Insulation for the floor: all materials that can be used, their description, characteristics and application features. What insulation is better to use for floors in a wooden house, what to choose? Thermal insulation floor

When building a cozy and comfortable home, you need to isolate all areas through which the cold penetrates inside. The floor is just such an area, its proximity to the ground and insufficient thickness significantly reduce the temperature of the coating. Large heating costs change the situation insignificantly, so home owners have to decide what is the best way to insulate the floor.

You can perform floor insulation work in a house or apartment on your own, the main thing is to choose the right material. To avoid mistakes, you need to analyze the main characteristics of thermal insulation materials:

fire resistance;
low thermal conductivity;
environmental safety, absence of toxic fumes during operation;
strength, no deformation;
life time;
vapor permeability, the material should easily release the accumulated moisture;
the complexity of styling.

Floor insulation technology

The purpose of performing thermal insulation is to create a reliable barrier to the cold. To do this, a layer of insulation is placed between the base of the floor (concrete slab, earthen embankment, logs) and the topcoat. The material is covered with a vapor barrier film. To achieve the maximum effect and protect it from moisture, it is necessary to install waterproofing before insulating the floor.

The sequence of work depends on the type of base, operating conditions of the room, the permissible thickness of the insulation layer.

Floor insulation, what to choose?

Polyfoam is popular not only because of its low cost, the material has low thermal conductivity and is resistant to moisture. It will be the best choice for basement and basement insulation. Polyfoam is environmentally friendly, and when located under a layer of concrete screed, it is not exposed to the danger of fire. Insulation for the floor is universal in use; it is laid on concrete, ceramics, wood or brick.

Expanded polystyrene is an improved version of Styrofoam. It is denser (40 kg / m3 versus 10 kg / m3), absorbs less moisture, and has a homogeneous structure. Expanded polystyrene does not rot, has low thermal conductivity and weight. Insulation plates do not crumple, serve as sound insulation, suitable for concrete and wood floors.

Expanded clay is a natural material that is used dry and as an additive to concrete. It is made of clay, therefore it is safe for health. Expanded clay does not burn, it is resistant to temperature changes. As part of the screed, it significantly reduces the thermal conductivity. When used in the form of loose granules, the insulation is sensitive to moisture, therefore waterproofing is required. An effective layer of material is up to 20 cm, it is not always possible to raise the floor level to such a height.

Mineral wool is offered in three types:

Glass wool is an elastic and durable insulation for the floor, excellent heat and sound insulator. Its disadvantage is fibers that irritate the skin. Modern mineral wool is made from quality raw materials, it is less dangerous and prickly.
Stone - a fragile insulation with high hygroscopicity. Plus mineral wool - low cost.
Basalt wool is resistant to combustion, frost and biological effects. Insulation made in the form of rigid plates is not prone to creasing and deformation. Its density is 30-35 kg / m3. Basalt wool is safe for health, has good vapor permeability, and can be used for up to 30 years. The material loses its properties when wet, therefore, during installation, it is carefully protected from moisture. Basalt wool is most often used as thermal insulation for wooden floors.

Cork insulation is characterized by high elasticity and sound absorption. It is environmentally friendly, retains heat and is not afraid of moisture. It is produced in rolls that allow you to quickly cover the floor in the room. Cork material in the form of slabs is placed between the logs under a wooden floor.

Polyurethane foam has a minimum thermal conductivity due to its low density. When sprayed, the composition forms a cellular structure that provides high insulating properties. When cured, polyurethane foam forms a continuous surface without seams. Due to the high moisture resistance of the insulation, it is not required to lay a vapor barrier sheet. The polymer composition is used under a screed or subfloor made of plywood.

High moisture resistance allows you not to cover the polyurethane foam with a vapor barrier film.

Thermal insulators with a layer of foil, such as penofol, reflect infrared waves back into the room. A thin layer of foamed polyethylene with an aluminum coating is indispensable as a substrate for laminate or linoleum. The density of penofol is quite high, it does not deform under load. The material is used alone or in combination with another insulation.

Underfloor heating system - types and installation options

The device in a private house of a water heat-insulated floor will forever solve the problem of a cold coating. It is installed under the concrete screed and is an economical way to maintain a comfortable room temperature.

In addition to hot water circulating through plastic pipes, an electric cable can be used to heat the floor.

It is impossible to arrange such a system in an apartment due to the high load on the floor. An infrared floor on a film has become a substitute for wires and pipes under the screed. Covering strips are easy to install and lay under tiles, laminate, parquet and linoleum.

Thermal insulation of a wooden floor

The wood has a low thermal conductivity, but the thickness of the boards is not enough to exclude the penetration of cold, in addition, over time, cracks form in the coating, creating a draft. Recommendations on how to properly insulate the floor will help you cope with the work yourself.

