What materials are needed for roof insulation. What is the best roofing insulation? Foamed roof insulation

Just like any other part of the house that comes into contact with the outside world, it needs high-quality insulation. Only insulation will help you get rid of unnecessary heating costs. With this procedure, you can significantly improve the insulation of your home and raise the temperature in it by several degrees.

In addition, although the process of warming cannot be called very cheap, it is a real investment in the future. If you once insulate the roof of the house, then you can forget about the problem of heat loss for many decades.

1 General information

Roof insulation, along with wall insulation, is considered a mandatory procedure. It is enough to carry out at least a superficial calculation to be convinced of this.

It should be understood that if the walls still have at least some protection against freezing, then the roof remains completely defenseless. And indeed, can a plank made of wood, bars and the same metal tile be able to hold back the cold? Obviously not.

Therefore, the calculation shows that the owner simply has no choice but to start insulating the roof.

If the roof is properly protected from heat loss from, then the temperature in the attic can be raised by 3-5 degrees. And immediately, as soon as the work on the thermal insulation device is completed. Then, when the house warms up, this temperature will increase even more, and there will be no more heat loss.

If you intend to build houses with attic floors, then roof insulation becomes a real necessity. Otherwise, no one will want to live on the attic floor of the house.

The principle of useful action of roof insulation lies in the physical processes that take place inside any building.

Everyone knows that hot air always tends to rise, and cold air tends to fall, replacing hot. Since the house is a closed structure, the air masses here move according to a certain technology.

Therefore, the warm air in the house will always move closer to the roof, while the cold air will replace it inside.

But if the roof of the house is not insulated, then this already leads to many problems. After all, hot air from the heating elements will move up, but at the top it will mix with cold air from outside. When the temperature drops, it will drop again, and already heated air will come in its place.

Thus, something like reverse air circulation is provided with, which contributes to its cooling. The calculation shows that in such a situation, heat loss in the house becomes simply catastrophic.

The reviews also signal that in a house with an uninsulated roof, the temperature can be equalized to comfortable values only with the help of extreme measures.

And these measures will cost you a serious amount of money. It is quite obvious that under such conditions, the installation of insulation, the thickness and density of which will allow blocking the cooling of air masses at minimal cost, does not seem to be such a costly affair.

In any case, it is better to act this way than to spend huge sums on non-normative heating.

1.1 Types of roof and features of its insulation

We note in advance that two types of roofing are used in modern construction. It depends on the types of roofing which thermal insulation material is best used in a given situation. Also, the type of roof affects the method of insulation, as well as its return and efficiency.

flat;
pitched.

The first option is the roof, which consists of a floor slab. The ceiling can protect the house well from heat loss, because it consists of solid reinforced concrete up to 20 centimeters thick. But this is still not enough.

Insulation for a flat roof must have an extremely high density. Such a density is necessary in order to be able to withstand the loads that may fall on the floor.

This is especially true for flat roofs in exploited attics. Here the density is raised to the absolute, since it is planned to put serious loads on the floor.

The pitched roof is assembled from wooden shields, slopes and other similar materials. It is better to select the characteristics of insulation for a pitched roof of a house according to a separate procedure. Which one is up to you.

Here, a qualitative calculation is important, as well as taking into account the factors of the roof itself. The fact is that the insulation here should be extremely light so as not to load the structure. In this case, the material must have a good density, not react to moisture, etc.

Moisture can be removed if Izospan type insulation is used (using Izospan insulation is generally good practice in construction), but this does not change the basic requirements for the characteristics of the insulation material, they just become less stringent.

2 Roof insulation

Let us turn directly to the selection of insulation, which can be used to protect the roof from heat loss. In fact, there are a great variety of thermal insulation materials.

And they are produced almost everywhere. Mineral wool insulation alone is produced by companies: Rockwool, Isospan, Knauf, TechnoNikol, etc.

Some of these companies (for example, Isospan) are also engaged in the production of insulation for roofs, which makes it even easier for a person to work.

But here comes the problem of choice. It is quite difficult to choose the best option from such a serious variety. Of course, a special calculation will help you, but not everyone knows how to perform it correctly.

Note that although there are a great many heaters, objectively most often performed:

roof insulation with foam plastic and the same.

Also, in rare cases, the roof is insulated with extruded polystyrene foam, which is a type of foam with unique characteristics.

2.1 Roof insulation with mineral wool

Mineral wool, being a relatively light material with excellent thermal conductivity characteristics, is almost ideal for insulating pitched roofs.

It also affects the ease of installation. If the foam must be pre-cut and very precisely adjusted to the frame, then the mineral wool can simply be shoved between the rafters.

Many modern manufacturers of insulation, such as Isospan, Rockwool, etc. they specially create light air slabs of mineral wool, which, moreover, are very easy to deform in the way that suits you.

That is, the plate is easily compressed, placed between the rafters, and then returns to its original position in a few tens of seconds. As you yourself understand, this greatly simplifies the calculation of the entire procedure.

Also, stone wool, if we are talking about branded samples, practically does not absorb water, but at the same time it is vapor-permeable.

In extreme cases, Izospan insulation can be laid on the insulation layer, and finally get rid of all potential problems.

At the same time, mineral wool is non-combustible. When insulating a pitched roof, which almost entirely consists of wood, this parameter is immediately taken into account.

The only problem with mineral wool is that it is quite expensive, and the effective thickness for insulating slopes can be 10-15 centimeters.

For a flat roof, mineral wool is also used, but much less often than. Since here its thickness should be even greater, as well as the density.

2.2 Roof insulation with polystyrene foam

Roof insulation with foam plastic is also carried out, but not so often when compared with the scope of mineral wool.

Of course, the foam has excellent characteristics and does its job perfectly, but it also has disadvantages.

Chief among them is flammability. Pitched roof, of course, can be finished with foam. This is quite an interesting and useful option. But you need to understand that in this case you are at serious risk.

Styrofoam is also a little more difficult to install, as it must be cut very carefully, it can collapse during operation and is completely vapor-tight.

But polystyrene, especially its extruded variety, is very often used when there is a desire to carry out insulation on a flat roof.

Here, there is much less fuss with it, more convenience, and due to installation on a thick concrete slab, the problem of flammability of polystyrene foam is practically leveled. If the fire does get to the foam through all these concrete floors, then the house by that time, most likely, will simply not be saved.

Ordinary polystyrene is used to insulate non-exploited roofs. Extruded can also be used to insulate operated structures, since its density is almost 2-3 times higher.

The thermal insulation layer is an important structural element of the building, turning four walls and a roof into a full-fledged modern residential building. In the summer heat, it will provide the tenant with coolness, in the winter cold - with warmth, reduce energy costs for heating and air conditioning, muffle street noise. Due to air convection, the most important part of the arrangement of the thermal insulation layer is roof insulation.

There are a large number of different types of insulation, with a wide range of characteristics such as density, insulating properties, hygroscopicity, mechanical characteristics, fire resistance, durability. For the use of each of the materials, it is necessary to take into account its advantages and disadvantages.

