Which is the best insulation for the attic? What thickness of attic roof insulation is needed, depending on the material

September 7, 2016
Specialization: Capital construction works(laying a foundation, erecting walls, constructing a roof, etc.). Internal construction work (laying internal communications, rough and fine finishing). Hobbies: mobile communications, high tech, computer technology, programming.

I recently started converting the attic in my client's house from junk storage into living space. And I wondered what better insulation for the attic to use in this case? After all, each of the heat insulators on the market has its own characteristics, which are better manifested in certain conditions.

Therefore, today I will tell you how to choose a thermal insulation material for the job. I think this information will be of considerable interest to everyone who is going to build a house and equip it with their own hands.

Features of choosing insulation for the attic

When arranging an attic, it is necessary to carry out insulation. Moreover, regardless of whether this room will be used in winter or not. Properly selected and installed thermal insulation material not only prevents unproductive heat loss, but also protects the room from heat, creating a microclimate inside that is comfortable for people to stay in.

In addition, the insulating pie makes it possible to protect and increase the service life building structures – roofing material, rafters, lathing and so on.

After insulation, all parts will be protected from moisture and temperature fluctuations, which destroy the internal structure of the material. However, to achieve the benefits described above, you must use the right insulation material.

When considering the question of which insulation to choose for the attic, first of all, it is necessary to take into account the climatic conditions of the area where the dwelling is built. The characteristics of the material used depend on this – primarily its density and thickness.

In addition, it is important to pay attention to the design features of the walls, roof, gables, roof angles, shape of the room, etc. In some cases, the attic configuration is so complex that sheet materials It will be very difficult to perform thermal insulation and you will have to choose more technologically advanced options.

Choosing the most best insulation for a room in the attic, I would advise you to pay attention to a few more important criteria which are shown in the table below.

Characteristic	Description
Temperature resistance	Thermal insulation must maintain its technical characteristics and operational properties both in severe frost in winter and in hot summer. Consecutive cycles of defrosting and thawing should not reduce the thermal conductivity of the insulation and destroy its internal structure.
Hydrophobicity	The material must be waterproof or not accumulate water inside the insulating pie. Moisture not only reduces the performance properties of the heat insulator, but also destroys it, reducing its service life.
Fire safety	Preference should be given to those materials that do not ignite during a fire and do not support the spread of flame. As a last resort, you need to buy insulation materials that contain fire retardants, which contribute to the self-extinguishing of the insulating layer. Please note that some types of insulation, when ignited, emit toxic smoke, making it difficult for people to evacuate.
Saving dimensions	The insulating material must maintain its geometric dimensions throughout its entire service life. Otherwise, after installation, the thermal insulation will shrink, forming islands of cold that nullify all efforts to insulate the under-roof space.
Strength	If you are thinking about which insulation to choose for arranging a floor, then give preference to durable heat insulators that can withstand constant dynamic and static loads. Otherwise, you need to design a system with logs to protect the insulating pie.
Ease	It is better to purchase insulation that has minimum weight so that after installation it does not place a significant load on the structural elements of the roof, attic floor and load-bearing walls of the building.

Considering the above, I cannot say 100% which is the best insulation to use to insulate an attic. Therefore, I will describe the technical characteristics of the materials that are most acceptable, from my point of view, so that you can choose the option that suits you.

Specifications

There are many insulating materials, but for arranging a room under a roof, in my opinion, those indicated in the diagram below are most suitable:

Option 1 - Mineral wool

When talking about this type of insulation, I will have in mind one type of thermal insulation - basalt wool, since it has higher technical characteristics than glass wool and slag wool.

This heat insulator is made from a volcanic mineral - basalt. The raw material is melted in furnaces at high temperatures, after which it is formed into thin fibers, which are then glued together with resins.

Thanks to this, the material acquires increased strength and does not pose a danger to human health. However, these are not all the advantages that I personally value and thanks to which I most often use basalt wool in my work.

Other advantages are:

Low thermal conductivity. The fibers in basalt wool are spaced a certain distance apart, and the spaces between them are filled with air, which is known to be a poor conductor thermal energy. The thermal conductivity coefficient of the material is 0.032-0.048 W/(m*K), therefore the thickness of mineral wool for effective insulation is no more than 10 cm.
To convince you, I will resort to some comparison. A standard 10 cm layer of insulation with a density of 100 kg per cubic meter retains heat with the same efficiency as a 110 cm wall made of red brick or a 160 cm wall made of silicate blocks.

High vapor permeability. Insulating the attic with mineral wool from the inside in no way prevents air from penetrating through the roof structure. This is due to the fact that the material has an open cell structure filled with air.
This is very important for residential premises, where a large amount of water vapor is formed as a result of human activity. Excess moisture will escape through the insulation layer, creating a comfortable microclimate for living in the attic. The vapor permeability of mineral wool is 0.3 mg/(m*h*Pa).
Minimal moisture absorption. The material has hydrophobic properties, so it does not lose its technical characteristics when water flows through the roof space. The fibers themselves basalt wool are absolutely waterproof, and the accumulation of moisture inside the insulating cake is prevented by hydrophobic additives in the adhesive resins.
Research shows that in direct contact with liquid, high-quality basalt wool absorbs no more than 2% of the liquid from its own volume. However, I still recommend using waterproof membranes when constructing a roofing pie.

Fire safety. Cotton wool is made from a mineral of volcanic origin, so it does not ignite in a fire. According to the classification of building materials, the described insulation has the NG index (non-flammable). Basalt wool melts and loses its properties when the temperature exceeds 1100 degrees Celsius.
Based on the above, basalt wool is like no other material suitable for arranging attics. The insulation layer in this case will not only perform heat-insulating functions, but also serve as a fire barrier.
Mechanical strength. As I already said, the fibers of basalt wool in the insulation are located chaotically and many of them are oriented perpendicular to the insulating mats, which determines the ability of the material to withstand high compressive loads.
When the insulation mats are deformed by 10%, it has a compressive strength ranging from 5 to 80 kPa ( exact value depends on the density of the material).
Translated into simple language, this means that dense mineral mats can be used for insulation attic floor under . At the same time, the integrity of the insulating layer is fully guaranteed throughout the entire service life.