A wooden beam (logs) is laid along the entire length of the floor.
Plywood or trim boards are attached to the lower part of the log, which will become the basis for the insulation.
Thermal insulation material - mineral wool, penofol, expanded polystyrene is tightly placed between the timber. The thickness of the insulation for the floor depends on the location of the room - a more solid layer will be needed on the first floor.
The insulation is covered with plastic wrap or glassine for vapor barrier.
Floor boards are being laid.

How to insulate a concrete floor

It is impossible to use a concrete base in a residential area without multilayer insulation. For work, you will need a dense, durable material that is resistant to stress and moisture. Choosing how to properly insulate a concrete floor, we will consider several options.

Laying the heat insulator under the screed.

During the initial installation of the floor, a cushion of a mixture of gravel and sand is made, which is poured with a thin layer of concrete.
Roll waterproofing is laid on top of the screed.
Insulation is placed on the canvas, which protects against moisture: expanded polystyrene, basalt wool, foam glass. Plates of material are laid close to each other so that cold bridges do not arise.
A damper tape is placed between the insulation and the wall.
A polyethylene film is laid on the insulation and a reinforcing mesh is laid.
The concrete screed is poured.

The addition of perlite or expanded clay to concrete reduces the thermal conductivity of the material. Installation of a "raised floor". This method is suitable for rooms with high ceilings.

Wooden logs from a 5 × 10 cm bar are laid on a concrete base.
Waterproofing is laid with a 10 cm approach to the walls.
Insulation is placed between the lags: expanded clay, polystyrene, basalt wool.
The heat-insulating material is covered with moisture-resistant plywood or fiberboard.
The topcoat is being laid.

Having studied the performance and installation technology of popular heaters, you can easily insulate the floor.

September 7, 2016
Specialization: Capital construction works (laying of foundations, erection of walls, construction of a roof, etc.). Internal construction work (laying of internal communications, rough and final finishing). Hobbies: mobile communications, high technologies, computer technology, programming.

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

Today I will tell you about different types of thermal insulation materials and tell you what kind of insulation to use for the floor. The instructions below will provide considerable help to home craftsmen who are going to do insulation with their own hands.

The role of the thermal insulation layer for the floor

In order to achieve comfortable living conditions for people, 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 structure on the ground.

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

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 of heating systems, and so on.

I have compiled a small table in which I indicated the most important requirements that insulation under a warm floor must meet:

Characteristic	Description
Strength	The material used must be strong enough to withstand the stress of the heating used (pipes filled with water), the finishing material (screed), installed furniture and people on the move.
Heat resistance	The 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.
Resistant to aggressive environments	The insulation you choose should withstand well contact with other building materials (in particular, cement mortar), which are usually used for arranging the floor. In addition, the heat insulator should not collapse under the influence of aggressive compounds.
Low thermal conductivity	The thickness of the underfloor heating depends on the coefficient of thermal conductivity of the insulation. A thin but tough thermal insulation layer will maintain a greater distance between the floor and the ceiling.
Hydrophobicity	Insulation must protect the heating system and the living space 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 would like to note that insulation for a water-heated floor and electrically heated floor coverings is perfect for thermal insulation of ordinary floors. Because if the material can withstand operation in extreme conditions, it will perfectly cope with the tasks set in all other cases.

Varieties of thermal insulation materials

Well, now we will come to grips with the question of which insulation is better for the floor. Here you need to choose according to the most important performance properties. I have already done some of the work for you and selected several of the most interesting options, which I reflected in the diagram:

Well, now about each of them in more detail.

Expanded clay

This natural insulation is a free-flowing mineral material obtained from natural clay by firing it in ovens at high temperatures. As a result of this treatment, the surface of individual pieces of clay melts 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 quite durable. Expanded clay can be used as a mineral aggregate in concrete, mortars for the formation of wall blocks and in the form of filling under a cement screed when arranging a floor.

I myself have repeatedly performed a 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 electric heating system can be installed without fear.

To make it easier to work with the material, there are three types of it on sale:

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

Crushed stone. Expanded clay, individual particles of which are rather large. This type of insulation is formed by splitting large stones into smaller ones, as a result of which pebbles with sharp edges are formed. 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 when 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 understand how effective expanded clay is as a heater, I will focus on a description of 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 insulating layer of the floor will be filled as tightly as possible and there is no need to fear the appearance of failures during operation.

In addition, dense backfill reduces air convection, which is known to reduce the insulating qualities of the material used.

Density. According to GOST number 9759-90, seven density values are established from 250 to 600 kg per cubic meter. There is also a denser expanded clay, but it is produced only by order for specific areas of application.

