Which insulation for the attic is better to choose - a review of insulation materials. Insulation of an attic roof - comfortable housing instead of an attic Types of insulation for an attic roof

The space under the pitched or sloping roof of a wooden house is often used not only for technical purposes, but also as a living space. But to create comfortable conditions, the attic must be carefully insulated from heat loss and external noise, and normal ventilation of all rooms must be ensured.

To understand which insulation is best for an attic, you need to carefully study the parameters of the materials on the market and correlate them with the requirements of the project for thermal insulation of the room and the degree of preparation of the roofing system.

Depending on the type of roofing materials and the general roof installation system in a wooden house, the basic requirements for thermal insulation materials are assigned.

During the construction of an object, lathing and counter-lattice for metal or soft types of roofing can be performed according to different schemes. As a result, there are two types of roofing devices:

• with laying a waterproofing film or diffusion membrane;
• without installing a counter-lattice and a layer of waterproofing.

The second option is considered a gross mistake, but periodically builders do not leave space for natural ventilation of the rafter system and do not protect its elements from moisture.

Material requirements

Requirements for insulation materials may differ depending on the type of roofing device, but the basic characteristics must remain unchanged:

• thermal conductivity no more than 0.045 W/mK;
• material density in the range of 30 – 50 kg per cubic meter;
• rigid or semi-rigid structure of the heat insulator.

Thickness

The thickness of the insulation layer directly depends on the purpose of the attic floor. When installing living rooms and a bathroom within this space, it is necessary to protect the structure as much as possible from heat loss and freezing.

That is why experts advise using a layer of insulation of at least 100 - 150 mm. Moreover, the material is laid in 2 layers for more effective protection against heat loss.

Density

It is also worth remembering that the lower the density of the material, the greater its thermal insulation ability and the less impact on the rafter system. We must not forget that making the roof heavier can negatively affect the condition of the entire structure of the house, because the pressure of the rafters on the walls increases, and this can lead to their deformation.

That is why, before choosing the optimal insulation for the attic, you need to carefully study its properties and calculate the approximate load on the rafter system.

If there is no waterproofing film or diffusion membrane that protects the rafters from moisture accumulation during steam condensation, it is best to choose one of the polymer insulation materials.

Most often, a similar situation arises during the construction of a house in which a residential attic was not intended. That is why materials with extremely low permeability, such as polyurethane foams and polystyrene foam, become the best option.

Such insulation perfectly protects not only from freezing of the structure or a decrease in room temperature, but also from constant exposure to moisture. They are harmless to humans, but require the creation of ventilation systems, as they interfere with normal air circulation.

An interesting option for roof insulation is a material based on polyurethane foam. This insulation is applied by spraying, which ensures the absolute integrity of its layer without the formation of cold bridges.

In addition, this material does not require additional fastenings or fixation due to good adhesion to the base. To treat a roof of 100 square meters it will take no more than 4 to 8 hours, which significantly reduces the process of arranging the attic floor.

The thickness of such insulation to protect the attic compared to classic mineral wool can be reduced by 1.5 - 2 times and amounts to 80 - 100 mm. It is thanks to the integral structure of the applied layer, as well as the formation of absolutely closed air cavities, that polyurethane foam perfectly protects the room from heat loss.

But it must be remembered that when using such insulation, home owners should install forced ventilation, otherwise the accumulated moisture will lead to the development of fungi and pathogens.

In this case, both classic polystyrene foam and extruded polystyrene foam will cope perfectly with the task of insulation.

Both materials have excellent thermal insulation properties, but the extruded version is more reliable and durable. Its thermal conductivity is lower, so the effective layer is reduced to 80 mm.

The cost of polystyrene foam is lower, but taking into account the difference in the required amount of materials, the total costs remain approximately equal. The undeniable advantage of extruded polystyrene foam over polystyrene foam is its non-flammability.

Extruded polystyrene foam, unlike polystyrene foam, is not susceptible to rodents; its structure simply does not allow them to create their nests in the thickness of the material. Nevertheless, polystyrene foam still remains one of the most popular insulation materials.

The density of both types of expanded polystyrene is also selected in the range of 30 – 50 kg/m3 to prevent the weight of the structure. They are fastened using special disc-shaped dowels with large polymer caps.

Fiber and natural insulation

When creating a roof with a counter-lattice and any type of waterproofing device, it is worth choosing semi-rigid materials, such as mineral and stone wool or composites based on natural fibers.

Such materials require additional protection from getting wet, since when exposed to water they lose their properties completely or partially. In addition, their fastening involves the creation of an additional frame, which complicates the work. But such wools have excellent permeability, therefore they support natural air circulation, ensuring a normal level of humidity in the room.

Mineral and stone wools

In fact, such materials are the most budget-friendly option for attic insulation. They are lightweight and dense, so they do not weigh down the structure. Installation of such insulation is simple, but will require several days.

Most often, mineral wool is laid in the space between the rafters. To increase the effectiveness of thermal insulation, complete overlap of beams and rafters is periodically used. The required layer of such materials is 150 - 200 mm.

The main disadvantages of mineral wool are the complete loss of properties when wet, as well as harmfulness to humans when weathered. Exposure to wind can knock out small stone or glass fibers from the bulk of the material.

If they enter residential premises, allergic reactions can occur and respiratory tract diseases can be provoked. That is why mineral wool must be protected on both sides.