Soundproofing properties. The open structure of the material ensures that the insulating layer absorbs sound waves very effectively. For an attic, this criterion is one of the most important, since the noise made by rain falling on a hard roof often causes discomfort for people living in the attic.
Moreover, mineral wool has the ability to reverberate sound waves, therefore protecting not only the attic itself, but also the adjacent rooms from noise.
Environmental friendliness. Mineral fibers themselves are absolutely safe for humans, however, formaldehyde resins used for gluing can become a source of emissions harmful to health chemical compounds. To avoid this, the material is subjected to secondary heat treatment, during which the phenol is neutralized. The final emission is much less than the safe level established by regulations, and is no more than 0.05 mg per square meter. meter of material per hour.
Another advantage of basalt wool is that the mats themselves do not prick and do not cause irritation. skin and allergic reactions in people prone to this.

Biological and chemical resistance. Mineral wool is absolutely neutral to aggressive biological environments. Mold and fungus do not develop in the thickness and on the surface of the insulation, the material is not prone to rotting, and is not damaged by rodents and insects.

In addition, basalt fiber withstands exposure well chemical substances, therefore it can come into contact with building mortars and is not damaged by acids dissolved in rainwater, which can leak under the roofing.

High price. There are more economical solutions that are not inferior in efficiency to the material described above.
Presence of seams. Mineral mats are joined to each other and to the rafters. As a result of a loose fit, cold bridges may form in these places.

Option 2 - Expanded polystyrene

I often used ordinary polystyrene foam, which is correctly called polystyrene foam, to insulate attics, although with some reservations. And the point here is not only in cost (and the price of polystyrene foam is really the lowest among alternative materials), but also in large quantities other benefits.

I'll tell you about the most important of them:

Low thermal conductivity. As with mineral wool, polystyrene foam does not conduct heat well due to the air contained inside. However, here the gas is enclosed in small closed cells glued together. Moreover, the polymer occupies only 2% of the total volume of insulation, and the rest is filled with air. Considering that the latter is devoid of convection, this has a positive effect on the heat-retaining properties.
The thermal conductivity coefficient of expanded polystyrene is lower than that of mineral wool and ranges from 0.028-0.034 W/(m*K). However, the exact answer to the question of what layer is needed to insulate attic walls depends on the density of the selected material. In most cases, 5-10 cm is enough.
Classic construction foam does not allow air to pass through due to its hermetically sealed structure. To equip the attic, you can use extruded polystyrene foam, which transmits from 0.015 to 0.019 mg/(m*h*Pa).
And if we talk about water absorption, then the opposite is true. Simple polystyrene foam can absorb up to 4% of liquid from its own volume, and extruded polystyrene foam - no more than 0.5%.

Good strength. Both regular and extruded polystyrene foam tolerate mechanical loads well. But if you are going to insulate the attic floor using a reinforced concrete slab, then buy EPS. If ordinary foam plastic can withstand a bending load of 0.02 to 0.2 kg per square centimeter, then for extruded this figure is 0.4-1 kg.
Chemical cost. Polystyrene foam is good because it does not react in any way to household detergents, alkaline solutions and mineral fertilizers. In addition, it can be coated with bitumen resins, cement mortars and similar materials.
However, polystyrene foam disintegrates upon contact with acetone, turpentine, varnishes, drying oil and petroleum products. In addition, it is not recommended to expose polystyrene foam to direct ultraviolet rays, so the insulating layer in the attic must always be protected with external decorative materials.

Sound absorption. Expanded polystyrene does not absorb sound well. However, if you lay it in a layer of 10 cm, it copes with the absorption of noise during rain. But if necessary, polystyrene foam must be combined with effective sound insulators in order to completely damp out noise from outside.
Antiseptic. Manufacturers of expanded polystyrene have conducted scientific studies that have proven that the development of any living organisms on the surface of this insulation is impossible. Therefore, using polystyrene foam to insulate the attic, you can be 100% sure that mold and mildew will not appear in the insulating layer.
Rodents are a different matter. Although they do not feed on polystyrene foam granules, they still like to build passages and nests in the thermal insulation layer. Damaged foam loses its heat-retaining properties. If your house is located in a remote summer cottage, abounding in mice, it is better to give preference to basalt wool, which is too tough for them.

Flammability. Polystyrene foam, as you probably know, belongs to the category of the most flammable insulating materials (G3 and G4). In addition, the material is highly flammable and contributes to an increase in the source of fire, while emitting toxic smoke that is harmful to human health.
To insulate the attic, it is necessary to use only such polystyrene foam, in the production of which substances - fire retardants - are added to the composition of the raw materials. They will not protect the foam from fire, but will limit the spread of fire and make it possible to evacuate people from the attic floor.
Lifetime. The service life of the insulation provided by the manufacturer is 30 years. However, such results can be achieved if the technology for installing and operating polystyrene foam is strictly followed.
The most important thing is to choose the right thickness of the insulating layer during the insulation process. For middle zone In Russia, it is enough to install a sheet of polystyrene foam 10 cm thick or two sheets of 5 cm each. If you use thinner foam, the effectiveness of thermal insulation will be low; if it is too thick, the insulating cake will collapse as a result of exposure to some external factors.

