Tiled hard insulation for the floor. How to choose a heater for the floor. Insulators for floors under concrete or cement-sand screed

Mandatory when arranging the floor is its insulation. Thermal insulation will protect from the penetration of cold from below, retain heat in the room and distribute it correctly. This will reduce the cost of heating the premises in the cold season. When choosing a heater for the floor, it is necessary to take into account many aspects so that it lasts a long time and is “out of place”, performing its functions with high quality.

When choosing a heater for the floor, consider the operating conditions

Types of heaters

Mineral heaters made from natural materials:

Mineral wool: fiberglass, stone wool, slag wool. It is a shaded fiber of rocks or other materials.
Foam glass.
Expanded clay - granular burnt clay.
Cement-based mixtures with aggregates and additives.

Wood chip materials used for dry screed or filling empty space:

Waterproof plywood.

Cellulose wool is used to insulate wooden floors

Cellulose wool - blown or simply filled and rammed.

Polymer materials are not environmentally friendly:

Polyurethane foam.
Reflective polymer insulation.
Roll heater.
Liquid polymer insulation with a foam structure.
Liquid thermal insulation paint.

When choosing which insulation is best for the floor, be guided by their technical characteristics and future operating conditions. The ideal option would be to use several materials at once at different stages of floor insulation. For example, expanded clay, basalt wool and rolled insulation on top of the screed are suitable for a concrete floor.

Important! Polystyrene, polyurethane foam and extruded polystyrene foam, when burned, release a toxic gas that can be fatal in two breaths. Therefore, if you decide to use them in construction, then lay them under a concrete screed, where there will be no contact with fire.

How to choose floor insulation

First of all, it is necessary to take into account what kind of floor - wooden on logs, concrete or the "warm floor" system. In all three cases, different materials will be needed.

To insulate a wooden floor, mats or insulation sheets are laid between the joists.

For warming a wooden floor, a loose porous material is suitable that does not hold its shape, loose. It can be poured into the space between the lags, or mats, slabs, linens can be laid, depending on the form of release of the insulation. It is very important that in this case the insulation "breathe" and let steam through. After all, the wooden floor is equipped precisely so that the house "breathes".

For a concrete floor, solid heaters are suitable, which keep their shape well and do not deform under compressive and bending loads. This is important, as a concrete screed will be poured from above. In this case, it is not necessary that the insulation “breathe”, but it is imperative that it does not absorb moisture.

For the “warm floor” system, heaters will be needed the same as for the concrete screed, with only one caveat: they must have a foil film to reflect the heat coming from the “warm floor” towards the lower floor. You can use materials with aluminum coating or lamination.

Characteristics of thermal insulation materials

Coefficient of thermal conductivity determines the ability of a material to conduct heat. It is equal to the amount of heat that passes through a material 1 m thick, with an area of 1 m 2 per hour, provided that the temperature difference on the two sides of the material is 10 ° C.

Porosity is a very important indicator, it is determined by the ratio of the number of pores to the total volume of the material. Affects all other characteristics of heaters.

Vapor permeability material determines its ability to "breathe".

Water absorption affects the possibility of using the material in conditions of high humidity. The lower this figure, the better.

Strength material is important for its use in structural elements where there are compressive loads.

Biostability means whether the material is able to resist the action of pathogenic flora.

fire resistance determines the ability of a material to withstand high temperatures for a certain time without breaking down.

Heat capacity- the ability of the material to retain heat in conditions of frequent temperature changes.

There are several other important features:

Density;
Humidity;
temperature resistance;
Frost resistance;
Flexural strength;
Fire safety indicators: combustibility, flammability, smoke formation, toxicity of combustion products, etc.

Insulation for underfloor heating

When choosing a heater for the "warm floor" system, it is necessary to pay attention to the ability of the material to redirect heat in the right direction and block its spread in an undesirable direction.

To reduce heating costs, while not heating the ceiling to neighbors or the basement in a private house, it is advisable to choose a heater with a foil or laminated layer. Such material will prevent the penetration of cold from below and direct the heat coming from the "warm floor" system upwards.

For the "warm floor" system, the insulation must have a foil structure

It can be found under different names and trademarks: Isolon, Penofol, Isoflex, Energoflex. The material is produced in rolls 90-120 cm wide, 2-3 mm thick. It does the job well despite being so thin.

Extruded polystyrene foam is one of the strongest, most durable and moisture resistant insulation materials.

It is produced in plates that are easily cut into the necessary pieces, easy to install and use. It has a very dense structure that does not deform or break. The cellular structure is filled with gas, the cells themselves are impermeable, due to which this material is not affected by moisture: it does not swell, does not absorb moisture. Extruded polystyrene foam is resistant to acids, alkalis or alcohols. Fungi and bacteria do not take root on its structure. It is durable, as it does not collapse under the influence of precipitation and the sun and does not react with most substances. Despite the undeniable advantages, extruded polystyrene foam has a number of significant drawbacks: it "does not breathe", which means that it makes no sense to use it to insulate a wooden floor, and it is combustible. Although this material is non-toxic in its normal state, it releases poisonous gas when it burns. In the "warm floor" system, it will be absolutely isolated from the environment with a concrete screed, so it can be safely used.

Cork material is the most environmentally friendly and natural insulation.

Produced from the bark of the cork oak. This material is the most environmentally friendly and natural. It does not rot, does not “shrink”, is inert, resistant to bending and compression loads. In addition, the cork is easily cut, which affects the speed of working with it. The service life of a cork substrate can be about 50 years. Cork material does not burn, and during smoldering it does not emit harmful substances. Withstands temperatures up to 120°C. It is produced in the form of plates with a thickness of 25-50 mm.

Insulation for the floor under the screed

It is better to insulate the concrete floor in several stages, since it is the coldest.

Expanded clay is convenient to fall asleep under a concrete screed or add to concrete instead of crushed stone

- an ideal option for floor insulation on the ground. It is a rounded granule, made from clay by firing it with the addition of peat, sawdust and other additives. The size of the granules can be different, and the heat-conducting characteristics of the material also depend on this. Expanded clay is resistant to changes in temperature and humidity, light and does not create a large load on the foundation. Due to the porous structure, in addition to heat-insulating properties, it has good sound-proofing characteristics. The indisputable advantage of expanded clay is its environmental friendliness and naturalness.