Natural fiber materials

Insulation materials are semi-rigid wools formed from plant fibers, natural binding components and antiseptics. The latter help prevent biological corrosion and increase the durability of the insulation. In addition, fire retardants are introduced into ecowool, which reduces their flammability.

Such materials are afraid of waterlogging, but partially retain their properties when wet and completely restore them after drying. Natural wools are suitable for insulating any home, but also require a vapor barrier and diffuse membrane.

Protection of insulation from external and internal moisture

When using semi-rigid wool to insulate the attic of a private house, it is necessary to protect the thermal insulation materials both from condensation forming under the roofing material and from internal moisture in the premises.

Pie device

The interior decoration of the attic of the house is a kind of layer cake:

• waterproofing film or diffusion membrane over the rafters;
• insulation layer;
• vapor barrier;
• frame for interior decoration;
• directly finishing material.

It is the presence of two films that allows you to completely protect the selected insulation.

Superdiffusion membranes

When using superdiffusion membranes, the selected material can be attached so that it is pressed tightly against the film. Due to the high throughput of such membranes, water vapor from the premises quickly passes through the insulation without condensation.

Ventilation gap

When using waterproofing with low throughput, it is necessary to leave a ventilation gap of at least 2.5 - 3 cm between the insulation and the film. In this case, the steam will circulate freely in this space, gradually being released outside and not condensing in the body of the heat insulator.

With proper insulation, an attic can be a wonderful additional space in any home.

The popularity of attics is growing rapidly. Developers consider this type of housing less expensive compared to the cost of equipping floor premises. In addition, many homeowners are attracted by the opportunity to implement specific architectural and design solutions, specifically developed by European specialists. Why has the transfer of under-roof zones to the housing stock been actualized in our country only in the last 10 - 15 years? The answer lies in the climatic difference between continental Europe and the European part of the Russian Federation. Only modern technologies in the field of insulating materials make it possible to choose insulation for the attic, providing a comfortable microclimate in a “house without walls” located somewhere in the Moscow region.

It is important to choose the right insulation for the under-roof space

The installation of attic roofs is functionally and technologically different from the work carried out on the main floors and in unheated attic spaces. Insulating the attic is associated with increased complexity of installation processes, the need for thermophysical calculations, as well as the importance of proper development of ventilation and vapor protection.

In non-residential attic spaces, thermal insulation is laid in the niches between the ceiling beams. In this case, the roof structure plays the role of a barrier that protects the building from wind load, temperature expansion and precipitation. Insulation for an attic roof, on the contrary, is part of a roofing sandwich designed to simultaneously perform all the functions inherent in the walls, ceiling and roof.

More moisture enters the attic than the floor spaces. Water penetrates from below in the form of rising vapor. Vapor barrier of the floor ceiling reduces the flow of moisture, but does not eliminate it.

The second factor in air humidification is associated with the inevitable condensation on the lower surface of the tiles or other roofing material. Moreover, the amount of this condensate on insulated roofs is greater than on cold roofs due to the increased temperature gradient. In addition, a ventilated cold attic forms a buffer air cushion, effectively drying the roof from below. The absence of such a buffer in attics reduces the natural ventilation of wooden rafters and the insulation itself.

Placing thermal insulation directly under the roof slopes increases the rate of heat transfer, so insulation for the attic should be more energy efficient than insulating the floor between the home and the cold attic.

Criteria for selecting insulating material

What is the best way to insulate an attic? Studying the properties of thermal insulators cannot give a substantiated answer to this question. It is necessary to correlate the characteristics of materials with their operating conditions. The specificity of attics is expressed in three main rules for their insulation:

1. Timeframe for completing thermal insulation work. Typically, freshly sawn wood is used for rafters. In this case, it is necessary to wait at least six months before insulation is carried out with materials with high vapor permeability.
   

   Even when using dried wood, a pause of at least 2 weeks is necessary after installing the roofing.

2. Choice of insulation thickness. The intensity of heat flow through the roof is much greater than the energy lost through the walls or foundation. The usual thickness of mineral wool of 100 - 150 mm does not solve the problem of attic insulation even in the southern regions of Russia. It is necessary to use special calculator programs where climatic conditions, dimensions of building structures and materials of all layers of the sandwich are substituted. In a temperate continental climate, the required design thickness of the insulator for a mansard roof is almost never less than 300 mm.
3. Design of rafter beams.

The height of the lumber profile should be 30 - 40 mm higher than the thickness of the thermal insulation layer. In this case, a sufficient ventilation gap is formed between the waterproofing and the insulation.

If work is underway to convert a cold attic into housing, then additional sheathing is usually used at the bottom of the rafters, increasing the installation height to accommodate the insulating layer.

To determine which insulation is best for your attic roof, make a comparative assessment of the materials, taking into account the three rules outlined in the following order:

1. Eliminate options that do not meet your fire safety requirements.
2. Eliminate options with high vapor permeability of insulation if you do not have time to dry the rafter wood.
3. Calculate the required insulation layer thickness for several options.
4. Create budget options. In this case, it is necessary to take into account the exclusion of a vapor barrier membrane from the sandwich composition in the case of using insulating materials with hygroscopicity close to zero.

Types of insulating materials used for insulating attic roofs

First of all, it should be noted that insulating inclined surfaces with bulk materials is not only inconvenient, but also impractical, since the fragments rolling down will block the ventilation gap. Therefore, sawdust, fluff pulp, expanded clay and similar insulation materials should be abandoned. On the other hand, it is permissible to carry out insulation with slabs obtained from a mixture of the listed materials with clay or cement. However, the weight of such slabs should be taken into account when calculating trusses.

