Recently, the fashion for a flat roof is increasingly taking over the CIS countries. The fact is that its arrangement has a relatively small price when compared with the same gable. In addition, the so-called exploited roofs are actively practiced in Europe. They equip workshops, lawns, swimming pools and ornamental gardens. Regardless of whether the roof will be used as additional square meters or this plane will remain untouched, it is important to properly equip it. Warming flat roof- an important part, because its appearance does not provide for the creation attic space therefore, the ceiling will be a roof and one cannot do without thermal insulation.
Options for arranging flat roofs
Warming flat roof matter is obvious. If you have listened carefully to your physics teacher, you will probably remember the process called convection. Its essence is that warm air will always be on top and cold will always be on the bottom. Therefore, if at the construction stage you do not take care of the arrangement of the heat-insulating layer, warm air will very quickly leave the living space, and large resources will be spent on heating it.
In addition to preventing heat loss, the insulation evens out temperature regime in the roofing cake, thereby protecting it from the appearance of condensate. The moisture that got inside the cake has a very negative effect on all its components, but it causes the greatest damage to the insulation boards. A small amount of water can reduce the useful protective qualities of the roof by more than 50 percent, and with prolonged exposure it will completely disable the thermal insulation boards. Without functioning protection, the roofing system will not last long, therefore, it will soon become unusable.
Roofing cake provides for the device of several layers. It should be noted that flat roofs can be laid in two ways.
- Classic
- Inversion
If we consider the first type of device, then everything is simple here. First, the base is laid, as a rule, it is a reinforced concrete floor slab, then there is a vapor barrier layer, on top of which insulation boards are laid. After the laying process, waterproofing work is carried out. As it is customary to use materials based on bitumen. These types of roofs are widespread in all high-rise buildings with a flat roof. Certain Gain roofing system can make it exploitable. But, as a rule, the arrangement of such roofs on high-rise buildings is impractical, so they are made unusable.
The second option is practically no different, but is more thoughtful than the previous type. For the installation of an inversion roof, the same reinforced concrete slab is laid as the base, but not a vapor barrier layer is placed on it, but bulk material. As it is used gravel, expanded clay or gravel. The thickness of this layer is calculated according to some formulas, but the minimum value is 5 centimeters. Waterproofing is placed on the bulk layer, and insulation is closed on top. On top of the thermal insulation layer is arranged cement strainer, which will be the final layer of the base.
The essence of this method is to protect the waterproofing layer from the effects of the external environment. This will allow him to perform his functional tasks longer. Practice shows that this method really works, and many developers prefer it. An inverted roof can also be created both in operation and not. If you still decide to equip your roof, then keep in mind that this requires additional calculations. Special attention pay attention to the screed, because in addition to the coating, it is a barrier against destructive moisture, which, at the slightest opportunity, will penetrate the roofing pie.
Insulation for flat roofs, however, like the rest of the layers roofing cake must be selected according to the requirements. The fact is that if the roof is operated, then in addition to the main loads that will occur during its use, there are additional ones, for example, snow or pressure from its own weight. When buying these materials, you should first ask for recommendations from specialists and only then go to a hardware store.
Ways of laying thermal insulation
Insulation of a flat roof from the outside can be carried out in one or two layers.
The first option has found its application in industrial buildings, temporary structures. One layer is suitable for both operated and non-operated roofs. It should be understood that with increased loads that arise as a result of using a roofing plane, the reliability of a thin layer will not be enough, therefore, to give additional rigidity, it fits into the base reinforced mesh. Make sure that the insulation plates are located in the same plane, this will prevent temperature drops and condensation.
Two layers of thermal insulation will give the roof the required thickness, which will lead to more comfortable living in such a building. The material of the lower layer of thermal insulation should be slightly different from the upper one. It must have great thermal stability, despite its small size. As a rule, the thickness of such a product is from 70 to 170 millimeters. As for the top layer, it will distribute the mechanical loads arising from the upstream elements. The thickness of the upper plates is significantly less than the heat-resistant layer and is about 30-50 millimeters. Despite such small parameters, they perceive high loads well.
How not to make a mistake when buying insulation for a flat roof
Absolutely any materials that meet certain requirements can be used as insulation products. These include maximum hydrophobicity, high strength properties and good density. So, let's see which materials from the construction industry are the most suitable for us.
Urban and private developers most often use bulk products. They explain this by the fact that this material can be purchased almost everywhere, and for a small price. Expanded clay and perlite are products from this list. The first is the result of foaming clay under pressure, as for the second, its main part is coarse-grained sand, which has high thermal insulation qualities.
