How to properly insulate a mansard roof

What to look for when choosing a heater for the attic?

When buying a particular thermal insulation material, be sure to pay attention to:

• versatility of application;
• thermal insulation properties;
• ability to repel moisture;
• the presence of soundproofing properties;
• price;
• ease of installation;
• service life of the heater;
• resistance to temperature changes;
• environmental friendliness.

Obviously, the main selection criterion is precisely the property to keep warm

Indeed, for the attic room, this is especially important. In addition, the versatility of application is important: it will be great if the material can insulate both the roof and the floor, walls

And if you do not want to hear the noise coming from the outside, then choose a heater with soundproofing properties. All these parameters are important. Ideally, the selected heat insulator should correspond to most of them.

Key Features

When insulating the attic, it is necessary to consider high-quality thermal insulation. At the same time, the room under the roof has many features that should be considered during the repair.

Professionals recommend before insulating the roof of the attic from the inside, to provide for the following points:

1. roof configuration. Most often, the roof has an inclined surface. It is rare to find a strictly horizontal roof. Accordingly, the heat-insulating layer will have to be laid on an inclined plane. Solid sheets will not cause any particular difficulties. But with soft rolls you have to work hard.
2. Thermal insulation. For roofing, wood or other lightweight materials are usually used, which are characterized by water-repellent characteristics. But such a roof often does not have sufficient thermal insulation. You can often see gaps in the wooden crate. And this provides even more heat loss.
3. Gable insulation. The attic consists not only of the roof. Therefore, do not forget about the frontons. Attic insulation will not provide the necessary thermal insulation if you do not insulate these walls.
4. Vapor permeability. Steam condensate rising from the rooms accumulates under the roof. Therefore, when choosing insulation for the roof, be sure to choose a material that has excellent vapor permeability.
5. Safety. Since the attic will become a living space, choose an eco-friendly material. It must be non-flammable and completely fireproof.In addition, this material should not be harmful to health.

Roof structures

The reliability of the house is determined, among other things, by the roof structure. The roof can be gable, broken, differ in slope. Due to the design features of the attic, it is possible to obtain additional usable area. To do this, it is necessary to correctly manage the attic space of the house, especially for low-rise buildings. An important role in this case is given to the characteristics of the roof. Traditionally, pentagonal gable structures with a slope of various sizes were suitable for organizing an attic room. A convex fracture on such roofs was formed due to the difference in slopes.

Externally, the shape of the attic structure can be assessed by several parameters.

By slope and roof configuration:

• a triangular roof with a multi-level slope of the lower and upper parts in the form of a gable structure without kinks;
• pentagonal variations on the theme of the roof with slopes at convex corners (two joined parts clearly appear in the design).

Mansard roofs have a multi-tiered truss system. In the lower tier there is a usable area 2-2.5 m high (the scheme is being prepared in advance). The height parameters are indicated for ease of movement inside. The second tier is the shape of the top of the roof, which can have an arbitrary height. Although here you can experiment with the height to get the optimally comfortable roof shape. In this aspect, it is more advantageous to use a pentagonal attic, in which the corners seem to pass along an imaginary circle. It is worth considering that the attic can be equipped not only with a gable roof.Using basic technologies, it is possible to arrange and insulate the attic in shed or hipped roof structures.

The main technologies for the device of a pitched roof, known today.

• Inclined. The lower tier of the attic is being built, then the upper part is being equipped.
• Hanging. Depending on the technical features of the roof structure, the upper part is equipped. With a schematic section of the attic roof, you can see that at the bottom it looks like a trapezoid, and from above it looks like a triangle.

If nothing needs to be done with the shape of the attic, then you can proceed directly to the work on warming the room from the inside, choosing a suitable high-quality material.

Attic and its subtleties as a building object

A bit of interesting history to make it easier for you to understand why attics are such problematic in terms of heat.

For the first time, the concept of an attic was introduced into this world by the French architect Francois Mansart, in the 17th century, who proposed using the attic space for household and residential purposes. And from the beginning of the next century, the poorest people began to live under the usually uninsulated roof. And only much later - bohemia, i.e. wealthy youth, free artists and poets.

The joy of the Parisians can be understood: at that time, the tax for a house was taken based on the number of floors, but the attic was not considered a floor. Those. it made sense to equip this nice room because of the economy, and therefore the fashion for a residential attic came to Russia much later. And only since the 1990s, the attic has come to grips with: the market has sharply become inundated with a variety of heaters and new building materials.