Fireproof insulation

The only relatively inexpensive fireproof heat insulator is mineral (basalt) wool. It is for this reason that it has long remained the most popular option for use in attic sandwiches. How to choose a good mineral wool insulation for the attic? Is the usual rolled isover that we use for walls suitable? Such material will work well, but... not for long. The reason for this is high capillary activity. Therefore, it is necessary to choose materials with special impregnations that reduce hygroscopicity: ROCKMIN PLUS mineral wool, Izover Pitched Roof and other brands, the names of which have a direct indication of the field of application suitable for us.

Mixtures of insulating backfill with clay are also fireproof. The main problem with clay-mixed insulation is the very large thickness of the insulating layer and its excessive weight.

Among the most modern developments, PIR boards lined with heat-reflecting foil should be highlighted. They do not support combustion and have a record low thermal conductivity coefficient (0.024 W/m*K).

Insulation materials with the highest energy efficiency

Manufacturers of building thermal insulation have developed brands of extruded polystyrene foam (EPS) slabs specifically designed for the installation of attics and cold attic roofs. These are Penoplex Pitched Roof, TechnoNIKOL Carbon Solid and other materials with a thermal conductivity coefficient of no higher than 0.030 - 0.034 W/m*K. Brands are distinguished by the ability to order panels of increased length (up to 4.5 m), which significantly speeds up installation work.

EPS is a flammable material, but building codes allow its use in attics. To increase fire safety, infrared screens with a foil layer should be used. Despite the fact that their vapor barrier function is not needed by EPS, foil can significantly increase the fire resistance of the sandwich.

On average, polystyrene foam boards make it possible to reduce the thickness of the attic insulation layer by 20% compared to mineral wool. The champions in heat conservation are sprayed polyurethane foam (PPU) and the already mentioned PIR boards. Due to the high toxicity of gases released during thermal destruction of polyurethane foam, this material is not recommended for use in residential attics. PIR slabs do not have this drawback and are able to replace mineral wool with a 1.5-fold reduction in layer thickness.

Insulation materials with high specific noise absorption

Insulation with Zhivoizol - linen heat insulator

The noise insulation properties of attic roof insulation can be very important when using metal tiles, which enhance the noise of natural precipitation. Currently, slab materials have been developed that are characterized by a high noise reduction coefficient with a slight loss in energy efficiency to mineral wool. Among such developments, it should be noted pressed flax insulation, known under the market brands “thermolen” and “ZhivaIzol”. Plates made of this material absorb noise in all frequency spectra 20% - 30% more effectively than mineral wool and EPS.

Conclusion

The choice of insulation for an attic roof should be carried out in parallel with the development of roof trusses and the design of the entire sandwich, including roof cladding, membranes and sheathing. When converting cold attics into housing, it is important to minimize the thickness of the insulating layer and use insulators with the lowest thermal conductivity coefficient.

The wrong choice of insulation, or its insufficient thickness, not only leads to cold in the attic room. Even if you compensate for the low temperature with intensive heating, you may encounter:

• increased roof icing;
• reducing the service life of the roofing covering;
• failure of the drainage system.

Thus, competent design of a roofing sandwich for attics is important not only to ensure comfort for residents, but also from the point of view of increasing the service life of the building.

Video on the topic: how to properly insulate an attic

The problem of lack of useful living space in a country house can be solved by arranging an attic space. This part of the building is not distinguished by thick enclosing structures, so for all-season use, the owner of the building must install correctly selected thermal insulation. In our article we will talk about which insulation is best for an attic roof.

At the moment, there are many products on the domestic construction market that can be used as insulation for an attic roof or other enclosing structure, gable.

How does heat exchange occur in the attic?

Work on insulating the attic began after the installation of the heating system in the attic, because such materials allow you to retain warm air in the middle of the house. In the absence of a heating system, laying thermal insulation does not always give the desired effect. The heat here is retained by a small air gap, which is located between the ceiling and the roof; this is also facilitated by a layer of snow on the roof.

When installing a heating system on the attic floors, the heated air will tend to rise, it will quickly heat the roof and melt the snow. To reduce energy losses, the owner of the house must provide insulation for the facade of the building. This work can be done using one of the methods described below:

1. Insulation of the roof of the house from the inside. In this case, it would be advisable to lay insulating mats in the space between the roof rafters. This method of reducing energy losses is considered one of the most expensive, but in some cases it is considered the only possible solution. Many people ask what is the best way to insulate an attic roof. One of the possible options is the installation of mineral wool with further installation of a vapor barrier film.

2. Another method of insulation is external thermal insulation. Experienced builders recommend this particular method, because when joining insulation boards, the possibility of the formation of cold bridges is reduced. It is advisable to carry out such work during the installation of the roof, in which case the thermal insulation materials are laid on a vapor barrier film. This element is fixed to the rafters using staplers. At the final stage of the work, the insulation is protected from moisture with a waterproofing film, the rolled products are fixed with the same stapler and installation of the roof covering begins.

If we compare internal and external insulation, the latter option has worse protection against precipitation. Materials for external insulation must hold their shape well and not allow moisture to pass through. For those who do not know what is the best way to insulate an attic roof from the outside, it is advisable to choose polystyrene foam.

What characteristics should the insulation have?