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 heat engineering calculations. After all, the density of the material is directly proportional to the strength, but inversely proportional to the thermal conductivity. And it is important to find a middle ground between these two parameters. I use expanded clay grades 300 or 400 in my work.

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

The strength of both types of material of the same brand is different and this must be taken into account when buying. For example, P100 gravel 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 material as a result of compaction during 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 for floor insulation, then you need to buy 2x1.15 = 2.3 m3 of material. Additionally, I note that expanded clay in bags is sold already compacted and there is no need to apply an amendment there.

Thermal conductivity. It is this parameter that determines the thickness of the insulation layer used when installing the floor (including underfloor heating). 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 insulation of the surface, 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 insulating layer absorbs a considerable amount of moisture. The water absorption coefficient (like 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 using waterproofing membranes. Especially when it comes to the bathroom (I wrote about how to lay expanded clay under a dry screed in a sanitary room in one of my articles on this blog).

Soundproofing. Like other thermal insulation 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 ceilings in residential buildings made of wood. The material is poured between the floor joists and does not allow noise to pass 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.
Long-term 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 waterproof membranes.

Despite the disadvantages, 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 ranges 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 bark of a cork tree. Multilayer slabs are formed from it, which contain a minimum of solid matter and a maximum of air layers. Thanks to the latter, cork slabs get such a low coefficient of thermal conductivity.

I can tell right away that I really like this insulation as a material for increasing the thermal resistance of the floor. This is due to the many advantages of cork:

has a very low coefficient of thermal conductivity (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, it 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 degrade 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 the cork;
has fire-fighting properties, is poorly flammable, does not promote the spread of flame and does not emit poisonous combustion products into the air.

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

There are two types of insulation on sale:

white agglomerate;
black cork agglomerate.

White is more suitable for decorative finishing of premises, 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 agglomerate cork is available in the following slab sizes:

91.5 by 61 cm;
93.5 by 64 cm.

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

Black cork agglomerate is made from pieces of cork oak bark. Raw materials are crushed, heated and pressed into plates. 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 bark.

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 insulation of floors, including underfloor heating, black cork agglomerate, produced in the form of individual sheets with dimensions of 100 by 50 cm and a thickness of 1 to 32 cm, is quite suitable.

But I advise you to pay attention to the cork 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. It is difficult to overestimate the thermal insulation effect of this material. A 3 mm layer of cork replaces 4 cm of mineral wool or 150 cm of reinforced concrete floor slab.

The big disadvantage of such a solution is the very high cost. A square meter of 1 cm thick material costs 640 rubles, and if you take a thicker one, the price rises to 1800. More precise 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 coefficient of thermal conductivity, and the metallized layer reflects inward almost all (up to 98%) thermal energy produced by the underfloor heating system.

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

There are heaters on sale with one or two metallized surfaces. For work, I recommend using insulation with one aluminum layer, which, when installed, unfolds inside the room (for example, Penofol Type A). Some varieties of the material in question have markings on the foil, which makes it easier to lay pipes or cables.

The material is sold in rolls with a thickness of 3 to 10 mm. Foamed polyethylene can be used as an independent insulation or in tandem with traditional thermal insulation 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 insulation:

Thermal conductivity. The thermal conductivity coefficient of foamed polyethylene is 0.049 W / (m * K), but 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 precisely to the presence of a heat-reflecting layer. It reflects infrared rays, thanks to which the air in the room is warmed up. As a result, the final resistance to heat transfer of the floor is equal to 1.2-1.23 W / (m2 * K).

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

Hygroscopicity. Unlike cork and expanded clay, foamed polyethylene has a closed cellular structure, therefore it does not absorb water at all. Moreover, this parameter does not depend on the season 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 sufficient to properly seal the substrate with adhesive tape.

Soundproofing properties. Insulation class A (with foil glued to one side of the material) is able to effectively absorb sound waves with a power of up to 32 dB.

Foamed polyethylene is most effective in frame structures when laying it on floors made of logs. Like cork, this material is capable of absorbing both structural and airborne noise.

Water vapor permeability. Aluminum foil glued to a layer of foamed polyethylene 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 moistening the latter with water vapor generated 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, you can safely lay electrical ones 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 complicate the evacuation of people from living quarters.

Life time. The polymer from which the polyethylene foam is made is capable of retaining its original performance properties for at least 200 years. This is much more, which is what 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 material of the Penofol trademark, foiled with aluminum on one side.

The cost of a roll of Penofol Type A 15 m long, 1.2 m wide and 10 mm thick is about 1400 rubles apiece.