And today, the attic as a living space is recognized by modern building codes and regulations (SNiP), which state that this term can be called the attic, where the line of intersection of the facade and the roof plane is not lower than 1.5 m from the floor level. But with all confidence we will tell you that the attic insulation and waterproofing technology is the most complex and demanding of all existing ones.

Preparing the under-roof space for insulation

You should be aware that, according to GOST standards, the ceiling height in the attic cannot be less than 2.5 meters. But this does not apply to the entire attic area, but only to half of it, that is, on the remaining 50 percent, the height of the room may be slightly less.

What factors affect the heat loss of the attic floor:

• type of the main building material of the house;
• the presence of common communications with other premises of the house;
• features of the geometry of the roof, the number and shape of slopes;
• type of load-bearing materials of the roof;
• placement of the attic relative to the main building (with or without going beyond it).

All these factors must be considered before proceeding with the insulation of the roof from the inside with your own hands. Building rules dictate that the insulation of the house must be carried out from the outside so that the freezing point moves to its outer part. But this rule does not apply to attic floors. Here, the specifics of construction require precisely internal insulation, since roofing material must be placed outside.

The only surface that can be thermally insulated from the outside is the gable of the roof

In terms of preparation for insulation work, you need to carefully study the options for thermal insulation coating and select a high-quality waterproofing film.

What material to choose?

Before starting work, it is necessary to decide on the choice of insulation material, since it determines how many layers there will be in the heat-insulating cake, as well as what is the thickness of its layer.

Especially popular are glass wool, mineral wool, foamed glass, extruded polystyrene foam, polyurethane foam, polystyrene

Do not ignore natural heaters: straw, wood shavings, paper.
When choosing one or another material for the insulation of the attic roof, you need to pay attention to four main indicators

The first and most important is the coefficient of thermal conductivity. The best choice is a heat insulator, the coefficient of which is not more than 0.05 watts per square meter.

The second parameter is moisture resistance. The higher this indicator, the better the quality of the material.

The third indicator: fire resistance.

Fourth: environmental safety.

It is especially necessary to concentrate on the first two characteristics: resistance to fire and environmental friendliness are not decisive factors when choosing.

When choosing glass wool or mineral wool, it must be borne in mind that over time, the thermal insulation qualities of these materials deteriorate significantly. This process is due to two reasons.

The first is that the material may clump or crumble.

The second reason is the excess of permissible humidity levels, since cotton wool absorbs water.

The disadvantages of the material include the fact that it does not differ in particular strength, does not cope well with mechanical loads and collapses under their influence.

Another disadvantage of wool is that when using it, it becomes necessary to create a thick cake, consisting of 3 or 4 layers of insulation to achieve the necessary thermal insulation. In addition, it is necessary to arrange several layers of hydro and vapor barrier.

The positive qualities of mineral wool and glass wool are their availability and reasonable price.

It is also possible to make foam insulation. Its main advantages are moisture resistance and excellent thermal insulation qualities. However, you should be careful when choosing, since not every type of this insulation is suitable for this purpose.

Extruded polystyrene foam is as close as possible in terms of quality to foam. It is also distinguished by high water resistance, its flammability class is from G1 to G4, and the thermal conductivity coefficient is 0.05 W / m * K.

The negative quality of expanded polystyrene is its high price, as well as its synthetic origin.

For supporters of sustainable materials, foam glass, granulated paper, straw, reeds, seaweed-based ladders are excellent choices.

These heat insulators have a low level of thermal conductivity and meet all environmental requirements.

However, each of them has its drawbacks. Foam glass is extremely fragile, and straw, reeds, seaweed are fire hazardous. In addition, laying thermal insulation based on natural materials requires certain skills. When using granular paper, in addition to skills, you will also need special equipment.

The choice of insulation

At the stage of preparation for the installation of the roofing cake, you should decide on the choice of material for insulation.The number of layers and the thickness of the thermal insulation depend on the correctly selected type and technical characteristics. A wide range of materials for the insulation of roof structures is presented on the modern construction market. Among the most requested are :

• polyurethane foam;
• extruded polystyrene foam;
• glass wool;
• mineral wool.

Foamed glass can also be used, various types of natural insulation for installation from the inside (wood chips, seaweed, granulated paper, etc.).