Environmental friendliness. In the production of polystyrene foam, no gases are used that are harmful to the environment. However, during operation the insulation begins to oxidize. Moreover, this process takes place faster in classic polystyrene foam compared to EPS.
The oxidation process begins when the surface is heated above 30 degrees Celsius. This releases toluene, formaldehyde, methyl alcohol, acetophenone and many other dangerous substances. Therefore, when using polystyrene foam to insulate attics, it is necessary to provide ventilation gaps to help cool the material.

As you can see, expanded polystyrene - regular and extruded - can be used to insulate the attic, albeit with some reservations. However, the latter are entirely justified by the savings in money.

If for you economic factor it doesn’t matter, I recommend paying attention to sprayed insulation, which I will discuss below.

Option 3 - Polyurethane foam

This insulation belongs to the category of sprayed heat insulators. It is made from polymer raw materials, which foam as a result of a special chemical reaction and, after hardening, form a porous insulating layer of closed cells filled with carbon dioxide.

To insulate attics, you can use two types of insulation:

Two-component. It is formed by mixing polyol (component A) and polyisocyanate (component B) in a special device, followed by spraying the mixture onto insulated structures using a gun connected to a compressor. This composition is used to insulate large surfaces.
One-component. Supplied in metal cans with a capacity of 1 liter, completely ready for use. Spraying occurs using a gun on which the container is placed. Such insulation (for example, Polinor) is used to treat small, hard-to-reach areas of the attic and is often combined with other insulation materials.

Two-component polyurethane foam comes in different densities and structures. For interior works For insulation of the roof space, I recommend using Ecotermix 600 with an open cell structure and a density after hardening of 9 to 12 kg per cubic meter.

Due to its porosity, the material has a low thermal conductivity coefficient and effectively protects the room from unproductive heat loss.

Now I’ll tell you about the specific technical characteristics of sprayed polyurethane.

Low thermal conductivity. Carbon dioxide is as bad a conductor of thermal energy as atmospheric air. Therefore, in terms of thermal conductivity, this insulation is not inferior to the alternatives described above.
The exact value of λ is 0.023 W/(m*K) for a material with a density of 32 kg per cubic meter. I usually spray polyurethane foam so that its surface, after hardening, is at the same level as the lower edge of the rafters. That is, the insulation layer is 100-150 mm.

Moisture absorption and air infiltration. The material does not absorb water, so there is no need to take additional measures to protect it from moisture. In addition, it well protects insulated structures from exposure. This property is used to insulate metal parts and pipes, which are simultaneously protected from corrosion.
As for vapor permeability, it all depends on the structure of the cells. The material for outdoor use has closed pores and is therefore not classified as “breathable”.
And the attic can be insulated with a heat insulator with an open cell, which allows you to remove excess moisture from wooden rafters and regulate the level of water vapor in the air.
Good strength. After hardening, polyurethane foam has sufficient compressive strength. Therefore, the insulation layer can not only be covered with sheet materials such as plywood or plasterboard, but also plastered thin layer cement mortar.
What also attracts me personally is the ability of polyurethane foam to further strengthen the very truss structure roofs, strengthening the enclosing walls of the attic and not placing a large load on other structural elements.

Chemical resistance. The insulation tolerates contact well with alkali-containing building materials, as well as acids dissolved in rainwater. What you should be wary of is contact with petroleum distillates, which melt the foam.
Another important point– UV protection. Polyurethane foam disintegrates due to irradiation sun rays, so it must be carefully protected from them.
Sound absorption. According to this indicator, the foam is more reminiscent of polystyrene foam than mineral wool. It protects the room well from impact noise created by raindrops falling on metal tiles or profiled sheets. But polyurethane foam cannot be used as an independent sound insulator.
Better absorbs airborne noise Spray insulation has an open cell structure, so use that.

Antiseptic. The presence of polymers in the spray foam composition and zero water absorption means that microorganisms cannot develop on the surface and in the thickness of the insulating layer, so additional antiseptic treatment of the insulating layer is not required.
The same applies to insects and rodents. Mice don't like foam, so you don't have to worry about such an unpleasant neighborhood.
Flammability. The material, due to the presence of fire retardants in component A, belongs to categories G2 and G3. Although the insulation is flammable, it does not contribute to the spread of an open flame.
In addition, the material has the ability to self-extinguish, since when melted, carbon dioxide is released from the cells, reducing the oxygen concentration at the site of fire.

Lifetime. Research shows that polyurethane foam is guaranteed to retain all technical characteristics and performance properties for at least 50 years.
And if the installation technology is followed, the insulating layer will last as long as the rafter structure of the enclosing walls of the attic itself.
Environmental friendliness. The level of emission of harmful chemicals after application and hardening of polyurethane foam does not exceed those specified regulatory documents quantities .

Despite high cost not only the material, but also the services for its installation, polyurethane foam is often used for thermal insulation of attics, as it has many positive properties:

High adhesion to any surfaces. When sprayed from a mounting gun, polyurethane foam adheres to any surface, regardless of their porosity, roughness, temperature, slope, and so on. Therefore, you can spray foam directly onto rafter system roofs, without the use of additional fasteners.
Simplicity and speed of application. Thanks to the installation procedure mentioned above, the time required to process the room is minimized. Usually, it is possible to insulate a medium (and even large) attic within one working day. But for this you need to have the necessary equipment, the purchase or rental of which is quite expensive.
Multifunctionality. The material plays the role of not only an effective heat insulator, but also protects the attic rafter system from destructive influence moisture and cold.

But, as in all other cases, only you will have to decide whether to use polyurethane foam. Although I personally see no reason to abandon the described insulation technology.

Summary

Now you know about all the technical characteristics of popular materials and can make an informed choice yourself. The video in this article, presented below, tells how to insulate an attic from the inside with your own hands using mineral wool.

What insulation did you choose? You can post your answers in the comments to the material.