Kinds

glass wool- the most common and cheap thermal insulation material, made from sand or glass fragments, a type of mineral wool. Does not burn, withstands temperatures up to 450 degrees, has good elasticity and fairly low thermal conductivity. Disadvantages - caking over time, strongly absorbs moisture from the air and reduces the insulating properties. During installation, it creates a danger to the health of builders, it is advisable to use a special protective suit and a respirator.
Mineral wool- fibrous material produced from fragments of rocks and volcanic rocks. Resistant to temperatures up to 600 degrees, does not shrink over time, has low hygroscopicity and low thermal conductivity, easy to install. Disadvantages - significantly more expensive than glass wool, low elasticity requires precise fitting of sheets to the size of the opening.
Extruded polystyrene foam (EPS)- High pressure foam. It has significant strength, low density and thermal conductivity, slight water absorption, is resistant to chemical attack, perfectly retains its shape for 50 years or more. The main disadvantage is low temperature stability (deformation at 80 degrees) and high flammability. Treatment with flame retardants helps to reduce the flammability of expanded polystyrene to class G1 - it burns, but does not support fire.
Polyurethane foam (PPU)- elastic polymeric heat-insulating material, hard version of foam rubber. The technological process of obtaining does not require factory conditions, therefore, spraying of fast-curing polyurethane foam is used to insulate the roof, which is similar in composition to mounting foam. The finished monolithic coating surpasses any type of wool in terms of insulating qualities, partially replacing even vapor barrier. PPU is essentially a universal adhesive, the coating of it does not require additional fastening. Temperature resistance is quite high for organics - 150 degrees, it burns poorly. The only drawback is the very high price, which includes hiring a specialist in spraying with equipment.
Ecowool- bulk shredded waste paper impregnated with antipyrines and antiseptics. It is considered the best soundproofing material, thermal insulation properties - at the level of polyurethane foam. Cheap and environmentally friendly, but cakes and absorbs water even more than glass wool. It is applied using a special compressor, dry or wet (for vertical spraying) methods. It is mainly used as an additional insulating layer in the arrangement of the attic floor and to fill the gaps between the crate. For full-fledged insulation of pitched inter-rafter spans, you must first complete a continuous sheathing by installing a kind of fixed formwork. Ecowool is not very popular among domestic builders due to difficulties with special equipment.
foam concrete- concrete from sand, cement and granotsev, made using gasification. Due to its good mechanical characteristics and reasonable price, it is excellent for flat roofs. One of the heaviest types of insulation.
Expanded clay- a hard porous material made from clay in the form of granules. Fine and medium fraction (1-20 mm) is used as bulk insulation, medium and large (10-40 mm) - as a component for lightweight concrete with thermal insulation properties. A little more expensive than glass wool, has many advantages. The main limitation in use is the bulk nature and the density increased tenfold, compared with wool and organic types of insulation. Another drawback is the large thickness of the insulating layer (10-30 cm).
Foam glass- the most expensive type of insulation, is a gasified glass. Undoubtedly, the best material for installation on flat exploited roofs. It is 2 times lighter and stronger than foam concrete, has the lowest thermal conductivity among rigid materials, is completely environmentally friendly and chemically neutral.

What insulation is best for the roof

Thermal insulation material for the roof is selected taking into account several of these factors:

structural features of the roof - single-pitched, double-pitched, flat, with a cold attic, with a warm attic, attic and so on;
requirements for the level of thermal insulation and sound insulation;
requirements for lightness, physical strength and elasticity of the insulation;
the need for fire safety material;
the possibility of creating special conditions to protect the insulation from moisture.

By and large, the choice of material depends on what requirements are put forward for the insulation of the building under construction, and what kind of roof it is equipped with.

For the roof of the house, the best, although the most expensive option, will be the use of polyurethane foam. This versatile material is suitable for flat roofs, pitched and attic floors. As the best option for the price, it is possible to suggest the use of mineral wool for pitched roofs and ceilings, XPS for flat roofs.

The ceiling of the bath is a shed roof or attic floor. The specificity of the bath room involves high temperature and humidity. The most versatile, optimal in price and quality for a bath is mineral (stone) wool. For a pitched roof, polyurethane foam can be the best, but much more expensive option.

For arranging the ceiling, you can also use bulk expanded clay or ecowool, providing the ceiling with a powerful vapor barrier. It is not recommended to use glass wool and XPS in the bath.

To insulate a garage, the requirements for environmental friendliness and the degree of insulation are much less. To equip a pitched roof, you can use XPS without vapor barrier. Also a good option would be the use of glass wool with a vapor barrier. A solid concrete floor in a garage is most often not insulated at all, limited to waterproofing, but if necessary, bulk expanded clay insulation or a concrete screed over the XPS layer can be performed on such a roof.

Choosing the best thermal insulation material for the attic

To make a living space out of the attic, it is necessary to insulate the roof as much as possible, not allowing a single gap in the thermal insulation. Sprayed materials are best suited for this - polyurethane foam or ecowool. If you do not want to spend money on the services of professional installers, you can use XPS sheets. The worst option in this case would be the use of cotton wool, its heat and sound insulation qualities are the lowest among the named materials, and durability is not up to par.

How to correctly calculate the required material thickness

A professional calculation of the thickness of the insulation is made on the basis of the normative document SP 50.13330.2012, an approximate calculation is easy to do on your own, having found out the resistance to heat transfer required for your region. Roughly, the heat transfer resistance should be equal to 4 for a minimum winter temperature of -20 degrees Celsius, and an additional 1 for every 15 degrees of decrease.

To get the desired thickness, this value must be multiplied by the thermal conductivity of the insulation.

For example, the required resistance to heat transfer in Moscow is 4.6, the thermal conductivity of glass wool is 0.04. We multiply 4.6 * 0.04 \u003d 0.184 m - the desired thickness. Considering the thermal resistance of vapor and waterproofing, under-roof space, roofing and interior decoration, a thickness of 15 cm is sufficient.

In practice, EPPS 10 cm thick, mineral wool 10-20 cm, polyurethane foam layer about 10 cm, ecowool filling 15-20 cm are most often used. The thickness of the bulk coating for flat roofs is determined taking into account the insulating properties of the monolithic ceiling.