Foil polystyrene

Another insulation that is specially designed for warming heated floors (and is not used for thermal insulation of ordinary floors) is foil-coated polystyrene. For its manufacture, block polystyrene foam with a density of 20 kg per cubic meter is used, which corresponds to 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.

A protective film on the surface is placed in such a way as to protrude beyond the edge of the foam plates 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 leakage of the liquid component when pouring the cement screed and ensures high-quality dehydration of the solution.

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

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

Structural stability. Polyfoam retains all its original physical and chemical properties during installation, pouring with concrete and further operation. The insulation can be used at temperatures from - 180 to + 180 degrees Celsius.
High sound insulation properties. Insulation for underfloor heating perfectly insulates the room from structure-borne noise transmitted through the ceiling. In other words, the occupants of the lower floor will not suffer from the rumble emitted by the occupants located above.
Chemical stability. Polyfoam perfectly tolerates the action of an alkaline environment, characteristic of a mortar 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 does not appear or develop on its surface, which cannot feed on styrene. This is very important, since the high temperature with the heating system turned on creates favorable conditions for the multiplication of microorganisms.
Hygroscopicity. Block foam with a heat-reflecting layer has a high coefficient of moisture resistance. The insulating layer does not absorb moisture, does not swell or dissolve, regardless of the moisture level.
Strength. Despite its low density, the material is characterized by high deformation strength. Static and dynamic loading on the floor will not lead to its destruction and damage to the integrity of pipes or electrical cables.

Summary

Unfortunately, I cannot say which is the best thermal insulation material for floor insulation. But based on the above technical parameters, you can make a completely informed choice. If you need advice on how to install, for example, bulk insulation, watch the video in this article, where the corresponding technology is described in detail.

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

September 7, 2016

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Publication date: 31-10-2015

"What insulation is better for the floor?" - a question that is asked by everyone who values comfort. After all, it is always pleasant to walk on the floor with bare feet, without fear of bad weather outside the window, this is especially true when the central heating is not turned on. When choosing an insulation material, it is important to take into account the characteristics of the room and the climatic zone in which you live. Where to stop? We will talk about this today.

Warmth from "warm floors"

In children's rooms and kitchens, low-temperature water heating systems and "warm floors" are often made. The first option is based on laying pipes under the floor in which hot water circulates. These elements of the system are usually made from polymers, they are strong, flexible, resistant to thermal aging, they are not afraid of corrosion.

Water heat-insulated floor: scheme

This method is considered effective, but rather troublesome, because in addition to pipes, the design requires collectors, special risers, shut-off valves, and an automatic shutdown device.

Underfloor heating means laying a cable under the floor covering that generates heat. The disadvantage of this option is that in the event of a breakdown, the entire system will have to be completely dismantled.

But difficulties will have to be faced even during installation; it is not an easy task to install such a structure. The organization of the infrared floor is much simpler in this sense. The film cover does not require a tie, it is easy to install and quickly connected. On top you can lay tiles, linoleum, parquet or laminate. Another plus - the system is easy to remove (you can move to another room).

Back to the table of contents

Versatile material

Polyfoam (aka expanded polystyrene) is a material that does not require special communications, it is the most common floor insulation. Its thermal insulation performance is 25 times better than that of its counterpart in the workshop - expanded clay concrete. Such a floor absorbs heat slowly, which means that it is pleasant to walk on it, its temperature is always approximately the same.

Lay the foam as a floor insulation when erecting a floating screed, it is poured with cement or concrete. You can also fill the gaps between the joists with expanded polystyrene when installing a wooden floor. Another option is to lay the slabs on a concrete floor with plywood sheets on top.

Polyfoam is much better than its competitors in many respects, it is not afraid of water, “bio-resistant”. The scope of its application is not limited, it is used in apartments and private houses, on balconies and in rooms with high levels of humidity.

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Efficiency and cost

Expanded clay is one of the most affordable materials. It is added to concrete and used in the construction of a dry screed. It is distinguished by its high efficiency (three times more heat storage than wood) and low price (ten times cheaper than bricks). The basis of expanded clay is clay, which means that such insulation is better than many others withstand temperature extremes, it does not burn, it will not be damaged by rodents.

Expanded clay - the owner of excellent noise-insulating properties - what a resident of multi-storey buildings does not dream of silence! In addition, it can be used in almost any climatic conditions (even the most extreme). Expanded clay is an environmentally friendly product, and in the modern world it is especially important.

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Subtlety and warmth

Compared to the same expanded clay, the thickness of polystyrene concrete is much smaller. Just 5 cm of the product is enough to ensure good thermal insulation of the room. In addition, with this material, the pressure on the floors will be less. Polystyrene concrete allows you to level the floor. It is best to install tiles on top of a layer of this insulation, although other floor coverings are not prohibited.