There are four main criteria for choosing a thermal insulation material :

• coefficient of thermal conductivity;
• moisture resistance;
• fire resistance;
• environmental Safety.

Note! To insulate a mansard-type roof, it is recommended to use a material with a thermal conductivity coefficient of 0.05 W / m * K and below. The higher the moisture resistance of the insulation, the longer it will retain its functional qualities. The fire resistance index is an important criterion for ensuring the safety of the home

The fire resistance index is an important criterion for ensuring the safety of the home

It is also important to consider the environmental friendliness of the material and its safety for humans. But the last two parameters do not affect the durability and effectiveness of roof insulation. The higher the moisture resistance of the insulation, the longer it will retain its functional qualities.

The fire resistance index is an important criterion for ensuring the safety of the home

The higher the moisture resistance of the insulation, the longer it will retain its functional qualities. The fire resistance index is an important criterion for ensuring the safety of the home

It is also important to consider the environmental friendliness of the material and its safety for humans. But the last two parameters do not affect the durability and effectiveness of roof insulation. Mineral wool - insulation made from molten rocks

The material holds heat well, does not rot, is resistant to temperature extremes and aggressive environments, and practically does not absorb moisture. Mats of various thicknesses made of mineral wool are especially convenient to use for roof insulation if the pitch of the rafters matches the width of the mat

Mineral wool - a heater made from a melt of rocks. The material holds heat well, does not rot, is resistant to temperature extremes and aggressive environments, and practically does not absorb moisture. Mats of various thicknesses made of mineral wool are especially convenient to use for roof insulation, if the pitch of the rafters matches the width of the mat.

Glass wool is made from molten glass, in terms of its properties this type of insulation is close to mineral wool, but has a lower thermal threshold of -450 ° C. It has good heat and sound insulating characteristics. Glass wool is frost resistant. Moisture can accumulate between the glass wool fibers, so waterproofing must be done correctly.

Mineral wool and glass wool allow you to insulate the roof with minimal financial investment. The disadvantages include the need to create a thick layer of insulation and several layers of vapor and waterproofing.

It is possible to insulate the roof structure from the inside with the help of polymeric materials - expanded polystyrene or polyurethane foam.The advantages of polyurethane foam (gas-filled plastic) include a high ability to retain heat, lightness, and durability. Polyurethane foam does not pass steam and is not affected by moisture. Extruded polystyrene foam allows you to effectively insulate the roof - its thermal conductivity coefficient is 0.05 W / m * K. The material has hydrophobicity, does not pass steam. Flammability class from G1 to G4, depends on the brand of material. The disadvantages of polymer insulation include their artificial origin and relatively high cost.

How to properly insulate: structural laying schemes

Insulation of the attic roof is an issue that requires the most careful consideration, since insulating a sloping roof is one of the most difficult procedures, since it requires simultaneous insulation of several planes. In addition to the internal living space, remote balconies and windows can be provided on its lower slopes, which, in turn, further complicates the thermal insulation procedure. Thus, before insulating the attic, it is necessary to evaluate the design features and the actual state of the attic space.

Let's look at several options for attic insulation.

Budget option: interrafter insulation

• Mineral wool is an elastic heat-insulating material, and it is precisely due to this that it is held between the rafters.
• The insulation is pre-cut into slabs 4-5 cm shorter than the height of the rafters. Its thickness is chosen based on the climate of the construction area and the material of the inner lining.
• In the space between the rafters with attic sheathing, it is separated by a layer of vapor barrier.And on top of the roofing "pie" a hydro-vapor barrier film is stretched (along the rafters), which is pressed with bars.
• Obtained between these layers: thermal insulation - film and film - roofing, two ventilation gaps must be left open at the ridge and eaves assembly to allow free movement of air. To do this, in particular, the film near the ridge cannot be overlapped onto another slope, on the contrary, it does not reach 5-10 cm to the ridge.

• The waterproofing film can break from temperature changes at the attachment points, so it is fixed to the rafters with a sag - about 2 cm.
• The airflow should be at least 2 cm higher than the sagging film and insulation. However, this insulation technology has a significant drawback - the likelihood of “cold bridges” forming along the rafters.

Full attic insulation

• Work begins with the first option, with the only difference being that when the roof is insulated with mineral wool, the inter-rafter space is completely filled, to the very top. Next, wooden bars are sewn across the rafters. Their height should reach the estimated height of the mineral wool.
• A second layer of heat-insulating material is inserted into the resulting frame, and it should cover both the rafters and the joints of the mineral wool of the first layer. That is, in this way all possible "cold bridges" will be removed.