In fact, apart from the low price, these materials cannot stand out in any way and are significantly inferior to fibrous and polymeric heaters. Their significant disadvantages are the large mass and complexity of installation work.
The second line of popularity is occupied by mineral wool boards and known to all Styrofoam. If mineral slabs are used in the construction of the roof, then high-quality waterproofing will be required. The article has already mentioned that if moisture enters the thermal insulation layer, then over time it will disable not only it, but the entire truss system. The second type significantly wins not only in this matter. Styrofoam is not afraid to get wet, is relatively durable, it is very easy to install, affordable price tag. And everything would be fine, but it is undesirable to use it on an inverted roof, which is the most common. The fact is that expanded polystyrene is very sensitive to direct sunlight and is unsafe in terms of fire.
Evolution building materials relatively recently produced mineral wool in slabs, the main components of which are rocks. This product is characterized by increased strength compared to old analogues, moisture does not affect its characteristics so much, the structure of the material allows you to do without reinforced concrete screed.
If we talk about new products, then it is worth mentioning about polyurethane foam. Installation of this material is carried out by spraying on a base prepared for this. After contact with the surface, it reacts and foams, creating a durable waterproof shield that is not afraid of even prolonged exposure. sun rays. It is worth noting that this method of insulation has long been actively used in Western countries, but this material came to us quite recently, and developers have just begun to appreciate it.
I have asked my colleagues a lot about polyurethane foam and practically no one knows anything about it. After a short search on the net, I wrote out for myself the main positive traits this product.
- Low thermal conductivity. For comparison, let's compare mineral wool, in which this indicator is 0.055 W / m 2 and the material in question with a value half as much - 0.022 W / m 2
- Preparatory processes do not take much time. It is enough just to remove large debris from the surface and sweep
- To create the necessary layer, a small amount of polyurethane foam is enough, only 5-6 centimeters
- Minimal risk of leakage due to the creation of a monolithic surface
- If it is sprayed with high quality, then there is no need for waterproofing the roofing pie, therefore, this can be saved
- Multifunctionality. This product is an excellent alternative to waterproofing materials. It can be laid not only on the roof, but also in other places.
- Low weight due to low density
- Environmentally friendly product
- Due to the laying method, it can cover any kind of elements, such as downpipes
- Non-flammable and non-flammable, therefore completely safe
- High operational period (about 25 years)
- Ease of installation
Thanks to the application of polyurethane foam, thermal insulation acquires slightly different properties. It becomes completely immune to moisture, which will positively affect the shelf life of roofing elements. In fact, this material is able to completely replace the roofing pie.
A significant drawback of its installation is considered to be the need for special equipment. So self-laying you are unlikely to accomplish.
The technological process of laying insulation
As materials under consideration, I will take mineral wool boards and foam. The thing is, I don't think it's appropriate to use bulk materials in this regard, and the installation of polyurethane foam cannot be done independently. Therefore, I will focus on them.
How to insulate a flat roof with mineral wool boards
Before explaining the laying process, I note that not all types of mineral wool boards can be used as a flat roof insulation. The most suitable variety is a basalt-based product. The structure of such plates lies in the fact that its fibers are directed in opposite directions, as a result of which strength indicators increase.
Thermal insulation of a flat roof with mineral wool occurs in the following sequence:
- Foundation preparation. Typically, this process includes cleaning reinforced concrete slab from excess waste
- Laying a vapor barrier. Regardless of the material used and the method of laying the roof, the vapor barrier must not be neglected. This material will be the very first assistant in the fight against condensate. Some developers who forgot or did not want to lay this layer soon paid for their mistakes. Their roof, under the influence of water, began to collapse very quickly. Hardware began to rust and the wood to rot.
Vapor barrier membranes are available both unidirectional and double-sided. Laying the first implies that you have taken care of reliable natural ventilation, which will remove the moisture removed by the membrane. Alternative option is polyethylene or bitumen
- Installation of mineral wool boards occurs over the vapor barrier. Their device is best done in two layers. It should be understood that a thick roofing pie has a rather large mass, so all calculations should be carefully checked before laying. However, you can get by with one, as a rule, it is quite enough for the warm regions of the country.
- After distribution on the surface insulation boards they are attached to the base. Dowels or bitumen are used as fasteners. In the case of using mechanical fasteners, the vapor barrier must be securely glued to the base by fusing.