September 7, 2016

If you want to express gratitude, add a clarification or objection, or ask the author something - add a comment or say thank you!

Insulation for mansard roof: how to choose and which one is better

Why do you need to insulate the attic?

Before examining in detail how to insulate an attic from the inside, it makes sense to consider the structural features of the coating pitched roof. It is a multilayer system consisting of the following elements:

vapor barrier;
insulation;
ventilation-air gap;
waterproofing;
external roof.

Some homeowners, trying to save on material, exclude one of the layers, but this mistake can be costly later. The fact is that, according to the laws of physics, heat always rises, and if the roof is poorly insulated, it will leak out onto the street, which will cause the cost of heating the house to be significantly higher.

Identifying a poorly insulated attic in winter is quite simple: if negative temperature the snow does not lie on the roof, but melts - this means that heated air penetrates through the roof layer.

It is worth saying that the negative consequences of insufficient attic insulation will be felt not only in winter, but also in summer: summer sun heats the roofing up to high temperatures, and heat penetrates into the room.

Which insulation for attic roof is better?

The construction market has a huge number thermal insulation materials with similar properties that can be used to insulate an attic.

Criterias of choice

When choosing insulation for an attic roof, you should pay attention to several main factors:

coefficient of thermal conductivity;
fire resistance;
moisture resistance;
environmental friendliness of the material.

Thermal conductivity coefficient is the main criterion for heat-insulating material, which should be taken into account when deciding how to insulate an attic roof. This coefficient reflects the ability of the material to release heat to the outside or transmit it from the outside. The lower the value of the thermal conductivity coefficient for a heat insulator, the better it is thermal insulation properties.

Fire resistance is the ability of a heat insulator to withstand high temperatures (fire). In contrast to the thermal conductivity coefficient, the quality of the thermal insulation material is better at maximum fire resistance values.

Moisture resistance is an indicator that reflects the ability of a material not to transmit or absorb moisture. Living in a house will be comfortable only if the heat insulator does not emit carcinogenic substances. There are heat insulators that are made from natural materials; they are distinguished by the best environmental friendliness. All these indicators should be taken into account before insulating the attic from the inside.

Which insulation is best for the attic?

Taking into account the characteristics described above, you can begin to select the type of insulation, and then the manufacturer. Let's consider the most popular insulation materials for an attic roof, these include:

mineral wool;
linen or cotton fabric insulation (a modern analogue of glass wool, has a fibrous structure, breathable, environmentally friendly);
glass wool;
extruded polystyrene foam.

Mineral wool

From this list, mineral wool has the best characteristics: this porous heat insulator is made from mineral raw materials, which means it is highly environmentally friendly. In addition, this material is easy to work with, and with its help you can insulate the attic yourself. One of the disadvantages is the need for careful waterproofing, since the material absorbs moisture and is susceptible to rotting.

Mineral wool is fire resistant, and the thermal conductivity coefficient is in the range of 0.35-0.47. Insulating the attic from the inside with mineral wool allows for good heat conservation and good sound insulation.

Glass wool

It has the same properties as mineral wool, but is more durable. However, it has a low fire resistance coefficient and is quite toxic when burned. Its cost is lower than other thermal insulation materials, so it is used quite often for insulating technical premises.

Mineral and glass wool also have a very attractive price, so insulating the attic from the inside with these materials will not require significant investment.

Extruded polystyrene foam

Durable heat insulator, made in the form of plates with a porous structure. Repels moisture without absorbing or letting it pass through, therefore it is often used as external (facade) insulation load-bearing walls buildings and attics, with a broken roof structure. Significant disadvantages of this heat insulator are high flammability, release of toxins during combustion and oxidation from heat, and air tightness.

Environmentally friendly and natural materials

Modern solutions are aimed at preserving health and the environment, containing a minimum chemical fibers and are non-toxic when burned. To such building materials These include domestic and foreign innovations for insulation, such as:

Ecolen;
Ecowool;
Cotton fabric insulation.

The main differences between these materials are that they allow air to pass through, while providing high-quality heat and sound insulation. They are hypoallergenic and filter odors well. In addition, laying such insulation for an attic roof is much easier, since Ekolen and other fabric insulation do not emit toxic substances and practically do not disintegrate into fibers; you will not need PPE OD (personal respiratory protection equipment) when working.

When laying ecowool through a sprayer, you must first cover the surface of the attic with film, leaving a hole that can be insulated later. It is also recommended to cover the floor and walls, especially if the room has already been used as a living space and will not be used for production. major renovation.

Do-it-yourself insulation of an attic roof from the inside video

Insulation of the attic roof: installation stages

So, the thermal insulation material has been selected, now you can insulate the attic roof from the inside. This work consists of several stages:

preparing a site for installing insulation;
installation of material;
fastening the heat insulator.

The insulation is laid in a cellular structure in the space between the rafters, so the width of the insulation mats must correspond to the pitch of the rafters. The heat insulation is laid from the lower edge of the roof arch, while the heat insulation mats are laid overlapping. This technology allows us to minimize heat loss and reduce material waste.

With sudden changes in temperature outside the roof and inside the room, condensation occurs. To remove this moisture, you need to take care of the design of the ventilated space. This space is created by screwing the insulation onto self-tapping screws to the rafters of a wooden counter batten, the height of which will create the ventilation space.

To ensure the highest possible thermal insulation, it is necessary to exclude any cold bridges, so another thinner, continuous layer of material is laid on top of the rafters. The only drawback of this method is that visually the rafters become hidden, and subsequently the installation of new ones to them structural elements(most often facing) becomes difficult. The way out of the situation will be to mark the location of the rafters with a marker. If problems arise at any stage of the project, the video will help you sort out controversial issues and perform insulation as efficiently as possible.