Recommended
The insulation must completely fill all the space provided for it. It should not leave depressions and cavities - loopholes for the passage of air.

After laying the insulating layer, a superdiffusion membrane is laid directly on top of it, which is pressed with wooden bars.The height of the bars should correspond to the height of the ventilation gap, which should be at least 5 cm. After that, the crate and roof are mounted along the bars of the counter-lattice.

• The super-diffusion membrane is laid over the entire plane of the roof and, unlike the waterproofing of the roof, with an overlap through the ridge and without any gaps for ventilation. This method assumes the presence of a single vent, which is located above the superdiffusion membrane.
• The second layer of insulation is laid from the inside of the room using the same technology as on top of the rafters. Across the rafters, bars of counter-lattices are sewn and mineral wool is laid between them. Next is the vapor barrier: depending on its type, they either shoot it with brackets to the rafters, or press it with wooden blocks.

Important
If a foil vapor barrier is used, then it must be installed with foil inside the room. The reflective layer will only work if there is a gap of 2 cm or more, otherwise the thermal infrared rays will not be reflected from the foil.

Attic sheathing, of course, depending on the type, is attached either directly to the transverse or to additional bars that hold the vapor barrier.

2020

Types of heaters

Mineral wool is the undisputed leader among other thermal insulation materials. Its additional advantage is high sound insulation. This material is recommended for beginners as it is light weight and easy to install. Mineral wool is produced in slabs and rolls.For attic insulation, the first option is best.

Mineral wool has one significant disadvantage - it absorbs moisture well. Therefore, if you opted for this material, you need to consider reliable waterproofing.

It is recommended to pay attention to the photo of various thermal insulation materials. This will allow you to visually evaluate their advantages and disadvantages.

It is also worth talking about ecowool, which does not deform over time, such as mineral wool. Another advantage of ecowool is that it is not susceptible to mold and fungi. However, for its installation, it is necessary to invite a qualified craftsman who is able to correctly drive the material under the vapor barrier.

Another fairly popular material is expanded polystyrene (EPS). It also has high thermal insulation performance, which explains its wide distribution. PPS is resistant to moisture, which allows it to maintain its characteristics under any conditions. The disadvantage of expanded polystyrene is its cost.

A budget option for insulation, which is also in demand, is the purchase of foam. This material does not have high strength characteristics, but is able to retain heat in the room. The thermal insulation performance of foam plastic is lower than that of mineral wool and PPS.

Polyurethane foam is a great option if you need to insulate your attic space. This material has a high density and does not deform over time. In addition to everything else, it is worth highlighting its moisture resistance.

Also, attic insulation can be performed using sawdust. However, this option has some disadvantages, which are quite acute during the operation of the thermal insulation system.Sawdust is not able to withstand moisture, and this increases the likelihood of fungus. Sawdust swollen from moisture loses its thermal insulation qualities.

How to properly insulate the attic if the roof is without waterproofing

The same mistake of roofers often occurs - they do not install waterproofing. For a cold roof, this is not scary. Condensation and frost will not form if the temperature inside the buildings and outside does not differ. But if, nevertheless, it is decided to install a roofing pie for a warm attic without waterproofing, then the insulation will get wet, and all its properties will be lost.

Therefore, the process of warming such a roof is carried out using a different technology. The best way is spraying with polyurethane foam. By choosing this material the attic is well insulated for several decades, and there will be no problems with the roof.

This material is not suitable if the roof is covered with corrugated board or made of metal tiles.

Also, experts advise using Penoplex plates, since such material is resistant to moisture. In addition, he is not afraid of the lack of hydro and vapor barrier and must completely and tightly fill all the openings between the rafters, and also fit snugly against each other. This will prevent the formation of cold bridges.

In the case of roof insulation with mineral wool, the waterproofing should be fixed by bending around the construction legs. Hangers are initially attached to the rafters, and already a profile is attached to them.

After that, you need to use the usual technology. Under the crate, it is necessary to get a heater, vapor barrier and attach the cladding. This method has a drawback - the rafters, which are shrouded in waterproofing, cannot be ventilated.And wooden elements quickly rot.

Warming the attic is an important step in preparing the house for winter, if you plan to live in it during this period of the year. To avoid mistakes, you need to take into account various aspects, including the choice of insulation and the type of roof.