In the case when bitumen is used in laying the insulation, all assembly process not only slows down, but also rises in price. Despite this, it is a necessary component for concrete surfaces so that moisture cannot penetrate the roofing cake
- You cannot combine two fastener methods, i.e. if you used dowels, then continue to fasten only with them and do not use bitumen
High-quality work will bring not only satisfaction, but also a positive impact on the life of your building. If you find it difficult to do the above work yourself, then hire experienced workers for this.
Installation of foam as a heater
This material is relatively high rates strength and completely waterproof. That is why it is the most popular insulation for inverted roofs.
Styrofoam laying technology is not hard work. It is enough to know the laying technology.
- As elsewhere, some preparatory work is going on first.
- Then, on the prepared base, as a rule, this is a reinforced concrete slab, the material begins to be laid. Please note that the surface is not smeared and no additional layer is laid on it. All foam tiles are fastened together with construction tape. If there is a need to build a second standing, lay the tiles in such a way that their seams do not coincide with the previous layer
- When this layer is completed, the laying of geotextiles begins. 5-10 centimeters will be enough. It is a reliable protection of the lower layers from dirt and mechanical damage
- Next, gravel or small gravel is poured, and the entire surface is poured with a screed
If you plan to grow any plants on the roof, and for this you need to pour soil on its surface, then to protect the roofing cake, it is better to increase the geotextile layer by 15-20 centimeters.
Flat roof is perfect solution for country building, you significantly save on materials. Modern roofing products allow you to create a roof that is completely protected from moisture, which will positively affect the life of the building as a whole.
Flat roofing is an inexpensive and practical way to equip any building. Often it is erected over multi-storey residential buildings, industrial facilities, garages and extensions (verandas, terraces). In case of residential buildings a flat roof must be insulated, otherwise there will be little sense from it. This is what we will talk about in today's article - do-it-yourself warming of a flat roof.
The need for roof insulation, including a flat one, is obvious - anyone familiar with the concept of convection from a school physics course should understand that air, heating up, rushes up. If at the top he does not meet a worthy barrier, then he will freely leave the room. In other words, all efforts to heat the house under a flat roof will come to naught.
However, the beneficial aspects of roof insulation do not end there. In addition to the fact that thermal insulation traps warm air, it prevents the occurrence of sudden temperature changes inside the roofing pie. Let's turn to the same school physics course. When cold outdoor air collides with heated currents rising from the house, the reaction creates condensate - tiny droplets of water. Accumulating, condensate impregnates the layers of the roofing cake and wooden elements, provoking their rapid wear. For this reason, laying only one insulation under the roof sheathing is indispensable - it is necessary to protect it vapor barrier membrane, which will remove condensate from the thermal insulation and contribute to its rapid evaporation.
It turns out that the flat roof insulation device involves the use of not only heat-insulating material, but also vapor barrier. The sequence of laying depends on the type of roof. Flat roofs are classic and inversion. In the first case, it is based on a carrier plate, on which a vapor barrier is laid, and then a heater. It, in turn, is covered with bitumen-based roll waterproofing. It simultaneously protects the insulation from moisture and is a topcoat. Such roofs can be found on high-rise buildings in any city. It is also worth mentioning that a classic roof can be exploited and non-exploited. As the name implies, you can use the operated roof, that is, place equipment, furniture there, make add-ons, in general, use it to the full as an additional surface. Coating unused roof not adapted to increased loads, but the warming of both types follows the same scenarios.
The inverted roof is technically much more perfect than the traditional one. First, a layer of gravel, expanded clay or gravel is poured onto the carrier plate. The thickness of the powder should be at least 5 cm. A waterproofing is placed on such a drainage cushion, then a heater, everything is poured with concrete and the screed is covered with a finishing material. The main difference is in laying the insulation over the waterproofing, which allows you to protect the hydrophobic layer from harmful ultraviolet rays, temperature changes and mechanical damage. As a result, an inverted flat roof lasts much longer than a traditional one and automatically becomes exploitable - a strong concrete screed (especially if it is reinforced) allows you to arrange outdoor recreation and sports areas.
It should be borne in mind that the insulation, as well as all other layers of the roofing pie, will be Various types loads: snow weight, wind force, mass of overlying materials, etc. Therefore, increased physical and mechanical requirements are imposed on heaters for flat roofs. In addition, experts strongly recommend choosing the most hydrophobic material, since it is impossible to guarantee 100% protection from moisture. We will talk more about the choice of insulation a little later.