Most roofers know that the effectiveness of insulation of the roof, as well as the gable part of the building, depends not only on the quality of the work performed, but also on the type of thermal insulation material. Before you start purchasing a product you need to familiarize yourself with the requirements that the selected insulation must meet:

1. First, you need to take into account the resistance of thermal insulation to external aggressive factors. The best insulation for the roof and gable of a building should retain its original dimensions and structure throughout the entire period of operation. Insulation materials are resistant to influences such as sudden temperature fluctuations, moisture ingress, and changing freezing and thawing cycles.

2. The second requirement is low hygroscopicity. The term “hygroscopicity” itself indicates the ability of a material to absorb moisture. Moisture in the insulation structure reduces the thermal insulation properties of products, promotes the formation of fungi and mold, and increases the weight of a particular element.

3. The third requirement is low thermal conductivity, the possibility of hermetically joining adjacent parts. Products with low thermal conductivity retain heat indoors in winter. In addition, effective insulation for the attic roof will create coolness in the summer.

4. And the last, but important requirement is safety during operation. It is necessary to insulate the attic roof from the inside, as well as sheathe the pediment with elements of increased fire safety. Such products should not ignite when exposed to high temperatures and should support the combustion process. Another important point is that thermal insulation materials must be absolutely safe for human health and not cause allergies or other diseases.

If you don’t yet know what is the best way to insulate the roof of a house, carry out a thermal calculation and calculate the thickness of the thermal insulation products. This parameter is selected according to climatic conditions for a particular region. For example, in central Russia it is advisable to install a thermal insulation layer with a minimum thickness of 15 centimeters. In this case, the joints between adjacent products must be overlapped by the next row of slabs.

Types of materials for attic insulation

Mineral

This subspecies includes products that have a fibrous structure; they are sold in hardware stores in the form of rolls or slabs and are called mineral (basalt or stone) wool. The main types of raw materials for the production of such elements are waste from the glass industry and metallurgy. Stone wool is obtained from hard stone by melting, it has a fibrous structure. This material has excellent heat and sound insulation characteristics, is not affected by rot and mold, and can withstand high temperatures of up to 900 degrees.

Stone wool slabs and rolls have a soft structure, so they are used to insulate the attic from the inside. The thermal conductivity of this thermal insulation is within 0.4 W/m, but this value can double after moisture enters the structure of the material. To prevent this from happening, mineral wool is protected from dampness by attaching a vapor barrier and waterproofing film.

Thermal insulation materials based on polymers

Not everyone knows what is the best material to use for insulating the gable and roof from the inside and outside. Experienced builders recommend using polystyrene foam or polystyrene foam for this purpose. A similar method is used to insulate old civil buildings. The described technology has several advantages:

• Small mass. Each of the foam plates weighs several tens of grams, which reduces the load on load-bearing walls and the roof structure.
• Such products have minimal hygroscopicity. The surface of polystyrene foam repels moisture, so mold and mildew do not appear on it. The absence of moisture in the structure means the absence of destruction during freezing and thawing of the liquid, preserving the original properties of the insulation. There is only one answer to the question of which insulation to choose for the gable - polystyrene foam.
• The products in question, in addition to increased thermal insulation characteristics, do not conduct sound. In this regard, foam plastic is considered an indispensable material for finishing civil buildings located near highways. Expanded polystyrene will reduce the noise of rain on a roof covered with corrugated sheets or metal tiles.
• Another useful property of the described products is fire resistance. The plates do not burn, but melt under the influence of fire.
• An important characteristic of polystyrene foam is the simple installation of slabs on flat surfaces. The consumer can choose the insulation of the required thickness and install it with his own hands. Such products can be quickly cut using a handsaw or a sharp knife.

The main disadvantage of the material under consideration is fragility; its structure is destroyed under minor mechanical loads. A similar problem can be solved by using products of increased strength and density (extruded polystyrene foam) or penoizol. The latter is blown between the rafters over a pre-laid plastic film.

Thermal insulation of the attic using natural components

People who are responsible for their own health are trying to understand which insulation for an attic roof is better. In this case, it is necessary to pay attention to natural products that are made from fibers of agricultural crops such as flax or hemp.

Ecowool is quite expensive; it contains up to 12% antiseptics (additives that prevent rotting processes) and 7% antipyrine (minimizes the effects of fire). The technical characteristics of natural thermal insulation materials are as follows:

• Thermal conductivity indicators are the lowest among all described types of insulation - 0.032 W/m;
• The degree of moisture saturation in such products is almost 2 times less than in mineral wool or glass wool;
• Natural insulation materials have a second class of flammability. According to this indicator, they are significantly inferior to stone wool;
• Ecowool has a loose structure, its density reaches 75 grams per square meter;
• Another important advantage of natural thermal insulation materials is the high degree of sound absorption.

According to experienced builders, ecological wool ranks first among insulation materials for attics of frame, timber and log buildings. It goes perfectly with wood; its use can reduce 30% of the family budget’s heating costs.

Arranging an attic with a competent approach solves the problem of shortage of living space in a residential building. But in order to use the room under the roof all year round, you will need high-quality thermal insulation, especially if the construction site is located in central Russia or even further north.

The building materials market offers traditional and new ways to solve this. In order not to get lost in the abundance of materials, our article will tell you which insulation is best suited for an attic roof and gable, how to choose and install it.

Heat exchange in the attic

Thermal insulation of the attic is a relatively new construction technology that became popular after heating reached the under-roof spaces. In attics that are not heated, insulation is not so important.