Estimated cost and reviews

The average price of glass wool is about 15-25 dollars per cubic meter. The price of mineral wool is slightly higher - 20-30 dollars per cubic meter. “As for me, glass wool is good where it is a pity to spend money on expensive materials. And she pricks, after installing the insulation, I had to throw away the shirt ... " Rostislav, Lipetsk
The price of mineral wool is slightly higher - 20-30 dollars per cubic meter.“Great insulation, and inexpensive. Easily cut with a knife, does not cause severe irritation on the skin. The only thing is that it is very voluminous, glass wool is somehow squeezed, and this one is brought in huge packages of 0.3 cubic meters.” Valery, Krasnodar
The price of polyurethane foam together with laying will be 150-200 dollars per cubic meter of sprayed foam. If you have the necessary equipment and do the work yourself - 60-80 dollars. “I am a roofer, I insulated my own PPU roof, it cost 200 thousand rubles, the compressor will come in handy later in my work. The temperature in the house in winter did not fall below 23 degrees, only the stove was heated, heating elements were not used. Very happy with the result!” Vadim, Ryazan
The cost of extruded polystyrene foam ranges from 50-80 dollars per cubic meter. It is highly discouraged to use cheap simple polystyrene foam (styrofoam) for the roof, due to its high flammability and hygroscopicity. “I was thinking about insulating the EPPS roof, reading literature and websites - I changed my mind. It turned out that when burning, it emits toxic gases, and it is very expensive. Probably, it should be advised to those who cover flat roofs, rigidity and additional waterproofing of EPPS will come in handy there, and during combustion, the gas will be released outside, and not inside ... ” Igor, Kemerovo
The price of ecowool is low - 15-20 dollars per cubic meter, but finding a specialist with equipment for spraying it is not a cheap task. Installation for self-spraying will cost 500-600 dollars. “Seven years ago, the dacha was insulated with ecowool. The house became quieter and warmer, acquired a natural smell, ants and cockroaches died out. But there is more dust, maybe it’s paper falling out of the slots?” Lilia, Voronezh
The average price of expanded clay depends on the size of the fraction - the larger, the cheaper. When using a mixture of fine and medium fractions, you will have to pay about $ 25 per cubic meter of bulk material, $ 40 - including a cement screed. “12 years ago I made the insulation of the ceiling of the bathhouse with expanded clay, poured small and medium 20 cm and tamped it down. So far, there are no complaints about the bath.” Nikolay, Kolomna

Prices for foam concrete and foam glass used in industrial insulation of flat roofs are $40 and $300 per cubic meter, respectively.

The main ways of laying insulation

For a pitched roof:

Preparation of the roof for laying thermal insulation. Waterproofing is laid on the rafters from the bottom up with an overlap of sheets of at least 10 cm, and fastened with a counter-lattice.
Heater cutting. Cotton wool is cut to fit the rafter pitch or a little more (if the rafter leg is thinner than 75 mm), polystyrene foam - to the size of the inter-rafter opening.
Material laying. Cotton wool should be held between the rafters due to elasticity, expanded polystyrene is attached to glue or mounting foam. With a small thickness, the insulation is fixed in two layers with overlapping sheets from different layers on top of each other.
Vapor barrier fastening. The vapor barrier membrane is pushed to the lower surface of the rafters with a stapler, the entire structure is finally fixed with an internal transverse finish, for example, using a lining.

To cover:

Logs are knocked out from below with a vapor barrier membrane.
Install a crate from below for future ceiling decoration or a solid ceiling.
If a crate is installed, then sheet insulation material is laid on top of it in the spans between the lags, as on a pitched roof.
If a solid ceiling is installed, it is also possible to use bulk or polyurethane foam insulation.
Finishing work. From above, they are carried out only with plans to equip the attic, starting from the minimum cement screed on expanded clay, ending with a full-fledged two-layer floor with waterproofing for the attic.

For a flat roof:

Preparing the floor for work. The surface is thoroughly cleaned of debris and stones, unnecessary reinforcement is cut off, and so on.
Installation of a vapor barrier membrane.
Installation of a heat-insulating layer. Sheets of material (EPS or high density stone wool) are laid in two layers with overlaps.
Installation of a waterproofing membrane.

Summarizing, we can say that the most versatile material is polyurethane foam. Possessing insulating and mechanical characteristics close to XPS, it is much more environmentally friendly, durable, and heat-resistant.

Spray laying provides solidity and ideal conformity to the shape of the insulated gap, which cannot be achieved by any sheet insulation. A nice bonus of PPU will be zero hygroscopicity and the ability in some cases to do without vapor barrier.

During the construction or operation of the house, the owners are puzzled by the issue of roof insulation. Someone is trying to rationalize the year-round use of the premises bordering the roof for a comfortable stay, while someone seeks to minimize their material costs for the consumption of energy resources spent on heating or cooling (depending on the season). Among other things, the use of insulation contributes to:

creation of additional protection for premises from moisture and dust;

maintaining optimal humidity levels;

reduce the penetration of extraneous noise.

It would be most correct to take care of the roof insulation at the stage of designing and erecting an object, however, modern materials allow this to be done in already built and operated buildings.

The main characteristics of heaters

Specialized stores have an extensive range of insulating roofing materials, so when choosing them, you need to pay attention to the following:

Environmental friendliness and harmlessness;

Life time;

fire safety;

Indicators of water and steam impermeability, moisture resistance;

The ability to withstand an aggressive environment and maintain its original geometric parameters during operation.

Types of thermal insulation material

The most popular types of heaters today are:

expanded polystyrene (polystyrene);

extruded polystyrene foam;

mineral wool.

The demand on the market for the listed insulators is explained by:

optimal combination of reasonable price and quality;

the ability to independently carry out the installation of insulation.

Polystyrene boards

Styrofoam (expanded polystyrene) is produced by processing polymer granules with dry superheated steam. Due to thermal expansion, the granules placed in a special block form adhere to each other and, when sintered, leave intergranular voids (micropores).

This insulator is produced in sheets measuring 100 × 100 cm, 100 × 50 cm, 200 × 100 cm, 120 × 100 cm. Their thickness varies from 10 to 100 mm.

Extruded polystyrene foam does not have intergranular spaces in its structure, which significantly increases its functionality and provides a number of advantages over conventional foam plastic:

At a higher density, its thermal conductivity is less;

Indicators of moisture absorption and sound transmission are significantly lower;

It is 5 times stronger in bending and 30% more resistant to temperature fluctuations;

Possesses the increased resistance to mechanical influences (does not crumble).

This insulation is inferior to its related competitor only in price - almost 2.5 times more expensive than it. Extruded polystyrene foam is produced in the form of standard sheets 120 to 240 cm long, 50 to 60 cm wide, and 2.5 to 10 cm thick.

Polystyrene heaters, despite intraspecific differences, nevertheless, are characterized by common features inherent in each of them to a greater or lesser extent:

They have low thermal conductivity and vapor permeability;

Do not absorb moisture;

Resistant to acids and alkalis, but not resistant to benzene and acetone;

Easy to process (freely cut with a knife / hand saw);

They are not subject to rotting and damage by fungi and bacteria;

Do not weigh down the roof structure;

Easy to install;

When burning, they can melt, releasing harmful toxic substances.

In general, these materials are good. And, despite the significant advantages of extruded polystyrene foam, in cases where roof insulation requires a material that is not subjected to heavy loads during operation, ordinary foam can be purchased.