Solid basalt wool slabs are laid under a concrete screed

- one of the varieties of mineral wool, is a hard insulation in slabs. It is laid on the floor in a checkerboard pattern under a concrete screed, which must be at least 4 cm thick. This material does not burn, is resistant to deformation and vapor permeable. Basalt wool has high thermal insulation characteristics and withstands high temperatures.

Also used for insulation of concrete floors under the screed.

Styrofoam is one of the most common insulation materials due to its low cost.

Also can be used. Its main advantage is low cost and ubiquity. It is durable, easy to use, absorbs little moisture and has high thermal insulation properties. Among the shortcomings can be identified: it is combustible, exposed to sunlight, "does not breathe." When using polystyrene foam as a heater under the screed, these disadvantages are insignificant, and they can be neglected.

Properly selected floor insulation will create high-quality and durable thermal insulation. Compare the characteristics of heaters, weigh all the advantages and disadvantages, find a balance and be sure to consider the operating conditions.

The question "Which insulation is better for the floor?" everyone who loves comfort is asked. It is always nice to walk barefoot without fear that your limbs will freeze. And this is especially true in the off-season, when the central heating (if any) has not yet been turned on, and in winter, when the temperature is below zero outside the window. It is then that people often turn their eyes to floor insulation. We will tell you how to choose the material and how to lay it correctly. After all, a well-insulated floor is one of the components of heat preservation in a residential area.

When choosing heaters, it is important to take into account the climatic zone (how cold it can be in winter), the features of the room and its purpose, the type of existing or planned flooring. For example, floor insulation in an apartment and in a wooden house will differ significantly.

Option #1 - Styrofoam

Among the materials that do not require communications or connection to the network, the most common insulation for underfloor heating is polystyrene foam, well known to everyone as polystyrene.

Its thermal insulation properties are 25 times better than those of expanded clay concrete. Yes, and walking on a floor insulated with polystyrene foam is much warmer and more pleasant, because such a floor absorbs heat very slowly.

Styrofoam as a floor insulation is used when installing a floating screed. Then it is poured with a layer of cement or concrete. It is possible to lay the slabs in the gaps between the lag when constructing wooden floors. Another way - the slabs are laid on a concrete floor, and on top of them - sheets of plywood.

Expanded polystyrene is not afraid of moisture, so it can be widely used for floor insulation on the balcony and in rooms with a high level of humidity.

Option # 2 - expanded clay

Expanded clay is one of the most affordable inexpensive materials. It is used both when falling asleep under gypsum boards and added to concrete. Using expanded clay, a floating floor screed is also constructed when concrete or cement mortar is poured over it.

Floor insulation is best done with expanded clay from different fractions

The porous structure of this material, made of clay, allows the floor to be thermally insulated even in areas with very cold and frosty winters. But for this, the expanded clay layer should be about 10-15 cm, which is not always convenient, because it reduces the existing living space.

Option #3 - polystyrene concrete

In comparison with expanded clay and ordinary screed, the thickness of the floor insulation based on polystyrene concrete is much thinner. 5 cm of material is enough to provide both heat and sound insulation of the room. And the pressure on the floor in this case will be less, and the floor can be leveled, and the floor can be insulated.

Almost all materials can be laid on top of the polystyrene concrete layer, including tiles. In addition, it will create a perfectly flat surface for self-leveling floors.

Option #4 - glass wool and mineral wool

These types of insulation are widely used for insulation of roofs, walls and floors due to their low cost. There are such materials in the form of plates or in rolls. They are most often used for warming wooden floors due to the vapor permeability of the material.

Mineral wool and glass wool are laid between the lags. But the composition of these materials makes you think: the release, although in safe norms, is still present of hazardous chemicals.

Laying mineral wool between the log of a wooden floor

Glass wool must be carefully insulated so that dust does not enter the room when it is worn out. When laying such materials, it is important to leave a ventilation gap. The disadvantages of these materials include their weightiness and moisture absorption.

Option #5 - cork material

To insulate the floor with a light, safe and thin material, cork fiber is used. This is the best insulation for the floor under linoleum. The best, but also one of the most expensive. In addition to thermal insulation qualities, it has durability and moisture resistance.

This material can be laid both as a substrate under floor coverings, and used as an independent floor covering. In the latter case, cork slabs are additionally polished and varnished. Get a natural beautiful warm floor.

Option #6 - sawdust insulation

By themselves, sawdust for insulation is no longer used. They do not meet fire safety requirements. But from them, with the addition of flame retardants, antiseptics and glue, sawdust pellets, wood concrete, and ecowool are produced.

Option # 7 - ecowool

This loose cellulose-based material is used to insulate even hard-to-reach places. It is poured automatically or manually with a layer of 15-20 cm, which, according to thermal characteristics, corresponds to a layer of expanded clay of 80 cm.

Ecowool has soundproofing and heat-insulating properties, it is completely safe. But such material is afraid of moisture. Therefore, it is laid only in those places where there is no likelihood of an increase in the level of humidity. It is most often used when laying wooden floors.

Option # 8 - penoizol

Simply put, penoizol is a liquid foam, of which we have already talked about all the positive aspects. Penoizol is good because, due to its consistency, it can be poured into hard-to-reach places, they close up cracks and seams.

It is good to use it in the first stages of building and equipping a house. It fills all the air voids, thereby preventing the outflow of heat in the future.

Option # 9 - foil insulation

The effect of the material is based on the fact that it reflects heat back into the room, but does not transfer it to the external environment. Therefore, it is correct to lay it with the reflective side up. This material is durable, waterproof, so it can be used in all types of premises, including baths and saunas.

As you can see, there are plenty of materials for warming your floor, in whatever room it is located. It is important to take into account all the nuances and choose the most effective and safe insulation.