After all, the air gap between the ceiling and the slopes covered with a snow cap perfectly retains heat in living rooms. Installing a heating system in the attic changes the situation in the opposite direction: the heated air rises to the ridge and gives off its heat to the roofing material, due to which the snow from the roof melts.

To reduce energy losses, it is necessary to provide insulation of the attic roof and gable using one of the popular methods:

Compared to insulation from the inside, the outside is less protected from moisture. In addition, so that the weight of the roof and snow do not damage the integrity of the layer, materials that can hold their shape well are chosen for external thermal insulation.

General material requirements

Although the quality and method of installation to a certain extent influence the efficiency of insulation of the attic roof and gable, the main thing is to correctly determine which material will best cope with this task. The builder claims that good insulation must have the following qualities:

• Resistance to external factors. It is important that the thermal insulation material withstand sudden temperature changes, repeated cycles of defrosting and freezing throughout its entire service life, without cracking or changing its shape or structure.
• Low hygroscopicity. The insulation for the gable and attic roof has low hygroscopicity, that is, it does not absorb moisture. Since an increase in humidity reduces the effectiveness of thermal insulation by half, it increases the weight of the roofing structure, leading to the formation of mold and rot.
• Low thermal conductivity. Materials with low thermal conductivity do not heat up and “seal” heat from inside the room, reducing the cost of heating the attic.
• Safety. For cladding the gable and roof, insulation with a high fire safety class is used, which is non-flammable and does not support combustion. In addition, it is better to use materials that are not harmful to health and do not cause allergies.

When deciding which material is best to use for roof insulation, please note that the thickness of the layer is selected depending on the climatic conditions in the region of construction - for central Russia it is recommended to use insulation with a thickness of at least 150 mm.

Types of materials

Mineral thermal insulation materials

This category includes insulation with a fibrous structure, produced in the form of a roll or slabs, called mineral wool. It is made from waste from the glass industry and metallurgical production.

But for attic insulation, builders recommend basalt-based stone wool. Its operating temperature is 800-900 degrees, it does not burn and does not support combustion, and has high thermal insulation and sound insulation characteristics.

Typically, stone wool is used for, since the slabs, and especially the rolls, have a fairly soft structure that crumples under the weight of the roofing material.

The thermal conductivity of this type of insulation is 0.035-0.04 W/m, but during operation and moisture accumulation this value increases by half over 3 years of use. Therefore, for effective thermal insulation it is necessary to protect mineral wool from dampness using waterproofing and vapor barrier.

Polymer thermal insulation materials

Recently, builders have begun to widely use expanded polystyrene-based materials to insulate the pediment and roof from the outside or inside. This method has become the most popular method for renovating old residential buildings. It has the following performance qualities:

1. A light weight. Layers of insulation based on polystyrene foam weigh just a few grams, so they do not increase the load on the rafter system.
2. Low hygroscopicity. Expanded polystyrene does not absorb moisture at all, so it does not suffer from dampness, mold, and does not lose its thermal insulation qualities during operation.
3. Does not conduct heat or sound. These properties make expanded polystyrene indispensable for houses located in the area of ​​busy highways and buildings with resonant roofing materials (metal tiles, corrugated sheets), which increase noise during rain.
4. Fire resistance. Polystyrene foam insulation does not burn, but melts slowly, so it is considered safe.
5. Easy to install. A wide range of material thicknesses from 10 to 500 mm makes it easier to use for self-assembly. Also, its installation does not require a special tool, and you can cut the layers with a knife or saw.

The only drawback of polystyrene foam is its fragility. During installation and operation, the sheets are easily damaged and crumble. But this problem is solved by the use of extruded polystyrene foam, which is blown with special equipment under the film between the roof rafters.

Natural thermal insulation materials

Those who primarily value environmental safety, as well as the natural origin of materials, should take a closer look at natural insulation for roofing. They are made from fibers of industrial agricultural crops - hemp, flax.

In addition to cellulose, ecowool contains 12% antiseptic and fungicidal additives and 7% fire inhibitors. Performance characteristics of natural insulation compared to mineral insulation:

• Low thermal conductivity. The thermal conductivity of ecowool is lower than that of mineral materials, they are 0.032 W/kg.
• The absorbency of ecowool is two times less than that of mineral thermal insulation materials based on glass, basalt, and slag.
• Flammability class G1-G2, that is, in terms of fire safety, ecowool is less safe than mineral-based insulation.
• Ecowool has a looser structure than mineral wool, its density is 30-75 g/cu. m.
• Natural types of thermal insulation materials absorb sound 10% better.

Experienced builders note that ecowool is the best material for insulating the inside of log, frame, timber houses with an attic, since its characteristics are close to those of natural wood, its use reduces heating costs by 30%.

Thermal insulation of residential attic spaces is the same prerequisite for comfortable use as the organization of natural lighting and ventilation. Remember that insulating an attic during construction is much more convenient and effective than during operation.

Video instruction

If the roof of a country house forms a spacious attic space, then it can be used to expand the living space. The attic room can serve as a bedroom or office, a sports room, a cinema or a billiard room. To use additional space all year round, you need good thermal insulation. Insulating the attic will not require large material costs, especially since the work can be done with your own hands. It is only important to choose the appropriate thermal insulation material and carry out the installation correctly.