A vapor-proof film, which is attached over the insulation, will help protect the structure from moisture coming from the room. The next step is to secure the structure using lathing. On final stage Reflective thermal insulation is provided, on top of which finishing can be carried out.

Do-it-yourself attic roof insulation video

Finishing the ceiling in the attic

Finishing The ceiling in the attic has not only aesthetic, but also practical significance. Finishing the ceiling with fiberboard or plywood is one of the simplest and inexpensive options finishing. In addition, these materials have a thermal conductivity coefficient of 0.2. This means that the ceiling will become an additional barrier to the cold.

The French came up with the idea of using the attic as a living space; they made it not just a room, but a place of relaxation. Achieve the same effect in own home you can use a stretch ceiling, which will help hide the structural elements of the attic space and make it more attractive. Besides, suspended ceiling can be very practical.

The fact is that no matter how well you insulate the attic, the sound insulation of this room will still be much inferior to the main rooms (the thickness of the roof is significantly inferior to the thickness of the walls of the house). Therefore, in rain or hail, the attic can be a little noisy. A suspended ceiling will help reduce this disadvantage.

Bottom line

Using these instructions it is possible to ensure that a once unattractive attic can be called with complete confidence French word attic. Not only will this room not be inferior to all other rooms, on the contrary, at any time of the year and in any weather there will be a desire to be here.

The attic of a private house can be used to store unnecessary things, or you can equip this area with a full-fledged living space with all the advantages that it provides attic floor. The most popular option is a bedroom or children's room, but you can also arrange a gym or even a greenhouse here.

To bring these ideas to life, the roof needs to be insulated, so the question of which insulation is best suited for an attic roof is especially relevant for those who want to equip additional square meters.

General requirements for thermal insulation materials

The roof structure is not monolithic. If it is not completely insulated, then cold air penetrating inside through the cracks will inevitably lead to the formation of condensation on wooden structures and, as a result, the appearance of fungus and mold.

If you want to use the attic all year round, then it is necessary that the insulation meets the following performance characteristics:

Review of thermal insulation materials

About 30% of the heat is lost through the roof, so no matter what materials were used for the roofing work, the attic roof requires high-quality insulation.

The range of thermal insulation materials on the market today is so diverse that it is not at all difficult to get lost in this abundance. Below I have reviewed the most popular types of insulation, with all their advantages and disadvantages.

Modern glass wool is made from glass production waste and is radically different from the glass wool that everyone remembers from Soviet times. It's safe, soft material, which does not cause irritation when it comes into contact with the skin.

Glass wool – universal insulation, suitable for all types of surfaces and having the following technical characteristics:

low thermal conductivity;
does not ignite;
resistance to temperature changes in the range from -200 to +500° C;
vapor permeability;
water absorption coefficient up to 15%;
environmentally friendly;
excellent sound insulator.

In addition, glass wool has a number of disadvantages:

undergoes shrinkage during operation;
fibers have low density and increased fragility;
By thermal insulation characteristics inferior mineral wool.

When choosing insulation for the attic, you should not forget about small pests that are often found in private homes - glass wool is inedible, so you will not be in danger of being close to rodents.

Mineral wool

The structure of mineral wool consists of thin synthetic fibers, chaotically intertwined with each other. Air cells are formed among the fibers, which provide the unique thermal insulation properties of the material.

The fibers contain fine stone chips, clay, a small amount of fiberglass and many other ingredients. Among the advantages it is worth noting:

excellent vapor permeability;
low hygroscopicity;
noise-absorbing properties;
fire safety.

Even a non-professional can insulate an attic roof with mineral wool - the material is easy to work with and virtually waste-free. Thanks to its soft structure, it easily fills all voids and the thermal insulation layer has no seams (when using rolls, in the case of slabs there will still be seams).

Despite all the advantages, mineral wool also has disadvantages:

according to some experts, its fibers have carcinogenic properties;
as a binding component in the manufacture mineral slabs use phenol-formaldehyde resin, which is sufficiently for a long time releases free formaldehyde.

This is one of the varieties of mineral wool, which contains natural component– basalt. Under production conditions, it is melted and it turns into a thin fiber. The melting point of basalt is 1000°C, which is why the insulation can withstand heating to such a temperature.

Among fibrous insulation, basalt wool has the best technical characteristics and the highest price.

The only drawback, compared to similar materials, is the heavy weight, which must be taken into account when insulating the attic (the rafter system must be designed for such a load).

When buying basalt wool, give preference to a trusted manufacturer (for example, products from TechnoNIKOL), since some unscrupulous companies, in an effort to reduce the cost of their products, use components that emit toxic substances.

All mineral wool insulation is universal and is perfect for insulating the attic, as well as for insulating floors, walls and facades. However, due to the ability of fiber to accumulate moisture, before insulating the attic it is necessary to high-quality waterproofing surfaces.

Extruded polystyrene foam

It's relative the new kind insulation on the market of thermal insulation materials, but has already gained great popularity. Extruded polystyrene foam is a “relative” of polystyrene foam, but due to its manufacturing characteristics, it surpasses it in technical characteristics.

EPP passes through an extruder, resulting in a material whose structure consists of closed cells that can prevent the absorption of steam and moisture from the outside.

The properties of this unique material are striking in their versatility:

thermal conductivity is lower than that of many insulating materials;
even when completely immersed in water, there is no water absorption;
tolerates frost well;
resistant to most chemicals;
no need for additional waterproofing;
absolutely harmless;
service life up to 50 years;
fairly high compressive strength.

One could say that extruded polystyrene foam is the best insulation for roofing, since despite all its advantages it has a fairly low cost. However, there are two points that negate all its advantages - flammability and vapor permeability.

In view of this, it is strictly not recommended to use it for thermal insulation of a wooden rafter system, although there is a lot of material on the Internet about the use of EPP as insulation for roofs, including attic ones.