Such a heater may consist of a layer of mineral wool or polystyrene and a layer of foil. It is produced in the form of plates and in rolls. They are sheathed with wooden floors or laid under warm floors

An additional option is the "warm floor" system

More and more people are choosing underfloor heating systems. In the case of a water system under the floor surface, through which hot water will circulate. The method is effective, but troublesome. After all, in addition to the pipes themselves, you will need risers, collectors, valves, an automatic control device (shutdown).

For the installation of modern floor heating systems, as a rule, polymer pipes are used. Such pipes are very durable, resistant to thermal aging, have plasticity and flexibility, and are not afraid of corrosion.

You can also make an electrical system: in this case, a cable is laid under the floor covering, which converts current into heat. A layer of 3-7 cm of concrete or cement-sand mortar is laid on top of the heating elements, and only then the floor covering. Those. if a breakdown occurs, you will need to completely dismantle the floor.

There are also . Such floors are much easier to install and operate. The film heat-insulated floor does not demand a coupler, it is very quickly mounted and connected. On top of this floor, you can lay linoleum, tiles, parquet, laminate. This system can be easily removed and moved to another room.

The convenience and efficiency of underfloor heating makes them the most popular for residential and public buildings (kindergartens, schools, sports complexes).

Equipping the floors, do not forget about their thermal insulation, which will prevent the seepage of cold from below, save heat in the room and evenly distribute it. There are a number of things you need to consider when choosing floor insulation. In this article I will tell you what needs to be done so that the insulator serves for a long time, fulfills its purpose with high quality and is in place.

Criteria for choosing floor insulation

The wrong choice of insulation is the main cause of heat loss through the floor surface. Therefore, I will first of all eliminate the gap in your knowledge of the technical qualities and performance characteristics of the main types of heat insulators.

What to Consider

Before choosing a specific type of insulation material, consider:

what will be the operating conditions of the insulator;
condition and temperature of the soil base;
the presence, as well as the stability or periodicity of the level of groundwater;
the possibility of biological effects (damage to the heat insulator by rodents, the likelihood of reproduction of harmful fungi);
whether the floor insulation is compatible with their base material.

How to choose a heat insulator

Initially, you need to take into account the future design of the floors: are they wooden on logs, concrete, or will they be equipped with underfloor heating.

For all these options, you will need different types of floor insulation.

Porous and loose material is suitable for insulating wooden floors, which does not hold its shape, as well as loose analogues. Such a heater, based on its structure, can be poured into the gaps between the lags or put plates, mats, roll cuts there.

It is extremely important that in this case the insulator "breathe", passing water vapor. Wooden flooring is installed for this very purpose - to make the building breathe.

Rigid thermal insulators are well suited for concrete floor cladding. They perfectly hold their shape, do not undergo deformation from bending and compression loads. Such qualities are important when a concrete solution is laid on top of the insulation.

With this option, vapor permeability of the material is not required. However, the insulator must not absorb water.

The "warm floor" system requires the same heat insulators as for the concrete pavement. But with one condition. One side of the material should be foiled.

This layer will reflect into the room the heat that the warm floor will generate. Here you can use an insulator with aluminum foil or reflective film.

The material used to improve the thermal performance of the floor should ideally have the following qualities:

High level of strength, because the floor surface undergoes maximum mechanical stress.
Long service life. After all, flooring changes very rarely.

The quality of the insulation is very important, as an excellent insulating characteristic. It will reduce heat loss to a minimum.
Well, if the material will have a small weight. So it will not exert strong pressure loads on the supporting structures of the building.
The lower the level of water absorption the material will have, the better.

In a wooden house, the vapor permeability of the insulation is important.
Resistance of thermal insulation material to fire no less significant.
The material must be environmentally friendly and safe.
The insulator must be easy to use. This affects its costs and installation time.

properties of the insulating material

Before choosing a flooring insulation, pay attention to its most important technical characteristics:

Thermal conductivity coefficient. It indicates the ability of an insulator to transmit thermal energy.
This parameter is equal to the amount of heat passing through a layer of material 100 centimeters thick and 1 square meter in area for one hour. This is with the condition that the temperature difference on both sides of the heat insulator is no more than 10˚.

Porosity. This most important parameter determines the ratio of pore volume to the entire volume of the insulation. It affects almost all other material properties.
Vapor permeability. This indicator of the insulation determines its ability to "breathe", that is, to pass water vapor and air.

Water absorption. Indicates whether the material is moisture resistant or not. The smaller the setting, the better. Insulation with a low level of water absorption can be used in wet rooms.
Strength. It is important for its application where there are significant compressive or bending loads.
Biological stability. It determines whether the material can resist harmful flora and fauna.

fire resistance. It indicates the ability of the insulation, without its destruction, to resist high temperatures in a certain period of time.
The fire safety characteristics of the material are associated with this parameter. These are its flammability, combustibility, level of smoke formation and degree of toxicity of combustion products.
Heat capacity. It affects the temperature resistance of the insulator. That is, its ability to keep warm with frequent temperature changes.
Density. It determines the specific gravity of the insulation.
Frost resistance. Indicates how many freeze/thaw cycles it can withstand.

Types of floor insulation

Now about what types of insulators are according to the material of manufacture.

Mineral types of heaters are made from natural raw materials:

Mineral wool. There are several varieties of it: glass wool, basalt wool and slag wool. In fact, these are fibers from rocks or production waste, compressed into rolls (mats) or slabs.

Bulk materials: granulated slag, foam glass, expanded clay (fired and granulated clay).
Insulating concrete mixtures based on Portland cement with fillers and additives (perlite, expanded clay, vermiculite, sawdust, etc.).

Wood materials are used for arranging the substrate, dry screed or filling the gaps between the lags:

Arbolit.
Cork underlay.
Thick plywood.
Shavings and sawdust.
Cellulose eco-wool is used for thermal insulation of wooden floors. She can puff or just pour.

Polymer materials:

expanded polystyrene foam in slabs;
extruded polystyrene foam in slabs;
reflective (foil) heaters in rolls and plates;

liquid insulators having a foamed structure, such as polyurethane foam;
superfine insulation (heat-insulating paint).

When thinking about which insulation is best for the floor, pay attention to the technical characteristics of the material, as well as its operating conditions. The best solution is to use several types of insulation at various stages of flooring.