Mineral wool

Mineral wool forms

Mineral wool is perhaps the most popular roofing insulation. There are many varieties of this material (glass wool, slag wool, etc.), however, most often, when choosing a cotton wool insulation, preference is given to basalt mineral wool (stone wool), since it:

has low thermal conductivity;

most resistant to high temperatures;
non-toxic;

not exposed to aggressive substances, rotting, fungi, mold;

easy;

it is easy to process (cut with improvised materials);

provides excellent sound insulation;

The vapor permeability of mineral wool is significantly higher than that of polystyrene insulation, therefore, when using it as a heat insulator, it is necessary to line the surface in such a way that the vapor does not accumulate, but comes out.

Forms of mineral wool

For ease of transportation, storage and installation, this insulation is produced in mats, slabs or rolls. X. Depending on the purpose and options for laying the insulation, as well as based on economic feasibility, preference is given to one or another option. However, it must be remembered that in whatever form the mineral wool is produced, it is always necessary to pay attention to its main characteristics: heat capacity, moisture resistance, vapor permeability.

It is worth noting that, for example, they are more elastic compared to plates, and from the point of view of ease of installation, they are better than rolled ones. Mineral wool slabs have a higher density, so they perfectly withstand vertical loads and do not deform. Because of this, they are more preferable to use than mats, especially when insulating pitched and mansard roofs.

What insulation is best for the roof

Despite all the advanced technologies and the persistent efforts of manufacturers, the ideal insulation has not been invented. Unfortunately, the presented heat-insulating materials are still imperfect and competitive.

If you have to choose between foam, extruded polystyrene foam or mineral wool, then you need to take into account the advantages and disadvantages of each insulation and remember the tasks that should be solved when insulating.

In terms of heat resistance, weight, low cost, resistance to deformation, extruded polystyrene foam and ordinary foam plastic are superior to mineral wool insulation, but they are inferior to it in terms of fire safety and harmlessness to humans.

In turn, mineral wool, with all its advantages over polystyrene foam insulators, is hygroscopic, can shrink, forming cold bridges, and during installation requires additional hassle and costs for installing vapor barrier and ventilation.

The cost of heaters

Depending on the brand, density and specific type, the price of the material varies:

Styrofoam - from 26 rubles. per sheet

Expanded polystyrene - 60-70 rubles. per sheet.

Mineral wool -75-400 rubles. per m2.

Choosing for a mansard roof

However, it must have a thermal conductivity coefficient less than 0.2 W/m*K. At the same time, the thickness of the roof should be minimal so that the attic space does not decrease, and the frame does not experience heavy loads.

The most commonly used insulators for mansard roofs are:

Styrofoam;

extruded polystyrene foam;

mineral wool;

glass wool;

Polyurethane foam.

When it is mandatory to include and in the roof structure. preferably in two layers, tightly joining them to each other and avoiding holes.

A roof with an unused attic, as a rule, is not insulated - thermal insulation or the ceiling of residential premises.

Heat insulators for pitched roofs

For warm pitched roofs, apply:

Pitched roof thermal insulation

Mineral basalt wool;
polyurethane foam;
Penoizol;
Styrofoam;
Extruded polystyrene foam.

For cold roofs, when insulating the attic floor, all of the listed heaters are suitable, however, you can save money and, as an option, use cheaper glass wool.

However, it is important to know that roofing insulation, which is based on fiberglass, is not recommended for insulating roof slopes. Because, due to weak elasticity, after some time they begin to move away from inclined surfaces, and this seriously worsens the level of thermal insulation.

For different insulation systems are used, but in any case they contain:

vapor barrier layer;

Insulation laid in one or two layers;

waterproofing layer;

Control grid.

Insulating a flat roof

The choice of insulation for a flat roof depends on the degree of its operation. If she takes over

certain loads (snow, wind, installation, etc.), then the heat insulator is selected with high moisture resistance and a load limit of up to 250 kg per m2, while additionally a concrete screed is made on top of the heat-insulating layer.

For an unused roof, the load limit is determined by lower values, but the insulator must have good moisture resistance.

Most often, it is insulated with expanded polystyrene (ordinary foam or extruded material), foam concrete, expanded clay. Fibrous mineral heaters are used much less frequently for these purposes. As a rule, the latter are used if the installation of polymer insulation is not possible with high fire safety requirements.

Since expanded polystyrenes are characterized by flammability, in order to avoid fire situations, a non-combustible sand-cement screed is applied to them.

The flat roof insulation system includes:

floor slab;

vapor barrier;

insulation material laid in one or two layers;

hydrobarrier;

concrete screed (if necessary);

sloping waterproofing.

Flat roofs can be insulated both from the outside and from the inside.

The best insulation for any roof, as many years of installation practice shows, are light, non-combustible, heat-intensive, safe and durable materials. A wide range of heat insulators that meet all these requirements makes you choose the right insulation as responsibly as possible, because silence, warmth and comfort in the house depend on the right choice and high-quality installation.

The huge space under the roof of the house is now being turned not into a warehouse, but into a comfortable and spacious living space. But in order for the attic to be warm in winter and not hot in summer, it should be insulated in compliance with the technology. We will help you choose a budget-friendly, durable and easy-to-use heat insulator and familiarize you with the nuances of its use.

The building materials market offers many options for heat insulators, but sellers usually talk only about the merits of the material and rarely warn about the shortcomings. Therefore, it is important to understand which material and in what situation will be more preferable.

The effectiveness of heaters is very different: a more modern material can have ten times less thickness with the same heat-insulating ability

The “correct” insulation must meet the following requirements:

easy to install (since the roofs in our region are pitched, not flat, preference is given to materials that can be held on an inclined surface);
be safe in installation and use (for example, glass wool unpleasantly pricks during installation, and polystyrene releases carcinogens when heated);
do not support combustion (since the main roof structure is made of wood, the use of combustible insulation can lead to the rapid destruction of the house);
have a low weight (any heat insulator is an additional load on the roof structure, walls and foundation);
differ in small thickness (the larger the layer of heat insulator, the lower the ceiling height in the attic).

Styrofoam is one of the most popular heat insulators, as it is one of the cheapest. The slab material is convenient for transportation and installation, does not overload the roof structure, is completely unaffected by moisture, so it is not afraid of rot and mold.

Styrofoam is the best option for external insulation, so it is worth choosing if the roof of your house is flat. It will help to insulate the roof without losing internal space. If you bought an attic above your apartment in a multi-storey building, you can increase its height from 2.2–2.3 to 2.5–2.6 m only by transferring the heat insulator to the outer layer. True, for this you will have to agree on similar work with other residents of the upper floor or with the management company.

This material is quite dense, it is not afraid of water, so builders use foam plastic for thermal insulation of floors. Expanded polystyrene plates are poured into the screed when arranging the floor in the attic.

You will have to spend a lot of building foam to process all the cracks

However, with internal insulation of the roof between the rafters, shortcomings of the foam are found:

the plates are not elastic, so there are gaps between them that must be blown out with mounting foam;
expanded polystyrene interferes with the ventilation of rafters and other wooden frame elements, which can lead to their destruction by rot or fungus;
polystyrene foam has a rather low degree of sound insulation, so if it is important for you to cut off unnecessary sounds, it is better to choose a less dense insulation;
if the material thickness is incorrectly calculated, the dew point is inside the insulated space and the heat-insulating cake begins to collapse;
modern polystyrene does not support combustion, but melts at high temperatures and releases toxic substances, so if a stove or fireplace pipe passes through the attic, it is better to isolate the space around it with another material.