Ways to insulate flat roofs
Insulation of flat roofs is carried out according to one of two schemes: in one or two layers. Single layer insulation is relevant for industrial buildings, garages and warehouses. Suitable for operated and non-operated roofs (in the first case, a reinforced concrete screed is required finishing layer). Placing the insulation in one plane provides moderate protection against the appearance of condensate and excessive heat loss, however, only two-layer insulation allows creating a comfortable microclimate for a cozy life.
The two-layer insulation scheme, as you might guess, involves laying two layers of heat-insulating material in different planes. The lower main layer should be thermally stable with low strength and a thickness of 70 to 170 mm. The top layer is responsible for distributing the mechanical load over the entire surface of the system. Its thickness is significantly less than that of the lower layer, and ranges from 30 to 50 mm, but it is characterized by high compressive and tensile strength. Such a functional distribution of two layers of insulation significantly reduces the weight of the roofing pie as a whole, thereby reducing the load exerted by the roof on floors and foundations.
The choice of insulation for the roof
A variety of materials are used to insulate a flat roof from the outside, but after studying the above information, we can already identify several basic selection criteria. First, maximum hydrophobicity. Secondly, strength and density. Thirdly, if possible, light weight. Consider the materials used in modern construction.
Most often, in urban and private construction, backfill materials are used due to their availability and low cost. We are talking about expanded clay (foamed under high pressure clay) and perlite (light coarse-grained sand with good thermal insulation characteristics). Unfortunately, the advantages of these materials are limited by the low cost and availability - in other respects they are not able to compete with fibrous or polymeric heaters. They are relatively heavy, and it is ideal to create with their help. flat surface on a slight slope is quite difficult.
The second most popular are mineral wool boards and expanded polystyrene. Mineral wool retains heat well, is easy to use, does not burn, but needs high-quality waterproofing- if it gets even a little wet, it will cease to protect against heat loss. Extruded polystyrene foam is not afraid of water, it is characterized by high strength, ease of installation and relatively low cost. However, it is better to use it to create an inversion roof, since the material is very sensitive to ultraviolet radiation and is flammable.
Not so long ago, mineral wool in slabs made from basalt rocks appeared on the market. It is much stronger in compression and tear than older counterparts, is not so afraid of water and allows you to create enough durable coating without arranging a heavy concrete screed.
And finally, the newest, high-quality and expensive insulation is polyurethane foam. A special composition is applied to the prepared surface by mechanical spraying, after which it foams, hardens and creates a durable waterproof crust that perfectly retains heat and is immune to ultraviolet radiation. In the West, polyurethane foam has long been used to insulate roofs, including flat ones. In our latitudes, its advantages have only just begun to be appreciated.
The positive aspects of using polyurethane foam for roof insulation:
- very low thermal conductivity (polyurethane foam 0.022 W/m², mineral wool 0.055 W/m²);
- requires minimal surface preparation (clean of debris, you can not level and process);
- for quality insulation a layer 5-6 cm thick is enough;
- absolutely seamless coating, which eliminates the formation of potentially risky places for leaks and drafts;
- absolute hydrophobicity and vapor permeability (allows you to save on hydro and vapor barrier);
- spraying can be used to create additional waterproofing;
- the high rigidity of the hardened coating allows you to equip on top of it concrete screed;
- relatively low density (does not give a strong load on the bearing elements);
- environmental Safety;
- the ability to cover surfaces and objects of any shape (allows you to protect problematic places where pipes exit from leaks and heat loss);
- does not burn and does not support combustion;
- service life is more than 25 years;
- high speed of work.
Thus, polyurethane foam replaces both insulation, steam and waterproofing. The only drawback is that it will not work to do such work with your own hands, since this requires special equipment and skills in handling two-component material.
Warming technology
It's time to tell you how to insulate a flat roof yourself. Because the flaws bulk heaters not allowed to speak of them as the best options for furnishing, we will touch on the use of mineral wool boards and extruded polystyrene foam.
Mineral wool boards
Immediately builds to make a reservation that not all mineral wool boards can be used to insulate a flat exploited roof or a classic soft roof. Best suited for this purpose basalt slabs, the fibers in which are directed in different sides- this allows them to withstand high loads. Of course, you can protect the fragile insulation with a screed (dry or wet), but this will create an additional load on the supporting structures.
Mineral wool insulation technology:
Video about the insulation of a flat roof with mineral wool:
extruded polystyrene foam
Extruded polystyrene foam is highly durable and water resistant, and therefore is most often used for inverted roof insulation. There are slotted locks on the plates, which provide a very dense surface, but for greater reliability, it is recommended to glue all joints with construction tape.
The beauty of polystyrene foam is that working with it is very simple and fast:
- First, the slabs are laid on the base slab, gluing the gaps of the joints with construction tape. If you need to lay a second layer, the plates are mounted "in a run".