Styrofoam

It is a budget option for insulation. Its advantages:

Low price and the ability to install it yourself allows you to significantly save money.
it is practically weightless and does not create additional load on the roof structure.
Due to its environmental friendliness, it is suitable for all types of premises, including children's institutions.

Unlike EPP, which has a closed structure, there are technological pores between the foam granules that allow steam to penetrate through it.

The disadvantages include the property of polystyrene foam that it is easily flammable (although there are types with a flammability class of G1, i.e., that do not support combustion) and small rodents like to make their burrows in it, so experts do not recommend using this material for internal insulation attics.

The video below shows a combustion test for polystyrene foam and polystyrene foam.

PPU

Polyurethane foam is a modern material applied to the insulated surface by spraying. It is precisely due to the method of insulation that polyurethane foam has many undeniable advantages:

when insulating, the construction of an additional frame is not required;
the thermal insulation layer is monolithic and eliminates the appearance of cold bridges;
absolutely not afraid of moisture and at the same time vapor permeable;
if there are engineering structures or complex structures in the attic architectural forms, joints are easily sealed by spraying;
excellent adhesion to any type of surface, except polyethylene;
a layer of 25 mm can replace 80 mm of mineral wool;
polyurethane foam is not liked by mice and insects, it is not susceptible to rotting and mold.

The disadvantages include the inability to carry out insulation yourself - the work must be done by a team equipped with special equipment for spraying, which will require considerable financial costs.

Ecowool

What insulation could be better for an attic than an environmentally friendly material that does not cause allergic reactions? All these advantages have ecowool - insulation consisting of 80% waste paper and waste. paper production, and 20% - from antiseptics and additives that prevent inflammation.

Among its advantages it is worth noting:

at high quality– affordable cost;
seamless thermal insulation layer;
possibility of blowing into hard-to-reach places;
economical consumption when insulating the room;
high sound insulation properties.

Unfortunately, like any other material, ecowool is not without its drawbacks:

during operation it can decrease in volume;
accumulates moisture, which leads to increased thermal conductivity;
the application method is similar to polyurethane foam - you will need the help of specialists and the use of special equipment;
drying time of the heat-insulating layer is from two to three days;
not recommended for use near sources open fire, since under the influence of high temperatures ecowool can begin to smolder (after all, it is 80% paper).

Sawdust

The most ancient method of insulation, which, despite the variety of modern materials, is still used. There are good reasons for this:

this is the most cheap way insulation;
100% environmentally friendly;
work can be performed by a person with minimal experience;
a roof insulated with sawdust has fairly high heat-saving qualities if you add cement or clay mortar to the sawdust.

Despite all the advantages, sawdust insulation is very labor-intensive process, which is increasingly becoming a thing of the past, giving way to modern technological materials. In addition, it is of little use for insulating the attic, and is more used for thermal insulation flat roofs outbuildings.

Calculation of insulation thickness

The thickness of the insulation for thermal insulation of the attic is calculated using a table of thermal conductivity coefficients of materials.

Table 1. Thermal conductivity coefficients of insulation

The exact indicator is indicated by the manufacturer on the packaging - this value depends on the density of the material and the technology used in production.

The thickness of the thermal insulation layer is calculated by the formula:

where R is the thermal resistance for the roof of a certain region, λB is the thermal conductivity coefficient of the insulation.

City		City	Thermal resistance R (m 2 * 0 C/W)
Moscow	4.67	Nizhny Novgorod	4.79
Krasnodar	3.54	Omsk	5.34
Sochi	2.95	Magadan	6.1
Rostov-on-Don	3.96	Chelyabinsk	5.09
Saint Petersburg	4.6	Tver	4.71
Krasnoyarsk	5.37	Novosibirsk	5.5
Voronezh	4.46	Samara	4.76
Ekaterinburg	5.19	Permian	5.17
Irkutsk	5.62	Ufa	4.96
Volgograd	4.18	Kazan	4.91
Astrakhan	3.97

Table 2. Coefficient thermal resistance for the roofing of some Russian cities

Let's say that you live in Moscow and want to insulate your attic with extruded polystyrene foam. Minimum thickness insulation will be 4.67*0.036=0.16 m.

The best option for insulating the roof of a residential building would be basalt wool.

Installation of this insulation does not take much time, will help to avoid unnecessary debris (if you provide in advance the distance between the rafters is slightly less than the width of the roll or mat of basalt wool) and will save money if you do the work yourself. An additional important bonus is that the material is harmless to health and non-flammable, which eliminates the need for processing wooden structures flame retardants.

For a bathhouse, it is necessary to select insulation that does not absorb moisture, and extruded polystyrene foam and polyurethane foam will cope best with this.

They have similar characteristics, so when choosing, be guided by the amount you have (spraying polyurethane foam will be more expensive than finishing with polystyrene foam).

In conclusion, a video review of various insulation materials and their areas of application:

Of course, all of the above is about the choice of material for insulation mansard roof is not the ultimate truth, since much depends on financial capabilities, climate and a number of other factors. If you disagree with something or have personal experience attic insulation (even if negative) - be sure to share your thoughts in the comments.

The modern building materials market is replete with a variety of insulating materials. But when the question concerns complete thermal insulation for a home, you need to know the main requirements for insulating materials. In this article we will tell you which insulation for the attic is better and what characteristics of the material need to be taken into account to keep your home warm and cozy in winter.

Your insulation should be durable and immune to external factors

Any builder with experience in roofing work will tell you that the roof of a house must be well insulated. When choosing a material, focus primarily on the characteristics and needs of the structure. You and I live in conditions temperate climate, the characteristic features of which are heat in summer and severe frost V winter time of the year. This means that your insulation must be durable and impervious to external factors.