So, for a concrete coating, expanded clay is suitable as a backfill and mineral wool on top of a rough screed.

Please note that polystyrene, extruded polystyrene foam and polyurethane foam emit toxic gases when burned. They can kill a person in a few breaths. Therefore, I advise you to lay them under the screed only where the contact of the insulator with fire is excluded.

Now let's figure out what is the best thermal insulation for the floor, starting from its structure.

Insulation for underfloor heating system

When deciding on a heat insulator for underfloor heating, keep in mind that it should have one feature - to direct heat in a certain direction and stop its leakage in an unnecessary one.

Reflective insulation

To reduce the cost of space heating, I recommend that you choose foil insulation to work with underfloor heating. It will stop the seepage of cold from below. And also redirect the thermal energy coming from the heating system into the room.

We have the most popular brands of foil polyethylene foam:

Penofol;
Izolon;
Energoflex;
Isoflex.

Such insulation is produced in rolls. They are 0.99-1.2 m wide and 2-5 mm thick. Despite its thinness, such a material perfectly solves the problem of thermal insulation.

Extruded polystyrene foam

This is one of the most durable, strong and waterproof heat insulators.

The rest of its features are below:

This insulation is produced in slabs. They are easy to cut into desired pieces, convenient for installation.
Expanded polystyrene has a dense structure, so it does not break and does not deform from loads.
Has a cellular structure. The pores of the material are filled with air and closed. Therefore, the insulator is not afraid of water - it does not absorb it and does not swell.
Resistant to the action of chemically aggressive substances- alkalis, acids, alcohols.
Harmful bacteria and fungi do not multiply on the surface of the material.
This insulation is not destroyed under the influence of atmospheric and environment, does not react with most substances. Therefore, it has a long service life.

Extruded polystyrene foam also has some disadvantages.

The material is not breathable”, so it is better not to use it in conjunction with wooden floors.
This insulator is flammable. When ignited, it releases toxic gases.

However, in the underfloor heating system, it is cut off from the environment by a screed. Because of this, you can safely use it.

The table below shows the cost of popular brands of this insulator.

Cork insulation

This material is produced from the bark of the cork tree.

The advantages of this insulating substrate are as follows:

This insulator is natural and environmentally friendly..
The material does not rot, does not shrink, is inert to chemicals, resistant to compressive and bending loads.

Cork is easy to cut with their own hands, so it is easy to work with it.
Life time this insulation can reach 50 years.
Does not burn, but only smoldering.
Withstand temperature up to +120˚.

This material is produced in plates having a thickness of 2.5 and 5 cm.

Heaters for floors on logs

Logs for mounting flooring are placed in increments of 0.5-1 m. Insulating material is placed on boards or boards on top of the log. Or on boards nailed to the bottom or a metal wire between the timber. Or poured into the space between the lags.

Insulation of the floor in this case is carried out using mineral wool, bulk materials or foam. To prevent the insulator from getting wet from water vapor, it must be covered with a vapor barrier film on top of it.

Stone, slag and glass wool

Mineral wool is now the most common insulation, it is more in demand than polystyrene. There are two varieties of it: in plates (more dense material) and rolls.

Mineral wool breathes, that is, it is vapor permeable. Therefore, it will be the best option for thermal insulation of a wooden floor in a room.

The advantages of the material are:

Relatively low price.
Versatility of application.
Ease of installation.
Long service life - about 30 years.
Mineral wool not only has low thermal conductivity, but also has a high level of sound insulation and fire resistance.

Of the shortcomings: low level of moisture resistance of mineral wool.

Please note that when wet, this material loses most of its insulating qualities. Therefore, when insulating floors with mineral wool, do not forget to waterproof and vapor barrier it.

Most often, for the thermal insulation of floors along the logs, slab types of stone wool insulation are used:

Rockwool;
TechnoNIKOL;
Isover;
Tizol;
Linerock;
Knauf.

Or glass wool:

Tisma;
Isover;
Ursa.

In rolled wool, one side of the mat is covered with perforated paper. When laying insulation, this surface should be at the top.

In the slab variety of the mineral slab, one side is more rigid and dense. It is marked with a blue stripe and should also be located on top. The table below shows the cost of popular brands of mineral wool.

Glass wool is similar in its characteristics to mineral wool. It also does not differ in moisture resistance, in addition to this, it is quite weighty.

This floor insulation should be carefully insulated during installation. Otherwise, dust from the material, which has an irritating and allergic effect, will enter the room.

Expanded clay

Porous rounded expanded clay granules are obtained by firing heaving types of clay. During the production process, sawdust, peat and some other components are added to the raw materials. The quality of this bulk heat insulator for floors depends on the quality of the feedstock.

The cost of this insulation depends on the size of its granules. With an increase in fractionation, the thermal conductivity of the material increases and its cost decreases. Expanded clay can be used both for floors along logs and under a screed.

I quote the cost of this heat insulator, based on the size of its granules.

Floor insulation with sawdust

This type of heat insulator is often used in wooden houses for floors on logs. Sawdust is not as effective as polystyrene foam or mineral wool. However, this is the cheapest and most environmentally friendly type of insulation. On average, a 50-liter bag of sawdust or shavings costs only 200 rubles.

The material is laid between the lags in bulk or nailed to the beam in the form of shields. In the latter case, pressed chips are used, i.e. chipboard sheets. The thickness of the insulating layer of sawdust should be at least 20 cm.

Eco-cotton

This insulation is a loose material based on wood pulp. All its characteristics coincide by 80-90% with the qualities of wood. Eco-wool is foamed in the intervals between the lags.

Its advantages are:

The material is able to penetrate into the most inaccessible areas of the subfloor.
It forms a monolithic coating without "cold bridges".
Eco-wool has high rates of heat and sound insulation.
Just lay it down.

There are also disadvantages:

Low moisture resistance.
For the installation of eco-wool, it is necessary to use special equipment.
This material is combustible.

Insulators for floors under concrete or cement-sand screed

In the photo - expanded clay as an insulating layer for concrete floors.

I recommend insulating concrete floors in several stages, because they are the coldest. An excellent option for warming the screed on the ground will be expanded clay. It can be used as a backfill or used as a filler for concrete.