In addition, polystyrene foam is unpleasant for many people to work with, because when cut and rubbed with hard surfaces, it makes repulsive sounds (a similar reaction is caused by the grinding of metal on glass).

Use foam plastic for external insulation of facades, roofs, ceilings and protect it from atmospheric influences. Only in such a situation, expanded polystyrene will provide reliable thermal insulation and will not show its shortcomings.

By the way, when equipping a green roof with grass and ornamental plants, it is foam plastic that is used for thermal insulation, because it does not deform under the weight of subsequent layers of drainage and soil.

The green eco-friendly roof is not only beautiful, but also very warm, because there is foam under it

Roof insulation with foam

Penoplex from a chemical point of view is a new generation of foam. This material is produced in the form of rigid orange plates without visible granules. It differs from the usual polystyrene foam:

tenon-groove edge, which helps to join the plates without gaps, so the seams do not need to be foamed and then cut the foam;
higher density, due to which the roof increases resistance to snow loads;
homogeneity, due to which the plate does not crumble when cut;
lower thermal conductivity, which allows you to reliably isolate the slope with a 2-fold smaller layer of insulation and maintain the height of the ceiling in the attic.

From the older brother, penoplex inherited water and steam resistance, resistance to the influence of fungi and bacteria, the ability to serve for a long time and the absence of dust when cut. It can also be mounted in any weather and humidity level. It is allowed to install penoplex without insulating membranes.

In the roofing cake, when the roof is insulated with foam plastic, there may not be a hydro- and vapor barrier film

But despite all the efforts of the manufacturer to rid the material of combustibility, the polymer remains dangerous in a fire. Of course, it will not ignite on its own and will not burn without direct contact with fire, but the smoke released during melting can poison the residents of the house.

Video: foam roof insulation technology

Polyurethane foam is also a close relative of expanded polystyrene, but unlike the latter, it is not sold ready-made. The chemical reaction that forms the pimples of the polymer takes place already on your roof, so polyurethane foam is guaranteed to fill the smallest gaps between the rafters. In addition to providing a uniform seamless coating, the material has other advantages:

high heat, hydro and sound insulation without cold bridges with a moderately thick layer of material, which allows you to maintain the height of the ceiling (the final thickness is three times less than when using foam or cotton wool);
no need for additional work (installation of fasteners, battens), sufficient dedusting and priming of the surface;
fire safety (the material does not support combustion, does not melt at temperatures up to +220 ° C);
suitable for the northernmost regions (normal operating temperature up to -150 ° C);
not afraid of fungus and rot.

Experts note that if the material is protected from ultraviolet radiation, polyurethane foam insulation can last more than 30 years.

It is possible to insulate the roof with polyurethane foam not only inside, but also outside

What don't sellers say? For example, the fact that polyurethane foam should not be applied directly to the roofing material or the membrane adjacent to it. Since the foam adheres tightly to the base, it becomes impossible to equip the ventilation gap necessary for these materials, and the roof covering is slowly destroyed. Of course, it is possible to hem the slope with membrane-protected boards or OSB boards at a short distance from the main coating and apply foam to this sheathing. But such events will inevitably lead to a rise in the cost of the project, so some masters prefer not to mention the nuances when talking with homeowners.

Insulation with polyurethane foam is impossible without special equipment, so when comparing materials, consider the costs of the work of craftsmen. If you can do the laying of foam or cotton wool with your own hands, then you definitely won’t do the spraying of polyurethane foam yourself.

Considering all the requirements of the technology, polyurethane foam turns out to be a very good choice for all types of houses and roofs, because it is not without reason that in Europe and the USA it is considered the most popular heat insulator.

Video: how polyurethane foam is sprayed

Roof insulation with mineral wool

In our region, mineral wool is most often used to insulate a pitched roof. One of its main advantages is ease of installation. The technology is so simple that with its help even one adult with a teenage assistant can warm the slope. But the mineral wool is different:

glass (glass wool). It is excellent for insulating heated elements (for example, chimneys and chimneys), as it can withstand heating up to 450 ° C. In addition, wool isolates extraneous noise, quickly restores its shape after shock and vibration. One of the main drawbacks of glass wool is flowability. While working with it, the master runs the risk of inhaling a huge amount of tiny fragments of glass fibers, and when cotton gets on the skin, the hands and feet begin to itch and turn red (this is not an allergy, but micro-scratches). As a result, installation has to be done in overalls and a respirator, which makes the process long and uncomfortable;
Glass wool emits tiny particles of fibers interspersed with glass, which unpleasantly scratch open skin areas.
stone (basalt wool). Stone wool is more resistant to moisture, does not cake so quickly and keeps its shape longer. Therefore, you can not be afraid that the heat insulator will eventually slide down the slope. In addition, basalt wool can be installed without personal protective equipment, it is safe for health and practically does not cause itching.
Basalt wool is easy to distinguish by the brown-brown color of long strands.

Both types of cotton wool are produced in the form of mats of several standard sizes and in rolls. If the roof is simple and it is possible to adjust the sheathing pitch (and cell size) to the parameters of the mat, it is best to use soft slabs that will themselves stay in the cells. For roofs with complex slopes, ledges and bay windows, it is better to buy rolled wool, although it will require additional fastening.

Mineral wool - an effective material, but capricious in use. In particular, it should be protected from moisture from above and steam from below, as well as provide natural ventilation. Such requirements will result in additional costs for hydro and vapor barriers, and the work will take longer due to the construction of another crate.

Do not save on insulation by violating the mineral wool installation technology. It is better to properly insulate with cheap cotton wool than to leave an expensive one without ventilation.

Those who ignore the rules, after the first autumn, can admire the wet, rotting insulation and unpleasant cold in the attic. And if the situation is not corrected, the rafters will also begin to rot over time.

Video: roof insulation with mineral wool

If you see soft snow-white insulation in the store, this is not know-how, but a variation of quartz sand mineral wool with acrylic binder. Studies have confirmed its safety for health, so it is with this kind of wool that it is recommended to insulate the attic if it is planned to make a children's room in it. In addition, white glass wool holds better when installed by surprise, does not smell and does not tend to dust, so its installation process is much easier than installing ordinary brown glass wool.

Quartz wool is most often produced in rolls and is the safest type of mineral wool for health.

Roof insulation with ecowool

An even safer and more natural analogue of mineral wool is cellulose ecowool. This material is available in slabs or as loose fibres, slightly reminiscent of down. Among the advantages of ecowool:

natural composition;
resistance to burning (class G2);
good resistance to decay, insects, rodents and fungi (treated with safe impregnants - borax or boric acid);
preservation of properties when wet;
high degree of thermal insulation (4 times higher than that of expanded clay);
environmental friendliness. Does not cause allergies during installation;
formation of a seamless layer of thermal insulation;
frost resistance.