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Nothing to do with the "scoop"

Glass wool is a mineral fiber. In terms of the manufacturing process, it is very similar to mineral wool, these products are produced from the same raw materials, but the properties are slightly different. Their main difference lies in the length of the product, the length of the glass wool is 3 times greater than the mineral one, due to which this material has increased elasticity and strength. The product has high vibration resistance.

Glass wool is able to retain air in itself for a long time, so in winter heat does not leave the building, and in summer the room does not heat up. The soundproofing qualities of glass wool should be noted separately.

If you use it as a heater for the entire room, then a working TV will be heard only in the room where it is located. Glass wool takes the first place in the lists of thermal insulation materials. The modern product, unlike its Soviet predecessor, is much softer to the touch, does not burn, does not irritate the skin and, of course, meets all quality and safety standards. It is today a universal insulation: it is used both in attics, and in interfloor ceilings, and with internal wall insulation.

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"Brother" glass wool

Mineral wool slab is another item on the list "Which insulation to choose for the floor." It is a thermal insulation material made of mineral wool. It is distinguished by its resistance to high temperatures and the effects of many aggressive chemicals, for example, alkali, solvents. Minvata is the owner of a high vapor permeability coefficient, which helps to protect the product from the formation of mold and pests.

The advantages of a mineral wool board also include:

low moisture absorption,
complete incombustibility,
ease of use,
she does not need fasteners,
slabs are easy to cut,
does not deform even under severe loads,
good sound insulation and environmental friendliness,
durability (will last up to 25 years).

So the walls and the roof of a wooden house have been erected, windows and doors have been inserted. It's time to move on to interior finishing work. And they usually begin with the device of floors. This is one of the most important and crucial stages of work, because the overall microclimate in the rooms of the wooden structure and the level of heating costs will depend on how correctly and efficiently the floor cake will be made. At the same time, close attention should be paid to the choice of insulation for floors, because up to 20% of the heat in the house is lost through the flooring.

How to choose a heater?

The most important thing that determines the choice of insulation for processing the finished floor from below is the type of foundation and, accordingly, the floor structure:

If the foundation is strip, then the floor can be laid directly on the ground or on the floor, arranged along the beams.
A low grillage foundation assumes the same floor options as with a strip type of foundation.
With a high grillage foundation, the floor is arranged along the ceilings laid along the beams.
If there is a floating slab (this is often done when building wooden houses on wet soils), then the floor can be arranged along logs or on a screed.

So, it becomes clear that there are three options for flooring in a wooden house, on which the choice of material for their insulation directly depends. This is the device of floors on the ground, on a slab and on wooden floors with logs.

Therefore, when choosing a heater, it is imperative to take into account the mutual influence of the materials of the floor pie construction.

Wooden floors

Since the floors of a wooden house are also made of wood, then when using vapor-tight thermal insulation, all the moisture that will be inside the floor structure will be absorbed into the wood and, due to tight contact with the insulation, will not be able to get out. The result of this will be the appearance in a year and a half of fungus, insects and the spread of decay processes.

A completely different result is given by heaters that have the property of hygroscopicity.(sawdust, ecowool, cork granules, mineral wool, expanded clay) and due to this they absorb moisture in the same way as wood, but at the same time give it out.

Therefore, with this type of floor device, it is categorically impossible to use various heaters based on expanded polystyrene and foam.

Wood and similar materials are incompatible things.

Ground and slab floors

In this kind of flooring structures, the insulation is covered from above with a screed.

Loose and wadded materials will not be able to provide the required level of strength, although now they also produce mineral wool with a fairly high density.

In addition, these types of thermal insulation are hygroscopic and there is a possibility of getting wet. And, having got wet, they will not be able to give moisture out through the screed.

Therefore, for this type of floor, polystyrene foam insulation is most suitable - it is dense and does not absorb moisture.

In addition, when choosing thermal insulation for floors in a wooden house, one should proceed from the following factors:

maximum weight of the floor structure;
required thickness;
humidity and temperature conditions inside the house, the presence of temperature changes;
calculated loads on the floor structure and its operating conditions.

Separately, one should dwell on the thickness of the heat-insulating layer.

This indicator determines how warm it will be in a wooden house. It is calculated individually and depends on the climatic conditions in which the house is built, and the thermal conductivity of the insulation itself. To determine the thickness of the insulation, it is necessary to multiply the thermal conductivity coefficient specified in the technical description for a specific insulation by the thermal resistance of the structure (determined according to SNiP "Thermal protection of buildings"). This formula helps to accurately calculate what should be the thermal insulation layer in the floor structure in order to ensure the optimal temperature regime in the house.

