressure. As a result, the granules are mixed, and then a special reagent is added. It has the property of foaming. Due to its quality, the desired product has no analogues. Distinctive properties of expanded polystyrene are:
- The lowest thermal conductivity among similar materials.
- It is verified that it has excellent resistance to external influences. Also tested for exposure to chemicals.
- Mold does not form on it. Over time, the fungus does not appear.
- It has water-repellent properties and also does not penetrate vapors through it. The cells, which are located in the upper layer of the material, pick up moisture, but it does not penetrate deeper. The advantage is that you do not need to spend money on additional strengthening and protection of expanded polystyrene.
Nuances of insulation, fasteners
In order for the insulation to justify the investments spent on it, it is necessary to observe the strength of attachment to the base. There are two ways of fixing the material:
- Some people prefer to mount insulation on bitumen. This event requires a lot of effort and cost. This method is best used if the base for the insulation is made of concrete. In this case, you do not need to buy additional fasteners, such as dowels. Then time is saved that would be spent on drilling holes for fasteners.
- Most citizens choose a mechanical fastening method. It will require special telescopic dowels. They are distinguished by a large hat. It helps to ensure that the dowel does not pierce the carpet from waterproofing. The tightness of the coating remains intact. With this method of attachment, a polymer bitumen material is used as vapor barrier. The material used has increased elasticity. Due to this, the holes that still appear from the fasteners are tightened without a trace.
If the method of two-layer thermal insulation of the structure is used, then experts advise laying the boards “in the run”. With this installation, the lower joints will be covered by the upper. Each plate is fixed with a pair of dowels. It is possible to use more fasteners.
Frequently Asked Questions
Often the question arises as to which side to put the vapor barrier on. Usually it is laid with an intermediate layer using foil.
For outdoor work, aluminum foil is usually used. It covers the flat side of the surface. When choosing which side to put a vapor barrier on, it is also necessary to build on the type of work. In this case, they are external. The vapor barrier is put up with foil.
There is insulation of a flat roof with foam. This material is easy to use. Its advantage is economy in use and low cost. Therefore, it is quite popular.
Insulation of a flat roof with the use of foam is widely used in industrial facilities, as well as in private production. This material has excellent thermal insulation properties.
So, we found out what materials are used to warm flat roofs.