Ecowool is produced in different modifications, while the higher its class, the more it looks like medical

Table: comparison of the characteristics of basalt and cellulose wool

Among the shortcomings of ecowool, one can single out only the need for equipment for ventilation of the material and the difficulty in installation. Cotton wool in the form of fluffy fibers is best sprayed with a blow molding machine, but if you have time and are not inclined to save on the amount of material, this can also be done manually. This is the only cotton wool that can be wetted for ease of installation.

Among the natural analogues of mineral wool, it is also possible to note teplolyon (plates made of flax fibers), but in terms of appearance, characteristics and features of installation, it does not differ much from mineral wool.

Roof insulation with expanded clay

Expanded clay (granules of foamed clay) attracts attention with such properties:

environmental friendliness (it consists entirely of mineral components without the addition of polymer resins and other popular binders);
resistance to mouse teeth (it simply does not attract the interest of rodents, which are happy to nest in mineral wool and polystyrene);
long service life (50–60 years for expanded clay is not the limit);
extremely low thermal conductivity (a layer of 10 cm of expanded clay insulates heat like 25 cm of timber or 100 cm of brick).

At the same time, the cost of the material is not sky-high, it is considered one of the most budgetary heaters.

It looks like a roof insulated with expanded clay in a section

The slopes are hemmed from the inside (OSB, fiberboard, clapboard).
A membrane is laid on top.
A layer of expanded clay (14–16 cm) is poured on it and leveled.
Lay waterproofing.
Mount the crate, counter-lattice and roofing material.

It is almost impossible to qualitatively insulate a finished roof with expanded clay.

Expanded clay granules are fragile, try not to damage them during backfilling.

Foamed roof insulation

Among the rolled roofing insulation, fully polymeric ones are also offered, which look like a substrate for a laminate. In most cases this is:

penofol (foamed polyethylene) with a layer thickness of 3-10 mm, which can be supplied with one- and two-sided foil and adhesive layer;
penotherm (foamed polypropylene) 6–10 mm thick, with or without foil.

Products similar in properties and composition are also produced by the brands Izolon, Alufom, Polifom, Germaflex, Ecofol and others.

Foamed insulation is so thin that rolls for the entire roof can be brought in a passenger car

These materials are extremely thin, but in combination with foil they can provide reliable thermal insulation of the attic. Due to their low weight and small thickness, they are great for owners of older houses who are not ready to strengthen the structure of the roof and foundation. Foamed polymers are completely safe during installation, and thanks to the pure aluminum coating, they are not able to emit any harmful substances into the attic atmosphere. The material simultaneously serves as heat, moisture and sound insulation; no films or membranes need to be mounted with it. Penofol is also used when the ceiling height is critically low. To maintain the height of the attic, you can not even cover it with trim, the foil ceiling will look unusual and futuristic.

At the same time, penofol and penotherm can be used in combination with any other types of heaters, from mineral wool to fibrolite. Such a multi-layer cake will improve your thermal insulation several times, and foam insulation costs no more than a good waterproofing membrane.

When using penofol instead of a membrane, the effectiveness of mineral wool increases markedly

The only drawback of foamed heat insulators is low heat resistance, they begin to break down already when heated to 91 ° C.

Roof insulation with wood-fiber boards

Previously, ceilings and floors were insulated with a mixture of sawdust with the addition of cement. Fiberboard is a more modern variation of this technology, but it has been known for a long time. More than 40 factories producing this material worked in the USSR. Unlike chipboard, with which it is sometimes confused, fiberboard is not made of shavings, but of longer wood fibers (which resemble straw). In addition to them, the plates contain Portland cement and liquid glass, so this material is less combustible, heavier and is not afraid of moisture, like chipboard.

Fibrolite boards can simultaneously serve as a heater and a base for finishing (painting or puttying)

Now fiberboard is not considered a heater, it is more often used for sheathing the frame of a house, constructing partitions and a continuous roof sheathing. But at the same time, fibrolite boards have a low coefficient of thermal conductivity, therefore they are used for insulation both on their own (usually in two layers with offset sheets), and in combination with softer insulation materials (mineral wool, ecowool). At the same time, it is suitable for all types of roofs (flat, single, gable, complex). Unlike other types of heat insulators, fiberboard can be puttied, painted and wallpapered, which greatly simplifies the finishing of the room.

A distinctive feature of these wood fiber boards is their excellent thermal stability. For example, mineral wool under a metal tile on a summer afternoon will heat up in 2 hours, and fibrolite will not change the temperature for 10 hours. The material is so thermally stable that it is possible to equip built-up roofs (roofing felt, bituminous tiles) on it using burners with an open flame.

What insulation is better to use for a private house

In private houses, the roofs are usually pitched, so when insulating it is better to focus on soft materials, leaving polystyrene and polystyrene foam for external insulation of flat roofs. The final choice depends on the configuration of the roof and finishing material. For example:

When buying insulation, be sure to ask the consultant if the type you have chosen is suitable for the roof, since cotton wool, polystyrene foam, foam plastic and other materials for roofs, walls and ceilings differ in density, size, thickness of the plates and other characteristics. Do not be too lazy to read the information on the packaging - most manufacturers indicate the purpose of the material.

Video: testing different types of heaters

September 5, 2016
Specialization: Capital construction works (laying the foundation, erecting walls, constructing the roof, etc.). Internal construction works (laying of internal communications, rough and fine finishing). Hobbies: mobile communication, high technologies, computer equipment, programming.

For me, one of the most important steps in the thermal insulation of roofing is the choice of the right material. After all, the effectiveness of insulation, the laboriousness of the work, and the cost of this entire event depend on what insulation for the roof will be used.

Therefore, for those who are engaged in construction and repair with their own hands, I have prepared a short review in which I will talk about the most common types of thermal insulation materials, and also help you figure out which insulation is best to use.

Basic requirements for heaters

Before choosing a roof insulation, it is necessary to clarify the structural features of the roof that will crown your country mansion. In my opinion, you need to pay attention to the following points:

A kind of roof - it is flat and pitched. In the first case, the heat-insulating material is laid directly on the floor slab, and from above it is protected by waterproofing or corrugated board. Therefore, high density and, accordingly, strength are needed. In the second case, preference is given to a less dense material, which, however, has better heat-preserving properties.
Type of roofing material. There are hard and soft roofs. For hard, I would prefer to use a roofing insulation that has good soundproofing properties so as not to hear noise during rain. Soft roofing is usually a fire hazard, so it is better to lay non-combustible materials under it.
The possibility of using the roof. In the case of a pitched roof, the attic space can be converted into an attic. Therefore, not only the right thickness of the material is important (on which the coefficient of thermal resistance depends), but also environmental friendliness.

If we talk about a flat roof, then it often acts as the floor of a terrace, balcony, and so on. Therefore, it is important to ensure that the insulation maintains its integrity under significant dynamic loads.

Based on all of the above, I want to formulate several requirements that the best heat-insulating material for the roof must meet.