- over polystyrene foam insulation covered with geotextiles, designed to protect the lower layers of the cake from dirt and mechanical damage.
- A 5-10 cm layer of gravel or gravel is poured onto the geotextile. Sometimes, for additional drainage, a profiled membrane is laid between the geotextile and the powder.
- Finally, crushed stone or gravel is poured with a screed and laid top coat. If it is planned to land on the operated roof lawn grass or flowers, an additional layer of geotextile should be laid on top of the backfill, after which 15-20 cm of fertile soil should be poured.
Insulating a flat roof is not so easy, but this measure is necessary if you want to live in a warm house and not overpay for heating.
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Any roof for a building is a building envelope. Being in direct contact with external environment, she has to regularly bear the consequences of serious temperature drops of several tens of degrees. Given that the thickness of the overlap is some 40 cm, it becomes clear how high loads exposed to each of the elements of the roofing system.
In order to neutralize such a detrimental effect of such differences, it is necessary flat roof insulation. This event is aimed at improving its heat-saving, sound- and waterproof characteristics.
A flat roof is conditionally called, since any of them has a slope to drain precipitation from its surface. Creating a slope can, perhaps, be considered the first step for warming the floor. The issue of slope is solved, for example, by backfilling with expanded clay or using reinforced concrete structures.Flat roof insulation: device diagrams
A flat roof can be exploited and non-exploited. In the first version, this is a platform on the roof of the building, which is used for various needs. When using the floor of a building as additional area, it is necessary to perform a concrete screed over the heat-insulating layer. In the case of an unexploited roof, there is no need for such a screed.
Today, two main methods are used to insulate a flat roof. typical schemes devices: single-layer and double-layer. Schemes and installation technology for various roof bases (reinforced concrete, profiled sheet and others) are generally the same.
Single-layer flat roof insulation
This scheme is especially common for thermal insulation in the repair or new construction of industrial buildings, warehouses, garages. The layer of insulation used is completely made of heat-insulating material of the same density. If the flat roof is used for its intended purpose and device, then the heat-insulating layer is covered with a concrete screed.
Two-layer flat roof insulation
When installing a flat roof thermal insulation system on new buildings, a two-layer one is mainly used. This system has two layers of heat-insulating material - lower and upper. The insulation material used for the bottom layer is considered the main one. It should have maximum thermal resistance with low thermal insulation strength. Its thickness is 70–170 mm. Due to the upper layer, the mechanical load is completely redistributed to the flat system. The material of the upper layer is much thinner than the lower one - its thickness is only 30–50 mm, however, it has a greater compressive strength and strength. Such a functional redistribution between the layers of heat-insulating material can significantly reduce the weight of the insulation and, accordingly, the flat roof system.
Any element roof structure is under the influence of several loads, so it must meet fairly stringent requirements. In particular, flat roof insulation is directly under the following loads:
- snow,
- operational,
- wind,
- mounting.
Particular attention should be paid to the mass of snow in regions characterized by heavy rainfall in winter. The mass of wet snow accumulated on the roof can reach several tens of tons. So flat roof insulation must be reliable, with excellent properties, physical and chemical. Since the possibility of moisture getting inside the ceiling cannot be excluded, the thermal insulation must also be moisture resistant.
An important characteristic of roof insulation is its compressive strength. Thermal insulation of the roof, based on the technology of the device of a flat roof, actually performs the functions of the roofing material of its base, therefore, its compressive strength and density must be quite high. Any deformation during operation or installation can cause damage to the waterproofing layer.
thermal insulation material in a single-layer construction of insulation or upper layer in a multilayer one, it must have a high density, about 200 kg / m 3, which provides the material with special strength (you can safely walk on it).
Flat roof insulation technology and basic materials for thermal insulation
Flat roof insulation find it difficult technological process, one of the important components of which is the use of high-quality modern materials.
The approximate composition of the heat-insulating "pie" for a flat roof looks like this:- Floor slab made of profiled sheet or reinforced concrete.
- Vapor barrier coating.
- Thermal insulation layer. As a rule, mineral wool boards or expanded polystyrene are used, which are laid in one, possibly several layers.
- In the case of an exploited roof, a concrete screed is made.
- Sloped waterproofing.
The materials used for thermal insulation of a flat roof must meet the requirements of high vapor permeability, reduced thermal conductivity and water absorption, and fire safety.