One of the key criteria in choosing is the thickness of the attic insulation, on which the reliability and durability of the structure depends. For cold northern regions, you will have to choose thermal insulators as thick as possible, but for residents southern regions, where in winter the air temperature does not drop much below zero, you can choose those that are thinner and lighter.

Video about attic insulation

The most universal insulation is based on mineral wool. It is relatively inexpensive, but is suitable for almost any weather conditions. Although in some cases it is worth using polyurethane or other more expensive material, which is able to fill empty space more tightly.

We do not recommend using backfill insulation for roof insulation. Its thermal conductivity is quite high, which is why it simply cannot fully protect your home from the cold. It is much better to choose roll or slab insulation for an attic roof with low thermal conductivity.

Manufacturers, as a rule, set their own recommendations for laying insulation. If you follow them, you can significantly increase the service life and reliability of the structure. All currently available materials differ in the method of installation depending on their weight, appearance and other characteristics.

It is best to choose insulation materials that weigh little, but are quite strong and rigid. You also need to remember the density of the material.

It is best to choose insulation materials that weigh little, but are quite strong and rigid.

In our climate zone, snowfalls are very frequent in winter, so it is necessary to take into account the load from the snow cover. Heavy weight on the roof can lead to significant deformation. As a result, thermal insulation is greatly deteriorated. As a result, you will have to do the home insulation work all over again. And this is not only a big waste of time, but also money.

You also need to take into account the slope of your roof. The smaller the angle, the more snow will accumulate on it in winter, and during rain, the greater the likelihood of leakage.

The roof is one of the most important structures in the house. We advise you to make the choice of material strictly according to the following criteria:

Expect that there may be severe frosts in winter. The thermal insulation layer must withstand them. When a sudden change in temperature occurs, the material should not distort, crack or sag.
Take moisture resistance and fire safety indicators seriously. Even when directly exposed to fire, it should not ignite. Today on the construction market you can find materials with fire retardants that prevent combustion and slow down the spread of fire. We strongly recommend using these. If we talk about the dangers of moisture, then when the insulation is saturated with water, its properties are greatly deteriorated. Water itself is an excellent conductor of temperatures, so wet insulation simply will not perform its functions. In addition, when the material gets wet, it becomes heavily deformed and gains weight, and the entire roof structure comes under heavy load.
The selected insulation should keep its shape as efficiently as possible. It is better that the material is complete, without unnecessary seams, than to insulate the attic roof of the house with piecemeal remains in order to save money. Make sure you don’t have to pay twice - such material will not be able to fully perform its functions and even the most beautiful room it will be uncomfortable in the attic due to blowing air from under the roof.

The selected insulation should keep its shape as efficiently as possible.

There are really a lot of materials on the market. Among the most popular are fiberglass, mineral wool and polystyrene boards. But they are already quite outdated. We do not recommend using them. Today, much better quality products and liquids are being created that tightly fill voids and insulate the room from the cold.

Mainly heat loss during use modern means decreases by 50% or more. In addition, this allows you to save on other materials. For example, foam glass is extremely resistant to moisture, which eliminates the need to apply a layer of waterproofing. Foam glass is also characterized by very low thermal conductivity and impermeability to vapor particles. But let's consider other options.

Video about the process of attic insulation

Polyurethane. It is sold in a liquid state, but when you apply it to a surface, it hardens and becomes very durable. As with foam glass, waterproofing is also not required. It is very convenient for attics with complex design, where it is almost impossible to work with standard materials. All empty space is completely filled with foam, ensuring low thermal conductivity. Excellent performance properties, long term service and general ease of application – distinctive features modern polyurethane. The polyurethane board is blown out using a special machine and waited until it hardens. It's easy even without construction experience.
Ecowool. One of its main advantages is environmental friendliness. It is made from exclusively natural materials. Basically it is ordinary cellulose. In addition, many manufacturers add fire retardants and active antiseptics to the material, which make ecowool protected from fungus and mold. And it must be said that in comparison with other materials it costs an order of magnitude cheaper. With the worst weather conditions even a layer of 20 cm can handle it. If you can’t decide how best to insulate the attic from the inside, then this is one of the most affordable and practical options. When you use ecowool, it must be precisely adjusted to the size of the compartments between the rafters. It is laid in two layers for better heat conservation. But do not forget that it is sensitive to moisture, which is why a waterproofing layer must be installed.
Polystyrene and other hard materials. Working with them is somewhat more problematic. They need to be laid on a sheathing or rafter structure. But when blown in correctly, it is polystyrene that provides the best thermal insulation for the attic.

When blown in correctly, it is polystyrene that provides the best thermal insulation of the attic

Remember that improper thermal insulation can cause many additional problems - roof icing, icicles, etc. Therefore, it is very important not only to choose the right way to insulate the attic from the inside and outside, but also to correctly carry out all the work on installing thermal insulation.

If the master plans to make the attic space residential, then it is necessary to choose the right insulation for the attic. In this case, it is very important to take into account the basic requirements for the coating and its operating conditions. After all, a living space is somewhat different from a cold attic. We discuss in detail which insulation is best for an attic roof in the material below.