This material:

sustainable to humidity and temperature fluctuations.
Easy and due to this, it does not heavily load the foundation.
Has a porous structure, therefore, in addition to excellent thermal insulation qualities, the floor is well soundproofed.
natural and therefore environmentally friendly.

Basalt (stone) wool is a type of mineral wool. This durable and rigid material in slabs can also be used to insulate the screed.

Such insulation is laid out on the base in a checkerboard pattern before pouring concrete. The mortar layer must be at least 3 cm thick.

The instruction notes that extruded polystyrene foam can also be used for thermal insulation of concrete floors.

Material advantages:

hard and durable;
does not deform from pressure loads;
easy to install;
moisture resistant;
has excellent thermal insulation properties.

Of the minuses, I note:

combustibility of expanded polystyrene;
fear of ultraviolet;
vapor tightness.

But when laying this insulation under the screed, all these disadvantages will not matter.

For thermal insulation of concrete floors, you can also use ordinary foam. Most often, such floor insulation is used when pouring a floating screed.

Advantages:

Low cost.
Simple styling.
Good thermal insulation qualities.
Moisture resistance.

Minuses:

He is flammable.
It has poor sound insulation performance.
It serves for a relatively short time - about 20 years.
Sheets of material are fragile.

Conclusion

Properly selected floor insulation will give you the opportunity to equip this surface with durable and high-quality thermal insulation. For a particular floor design, different types of insulators are suitable, which ones, specifically, I described above.

The video in this article will give you even more information to think about. If you have any questions, then ask them in the comments.

Heating efficiency starts with blocking all energy leaks - through windows, doors and floors. The first two tasks are solved by seals and the installation of double-glazed windows. To eliminate the latter problem, it is necessary to choose the right insulation. It is important to do this so that in the future the floor temperature differs by no more than 2 ° C, otherwise the tenants will suffer from frequent colds.

It has been proven that heat loss through floors is 20%. This is how much you will have to overpay for heating in the presence of an autonomous system. Insulation is especially necessary in a private house (especially in old wooden houses), on the 1st floor, as well as in the bathroom, kitchen, loggia and wherever the concrete floor is tiled.

Kinds

All heaters intended for thermal insulation of the floor can be divided into four types:

cotton;
foam;
concrete (expanded clay);
natural (linen, jute).

Many factors affect their quality and wear - loads, moisture, fungi, insects, rodents. They themselves can influence positively, negatively or neutrally on the health of people living in the house. There is no ideal type of insulation - each has a set of certain characteristics and its drawbacks due to the lack of certain qualities. Therefore, when choosing a heater for the floor, pay attention to the following characteristics:

safety for health and the environment;
resistance to temperature influences and high humidity;
thermal insulation and vapor permeability;
resistance to rotting, decomposition and aging;
ease of installation and durability.

What is the best heater to choose?

1. Mineral wool. It is also made of stone, made from alloys of rocks, as well as from slag. It can be sold both in rolls and mats. It has good sound insulation, little combustible, but is afraid of excessive moisture. Therefore, it must be additionally waterproofed or the integrity of the protective film must be monitored. Depending on the amount of slag content, it may have an acceptable (but undesirable) radioactive background.

2. Glass wool. It is made from fiberglass - waste from the glass industry. It is similar in properties to the previous material, only it does not have a radioactive background. However, it has a lower thermal conductivity (this is a plus), but also a lower density (this is a minus). Suitable for wooden floor. Unfortunately, it can ignite in case of fire.

3. Ecowool. Consists of 80% recycled paper, 8% borax, and 12% antiseptic. It is environmentally friendly, has good thermal conductivity, heat resistance, durability.

4. Polyurethane foam, polystyrene, polystyrene foam (polystyrene). The most popular, widely used in suburban buildings, in summer cottages. It is very convenient to use - just put on the bottom and connected with foam or construction tape. Moisture resistant, but flammable. Thermal insulation of floors with foam is not only convenient, but also affordable.

However, there is an opinion that floor insulation with expanded polystyrene is not very environmentally friendly - when heated, it exudes substances that eventually harm people's health.

5. Izolon. Refers to foamed polyethylene, rodents, insects and fungi do not start in it. 1 cm of isolon replaces 4.5 cm of mineral wool, has high rates of not only heat, but also sound insulation. Resistant to a wide variety of adverse environments, including chemical and oil solvents.

True, due to its small thickness, it cannot provide sufficiently reliable sound insulation, so it makes no sense to use it in a multi-storey building, for example, on the bathroom floor, where such a need often arises.

6. Linen. Natural insulation: durable, resistant to moisture and adverse environmental conditions. Does not rot over time and does not give in to a mold. Effectively resists frost, protecting from the cold. Those who are prone to allergies or take care of their health can choose this option for floor insulation, as the most environmentally friendly of all.

7. Jute. Natural fiber, which is produced from plants of the linden family. It is often used for the manufacture of carpets, furniture pads and as a heater. In this case, it is made in the form of rolls like a gray carpet.

8. Expanded clay. Fine porous crushed stone, which is obtained by firing clay shale, has either a smooth oval or pointed shape. It is often used as a cushioning and drainage material.

Insulation of floors along the lags

This insulation method is applicable for floors built both on the ground and on the reinforced concrete floor. It is also suitable for installation in a brick and wooden house. For soil, you must first tamp the soil and fill it with rubble. Brick pillars should be installed on the prepared pillow at a distance of 2 × 0.5 m. Then they must be waterproofed, after which wooden logs can be laid. Insulation is placed between them overlapped. It can also be placed on beams to prevent boards from creaking.

Expanded clay is most often used under the screed on the ground if the house does not have a basement. At the bottom of the base, first sand 100 mm thick is poured, and then insulation up to 300 mm. To make the base strong, it is rammed and covered with a reinforcing mesh, then a concrete screed is poured.

Insulation under linoleum

By itself, it has low thermal conductivity. For linoleum, you can use any materials, preferably not rotting or moldy. It is unacceptable to get moisture under the floor during work. If they are carried out in compliance with these measures, then the structure will last for many years.