Flat roof insulation with mineral wool
Thermal insulation slabs are attached to the base with the help of specific dowels or glued to a reinforced concrete slab, but only if the fastening strength of the adhesive is greater than the tear strength of the insulation layers. If the presence of a protective layer of cement-sand screed is assumed, the issue of fastening naturally disappears. In the case of using a two-layer system, for the second upper layer, which plays a protective function, special dish-shaped fasteners are used. Their length should be sufficient to pass through the mineral wool array and go deeper into the base by more than 50 mm.Flat roof insulation with polystyrene foam
Other popular . It can be said that it completely consists of air bubbles, which are enclosed in closed cells made of polystyrene. During the manufacturing process, a flame retardant is added to the material. Expanded polystyrene is distinguished by excellent thermal performance, performance and high strength. This thermal insulation material.
Flat roofs are less popular in private buildings compared to pitched ones. They are mainly used in the construction of multi-storey residential buildings and industrial facilities. According to statistics, only 5% of private houses and cottages have this type of roof.
But in the construction of outbuildings, garages, terraces, this type of roof is used quite often. A flat roof is affected by various types of loads: precipitation, wind, temperature difference, sun, mounting loads, etc. Therefore, flat roof insulation is a complex undertaking that requires a thorough approach.
Thermal insulation technologies
The method of insulation and the sequence of work depends on the type of flat roof. They are traditional and inversion. Inverted roofs are usually exploitable. traditional roofs additional features do not perform.
Thermal insulation of a traditional roof
The “roofing cake” of a traditional type of roof is made from the following layers:
- concrete base or metal profile;
- vapor barrier;
- insulating material;
- waterproofing layer.
The sequence of layers for thermal protection of an inverted roof is somewhat different. In this case, the insulation system looks like this:
- bearing base;
- waterproofing;
- insulating material;
- geotextile;
- crushed stone backfill;
- finish coating.
Exploited and non-exploited roofs
Unexploited roofs have only the main protective function.
The surfaces of exploited roofs can additionally serve as a garden, a terrace, a sports ground, a recreation area. Therefore, the insulating structure of the exploited roof must be especially durable and reliable. When installing a single-layer insulation system on such a roof, a concrete screed must be made on top of the insulation.
Green roof.
Single layer and double layer insulation
Depending on the number of layers of insulation, the insulation system can be two-layer and single-layer.
With a single-layer system, the heat-insulating layer is made of insulation material one density. In this case, the heat insulator must be sufficiently dense and durable.
This design is usually used in the reconstruction old roof or in the construction of warehouses, industrial buildings and garages.
When installing a two-layer insulation system, two layers of insulation are laid. The bottom layer has the main heat-shielding function. It has a greater thickness compared to the top layer, high thermal insulation characteristics. In this case, the strength of the material can be relatively small.
The top layer of insulation additionally carries the function of redistributing the load. Its thickness is less, while the density and compressive strength must be high.
The two-layer design allows to achieve high strength of the insulation system with relatively low weight. As a result, the load on the floors is reduced.
Material selection
When choosing insulation for a flat roof, you need to consider the following material characteristics:
- strength;
- density;
- thermal insulation properties;
- Fire safety;
- soundproof characteristics.
The following materials can be used for thermal insulation:
- mineral basalt wool, due to the air in the structure, the material has high thermal insulation properties, and the insulation fibers adhere tightly to each other, providing it with high tensile strength;
- ecowool - a cellulose material that is treated with fire retardants to make the insulation non-combustible;
- polyurethane foam - a modern sprayed heat insulator that forms a uniform surface without seams;
- extruded polystyrene foam - a popular insulation with good thermal insulation qualities, is not afraid of moisture, easy to install, affordable;
- foam concrete - modern material strong as concrete and light as foam.
Vapor barrier installation
When insulating a traditional roof, a vapor barrier material must be laid on top of the base. If this is not done, then the insulation will gradually accumulate moisture and lose its thermal insulation properties, air pockets will form, the roof will deform.
Polyethylene and polypropylene films or built-up bituminous materials can act as a vapor barrier. Lack of films in the presence of seams. Bituminous materials form a uniform, tear-resistant surface.
The vapor barrier must be laid not only on a horizontal surface, but also on the wall just above the level of the insulation.
Insulation installation
After laying the vapor barrier layer, you can proceed to the installation of insulation material.
Thermal insulation with mineral wool
Not every type of mineral wool is suitable for warming a flat roof. The material must have sufficient strength to withstand the loads during installation and operation. Therefore, special high-strength mineral plates are used.