Property	Description
Thermal conductivity	This property is fundamental when choosing a heater. The lower the thermal conductivity of the material, the smaller the thickness of the installed heat-insulating layer will be. Most modern heat insulators have a coefficient below 0.04 W / (m * K), which meets the requirements of SNiP. In order not to make mistakes with the calculations, I recommend using the calculator for calculating the thickness of the insulation, which is usually available on the websites of manufacturers of thermal insulation materials.
Rigidity	Do not confuse this property with density. The rigidity of the insulation means its ability to maintain its original shape during installation and further operation. That is, when laying insulation between inclined rafters, you must be sure that after a year it will not slide down, forming cold bridges that reduce the effectiveness of insulation. But I also do not recommend using too rigid materials, since they have worse heat-preserving properties.
Water absorption	One of the most important indicators. If you use a non-hygroscopic insulation, then the moisture that gets inside the heat-insulating layer will not only greatly worsen its technical characteristics, but will eventually lead to damage to the insulation layer. Moisture-absorbing materials can sometimes be used, but then serious measures must be taken to protect it from moisture (usually using polymer membranes).
Vapor permeability	We are talking about the ability of the insulation to pass through itself air with water vapor dissolved in it. A material with high vapor permeability contributes to the self-regulation of the microclimate in the attic, but requires the installation of protective vapor barrier membranes. Conversely, heat insulators that are impervious to air do not need to be protected with films, but an effective room ventilation system will have to be designed.
The weight	Everything is simple here. The lower the weight of the thermal insulation, the less load it will exert on the truss system, ceiling, load-bearing walls, foundation, and so on. Therefore, heavy materials are usually used for insulation of flat roofs, where it is not the weight that is important, but the increased strength and density of thermal insulation.
combustibility	To insulate the roof, use only non-combustible materials or those that have the ability to self-extinguish in case of fire. This is achieved by adding flame retardants to the heat insulators. In addition, in the case of using the attic as a living room, it is necessary to use heaters that, when ignited, do not emit toxic substances into the air that make it difficult to extinguish the fire and evacuate.
Soundproofing	This property is not so important, but I still recommend installing those heaters that effectively absorb shock and airborne noise. In this case, you will ensure proper silence and comfort in the attic, as well as save yourself from the annoying noise that a hard roof makes when it rains.

There are several other minor technical characteristics. For example, size. Despite the seeming insignificance, this parameter greatly affects the installation technology, the simplicity and speed of installing thermal insulation in the under-roof space. But I will talk about this in the process of describing certain types of materials.

Characteristics and features of individual heaters

Well, now I want to talk about the most significant technical characteristics and performance properties of individual heat insulators. Based on these data, you can independently determine for yourself which insulation is best for the roof.

Mineral wool

This is one of the common materials that I like so much that I devoted a separate article to it (if you want, you can read it). Nevertheless, I will dwell on the description of this insulation in terms of its use for roof insulation.

Mineral wool is made from microscopic fibers obtained from molten minerals. In my opinion, basalt insulation has the best performance properties, so I won’t even consider glass and slag wool. The first is not environmentally friendly, and the second is able to oxidize objects, from which truss supports are often made.

A basalt insulation boasts the following advantages:

Low thermal conductivity. This indicator for wool from basalt fibers ranges from 0.035 to 0.046 W / (m * K), depending on the density. Therefore, to insulate the roof, it is rarely necessary to mount a layer of material thicker than 10 cm. And in the southern regions of our country, 5 cm is enough.
High fire resistance. The melting temperature of volcanic stone fibers exceeds 1000 degrees Celsius. Therefore, when the roof ignites, the material not only does not ignite, but also retains the internal structure, playing the role of a fireproof partition. The insulation does not emit toxic smoke, so you can always have time to evacuate from the attic.
Good moisture resistance. Stone wool does not absorb or accumulate water inside. In addition, in the manufacture of insulation, the material is impregnated with hydrophobic substances that contribute to the speedy removal of moisture to the outside. Nevertheless, I strongly advise everyone to use hydro and vapor barrier films when laying wool.
Environmental friendliness. The product is made from a natural mineral that does not harm human health in any way. For gluing basalt fibers together, a small amount of formaldehyde resins is used, but they have a minimal emission of harmful substances.

In addition to the above, mineral wool tolerates significant temperature fluctuations well and does not deform during operation.

To insulate the roof, I recommend using basalt wool, which is not formed into rolls, but into mats of certain sizes. Their width is chosen to match the standard distance between the rafters (60 cm). Therefore, the installation of insulation does not require the use of a large number of fittings to fix the heat insulator.

As an example, I can cite the following types of Rockwool brand heaters:

Rockmin - mineral mats measuring 100 by 60 cm, 50 or 100 mm thick - non-combustible insulation for thermal insulation of ventilated pitched roofs with unused attic spaces;
Superrock - a material similar to the previous one that can be used for thermal insulation of roofing and attic floors;
Rockton is a specialized insulation that is used for thermal insulation of attic rooms.

Also, many varieties of mineral wool insulation are produced by the domestic company TechnoNIKOL. I devoted a separate material to the description of the technical characteristics of the materials of this brand. I refer everyone to him so as not to repeat myself.

At the end of this section, I want to say that basalt wool is not the cheapest way to insulate a roof. If the price is decisive for you when choosing a material, I recommend paying attention to the insulation described in the next section.

Styrofoam

This material, also called foam, is a heater with a closed cellular structure, due to which it has a low thermal conductivity. It is very popular in individual construction, including roof insulation, due to its low cost and several additional advantages.

I would include among them:

Good heat-retaining properties. According to this indicator, the material can be compared with mineral wool. However, the air inside the expanded polystyrene is closed into sealed cells, due to which the material receives slightly different performance characteristics.
Minimum water absorption coefficient. The structure of the material is such that even in direct contact with water, it absorbs no more than 4% of moisture from its own volume. Therefore, even if the roofing is leaking, the insulation layer will retain its technical characteristics.
Light weight. The insulation weighs very little and during installation does not require the use of additional materials (accessories, films, brackets, and so on). Therefore, the installed insulation layer will not exert a significant load on the roof truss system.
High strength. Styrofoam, unlike mineral wool, has a significantly greater strength to dynamic and static loads. Especially for compression. Therefore, it can be used to insulate flat roofs, including those in operation. Only for this you need to pick up and buy high-density foam.
Ability to tolerate significant temperature fluctuations. Styrofoam does not change its technical characteristics and operational properties during many successive freezing and thawing cycles. The material does not let water through, which can freeze inside, therefore it retains its internal structure for a long time.

Despite all of the above, I would advise using foam for roof insulation only in extreme cases (when cheapness is important). And all because it has many significant drawbacks:

Flammability. Styrofoam quickly ignites during a fire and spreads the flame to other areas of the roof. When exposed to flame, it emits toxic fumes that may be harmful to human health. Therefore, for the thermal insulation of the roof, only material containing fire retardant additives should be used.
Short service life. The guaranteed service life of the foam is about 10 years. And SNiP requires that the insulation layer retain its operational properties for at least 25 years, that is, as long as the roof itself must maintain integrity according to the standard.
Poor tolerance to ultraviolet rays. Expanded polystyrene is destroyed under the influence of sunlight, therefore, when installing it on a roof, care should be taken to ensure that the insulation layer is protected from harmful effects by roofing material.