When choosing thermal insulation for the floor, you should also pay attention to:

ease of installation material;
environmental friendliness;
efficiency, that is, maintaining its characteristics throughout the entire service life;
fire safety;
density and reliability;
the price.

How to insulate?

You can use different materials to insulate floors in wooden houses. Today the building materials market is replete with a wide variety of thermal insulation from the simplest to the most modern types.

Insulation materials

Sawdust

The simplest and cheapest insulation. It is easy to apply - just sprinkle on a rough sub-floor. This material is environmentally friendly and safe. But it has a serious drawback - a high degree of fire hazard. And also when using sawdust as a heater, they will have to be laid in a layer as much as 0.3 m. Sawdust, in addition, like any wood product, can rot, rodents can start in them. Therefore, sawdust is most often used to insulate the floor of unused attic rooms.

However, sawdust has recently been increasingly used as a raw material in the production of other more modern and effective thermal insulation.

Ecowool

Thermal insulation material made of cellulose with the addition of fire retardants and antiseptic compounds. This product has good thermal insulation and vapor permeability. It is environmentally friendly, non-flammable, resistant to rodents and fungi. But ecowool strongly absorbs moisture. This is its main drawback.

Expanded clay

Material with high strength and thermal insulation characteristics. Expanded clay is suitable for flooring on flat surfaces. To ensure optimal performance of thermal insulation, expanded clay must be laid with a layer of at least 15 cm. The convenience of this material also lies in the fact that all the necessary communications can be laid in it. Expanded clay is quite hygroscopic, therefore, before using it on the ground, it is imperative to perform waterproofing measures.

The main advantage of bulk floor insulation is their wastelessness and the ability to fill all kinds of (even the most difficult to access) voids.

Expanded polystyrene, polystyrene, polyethylene

These materials are vapor-tight thermal insulation that can be used to build the floor cake on a flat base. For floors on ceilings with a lag device (in wooden houses on piles, posts, strip and grillage foundations), such material will not work due to the laws of construction heat engineering.

The thickness of the insulation layer will be 5-10 cm for expanded polystyrene and 5-13 cm for polystyrene.

These types of thermal insulation materials have the following characteristics:

low thermal conductivity;
strength;
resistance to rodents and decay;
resistance to temperature extremes.

Expanded polystyrene insulation in our country is presented under the names "Penoplex", "Technoplex", "Knauf".

Insulation based on polyethylene foam is also used for thermal insulation of floors. One of the varieties of such insulation is the rolled foil material penofol, which has high operational and thermal insulation properties. Penofol is a polyethylene foam covered with foil on one or both sides.

High levels of thermal insulation of this material are provided due to the preservation of heat in air bubbles sealed in polyethylene balls. The foil acts as a barrier that traps heat in winter and reflects solar heat in summer, thereby maintaining an optimal thermal regime in the room.

Penofol is also a waterproofing material.

It is lightweight, non-hygroscopic, safe for health and has a long service life (up to 25 years).

Fibrolite

Not a very common type of insulation, which is made from a mixture of liquid glass, cement powder and wood wool. Such material retains heat well and has high sound insulation characteristics. Such insulation, due to its hygroscopicity, is not suitable for flooring on the ground, but ideal for floors on beams. To insulate the floor of the first floor, it is laid with a layer of 15 cm, the second - 10 cm.

Foam glass

Foam glass is obtained by foaming quartz sand. It is a durable slab or granular material with high vapor and noise insulation characteristics, which is able to withstand the weight of a truck.

Fiberboard slabs are used for insulating floors on a flat base, granules for backfilling between logs on rough floors. The thickness of the insulation layer is 18 cm for the first floor and 15 cm for the second.

Mineral wool

This type of insulation is by far the most popular. Mineral wool insulation is made from slag fiber, fiberglass or basalt.

The most budgetary mineral wool insulation is glass wool, which is made from broken glass, sand, borax, dolomite, limestone and soda.

The raw material for slag wool is blast furnace slag, which is a waste in the production of pig iron. Due to its excessive hygroscopicity, slag wool has practically not been used recently.

Stone wool is produced from basalt rocks such as gabbro, basalt. Diabase with the addition of carbonate rocks (limestone and dolomite).

The main advantages of such heaters:

they conduct heat poorly, and, therefore, retain it well;
vapor permeability. The insulation provides good air exchange, the floor structure is breathable, which allows you to maintain an optimal temperature and humidity regime in a wooden house. The probability of condensation in the insulation is small;
high density;
high noise insulation characteristics;
they are resistant to high temperatures and fire; when in contact with fire, no smoke is emitted;
waterproofness. Stone wool and glass wool do not absorb moisture, so you should not be afraid of dampness inside the field structure;
long period of operation - up to 50 years. This type of insulation is not susceptible to rotting and damage by rodents.