Installation of insulation can be done in two ways: dowels or bitumen. The process of fastening to bitumen is quite complicated and expensive. Therefore, this method of mounting plates is appropriate when laying on a concrete base. Then you do not have to buy specialized dowels, which are more expensive, and drill holes in concrete.
If the base is made of profiled sheet, then it is more convenient to fix the plates mechanically using adhesive compositions or dowels. In the case when it is planned to install a cement-sand screed, it is not necessary to fix the plates.
When choosing a mechanical method of fixing insulation for a flat roof, the vapor barrier must be made of welded materials so that the holes formed in the base can be tightened.
When laying insulation in two layers, the lower plates are coated with bitumen, and the upper ones are installed so that the seams between the plates of the upper and lower layers do not match. This is necessary so that cold bridges do not form.
The use of expanded polystyrene
The principles of roof insulation with extruded polystyrene foam are similar to mineral wool insulation. Wherein polystyrene boards have slotted locks, which greatly simplify the process of their installation. Tape all seams to prevent moisture ingress.
Waterproofing
To protect the roof from water, laying a waterproofing layer is necessary. At the same time, on traditional roofs, it is installed on a heater, and on inversion roofs - under a heater. Laying waterproofing membrane proceeds according to the same principle as the installation of a vapor barrier. Waterproofing can be made of rolled, built-up materials or profiled steel sheets.
Polyurethane foam insulation
The stages of work described above can be skipped if such a modern material as polyurethane foam is used as a heater. It is sprayed onto the surface to be insulated with special installations. The result is an even sealed layer without seams. Additional vapor and waterproofing is no longer required. The material can be applied to almost any substrate. Service life - from 25 years. The disadvantages of polyurethane foam insulation are its high cost and the need to call specialists.
How successfully the insulation of a flat roof will be performed depends on the strict observance of certain rules and generally accepted technology. Let's take a look at some of them.
Following instructions
Any modern insulation system involves the implementation of a number of rules established by the manufacturer. Basically, the order of work is the same everywhere. The difference lies in the details. Some types of insulation require the use of only certain adhesives. Take another - harm the surface. Therefore, when buying a ready-made system, be sure to read the manufacturer's instructions.
Foundation preparation
Before performing insulation work, the base must be carefully prepared. It must be cleared of ice or snow in winter and free of moisture and debris in summer.
Proper installation process
Installation of a heater is carried out "on itself". You should start from the edge, which is opposite the exit of the roof. You need to move along special inventory walkways in order to evenly distribute the mechanical load. The direction of laying periodically changes.
Requirements for the thermal insulation of buildings with a flat roof (most new buildings had such structures) erected at the time Soviet Union, were at the level of 1.5 m² ° C / W, but this was clearly not enough: the roof often froze. Modern standards increase this value by more than 3 times. The need to save energy resources that are increasing in price every year makes the insulation of a flat roof a widespread event. However, good results can be achieved only with the help of high-quality heat-insulating materials and subject to the technology of work. This will be discussed further.
Video instruction for laying insulation for a flat roof
Requirements for thermal insulation materials
To prevent heat loss through the roof, you can use materials with low thermal conductivity. The roof is the enclosing element of the structure and during operation it experiences serious loads associated with temperature changes. environment. Its inner surface (in fact, the ceiling) has almost the same temperature as the air in the room. The outer surface cools down in winter to negative temperatures and warms up in summer sometimes up to hundreds of degrees plus. But such conditions should not affect the ability of the roof to protect the premises of the building from both cold and heat.
When choosing insulation for a flat roof, it should be borne in mind that their service life depends on many factors, including the temperature and humidity conditions, the presence or absence of diffuse and capillary moisture, and mechanical influences. The heat insulator must have a long service life and at the same time retain all its qualities: be moisture resistant, environmentally friendly pure material, resistant to biological, chemical influences and meet the requirements of sanitary and fire regulations and rules. As regards the requirements for mechanical strength: thermal insulation materials must have sufficient resistance to compression and tear, they must not delaminate. Therefore, purchasing materials for roofing works, it is necessary to familiarize yourself with the accompanying documentation: the quality must be confirmed by the relevant certificates.
Flat roof insulation with polystyrene foam
Roof insulation device: general rules
Most often, attics under the roof in multi-storey buildings are non-residential premises and do not have thermal insulation. In this case, roof insulation does not make sense - only the floor of the attic should be insulated. If you need to arrange a living space under the roof, you can’t do without insulation.