Manufacturers and prices

The experience of companies has a great influence on the quality of insulation. The longer a company works on the market, the better heaters it offers, as a rule. Rockwool has been in business for over 70 years. During this time, by trial and error, good quality mineral and stone wool has been obtained with reliable sound insulation, vapor permeability, resistance to fire and moisture.

Plates "Penoplex" are suitable for ground floors, foundations, loggias and laying "warm" floors. They have zero water absorption, high compressive strength, are resistant to decay and are easy to install.

PAROC produces stone wool floor mats. Operating in 15 European countries, successfully helping customers reduce their energy consumption. Due to the promoted brand, its products are distinguished not only by high quality, but also by a less affordable price for the average consumer.

The Zhivoizol company offers linen and jute products: environmentally friendly, durable, do not cause allergies and do not emit harmful substances. Insects do not start in them, mice do not eat them.

Izolon is engaged in the production of a unique flooring material suitable as a substrate for parquet. The company's products are distinguished by high impact resistance, low thermal conductivity, vapor barrier with a minimum width of only 10 mm.

Name of insulation	Size, mm	Manufacturer	Price per m2 in rubles
mineral wool	1000×600×50	rockwool	from 410
stone wool	1000×600×50	rockwool	from 610
stone wool	1000×300×50	rockwool lite	from 510
penoplex	1000×600×50	"Penoplex"	from 980
stone wool mat	7080×565×50	PAROC	from 2000
thermolene	1000×100×50	"Zhivoizol"	from 114 to 164
thermal jute	1000×100×50	"Zhivoizol"	from 90 to 135
isolon	1500×1000×10	"Izolon"	from 10 500
expanded clay	fr. 20×40	"YUDIS"	from 210 per m 3

Articles

September 7, 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.

Floor insulation plays a very important role in improving the energy efficiency of a home. Especially if you are going to equip the underfloor heating system with a flexible self-regulating cable or hot water pipes. After all, the better the heat-insulating layer will work, the more thermal energy will be spent on heating the room, and not the floor slabs.

Today I will talk about the different types of thermal insulation materials and tell you which floor insulation to use. The instructions below will be of great help to home craftsmen who are going to do the insulation with their own hands.

The role of the thermal insulation layer for the floor

In order to achieve comfortable conditions for people to live, it is necessary that the air temperature in the room be the same throughout the entire volume of the latter. And according to physical laws, warm air masses rise to the ceiling, that is, cold zones appear in the floor area. Moreover, regardless of whether the floor is made on the floor slab or there is a construction on the ground.

Sometimes the temperature difference between the top and bottom of a room can be very significant. To avoid this, one or another floor insulation is used. And for greater efficiency, water or electric underfloor heating is additionally mounted.

Requirements for the used heaters

I must say right away that when choosing thermal insulation materials, it is especially important to choose the right insulation for a warm water floor. It is these operating conditions that are the most difficult, which often leads to a reduction in the service life of heat insulators, damage to floor slabs, breakdowns in heating systems, and so on.

I compiled a small table in which I indicated the most important requirements that a heater for underfloor heating must meet:

Characteristic	Description
Strength	The material used must be strong enough to withstand the load of the heating used (pipes filled with water), finishing material (screed), installed furniture and moving people.
Heat resistance	Thermal insulation must maintain its original size regardless of temperature fluctuations. That is, when the heating system is turned on, the width, thickness and length of the elements of the insulating layer should not increase.
Resistance to aggressive environment	The insulation you choose should be able to tolerate contact with other building materials (in particular, cement mortar) that are commonly used for flooring. In addition, the heat insulator should not be destroyed by aggressive compounds.
Low thermal conductivity	From the thermal conductivity of the insulation depends on its thickness under the warm floor. A thin but rigid thermal insulation layer will allow you to maintain a greater distance between the floor and the ceiling.
hydrophobicity	The insulation must protect the heating system and the dwelling itself from moisture ingress. In addition, the heat insulator itself should not change its technical characteristics (in particular, thermal conductivity) when wet.

In addition, I note that the insulation for water-heated floors and floor coverings with electric heating is also perfect for thermal insulation of ordinary floors. Because if the material withstands operation in extreme conditions, it will perfectly cope with the tasks in all other cases.

Varieties of thermal insulation materials

Well, now let's take a close look at the question of which insulation is better for the floor. Here you need to choose according to the most important operational properties. I have already done some of the work for you and picked up some of the most interesting options, which are reflected in the diagram:

Well, now about each of them in more detail.

Expanded clay

This natural insulation is a loose mineral material obtained from natural clay by firing it in kilns at high temperature. As a result of this treatment, the surface of individual pieces of clay is melted and becomes smooth.

The gases released from the raw materials during the firing process form a porous structure inside the individual granules, due to which expanded clay acquires high thermal insulation properties.

Despite the high porosity, the insulation in question is characterized by sufficient strength. Expanded clay can be used as a mineral filler in concretes, mortars for forming wall blocks and as an addition under a cement screed when arranging a floor.

I myself have repeatedly performed dry, semi-dry and wet insulated screed using expanded clay. As a result, a sufficiently reliable and solid floor is obtained, on which water pipes or cables of an electrical heating system can be mounted without fear.

To facilitate the work with the material, there are three types of it on sale:

Gravel. Classic insulation with oval or round granules. The material has a red-brown tint. It is this option that I recommend using when arranging an insulating layer for the floor.

Rubble. Expanded clay, the individual particles of which are quite large. This type of insulation is formed by splitting large stones into smaller ones, resulting in pebbles with sharp edges. This material is more suitable as a mineral additive in concretes with low thermal conductivity.

Screenings or sand. Very fine expanded clay, which is formed by firing or splitting expanded clay of the two previous varieties. It is not suitable for insulation, it is used as a decorative material in aquariums and for filtering liquids.

To figure out how effective expanded clay is as a heater, I will focus on describing some of its technical characteristics:

Fraction composition. On sale you can see three types of material: with a fraction size of up to 10, up to 20 and up to 40 mm. There is also a material with smaller particles, but it is not suitable for construction.

