Recently, the presence of an attic in suburban housing has become popular. And modern high-rise buildings are increasingly crowned not with the usual flat, but with a pitched roof, under which the attic is located. The reasons for the popularity of this building are obvious: an increase in living space and a special feeling of comfort in a room next to clouds and a starry sky. However, it should be understood that for the reliable operation of such a roof, its competent implementation is required. In the case of an attic, the roofing is much more complicated than in the case of a cold attic. To ensure reliability and durability, comfort and warmth, it is necessary, first of all, to correctly insulate it.
The roof as a whole will serve the occupants of the home faithfully when it is a thoughtful system. The roof is protected from the direct impact of precipitation by an external covering, which can be made of metal, shingles, natural shingles, etc. Under the cover there is a "roofing pie" - a multi-layer structure consisting of a ventilation circuit, a hydro-wind protection layer on the outside, a thermal insulation layer, and a vapor barrier layer on the inside. The main "filling" of such a "pie" is insulation.
The tasks of thermal insulation in the attic are clear: to protect the house not only from precipitation, wind, snow load, solar radiation, but also from winter cold and summer heat. Due to insufficient or low-quality insulation of the roof in winter, heat loss through this structure of the house can reach 25%, which entails a noticeable increase in heating costs.
The solution of the assigned tasks is only possible with high-quality materials, such as ROKLIGHT and TECHNOLIGHT EXTRA heat-insulating materials produced by TechnoNICOL Corporation.
The products are stone wool slabs based on rocks of the basalt group, designed specifically for thermal insulation of unloaded structures, which include attics. What are the advantages of these slabs? First of all, it is a non-combustible material (flammability group NG), therefore, it is safe and reliable both for humans and for the roof structure. This is the fundamental difference between stone wool slabs and foam plastic slabs (flammability group G2). In addition, when burning, polystyrene foam emit substances harmful to human health and poisonous gases. Glass wool, like stone wool, does not burn, but it has a very low fiber melting point - 550-600 ° C. In a fire, this temperature is reached 7 minutes after the start of the fire, so that the glass wool melts quickly and cannot prevent the spread of the fire. The melting temperature of stone wool fibers is over 1000 ºС. In a fire, the flame reaches such indicators two hours after the start of the fire, and during this time the material serves as a barrier in the path of the fire. It is also important that the effect of fire on the material does not lead to the formation of poisonous gases and toxic substances.
One of the advantages of ROKLIGHT and TECHNOLIGHT EXTRA materials is a low thermal conductivity (λB = 0.041 W / m2K), which guarantees low heat loss through the roof.
Considering the location of the material in an inclined surface, compressibility is an important characteristic when choosing thermal insulation. This value is measured under the load established by GOST and looks at how much the material will be compressed in thickness (in%). What does it mean? Since on a pitched roof the insulation is constantly in an inclined position, it is important that it does not "slip" and cold bridges do not appear. In addition, it is necessary that over time it does not become thinner: this will reduce its effectiveness and durability. Compressibility of plates of 20 - 30% is a guarantee that there will be no problems with sliding in the system.
Also, a feature of a slab based on stone wool is its high vapor permeability (0.3 mg / m.h. Pa). Considering that water vapor is constantly generated in a residential building, which, according to the laws of convection, rises upward, under the roof, this property is important. To prevent steam from reaching the insulation, a vapor barrier layer is provided in the attic roof - usually a film based on polyethylene or polypropylene, mounted on the inside of the insulation. But, given the high penetrating ability of steam, it is not able to completely "cut off" its film. Getting from a warm zone to a cold one, water vapor can condense, and the dew point often ends up in the insulation. And when it gets wet, it loses its insulating properties. If the insulation with a fibrous structure has good vapor permeability, then water vapor does not linger in it. Coming out through a vapor-permeable windproof film located outside the thermal insulation layer, it is eroded outside the roof through the under-roof ventilation system.
The thickness of the insulation for central Russia should be 200 mm, according to heat engineering calculations. In practice, the insulation is often placed in the space between the rafters. Therefore, it has a thickness equal to the thickness of the rafters, and the maximum section of the standard boards offered in our market is 150 mm. To solve this problem, TechnoNICOL specialists recommend arranging a two-layer thermal insulation.
Its first layer (150 mm) is placed in a spacer between the rafters. It can be 3 layers of 50 mm each, laid with a gap in the seams. Then, from the side of the room across the rafters, counter-beams with a section of 50 X 50 mm are nailed with a distance between the edges of the bars of 580-590 mm for tight installation of the slabs. Another layer of thermal insulation is installed with a thickness of 50 mm. Total - 200 mm.
It is worth noting that such an insulation scheme helps to reduce heat loss through the roof to a minimum. The fact is that wooden rafters are a cold bridge, but now, thanks to the overlap of the insulation through them, most of this bridge has been eliminated (it remains only at the junction of the rafter and the counterbeam). It is recommended to arrange a vapor barrier between two layers of insulation, thereby additionally protecting it from possible damage during finishing work in the attic. With regard to the dew point, in a single-layer construction, the surface of possible condensation of steam is removed by 1/3 from the cold part. So it is quite possible to shift the vapor barrier layer by 50 mm in a 200 mm thick insulation.
An obligatory part of the attic roof is the ventilation system. It is important to understand that when it is not provided or improperly organized, the service life of the insulation and wooden roof elements is reduced several times. The basic rules for its design are as follows: for the flow of outside air, gaps in the eaves overhang should be provided; for its circulation, channels are left between the thermal insulation and the roofing; for air extraction, holes are provided with the installation of pitched aerators or aeration skates.
In a well-planned roof, the difference between the outside and "under-roof" air should be no more than 2 - 4 ° C, which will eliminate the formation of icicles and ice. Moreover, it is important to understand that you need to ventilate each rafter opening.
It is necessary to exclude zones with stagnant air ("air bags") in the eaves, therefore it is not recommended to carry out the inflow with the help of dormer windows, it is better to install pitched aerators along the eaves. The number of ventilation ducts above the insulation depends on the type of waterproofing material. If a "breathable" membrane is used (which does not allow external moisture to pass through, but which allows steam to pass through well), then there will be only one channel - between the coating and the waterproofing, since such a membrane is laid directly on the insulation. If a film with an average vapor transmission capacity is used, then two channels are needed - between the film and the roof, as well as between the film and the insulation.
Remember, only a thoughtful combination of high-quality and reliable heat-insulating materials and competent installation guarantees that your roof will be warm, safe and beautiful throughout its "life".
Call us and we will tell you how to choose the right insulation material and properly insulate your house:
8-800-200-05-65. The call is free for all regions of Russia!
www.teplo.tn.ru e-mail: [email protected]
TechnoNICOL is Europe's largest manufacturer and supplier of roofing, waterproofing and heat-insulating materials. More than 200 million people around the world live and work in buildings constructed using TechnoNICOL materials. The TechnonICOL Corporation has 14 production areas, 38 factories in Russia and neighboring countries, its own trade network and representative offices in 36 countries of the world, own research centers in different regions of Russia, as well as a qualified team of professionals - 6500 people!