Requirements for thermal insulation materials

The same technology that is used in the construction of frame houses is suitable for insulating the attic, however, increased demands are placed on the materials and quality of work. The quality of the insulation of the attic space affects both the comfortable living conditions and the durability of the roof. This is due to the fact that the walls of the attic space form the gables and roof slopes - those surfaces that heat up the most in the summer heat. In winter, on the contrary, blown by cold air currents, they cool down most quickly. If the thermal insulation is of poor quality, the roof will let heat out. One should not think that the danger of such a situation lies in a banal increase in energy costs for heating the attic. Warm slopes will provoke snow melting, and this is fraught with many more serious troubles - from mechanical damage to the top covering by the resulting ice to the appearance of fungi and mold that destroy the roofing pie and wooden structures of the rafter system.

High-quality thermal insulation will make the attic comfortable to live in both the summer heat and winter cold.

When choosing a material for insulating an attic, you should remember that not only the thickness and number of layers of thermal insulation, but also the ease of installation depends on this. Based on the specifics of using insulation, the following requirements are imposed on them:

1. Ability to withstand peak temperatures. The material must be frost-resistant and not destroyed at high temperatures, maintaining its characteristics even after numerous cycles of freezing-thawing or heating-cooling.
2. Durability. The service life of thermal insulation should be no lower, or even higher, than other materials used on the roof. This is due to the fact that replacing a roofing pie is much more difficult than, for example, a top covering made of metal tiles or ondulin.
3. The lowest possible thermal conductivity coefficient. It is best to take insulation with a value of no more than 0.05 W/m×K.
4. Maximum moisture resistance. Since condensation may appear in the under-roof space, the material should not absorb moisture and lose its properties when wet.
5. Fire safety. Thermal insulation must not burn or support combustion.
6. Light weight. The insulation should be light so as not to create an increased load on the roof rafter system. The total weight of thermal insulation can be determined by multiplying its density by volume. Experts recommend using materials with a density of up to 50 kg/m3.
7. Ability to maintain a given configuration. The insulation is laid in the spaces between the rafters in an inclined position. If you choose a material that can deform under its own weight, then over time it can slide down, forming voids inside the structure. It is necessary to choose thermal insulation that can retain its original size and shape for a long time.

The type of thermal insulation chosen affects the thickness of the roofing pie. Later we will look at how to calculate the amount of material needed.

What materials are suitable for attic insulation?

You can make your attic suitable for living at any time of the year using various insulation materials. Let's look at their features and highlight their strengths and weaknesses.

Mineral wool

To insulate the attic space, you can use glass wool, mineral wool or slag wool. These materials have the following thermophysical and operational parameters:

• high thermal resistance - up to 1.19 W/(m 2 /K);
• low thermal conductivity - no more than 0.042 W/m×K;
• light weight - from 15 to 38 kg per 1 m2.

Cotton-type thermal insulation is a favorite option for home craftsmen if the roofing pie needs to be installed from the inside of the room. It does not support combustion, has minimal weight, and, importantly, rodents do not grow in its layer. The slab samples retain their shape perfectly, and when laying fiber insulation in the space between the rafters, no precise adjustment is required - the mineral wool is easily distributed without seams or gaps.

Mineral wool is produced in the form of roll and slab materials

The only drawback can be considered increased hygroscopicity. Due to the appearance of moisture between the fibers, the thermal insulation properties of the material drop by more than half, and the material itself begins to collapse. Therefore, mineral wool requires high-quality waterproofing from the roof side and installation of a vapor barrier membrane from inside the attic space.

Polymer thermal insulation

To insulate roof structures, polymer materials are often used - polystyrene foam and polyurethane foam. They retain heat well and, due to their hydrophobicity, are not at all afraid of moisture.

Simple polystyrene foam, otherwise called polystyrene foam, is one of the most popular insulation materials on the building materials market. Good performance characteristics - minimal density, low thermal conductivity, moisture resistance and the ability to hold a given shape contribute to the idealization of this material. As a result, it is often used in places where it is strictly not recommended. Firstly, only non-flammable foam plastic of the G1-G2 brand is suitable for insulating residential premises, and not the popular G3-G4, which ignites perfectly and burns out in a matter of minutes. If you choose the latter for insulating the attic, then surviving a fire in it will be unrealistic. Secondly, installing ordinary polystyrene foam is not an easy task, since it is difficult to cut and crumbles easily. Thirdly, this material is subject to aging and begins to quickly deteriorate over time. And in conclusion, it should be noted that polystyrene foam is a favorite material among rats and mice, so it is used only where it will be covered with a layer of concrete screed or hidden behind plaster.

Polystyrene foam is a type of gas-filled plastic that can be used to insulate an attic space.

Extruded polystyrene foam (EPS) is almost completely devoid of the disadvantages of polystyrene foam, which is well suited for thermal insulation of an attic room from the outside. To do this, insulation boards are laid directly under the roofing material, on top of the elements of the rafter system. Extruded polystyrene foam contains fire retardants, so it burns poorly. Compared to foam plastic, EPS has higher strength and rigidity, which makes it much easier to install. Like other polymer materials, extruded polystyrene foam is waterproof, does not allow steam to pass through, and has good energy-saving properties. This makes it the best option for thermal insulation of an attic roof from the outside. By the way, very little EPS is required - a 100-mm layer will be enough to insulate an attic space in most regions of our country.