For insulation, I advise using expanded clay, which is a mixture of fractions of all sizes - from 5 to 40 mm. In this case, the voids inside the floor insulation layer will be filled as densely as possible and you can not be afraid of failures during operation.

In addition, dense backfill reduces air convection, which, as you know, reduces the insulating qualities of the material used.

Density. According to GOST number 9759-90, seven density values \u200b\u200bare established from 250 to 600 kg per cubic meter. There is also a denser expanded clay, but it is only available on request for specific applications.

Here it should be borne in mind that the bulk density of the material will be 2 times less, since regardless of the quality of ramming, there will still be gaps between individual expanded clay granules.

The specific brand of insulation must be determined after thermal engineering calculations. After all, the density of the material is directly proportional to strength, but inversely proportional to thermal conductivity. And it is important to find a middle ground between these two parameters. In my work, I use expanded clay grade 300 or 400.

Strength. According to this parameter, 13 grades of expanded clay crushed stone and 11 grades of expanded clay gravel are distinguished, which are determined by squeezing the material in a cylinder.

The strength of both types of material of the same brand varies and this must be taken into account when buying. For example, gravel P100 withstands a compressive load of 2.5 MPa, and crushed stone - no more than 1.6.

Compaction factor. A parameter showing the change in the volume of the material as a result of compaction during the transportation and storage of expanded clay mass.

The compaction coefficient for expanded clay is 1.15. This means that if you need 2 cubic meters of gravel to insulate the floor, then you need to buy 2x1.15 = 2.3 m3 of material. In addition, I note that expanded clay in bags is sold already compacted and it is not necessary to apply an amendment there.

Thermal conductivity. It is on this parameter that it depends on how thick the insulation layer used when installing the floor (including with heating) should be. The exact value of λ for expanded clay is in the range from 0.1 to 0.18 W / (m * K) and depends on the density.

Usually, for high-quality surface insulation, it is necessary to pour a layer of expanded clay of medium density with a thickness of 10-20 cm.

Water absorption. Due to its high porosity and the presence of a large number of gaps, the expanded clay insulation layer absorbs a considerable amount of moisture. The water absorption coefficient (as well as several other parameters) depends on the density and is equal to 8 to 20% of its own volume.

From a consumer point of view, this means that the thermal insulation must be carefully protected from moisture by means of waterproofing membranes. Especially when it comes to the bathroom (I wrote about how to lay expanded clay under a dry screed in a plumbing room in one of my articles on this blog).

Soundproofing. Like other heat-insulating materials with an open structure, expanded clay is able to absorb sound waves of both air and structural origin well.

This property of expanded clay is widely used in the arrangement of interfloor floors in residential buildings made of wood. The material is poured between the floor lags and does not let noise through between floors.

Despite the large number of advantages, expanded clay has several disadvantages:

High tendency to dust formation. When working indoors, expanded clay backfill forms a large amount of dust, which is dangerous for the human respiratory system. To avoid negative consequences, I recommend using a respirator.
Prolonged drying of wet expanded clay. In order for the air humidity to remain within the normal range in rooms insulated with this material, the heat-insulating layer must be protected with vapor and hydroprotective membranes.

Despite the shortcomings, I still recommend using expanded clay for thermal insulation, if only because it is the cheapest material described in the article. The price for a bag of expanded clay is from 60 to 100 rubles, or about 1300 rubles per cubic meter in bulk.

But the most environmentally friendly will be discussed in the next section.

Cork

Cork insulation is a heat-insulating material made from particles of cork tree bark. Multilayer plates are formed from it, which contain a minimum of solid matter and a maximum of air gaps. Thanks to the latter, cork boards get such a low coefficient of thermal conductivity.

I can say right away that I really like this insulation as a material to increase the thermal resistance of the floor. This is facilitated by the many advantages of cork:

has a very low thermal conductivity coefficient (depends on the type of cork agglomerate);
prevents moisture condensation on insulated enclosing surfaces;
has a high sound absorption coefficient, protecting living rooms from airborne and impact noise;
is not a conductor of electric current;
due to its natural origin does not harm human health;
retains its original technical characteristics and operational properties regardless of the level of humidity, temperature fluctuations in the air and other external factors;
is chemically neutral, does not collapse under the influence of aggressive liquids and gases;
has antiseptic properties, mold does not multiply on its surface and fungus does not appear, mice and insects do not gnaw on the cork;
It has fire-fighting properties, does not ignite well, does not contribute to the spread of flame and does not emit toxic combustion products into the air.

The set of properties listed above makes cork just an excellent material for thermal insulation of the floor, including under the heating system. In addition, cork bark agglomerate can be used for thermal insulation of walls, floors, roofs. The appearance of cork slabs is so good that they do not require additional decorative finishing.

On sale there is a heater of two varieties:

white agglomerate;
black cork agglomerate.

White is more suitable for decorative interior decoration, although no one bothers to use it as an additional insulating layer. The exact technical characteristics of the material are presented in the table:

White cork agglomerate is available in slabs of the following sizes:

91.5 by 61 cm;
93.5 by 64 cm.

The thickness of the plates varies from 1 mm to 50 cm. Thin ones are used exclusively for decorating rooms, thick ones - for thermal insulation of the floor and other surfaces.

Black cork agglomerate is made from pieces of cork oak bark. The raw material is crushed, heated and pressed into slabs. No synthetic materials are used in the production process. For gluing the agglomerate, suberin is used - a substance located in the integumentary part of the cortex.

The exact technical characteristics of black cork agglomerate are presented in the table:

Cork insulation tolerates sharp temperature fluctuations well and does not change its technical characteristics during operation.

For floor insulation, including heated floors, black cork agglomerate is well suited, produced in the form of separate sheets with dimensions of 100 by 50 cm and a thickness of 1 to 32 cm.

But I advise you to pay attention to the cork in rolls. The thickness of the insulation in this case is from 2 to 6 mm, the width is 1 meter, and the length is up to 10 meters. The thermal insulation effect of this material is difficult to overestimate. A 3 mm layer of cork replaces 4 cm of mineral wool or 150 cm of reinforced concrete floor slab.