If the house is under construction, everything is simple: thermal insulation is laid on top of the crate and covered with waterproofing material. Roofs of buildings in operation can only be insulated from the inside. Both options have the right to life and are used equally successfully, but outer insulation requires certain skills and therefore only professionals can do it. Laying materials from the inside can be done and on your own. At the same time, it is necessary to carry out the work in a complex way: protection is also needed water pipes, weirs and water collectors, which are located in the attic.
It is easiest to work with mineral wool, glass wool materials and slabs made of foam and extruded polystyrene foam. They have rectangular shape, fit well and fit tightly in rows. But at the same time, it should be remembered that the minimum thickness of the material is 25 mm, and for high-quality insulation, at least 100 mm is needed: this means that mineral and glass wool slabs will have to be laid in several layers.
It is important during the execution of work not to forget about the need for laying vapor barrier material and waterproof protection. A significant temperature difference between inside and outside causes condensation to form under the roof, which does not in the best way changes the properties of thermal insulation materials, especially cotton. Yes, and for a wooden crate, moisture is not an ally, but the cause of the appearance of mold, fungus, decay: if wood damage was noticed during work, such parts are subject to special treatment or replacement. In addition, steam coming from living quarters is also harmful. Hydro and vapor barrier eliminates the need to replace the heat-shielding layer.
This is how the puff cake of an insulated flat roof looks like
It is necessary to repair or replace the electrical wiring laid in the attic, especially that attached to the roof: insulation failure or short circuit may cause a fire. Modern thermal insulation materials, although they meet fire safety requirements (do not support combustion), but in conditions open flame still won't last.
Flat roof device: insulation from the outside (operational version)
The exploited roof can be insulated with the help of rigid heat-insulating boards from the outside. bars load-bearing structure they are covered with panels that form the basis for heat-insulating slabs, on top of which, in turn, paving slabs are placed or a layer of pebbles is poured. At this stage, the help of specialists is needed, who must ensure that the supporting structures can withstand the weight of the materials, and the coating does not leak.
Such a roof, the surface of which can be used, for example, for the construction of a summer terrace, parking, winter garden, is called inversion. The cost of such a roof is very high.
The procedure for warming it is as follows:
- a screed is made over the reinforced concrete floor slab cement-sand mortar: it is laid under a slight slope (3-5 degrees);
- a layer of waterproofing material is laid;
- the turn of extruded polystyrene foam boards (EPS) is coming high density with closed pores: this material, due to its hydro-impermeability, does not prevent a small amount of leaked moisture from flowing to the water collectors;
- a filter fiberglass is laid on top of the EPPS: water passes freely through it, but solid particles are retained;
- a layer of gravel or pebbles without sand is poured: it will be washed away by rain;
- the top layer is arranged from paving slabs or paving stones.
The top layer of the exploited roof - paving slabs
A good insulation for an inverted roof is foam concrete: it is applied over the vapor barrier material with a layer of 0.27 m in the area of \u200b\u200bthe gutters. On top - foam-reinforced concrete in the form of a screed with a thickness of 0.03 m. The next layer is a built-up roof made of euroroofing material.
Insulation of an unused flat roof
Such a roof can be insulated both from the outside and from the inside. The main element of its supporting structure is a metal tile, profiled sheet or reinforced concrete slab. It is possible to insulate an old roof in one layer - glass or mineral wool is suitable for this. A new roof will need two coats.
board material(EPS) should be chosen with a high density: when laid on top, it will have to support the weight of a person. In sagging places, paths for heat loss, the so-called "cold bridges", can form. It is necessary to arrange the plates in a checkerboard pattern: there should not be long butt joints. Plates should be fixed with plastic dowels: metal ones are more expensive, and besides, they can also be “cold bridges”. Can be as additional funds use glue. The gaps in the joints should be sealed with mounting foam; places near the sides and parapets are also processed.
Scheme of insulation of an unexploited roof
The process of flat roof insulation in this case consists of the following steps:
- a layer of vapor barrier material is laid on top of the reinforced concrete slab: it is fixed with glue;
- a layer of mineral wool is laid or XPS boards are laid;
- expanded clay is poured: it is distributed in such a way that a slight slope is formed;
- the next layer is a cement-sand screed (about 40 mm) using reinforcement;
- waterproofing material is laid;
- soft roofing.
Recently, a sprayed coating of polyurethane foam is often used. It has the necessary rigidity and you can safely walk on it. This material does not require additional fastening, but it is necessary to protect it from UV radiation using a special paint.
Sprayed polyurethane foam is protected with a layer of special paint
Warming a flat roof is fraught with many difficulties, this business requires certain knowledge and skills. To prevent annoying mistakes you should use the services of professionals.