Extruded polystyrene foam is best suited for external roof insulation

Polyurethane foam

Polyurethane foam (PPU) is a gas-filled plastic that is applied in liquid form to the inner surface of the slopes. When set, the material forms a rigid foam with excellent physical characteristics:

• heat transfer - up to 0.027 W/m×K;
• thermal resistance from 1.85 to 9.25 W/(m 2 /K);
• thermal insulation density - from 30 to 86 kg/m 3 ;
• weight - from 11 to 22 kg.

To apply polyurethane foam, a special installation is used in which the liquid mixture foams when air or CO 2 is supplied.

To insulate a roof with polyurethane foam, you will have to turn to specialists - you cannot do this without special equipment and skills

This installation method largely determines the advantages of the insulation, since when the under-roof space is blown out, there are no cracks, gaps or cold bridges left in the form of open elements of the rafter system. Polyurethane foam does not support combustion and does not change shape. It does not deteriorate over time and resists moisture well. By the way, the last factor causes low vapor permeability - the insulation does not allow the roof to “breathe,” which can lead to increased humidity in the attic space.

To ensure that the air in the attic room is fresh and light, and the wall surfaces are not covered with mold and mildew, when insulating the roof with polyurethane foam, you should definitely consider a high-quality supply ventilation system.

Ecowool can be considered one of the best materials for thermal insulation work at home. This insulation consists of more than 80% cellulose fibers, so it has low thermal conductivity and is well suited for filling gaps between rafters. Since cellulose in its pure form burns well and is destroyed by fungi, borax is added to its composition as a fire retardant and boric acid to protect against damage by biological organisms, including rodents.

Basic physical properties of ecowool:

• thermal conductivity - from 0.037 to 0.042 W/m×K;
• density depends on the degree of laying and varies from 26–95 kg/m3;
• flammability - group G2 according to GOST 30244;
• vapor permeability - up to 03 mg/mchPa.

In terms of its performance properties, ecowool is close to mineral and polymer thermal insulation, surpassing them in many factors. So, unlike mineral wool, it absorbs moisture without significantly reducing thermal conductivity. With an increase in humidity by 1%, a basalt slab will lose a tenth of its thermal insulation properties, while ecowool, when saturated with moisture to 25%, will increase thermal conductivity by no more than 5%.

Ecowool in the form of slabs of various thicknesses is suitable for insulating the attic.

It is also important that when the cellulose insulation dries, it completely restores its original characteristics. At the same time, it can serve as a kind of buffer, capable of maintaining a comfortable level of humidity in the room. Ecowool allows for seamless installation, therefore it forms a monolithic layer without gaps or cold bridges. Its breathability is almost two times lower than that of mineral insulation, and at the same time it remains elastic enough to dampen sound waves. When using ecowool, the attic will be best protected from external noise. And finally, it is impossible to remain silent about the environmental friendliness and safety of this material. It does not contain a single chemical compound that could evaporate and release substances harmful to humans.

How to calculate the thickness of thermal insulation

To calculate what layer of insulation will be needed to insulate the attic, builders use the formula from SNiP II-3–79 δ in = (R - 0.16 - δ 1 /λ 1 - δ 2 /λ 2 - δ i /λ i) × λ ut, in which R is the thermal resistance of the slope, wall or ceiling (m 2 × ° C / W), δ is the calculated thickness of individual structural elements in meters, and λ is the thermal conductivity coefficient of the insulation (W / m × ° C) for structural layers used.

In private house building, the formula is simplified to a simple equation δ ym = R × λB, where the last factor characterizes the thermal conductivity of the insulation used in W/m×°C. The minimum thermal resistance of walls, roofs and ceilings depends on the region in which construction is being carried out.

Table: thermal resistance values ​​depending on the region of construction

The thermal conductivity characteristics of any thermal insulation material can also be found in the tables.

Table: thermal conductivity coefficients of materials

To determine the thickness of the insulation, it is not at all necessary to count everything manually. You can use an online calculator, which is easy to find on the Internet. All that is needed in this case is to enter the values ​​of the climate zone, the area of ​​the attic, the type of insulation and its scope. The program will do all other calculations for you.

Insulating the attic from the inside

The simplest and most convenient way to insulate a roof is to insulate it from the attic side. Almost all known thermal insulation materials are used for these purposes. Most often, mineral or glass wool is used - this is due to the low price of these insulation materials. Extruded polystyrene foam is used a little less often, the installation of which causes more difficulties. And unfortunately, ecowool or polystyrene foam blowing is still very rarely used - the relatively high price and complexity of installing thermal insulation play a role here.

When insulating an attic from the inside, not only the walls, but also the floor are insulated

The durability of the materials used and the comfort inside the attic depends on how accurately the technology of thermal insulation measures is followed. The most important role here is played by how correctly the roofing “pie” is laid. If we consider the structure from the inside out, it consists of the following elements:

• finishing with sheets of plasterboard, plywood or OSB, clapboard, etc.;
• vapor barrier;
• thermal insulation material;
• waterproofing;
• counter-lattice and lathing with a ventilation gap;
• roofing material.

It should be noted that vapor barrier will be needed only when cotton wool materials are used for insulation - in this case it will prevent the penetration of moist air from the attic space. When using polyurethane foam or polystyrene foam, there is no need for a diffusion membrane.

As for waterproofing, it is needed in any case, since it will serve as an additional barrier to protect the roofing pie and wooden elements of the rafter system from moisture coming from outside. If fiber insulation is used for thermal insulation, then superdiffusion membranes are used that are capable of transmitting water vapor in one direction. During installation, they are oriented in such a way as to ensure the removal of moisture from the cotton materials. In addition, to improve ventilation, a ventilation gap with a height of 5 to 10 cm is installed between the waterproofing and the roof.