If you don’t know which insulation to choose for an attic roof (what requirements should be placed on it), then pay attention to the following information. So that the insulation of the attic space not only serves for a long time, but also does not cause harm to the residents of the house who will live in it. attic rooms, the material must meet the following requirements:

Environmental friendliness. Especially when you consider that the attic rooms will be heated. And an increase in temperature provokes evaporation from the insulating coating. In turn, evaporation is what the potential tenant of the upper rooms of the house will breathe.
Low weight of insulation. The mass of the material will form the total load of the construction pie on the roof rafter system. And accordingly, the smaller it is, the stronger and more durable the roof will be.
Insulation density. The level of possible deformation under the influence of sedimentary load directly depends on its density. Thus, snow lying on the roof can over time deform the insulating material with its weight. And even if the crust disappears from the roof, soft insulation with low density will no longer restore its structure. In addition, deformation of the coating will lead to a decrease in thermal insulation properties. However, in turn, a material with a lower density will retain heat better. Here you should choose depending on the climatic conditions of the region. If snow prevails, then you can give preference to a denser coating. And if winds are a priority, then less dense thermal insulation materials will be relevant.
Low flammability. In particular for attic premises It is better to use insulation materials marked G-1 and G-2. They have the most low level flammability.
Good moisture-repellent properties. It is important to understand here that attic insulation will be exposed to fumes from inside the room. And if the vapor barrier is installed incorrectly or is deformed, the material can accumulate moisture. And this over time can lead to its deformation, which will reduce the level of thermal insulation.
Good soundproofing properties. This is because the sound of rain on a mansard roof can be disturbing to the residents underneath. Especially if the roof is covered with corrugated sheets or metal tiles. Although it is better not to do this for residential upper premises.
Inertness to biological microorganisms. That is, the insulation for the attic roof should not rot or mold. Otherwise, these same fumes will poison the residents of the upper rooms.
Low thermal conductivity. This is the most important criterion that will limit heat loss from the room through the roof space.

Important: if the insulating coating is laid on the rafter legs, then ideal option the material will be light and dense. If the design of the upper part of the house involves the use frame panels, then it is better to use heavier slab insulation.

Overview of insulation for the attic

Below we give a rating of insulating materials-thermal insulators for attic roofing. We will start with the most optimal ones, and end with the more budget-friendly and controversial ones. So, thermal insulation in the attic can be carried out using the following materials.

Stone wool

It is also called ecowool. This coating is the best insulation today. It is most popular when insulating attic floors. The material has proven itself well due to the following technical characteristics:

Excellent (low) thermal conductivity. For stone wool it is 0.039-0.045 W/m K. Thus, heat loss from the attic space will be minimal.
Non-flammability. Stone wool does not burn or melt, which is why it is most often used for roof insulation.
Does not accumulate moisture. This indicator is due to a special moisture-repellent impregnation, which is applied to basalt fibers in the production of ecowool.
Good sound absorption. Under a roof insulated with stone wool, you will sleep soundly and comfortably.
High strength plates. Even prolonged static load does not deform stone wool.
The ability to pass vapor through itself without moistening the structure of the material. That is stone wool simply breathes, providing air circulation in the space.

Important: if you decide to use a stone wool layer of insulation, then you must do high-quality vapor and waterproofing of the roof.

Extruded polystyrene foam

If you don’t know what is the best insulation for an attic roof, then you can use this type of foam. It is worth remembering here that extruded polystyrene foam can have different densities. And the higher it is, the heavier the coating slabs will be. It is worth knowing that for high-quality roof insulation, the thickness of the attic insulation should be from 10 cm. However, it is strictly forbidden to use polystyrene foam when insulating paint and varnish products on a nitro base. From such mixtures, the insulation will undergo deformation, which means that its thermal insulation properties will disappear over time.

The distinctive advantages of extruded polystyrene foam are:

Excellent moisture resistance;
Inertness to microorganisms and chemicals;
High sound insulation;
Excellent thermal insulation properties;
Non-flammability.

Important: when insulating an attic with slab materials, you must carefully seal all joints with polyurethane foam.

Penofol

Quite a modern insulating material, made in the form of rolls. Gradually, this insulation is replacing the usual rolled mineral wool. The features of this coating are:

Good sound and heat insulation;
Inert to moisture;
Protection of the insulated room from radioactive waves from the outside.

However, it is worth knowing that such a material undergoes significant deformation under prolonged static loads. This is why penofol is ideal for use in windy but snowless regions.

Liquid polyurethane

This type of insulation is suitable for both walls and floor panels of a house. Its main feature is that liquid polyurethane is sprayed in a continuous layer, which means that the material will completely lack cold bridges.

The advantages of the material are:

Good sound insulation properties.
Low thermal conductivity due to the cellular structure.
Inertness to aggressive environments.
Environmentally friendly (however, when spraying and for 10 minutes after the procedure, you should wear a protective mask). After hardening, the material is absolutely safe for humans.
Service life is about 30 years.
Low thermal conductivity.

However, liquid polyurethane also has disadvantages:

The material may become overgrown with condensation if the vapor barrier is not properly organized;
Under direct sunlight, it loses its basic properties;
It is flammable and capable of smoldering.

Important: with the correct installation technology, the liquid polyurethane fills even the most inaccessible areas of the roof.

Styrofoam

This is a budget option for insulating the attic roof perimeter. At the same time, foam plastic slabs are easy to install, provide excellent insulation and do not require knowledge of special complex installation technologies. However, it is worth paying attention to the fact that polystyrene foam is attractive to rodents, and an open flame leads to smoldering and fire of the insulation. If your house is a country house (not permanent), and you want to better insulate the attic of a small cottage, then this option will be quite acceptable.

Mineral wool

Long known to the masters roll material Today they are used less frequently for insulation of walls and roof spaces. However, during installation, the thickness of the insulating mineral wool layer for the roof should be 10-20 cm. However, despite the fact that mineral wool is laid almost without waste due to the possibility of cutting it, you should always remember that this insulation is capable of accumulating moisture. This means that when wet it will increase its mass. Thus, a large load will be placed on the roof frame. In addition, wet insulation from mineral wool rolls can slide down over time, which will form cold bridges.

Important: solid insulation materials such as polystyrene foam or extruded polystyrene foam must be laid on top of the roof sheathing. If we are talking about mineral wool or ecowool, then they are placed between rafter legs under the sheathing. And remember, no matter selected material alwaysneedbut strictly follow the technology of its installation.