The disadvantages of mineral wool thermal insulation are ambiguous. Currently, many large manufacturers have practically reduced them to zero, while the rest are successfully working to minimize them.

Of the shortcomings, it is noted that when working with mineral wool, especially with glass wool, a lot of dust arises, since the insulation consists of fragile fibers, which, if damaged, form very thin and sharp fragments. Getting on the skin during the installation of insulation, they lead to itching. It is dangerous for these fibers to enter the respiratory system. Therefore, such insulation can be laid only with the use of personal protective equipment, such as a respirator, overalls, glasses, gloves.

When wet, mineral wool loses its high thermal performance. Therefore, such heaters are specially treated with hydrophobes. To reduce the likelihood of mineral wool getting wet, it is recommended to install waterproofing from the side of the room, and from the side of the street - vapor barrier during installation.

Until now, builders argue that mineral wool releases phenol-formaldehyde resins into the air. But the data of recent studies indicate their very small amount, which cannot have a detrimental effect on human health.

Mineral wool can be produced in rolls or slabs. Mineral wool material in rolls has a lower density than thermal insulation in slabs. It is used more often as an addition to panel material or where a low level of thermal insulation is required.

The main trade marks of mineral wool are Isover, Rokvol, Knauf, Ursa, Technonikol, Ecover, Izovol, Park and others.

Professionals cannot give an unambiguous answer to the question about floor insulation for a wooden house - which is the best choice.

There is a wide selection of materials for thermal insulation on the modern market. They are designed to meet a variety of needs. The widest assortment of floor heaters, each type has its own operational characteristics, pros and cons. For high-quality thermal insulation of the floor, it is important to choose the right insulation that is suitable for the specific conditions of use.

The main purpose of floor insulation is to reduce heat loss. and reducing heating costs during the cold season. The task of floor insulation is especially acute:

In private houses
In apartments located on the ground floors of apartment buildings, as well as above arches

In such premises heat leakage through the floor is up to 10-15% of the total heat loss... For apartments located above residential, heated premises, this figure is lower. But floor insulation is required not only to reduce heat leakage.

It pulls cold from the floor laid on a concrete base, this often causes colds
If you use electric or, and do not insulate the base, a significant part of the heat will go down
Thermal insulation materials usually also provide sound insulation, their use contributes to increased acoustic comfort.

Types of floor insulation

Floor insulation can be divided into several categories:

Plated, hard- extruded and granular expanded polystyrene (foam), mineral wool
Roll, soft- mineral wool of lower density, stitched mats based on stone fiber, isofol (foil insulation)
Loose- expanded clay, sawdust, sand, expanded polystyrene granules, expanded vermiculite, ecowool
Mechanized application(applied using blow molding machines) - ecowool, liquid polyurethane foam or foam

Some modern materials are both structural and insulating. If you use polystyrene concrete instead of the usual concrete solution in a private house, you can do without additional insulation of the base.

Sprayed (blown) compositions are convenient in that they ideally fill all the voids. Mechanized application saves labor, but requires specialized equipment. In addition, liquid polyurethane foam has a high cost, ecowool is more affordable, but you still need to take into account the cost of work or equipment rental. So this method of floor insulation has not yet become widespread.

Let's take a closer look at the pros and cons of the most common heaters.

Expanded polystyrene

Granular polystyrene foam (PPS), which is more often called polystyrene foam, is the cheapest insulation... It is used less and less for floor insulation, since it has a number of disadvantages:

Extruded polystyrene foam (EPS) is usually colored green, orange, pink. It is produced using a different technology and compares favorably with traditional foam in a number of technical and operational characteristics:

High density and, as a result, better resistance to mechanical stress, lower thermal conductivity
Water resistance
Resistance to biological agents- fungus, microorganisms, rodents, insects

At normal temperatures, both foam and extruded polystyrene foam are non-toxic. The main disadvantage of extruded polystyrene foam is that it is flammable, although it resists fire well. Most of the types of this insulation belong to the G3 or G4 flammability class, more expensive products with flame retardant additives are assigned the g1 class (slightly flammable). When burning, extruded polystyrene releases highly toxic substances!