I will not talk about other nuances, since, in my opinion, they are insignificant from the point of view of use for roof insulation.

As for specific varieties, I would draw your attention to TechnoNIKOL products, which have an ideal price-quality ratio.

polyurethane foam

It is an effective insulation for thermal insulation of the roof, made on the basis of polyurethane. It is applied to treated surfaces with a compressor and after hardening forms a porous layer with small closed cells filled with air. It is thanks to them that the material has a low coefficient of thermal conductivity.

I often used foamed polyurethane foam for roof insulation, as it has many advantages:

Low thermal conductivity. Well, this is understandable, otherwise no one would use it for work.
Fire resistance. The beauty is that by adding various substances to the original mixture for polyurethane foam, you can give the insulation layer different properties. Insulation can be flame-retardant and self-extinguishing.
Low water absorption. Like polystyrene, polyurethane foam consists of sealed cells that do not allow liquid to enter the insulation layer. In addition, usually the material is given hydrophobic properties by adding castor oil to the original mass.
High density and strength. The material has a density of up to 80 kg per cubic meter, therefore, while maintaining acceptable thermal insulation properties, it tolerates mechanical loads well. In addition, a homogeneous insulating layer protects the rafter supports from the effects of external destructive factors (with the exception of ultraviolet radiation).
Long service life. The material retains its technical characteristics for at least 30 years.

A distinctive feature is the method of applying polyurethane foam. This is done using special equipment. The foam is sprayed onto all insulated surfaces where it adheres without any additional benefits.

This circumstance is both a plus and a minus. On the one hand, there is no need to mount the crate, protective membranes, brackets, and so on. On the other hand, roof insulation with polyurethane foam requires certain skills from the master (and, of course, the availability of the necessary devices).

I would call this insulation the best choice for roof insulation, if not for a few drawbacks:

Low vapor permeability of the insulating layer. Lack of natural air infiltration (especially if the rafters and sheathing for roofing material are made of wood) can lead to moisture condensation inside, mold and mildew, rot, and so on.
Poor tolerance to sunlight and low temperatures. Under the influence of these factors, the structure of polyurethane foam is gradually destroyed, and its technical characteristics deteriorate significantly.

Although these two shortcomings are easily leveled by protective measures. That's why I included this heater in my review. If you are interested in the details of working with polyurethane foam, ask questions in the comments.

Expanded clay

This is an insulating material obtained from clay during its heat treatment. Outwardly, it is a small porous pebbles of brown light. The material belongs to the category of bulk.

As for the features of expanded clay, the most significant, from my point of view, are:

Good tolerance to large temperature fluctuations. Seasonal changes in air temperature do not affect the internal structure of expanded clay, and it retains its properties until the end of operation.
High fire safety. Clay, and even burnt, cannot burn in any way. Therefore, in case of fire, the insulating layer is not only safe, but also allows you to limit the further spread of the flame.
Strength. The material perfectly tolerates mechanical loads. Moreover, this quality does not depend on air humidity, temperature, the amount of water that has entered the insulating layer, and so on.
Long service life. This material retains its characteristics much longer than all the heaters listed in this material.
Chemical resistance. Aggressive substances and compounds, getting on expanded clay, do not damage it and do not reduce work efficiency.

The disadvantages for me personally are high hygroscopicity (the material absorbs a large amount of water, therefore it requires reliable protection with waterproofing membranes) and the complexity of installation.

I usually use expanded clay to insulate flat roofs and non-exploited roofs. As for the pitched ones, in this case it is better to insulate the attic floor, and leave the under-roof space cold and ventilated.

Foam glass

A very effective insulation for various structures (including roofs), which is obtained by foaming glass (usually secondary cullet) using chemicals - gas generators or compressor equipment.

Externally, foam glass is like a frozen foam. In the process of processing, the material can acquire a different color - from pastel to black. The internal structure is a closed system of air-filled cells. Thanks to the latter, the material acquires a low coefficient of thermal conductivity.

Insulation can be supplied in the form of blocks of a certain size or small granules (round or angular).

As advantages of foam glass, I can note the following:

High resistance to external destructive factors. Foamed glass is in no way damaged by water, most chemicals and fire. It is great for insulating the space under the roof from cold, heat and fire. No external factors affect the change in the technical characteristics of the heat-insulating layer.
Environmental friendliness. In the manufacture of most heaters described in this material, formaldehyde resins or other substances (albeit in small quantities) are used that can be harmful to human health. Foam glass is absolutely harmless both for the environment and for people.
Antiseptic. The heat insulator is not subject to biocorrosion, fungus, mold and other microorganisms do not appear on the surface and inside the insulating layer. The material is not damaged by rodents and insects.
High strength. Foam glass perfectly tolerates significant external loads (except shock). Therefore, it is the best suited for installation on flat exploited roofs with flexible roofing material.
Light weight. Despite its massive appearance, the material weighs a little, so it does not exert a large load on the roof truss system and the load-bearing walls of the house. The specific gravity of foam glass does not exceed 180 kg per cubic meter.
Dimensional stability. The geometric parameters of foam glass blocks are preserved throughout the entire service life, which, by the way, exceeds 100 years. Therefore, when using it, you can not be afraid of shrinkage of the insulating layer, leading to the appearance of cold bridges.
Ease of installation. Block foam glass is easily cut with a hand tool, and fastened with nails, self-tapping screws or. The bulk material can be used as aggregate for concrete.

There is one factor that greatly limits the use of the described material for roof insulation - this is the high cost. The price of foam glass is more than all other listed materials.

Ecowool

A fairly new insulating material on the domestic market, which is made from cellulose fibers (most often - waste paper). To improve the performance properties of ecowool, antiseptics, flame retardants and boric minerals are added to the composition of the material.

Due to this, the insulation, despite the fact that it consists of wood, becomes non-combustible. Chemical additives contribute to the attenuation of ecowool under the influence of a flame, and boron minerals, when heated, release moisture, which forms an airtight crust on the surface.

In addition, ecowool has several other advantages:

high operational properties;
excellent sound absorption;
possibility of reuse.

Personally, I do not welcome the use of ecowool for roof insulation, since the presence of various chemical additives in its composition makes it unsafe for human health (despite the assurances of manufacturers).

Summary

As you can see, each of the heaters available on the construction market has its own characteristics, which are better manifested in certain conditions. Therefore, there is no universal instruction that is suitable for all possible cases. As for the technology of installing thermal insulation, it is described in detail in the video in this article.

And I wanted to ask you, what roof insulation do you prefer to use in your work? What density is better, in your opinion, to use a heat insulator? You can leave your answers, tips and possible questions in the comments to the material.