When insulating with mineral wool, it is necessary to use a vapor barrier film

The entire process of roof insulation can be divided into several stages:

• preparatory work;
• preparation of thermal insulation material;
• laying insulation in place;
• fastening thermal insulation;
• finishing activities.

You should remember about the insulation of the attic space, starting from the design stage, not forgetting to take into account the features of thermal insulation work at all stages of construction. You should decide from the very beginning what the walls of the attic will be like. If they serve as sloping surfaces of the roof up to the ceiling, then the roof slopes will be insulated. In the event that vertical wall structures are installed, thermal insulation is installed on the affected areas of the roof, walls and adjacent areas of the floor.

Thermal insulation is installed in used areas

Work order

Before you begin thermal insulation of the attic, the insulation cake should be protected with a layer of waterproofing. This work must be done before laying the roofing material, otherwise it will not be possible to achieve complete tightness of the heat-insulating carpet. They begin to lay the film membrane directly on top of the rafters. The work is carried out from the bottom up, overlapping the previous canvas by 15 cm and gluing the joint with special tape. There is no need to tighten the film; it is better to leave a little slack. A deflection of up to 20 mm per 1 linear meter of material will be enough to prevent the membrane waterproofing from breaking with the onset of winter frosts. To attach the film to the rafters, it is best to use a construction stapler. If such a tool is not at hand, then the waterproofing can be nailed with galvanized nails with wide heads.

You should think about protecting the thermal insulation pie from moisture at the stage of roof construction.

To ensure normal ventilation of the space between the film membrane and the roofing material, lumber with a thickness of at least 25 mm is used as lathing. They are attached to the rafter legs using corrosion-resistant screws or galvanized nails 50–70 mm long.

To avoid accidental damage to the waterproofing film, holes are made in the sheathing in advance.

If the roof is covered with a soft roof, then a solid base made of particle boards, OSB or moisture-resistant plywood is mounted on the sheathing. Metal tiles, slate and other rigid roofing materials are attached directly to the sheathing elements.

Then installation is carried out from the attic side. To avoid making mistakes, you should follow the order of work:

1. Thermal insulation material is unpacked. Slab and roll insulation is laid out on a flat surface and left for a short time so that its fibers straighten.
2. The mineral wool panel is cut into pieces, the width of which is 2–3 cm greater than the installation pitch of the rafter legs.
   

   The standard width of rolled thermal insulation is 1.2 m, so for ease of installation, you should choose the same or halved distance between the rafters. In the latter case, the insulation is cut lengthwise, producing two sheets 0.6 m wide.

3. Cut insulation boards are laid in the spaces between the rafters. Initially, the thermal insulation will be retained due to the installation “by surprise”, so each sheet is first pressed in the center, and then its edges are tucked in so that the insulation does not protrude beyond the rafters.
4. The mineral wool is covered with a vapor barrier membrane. As in the case of waterproofing, strips of material are laid horizontally, from bottom to top, with an overlap of at least 10 cm. The joints are taped, and the film itself is secured to the rafters with staples.
5. The bottom sheathing is made from lumber 2.5 cm thick. In the future, plasterboard structures or other finishing material will be attached to it.

   The insulation layer is covered with a vapor barrier membrane, on top of which the sheathing slats are stuffed

Sometimes it is necessary to equip an insulated attic in a house with an already installed roof. In order not to dismantle the roofing material, the waterproofing membrane can be installed from the side of the room. To do this, the rafters are wrapped in film, and the material itself is attached to the sheathing. The disadvantage of this solution is that the wooden roof structures remain unprotected if moisture begins to leak inside for some reason.

Video: thermal insulation of the attic floor with mineral wool

Features of insulating an attic roof from the outside

If the design of the attic space involves the presence of wooden beams on the walls or its dimensions do not allow using a single centimeter of space, then the roof is insulated from the outside. It is best to do this at the stage of roof construction, since otherwise you will have to remove the roofing material.

Insulation of the roof from the outside can only be done with rigid thermal insulation. The best material in this case is extruded polystyrene foam. As noted above, such a coating does not require vapor barrier, so the insulation cake consists of fewer layers:

• slab thermal insulation;
• waterproofing membrane;
• sheathing with ventilation gap;
• roofing material.

The main advantage of roof insulation from the outside is the uniformity of the thermal insulation layer. An undoubted advantage is the absence of cold bridges and the possibility of inspecting and repairing rafters without dismantling the roofing material.

The method by which the attic is insulated from the outside will increase the internal space of the attic and use the rafters as decorative elements of the interior

Work order:

All that remains to be done is to lay and secure the roofing material. Rigid types of coverings are attached directly to the sheathing, so the distance between the beams should be taken into account at the stage of its installation. Under the soft roof, a solid base of OSB or plywood is installed, which is protected with a layer of waterproofing. In this case, there is no need to install a waterproofing membrane on top of the insulation.

Video: everything you need to know about attic insulation

Thermal insulation of an attic room, in addition to actually preserving heat inside, allows you to solve a number of other problems. High-quality insulation will prevent the roof from overheating in the summer, which means that the room will be as comfortable as in any other room. In winter frosts, the thermal insulation cake will prevent snow from melting and ice from forming, and during rain or hail it will serve as protection from noise. It is only important to take into account the features of various insulation materials and carry out the work competently, taking into account the rules and installation technology.