Mineral wool

One of the most popular heaters made of stone (basalt), slag or fiberglass. It has a number of advantages:

Low thermal conductivity
Good resistance to mechanical deformation, especially with high density boards
Vapor permeability
High fire resistance and high temperature resistance
Invulnerability to rodents and other pests
Good sound insulation performance

The disadvantages of mineral or glass wool include:

High hygroscopicity and a decrease in thermal insulation properties when humidified. There is water-repellent mineral wool with minimal water absorption, but it has a high cost.
Release of toxic substances in small amounts, formation of hazardous dust during wear
High-density mineral wool with the best strength and thermal insulation characteristics is more expensive than EPS

Wired basalt wool mats are reinforced with steel mesh and covered on one side with a shielding layer of aluminum foil. They differ from slabs in lighter weight and are very easy to install. Rolled mineral wool is less dense, its thermal conductivity is higher than that of plate material... It can be used in addition to rigid insulation or in facilities where the requirements for thermal insulation are not very high.

Expanded clay and other bulk insulation

Loose heaters are good because they fill all the voids and when they are used, no waste is generated.
Sawdust- a cheap and environmentally friendly product, but in its pure form they absorb moisture, are prone to decay and are afraid of pests, they must be mixed with clay, cement. At present, sawdust is practically not used as a heater.
Ecowool- cellulose-based insulation with additives of antiseptics and fire retardants - has not yet become widespread. At a price it is comparable to expanded clay and has many advantages:

Ecological cleanliness
Excellent thermal insulation characteristics (4 times better than expanded clay)
Vapor permeability
Immunity to fungi, rodents
Incombustibility

Its main disadvantage is hygroscopicity, low moisture resistance.

The most common loose insulation, which has been used for a long time and managed to gain popularity, is expanded clay. It has the inherent advantages of ecowool, but differs from it in its higher mechanical strength.

It is a versatile material, it can be used as a screed backfill, and can also be added to a rough screed solution, reducing the load on the base and increasing the thermal insulation characteristics.
Expanded clay is practically the only insulation that is suitable for floors on the ground, but under it you need a cushion of rubble and sand. It is very convenient to lay communications in the expanded clay layer.

The effect of using expanded clay is noticeable when it is backfilled with a layer of at least 15 cm, and this is the main disadvantage of this material. It is recommended to use it where the increase in floor height is not critical.

Advice: in order to increase the density of the insulation layer and its resistance to mechanical stress, it is better to use a mixture of expanded clay of different fractions for filling.

Due to the porous structure expanded clay absorbs moisture, while its thermal insulation characteristics are reduced like mineral wool. Therefore, when backfilling expanded clay on the ground and using it in high humidity conditions, it is imperative to perform waterproofing. Read about materials for waterproofing.

The principles of choosing a heater

Almost any insulation can be used for thermal insulation of the floor, but a number of factors must be taken into account:

What base is insulated - concrete, wood, soil
Will the insulation be exposed to moisture
What is under the floor (ground, heated room, unheated room)
Is it planned to install a warm floor system
At what stage is the insulation work carried out

Insulation for concrete screed must have the following characteristics:

Rigidity, high density- he has to withstand the weight of the screed
Resistant to moisture contained in the solution
For board and roll materials - lack of open pores, into which grains of solution can be clogged
High resistance to heat transfer, allowing you to get by with a layer of insulation of small thickness

The best solution is extruded polystyrene foam or high density hydrophobized mineral wool. Expanded clay is also a good option, but using it will lead to a significant increase in floor height.

The main requirement for insulation for a wooden base under a prefabricated sheet screed is vapor permeability. If you put a layer of vapor-proof insulation between the base and the flooring made of wood, the main advantage of natural wood - the ability to "breathe" will be nullified.

Therefore, extruded polystyrene foam is not the best solution. The use of vapor-permeable foam is undesirable, since rodents and bugs successfully pass through it, which can damage the wood.

In apartments located above the first floor, the role of insulation can play. It is obligatory to lay insulation under the underfloor heating system, it can have a small thickness, more important is the presence of a shielding layer that reflects heat upward. Isofol can serve as such a heater, and on the ground floor - stitched mineral wool foil mats.

Important: under the water and cable electric floor, you can use foil insulation, under the infrared film - a metallized substrate.

Sometimes it becomes necessary to insulate the floors in a private house from the basement side in order to avoid dismantling the floor covering. In this case, bulk insulation is not suitable, you can use slab or roll.

Video

The choice of expanded polystyrene for floor insulation

Mineral wool for floor insulation

Outcome

For the insulation of concrete bases, the best choice is high-density materials - extruded polystyrene foam, mineral wool in slabs, expanded clay, for wood - mineral wool or ecowool, for insulation on the ground - expanded clay. Expanded clay must be covered with a thick layer, which limits the possibilities of its use.

Vapor-permeable insulation, which goes well with wooden floors, absorb moisture and need high-quality waterproofing. With underfloor heating systems, insulation materials with a reflective layer are used. The higher the requirements for thermal insulation, the denser the material should be used, or the thickness of the insulation layer will have to be increased.