The choice of high-quality insulation

You need to choose quality materials. Although it may seem that the choice of materials is the easiest step, in reality it is not at all the case. In the construction market, you will find a huge selection of thermal insulation, among which you need to find the one that will provide the room with a stable level of humidity. You also need to avoid sudden temperature fluctuations.

A good insulation should have the following qualities:

low hygroscopicity (resistance to water absorption);
low thermal conductivity (high heat retention);
Fire safety;
environmental friendliness (very important for residential premises), the absence of toxic components in the composition.

It is also required to select a heat-insulating material that is vapor-permeable - it should not interfere with the exit of water vapor from the room

If you do not pay attention to this requirement, then condensation will begin to accumulate in the room. But dampness is very harmful for the attic ceiling and walls.

The material should not lose its shape over time, it should hold well on any surfaces, even on inclined ones. Do not forget about soundproofing, otherwise it will be impossible to stay on the top floor in heavy rain. Often, metal corrugated board or metal tiles are used as roofing material, which conduct sound well and even amplify it. Therefore, without high-quality sound insulation, you will not be able to relax calmly in heavy hail.

Each type of insulation has its own advantages and disadvantages. For example, many people choose ordinary polystyrene because of its ease of use and its low cost. That's just it is not "transparent" to moisture, which rises with the air from the room. Therefore, it is better not to choose it for roof insulation if you are going to use the attic room as a living room.

Traditionally, glass wool is chosen as a heater, only it quickly deforms, cakes, because of this, its thermal insulation qualities also decrease. Polyurethane foam is also a popular material for insulation, only it has low vapor permeability, it is unable to withstand fire. At the same time, it is necessary to carefully calculate its amount for the roof, because when it hardens, the structure of the material will expand, the structure will simply “crawl”

Therefore, it is important to evaluate the strength of the load-bearing elements of the roof.

mansard pie

Before proceeding with roof insulation work, it is worth understanding the structure and thickness of such a structure. Otherwise, it is called "mansard pie."

Considering all the nuances of such a structure, the requirements that apply to the insulating layer are special.

This is explained by the fact that, according to the construction of the structure, the walls are represented by the slopes of the roof and the gables of the building, in some cases there is a tight fit to the slopes.

This causes the air masses in the room to heat up quickly in the summer and cool down quickly in the winter.

As for the structure of the structure, it is as follows:

• A layer of vapor barrier material;
• insulating layer;
• ventilation gap;
• waterproofing material;
• Roof covering.

More attention is paid to ventilation systems and the heat-insulating layer, it depends on them how convenient and comfortable it will be to be in the room.

Seal selection

Let's figure out which sealant is suitable for insulation.

1. Mineral wool is the most commonly used raw material. It has a number of significant advantages: it perfectly retains heat inside the room, and also has excellent sound insulation. It is also very easy to use, light weight, fire resistant. Release form - plates and rolls. The advantages of this material can also be attributed to a very affordable price, due to which it is very popular. However, along with this, there are some disadvantages. Cotton wool has an increased ability to pass moisture, and it also sags after a while. It is believed that it is best used with horizontal fasteners, otherwise it will sag under its own weight. With vertical insulation, it is preferable to use cotton wool in the slabs.
2. Penofol is the best combination of price and quality. However, it is not the main material and is used rather as an addition to the main insulation. It has excellent thermal insulation properties, and also prevents the penetration of moisture. It is thin, but at the same time quite dense. Ventilation must be provided to prevent condensation.
3. Expanded polystyrene (penoplex) also has good thermal insulation characteristics, combined with an affordable price. It does not absorb moisture, that is, at any level of humidity, its characteristics remain the same.Expanded polystyrene in granules, covered under the film, perfectly retains heat even in severe frosts.
4. Polyfoam is easy to install and relatively inexpensive. But as you know, it does not have such high strength as other materials, and it retains heat rather weakly. In this case, it is better to give preference to more reliable raw materials.
5. Polyurethane foam is one of the first-class heaters with high insulating properties: it fits tightly (does not leave gaps), does not deform over time, and repels moisture well. However, it is possible to insulate the attic in this way only with the help of a specialist using a special tool for this.
6. Sawdust is an environmentally friendly raw material that has been trusted for many decades. It is very reliable, but after some time, its shortcomings also appear: the moisture in them contributes to the development of fungus and rot. From moisture, they swell and significantly add weight, at the same time, their heat transfer capacity increases. It is much more advisable to use this material when insulating the floor of the attic, because it does not accumulate a large amount of moisture in itself.
7. Ecowool, on the contrary, is devoid of the disadvantages inherent in sawdust. It does not change its shape, does not rot and is not affected by fungi. Ecowool is considered an excellent material in all respects. The only caveat: it will not work to insulate the attic with its help. To do this, you need to contact a specialist who will "blow" it under the vapor barrier membrane.

