How to choose a heater for the attic roof - thickness and

Attic is a room located under the roof arches, used as a dwelling. Projects of houses with a mansard roof are deservedly popular, as they allow to equip an extra room, reducing costs to a minimum compared with the construction of the second floor. However, in order to comfortably use such a room even in winter, high-quality thermal insulation is required, which prevents heat losses through the slopes. In this article we will tell you what qualities insulation should have for attic, as well as how to choose the most suitable material.

Criterias of choice

Insulation is a building material with low thermal conductivity, which is used to protect the attic roof from the penetration of cold air from the street, as well as heat losses. According to the law of convection, the air heated by heating devices inside the house rises, therefore the main heat loss occurs precisely through the overlap of the second floor. To optimize the temperature of the attic, the slope is insulated. The insulation used for this process operation must meet the following requirements:

1. Thermal insulation of the second floor and the roof should have a low thermal conductivity and endure many cycles of freezing and thawing, without loss of integrity, elasticity and other thermal insulating properties. Neither in severe frosts, nor in the exhausting heat, the insulation must maintain integrity, not crack, not settle.
2. Insulation used to isolate the attic floor should have a low hygroscopicity, as they come into contact with water, condensate and vapors emanating from the dwelling. In addition, if the material retains moisture, the weight of thermal insulation increases, as well as the load on the rafters and the foundation.
3. Qualitatively selected insulants for the roof roof are made of non-combustible substances or contain flame retardants. Materials with a high resistance to fire on contact with time, all begin to melt, but this delay helps to put out the fire on their own or wait for the arrival of firefighters. Fire resistance is an important quality of the thermal insulation of the roof and the attic floor, as the chimney is laid through it, often causing fire.
4. Good insulation for mansard roof preserves the structure and integrity throughout the life of the product. If it is wrinkled and deposited, exposing the upper part of the ramp, the effectiveness of thermal insulation will significantly decrease, since heat loss occurs there.

Note! Choosing insulation for the attic roof, take into account the shape and slope of the slope, the climatic conditions in the region of construction and the nature of the use of under-roof floors. Thermal insulation thickness is calculated using a calculation, for a central strip of Russia a layer of 150–200 mm is usually enough.

Mineral wool

The most popular and affordable material for thermal insulation of the attic roof is mineral wool. It represents plates, rolls or mats of fiber insulation made from mineral substances (glass, gabbro-basalt, metallurgical slags). Insulation of this group are highly resistant to fire, low hygroscopicity, low thermal conductivity, as well as an elastic breathable structure. The following types of mineral wool are distinguished:

• Glass wool. Thermal insulation material produced from the finest glass fibers, the thickness of which does not exceed 15 microns. When laying glass wool use protective glasses and respirators, as the smallest contact with it is enough to get irritated.
• Basalt wool. Basalt or stone wool is made from gabbro-basalt with the addition of bentonite clay and composite substances. This heater has a more dense, elastic structure, so that it does not wrinkle and does not sink when mounted on a ramp.
• Slag. Insulation based on the waste of the metallurgical industry, the thickness of which is 4-12 microns. Among other types of mineral insulation materials slag has the highest hygroscopicity, high acidity and low efficiency.

Important! Mineral wool more often than other materials are used for thermal insulation of the roof, as they have good performance characteristics and low price. However, the highest efficiency of attic insulation with these materials is achieved with complex use with waterproofing and vapor insulating membranes preventing the material from getting wet. Increasing the moisture content of the mineral insulation by 5% reduces the efficiency of thermal insulation by 50%.

Styrofoam

Styrofoam – современный утеплитель на основе пенополистирола. По сути больше 98% объема этого материала занимает воздух, заключенный в тончайшие оболочки из полистирола. To understand the structure of the foam is enough to imagine a hardened piece of foam. Distinguish between simple and extruded polystyrene foam, which have the following features:

• A light weight. Compared with mineral insulation, polystyrene weighs many times less. Therefore, for the installation of this insulating material does not need to strengthen the roof frame of the roof. Even the panels, whose thickness is 140 mm lighter than other heaters.
• Low thermal conductivity. The coefficient of thermal conductivity of polystyrene foam is lower than that of mineral insulation, due to the air that is in the structure in a stationary state and does not conduct heat.
• Низкая гигроскопичность. Styrofoam не впитывает влагу, поэтому протечки через кровлю или конденсат не снижают эффективность утепления и никак не отражаются на эксплуатационных характеристиках материала.
• Good noise isolation. Polyfoam is considered the most effective material for sound insulation, so the masters recommend using it for installation on metal roofs with high resonating capacity. This measure significantly reduces the noise level during rain.
• Flammability Expanded polystyrene refers to materials with a class of flammability G3-G4, that is, it melts, burns and sustains combustion. Some manufacturers increase fire safety insulation to G2 with flame retardants, but this treatment lasts only 2-3 years.

Note! Many are worried about the low strength of the foam, however, the weakest point of this material is low resistance to ultraviolet rays. When exposed to direct sunlight, it eventually loses its elasticity, strength, and then completely destroyed. With proper installation and calculation of the thickness of the insulating layer, expanded polystyrene will last at least 30 years.

Polyurethane foam

Polyurethane foam – это полимерный утеплитель, он является разновидностью вспененной пластмассы с ячеистой структурой. Каждая такая ячейка заполнена газообразным веществом, которое является причиной низкой теплопроводности материала. For thermal insulation using rigid types of polyurethane foam with a density above 35 kg per cubic meter. It has the following characteristics:

1. Low thermal conductivity. In terms of thermal conductivity, polyurethane foam insulation is inferior only to foam plastic and mineral wool, but far superior to expanded clay or silicate.
2. Chemical Resistance. Polyurethane foam has a high resistance to aggressive chemical environments, it is not destroyed by acids, alcohol, caustic vapors.
3. Низкая гигроскопичность. Polyurethane foam практически не впитывает влагу, поэтому не боится контакта с атмосферными осадками. При намокании термоизоляционные свойства этого материала, а также срок эксплуатации не снижается.
4. Low flammability. Different grades of polyurethane foam belong to the class of flame-resistant, self-extinguishing and flame-resistant materials. This insulation is considered the most fire-resistant and safe.
5. Durability. According to the manufacturers, the guaranteed service life of the thermal insulation layer of polyurethane foam is 25-30 years, however, builders claim that in practice it is 1.5-2 times longer.
6. Versatility. Polyurethane can be applied to any materials and coatings, even to metal. The layer, whose thickness is 10-15 cm, protects against the penetration of cold air, effectively reducing heat loss.

Pay attention Polyurethane foam is produced in the form of plates and in the form of liquid mixtures, which are applied to the insulated surface of the slope with the help of a special installation. The liquid form of the application is the most effective, as it allows to close all the gaps and gaps in the roof.

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