The big disadvantage of this solution is the very high cost. A square meter of material 1 cm thick costs 640 rubles, and if you take a thicker one, the price rises to 1800. More accurate parameters are indicated in the table.

Foamed polyethylene

Another type of insulation that is suitable for insulating floor coverings (with and without heating) is cellular polyethylene foam with a heat-reflecting layer of aluminum foil. The polymer with cells has a low thermal conductivity, and the metallized layer reflects almost all (up to 98%) of the thermal energy produced by the floor heating system inside.

As a result, pipes or electric cables do not heat the floor slab or the ground under the house, but the room in which people live.

On sale there are heaters with one or two metallized surfaces. For work, I recommend using a heater with one aluminum layer, which, when laid, unfolds inside the room (for example, Penofol Type A). Some varieties of the material in question have markings on the foil, which facilitates the laying of pipes or cables.

The material is sold in the form of rolls with a thickness of 3 to 10 mm. Foamed polyethylene can be used as an independent insulation or paired with traditional heat-insulating materials - mineral wool, extruded polystyrene foam, and so on.

I will dwell on a more detailed description of some of the technical characteristics of this heater:

Thermal conductivity. The coefficient of thermal conductivity of foamed polyethylene is 0.049 W / (m * K), however, its use does not greatly increase the thermal resistance of the floor due to the small thickness of the insulation layer.

Nevertheless, the efficiency of the material is much higher than it might seem at first glance. This is due to the presence of a heat-reflecting layer. It reflects infrared rays, thanks to which the air in the room warms up. As a result, the final heat transfer resistance of the floor is 1.2-1.23 W / (m2 * K).

In other words, a 4 mm layer of polyethylene foil foam is just as effective as an 8 cm layer of mineral wool.

Hygroscopicity. Unlike cork and expanded clay, polyethylene foam has a closed cell structure, so it absolutely does not absorb water. Moreover, this parameter does not depend on the time of year or temperature fluctuations.

Foamed polyethylene foam can be used for thermal insulation of the floor under the heating system (water or electric) without the use of additional waterproofing membranes. It is enough to properly seal the substrate with adhesive tape.

Soundproof properties. Class A insulation (with foil glued to one side of the material) is able to effectively absorb sound waves up to 32 dB.

Foamed polyethylene is most effective in frame structures when laying it on floors made along logs. Like cork, this material is able to absorb both structural and airborne noise.

Vapor permeability. Aluminum foil glued to a layer of polyethylene foam makes the insulation in question absolutely vapor-tight. The vapor permeability coefficient does not exceed 0.001 mg/(m*h*Pa).

Thanks to this, the insulation can be used as a vapor barrier membrane. If you lay it on the floor on top of a layer of mineral wool, you can not be afraid of wetting the latter with water vapor formed as a result of human activity.

Fire safety. Foamed polyethylene belongs to the category of building materials that are difficult to ignite and do not support combustion. Therefore, it is possible to safely lay electrical on it without fear of ignition of the insulating layer as a result of a short circuit.

In direct contact with a flame, cellular polyethylene melts, releasing water and carbon dioxide, which are harmless to humans and do not impede the evacuation of people from residential premises.

Life time. The polymer from which polyethylene foam is made is able to maintain its original performance properties for at least 200 years. This is much more than even the most stringent building codes require.
The exact technical characteristics of foamed polyethylene insulation depend on the manufacturer of the material. I will indicate them using the example of the Penofol trademark material, aluminum foiled on one side.

The cost of a roll of Penofol Type A, 15 m long, 1.2 meters wide and 10 mm thick, is about 1,400 rubles apiece.

Foil foam

Another insulation that is specifically designed for warming underfloor heating (and is not used for thermal insulation of conventional floors) is foil foam. For its manufacture, block polystyrene foam with a density of 20 kg per cubic meter is used, which complies with the PN-B-20130 standard.

The thickness of this material varies from 2 to 10 cm. To increase the efficiency of the foam, a multilayer polymer film is glued to its surface, containing a metallized layer inside, which plays the role of a heat shield.

The protective film on the surface is placed in such a way as to protrude beyond the edge of the foam boards at a distance of 5 cm. Thanks to this tolerance, the joints of the insulation mats are overlapped, creating a sealed and moisture-resistant base for laying pipes or heating cables. In addition, the polymer film prevents the liquid component from leaking when pouring the cement screed and ensures high-quality dehydration of the mortar.

For ease of installation, markings are applied on the surface of the film in the form of squares with a side of 5 cm, which facilitate the placement of pipes at the required distance from each other.

I will briefly talk about the most important technical characteristics of foam mats with a metallized layer:

structural stability. Styrofoam retains all the original physical and chemical properties during laying, pouring with concrete mortar and further operation. The insulation can be operated at temperatures from -180 to + 180 degrees Celsius.
High soundproof properties. Insulation under warm floors perfectly isolates the room from structural noise transmitted through the ceiling. In other words, the inhabitants of the lower floor will not suffer from the rumble emitted by the tenants located above.
Chemical stability. Polyfoam perfectly tolerates the effects of an alkaline environment, characteristic of a solution with a cement binder. Therefore, it is often used in the arrangement of insulated heated floors, which are then leveled using the “wet” screed method.
Antiseptic. The insulation is biologically neutral; mold fungus that cannot feed on styrene does not appear and does not develop on its surface. This is very important, since the high temperature with the heating system turned on creates favorable conditions for the reproduction of microorganisms.
Hygroscopicity. Block foam with a heat-reflecting layer has a high moisture resistance coefficient. The insulating layer does not absorb moisture, does not swell and does not dissolve, regardless of the level of humidity.
Strength. Despite the low density, the material has a high deformation strength. The static and dynamic load exerted on the floor will not lead to its destruction and violation of the integrity of pipes or electric cables.

Summary

Unfortunately, I cannot say which is the best thermal insulation material for floor insulation. But based on the technical parameters outlined above, you can make a completely informed choice. If you need advice on how to lay, for example, bulk insulation, watch the video in this article for a detailed description of the relevant technology.

You can leave your options for which floor insulation is better to use in private construction, as well as advice, questions and wishes, in the comments below.

September 7, 2016

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