5 Installation from the inside - methods available for implementation

How to properly insulate a mansard roof with a roof installed? The principle of thermal insulation, regardless of the material and technology used, is the same - to fill the space between the rafters with insulation as tightly as possible. This can be done with polyurethane foam or ecowool, but you will have to hire specialized teams involved in this type of activity. With the help of polystyrene foam, polystyrene or mineral wool, you can create a reliable thermal insulation barrier yourself, saving a lot of money.

Consider how to insulate a mansard roof using medium-density mineral wool as a heat insulator, which is available in the form of piece mats. This material will reliably protect the interior of the attic from external temperatures and noise, while being permeable to steam, which will create a comfortable microclimate for living in the room.

The workflow consists of the following steps.

1. 1. If the roof was made a long time ago, most likely, a moisture-proof sheet was not installed under the roofing material. In this case, you need to start by installing a protective film. It will not be possible to attach it solidly, so we cut the canvas according to the pitch of the rafters (a little more) and fix it in the gaps between the supporting bars, overlapping adjacent fragments of about 15 cm.
2. 2. We proceed to the laying of mineral wool. The material is unpleasant to work with, especially when mounted at the top (fine prickly dust falls off), so you should take care of the presence of a respirator, goggles, gloves and a closed suit. We make a pattern of fragments of mineral wool so that they are slightly wider than the pitch of the rafters.By doing this, you do not have to additionally fix the material, it will be held on its own, moreover, there will be no gaps between the insulation and the rafters. If mineral wool is laid in two layers, make sure that the seams between the individual fragments do not match.
3. 3. When all the gaps between the rafters are filled with mineral wool, a vapor barrier must be created from an appropriate film. It is more convenient to roll the canvas perpendicular to the rafters and attach it to the supporting beams with a stapler. Adjacent canvases also need to be overlapped with each other.
4. 4. The last step will be the creation of a counter-lattice (the rails are fixed perpendicular to the rafters), which will become the basis for the installation of GKL or OSB boards.

Thickness calculation

A material with universal parameters - modern insulation, allows you to create the most comfortable conditions and the right microclimate in the upper part of the house, protecting it from heat loss. Installation of insulation depends on its technical characteristics. Consumption is determined by its thickness. There are different installation options, since almost everything is used in the construction business today - from mineral wool to polystyrene. It is possible to calculate the required thickness of the insulating material according to a certain scheme and based on the main parameters of SNiP. When calculating the thickness, the craftsmen are guided by regulatory requirements. The characteristics of both the heat insulator itself and the attic structure are taken into account.

Calculation rules.

When choosing a heater for an attic room, the operational density of the material is taken into account. The heat insulator is selected in such a way as to ensure the overall thermal conductivity of the wall materials.

• The indicator of the load on the structure during the installation of the insulation must be taken into account. Thermal insulation materials differ in weight - it is larger with a higher density of the insulator. So, if the structure is stone or made of brick, this will allow the use of any material for cladding. For a wooden frame, a lower density insulation is suitable.
• Dew point determination. According to this parameter, when calculating the choice of a heat insulator, the quality of the wall decoration both inside and outside is taken into account. The presence of dense plaster, for example, allows you to "save" on insulation. Insulation that is incorrectly selected in thickness will lead to the accumulation of condensate, which will negatively affect the performance of the entire structure.

The thickness of the heat-insulating material can be calculated using the formula: R = P/K, where

• P is an indicator of the thickness of the material;
• K is the value of the thermal conductivity coefficient.

When choosing heat-insulating materials, their thermal conductivity parameters are compared. So, the coefficient of thermal conductivity of expanded polystyrene (which is the most popular) is 0.042 with a thickness of 124 mm. Usually thinner material up to 100 mm is used. Mineral wool (the next most popular) has a thermal conductivity coefficient of 0.046, where the material thickness is 135 mm. The heat insulator is used in the form of plates or a roll.