How to insulate a floor if the floor is already poured. Modern methods of insulating concrete floors. Working with spray materials

The insulation is laid under the floor screed in two cases - on floor slabs or floors on the ground. Depending on the operating conditions (basement, attic or interfloor), flooring and the maximum permissible level of lifting of the finished floor of the pie structure and the location of individual layers in it will change.

Insulation of the floor under the screed is carried out in several cases:

In addition, insulation is laid under the contours of a heated floor on any floor if a decision is made not to use a massive ceiling as a heat accumulator. Therefore, all options will be considered in detail.

There are three types of screeds, which also affects the choice of insulation. For example, expanded clay sand is used, which has both heat-insulating and sound-proofing properties. For wet ones, the same insulation and principles of hydro-, sound- and vapor barrier are used.

Floor slab

When laying factory-made slabs or pouring them in place, it is impossible to ensure a vapor barrier for this structure from moist air from below. Therefore, a vapor barrier layer is applied over the ceiling, taking into account the following nuances:

The insulation is laid under the screed taking into account the following diagram relative position layers:

Important! Concrete and the acoustic material underneath form a single sound insulation system. Coming from below sound wave partially scattered in the acoustic material, then reflected by the massive concrete.

In the basement level

In this particular case, under the floor slabs there is either a basement or a technical underground. To ensure natural ventilation in the underground, the following products are used:

• the total size of all windows must be at least 1/400 of the underground area;
• the recommended height of windows from the blind area is 0.5 m, so that they are not covered with snow in winter;
• It is forbidden to close vents for the winter.

Screed pie on the basement floor.

These conditions are not always met, so there may be excess moisture in the underground. Therefore, thermal insulation must have minimal moisture saturation and be laid on top of the vapor barrier.

Between floors

Unlike the basement and attic levels, there is no heat loss in the interfloor ceilings. Work on all floors heating devices. However, to save energy, insulation is still included in the design:

• without this layer, part of the heat will be spent on heating the floor slab, which will reduce the efficiency of the heated floor;
• thermal insulation will reflect the heat flow and completely leave it inside the room.

Therefore, instead of extruded polystyrene foam and foam glass, foamed polyethylene is sufficient here.

Important! The most effective in screeds with heated floor contours on interfloor floor slabs is reflective insulation coated with aluminum foil. The reflective layer should be on top, that is, the polyethylene foam is laid with the foil facing up.

Attic

When installing thermal insulation of the upper floor in a building with an unheated attic space, the following factors must be taken into account:

• a dew point appears in this design, as the attic freezes completely;
• the dew point must be moved outward so that condensed moisture can be removed from the surface by natural ventilation;
• used to provide ventilation in an unheated attic dormer windows that should be open all year round by analogy with the vents in the underground.

According to the requirements of joint venture building regulations, the vapor barrier of individual layers in the floor pie should increase from the inside to the outside. When laying insulation over reinforced concrete slabs the overlap condition is completely preserved:

• steam penetrates from the lower floor room through the slab into the thermal insulation;
• then the moisture freely evaporates from it and is removed by the flow of natural ventilation to the street.

However, for normal walking on the insulation, ladders or a full-fledged boardwalk are often laid on it. In this case, the condition is no longer met and condensation forms at the boundary of the thermal insulation and the boardwalk. The insulation loses its properties, and the boards undergo rotting, and the development of fungus and pathogenic bacteria is possible.

Floor on the ground

The arrangement of the floor pie layers on the ground must correspond to the operating conditions:

• capillary suction of soil moisture and moist evaporation are possible from the soil;
• sound insulation is not needed here, since there are no noise sources inside the soil
• if there is thermal insulation on the outer edges of the foundation and under the blind area, the soil under the floor will never freeze;
• You can use any floor covering on the screeds, including tongue and groove boards on the joists;

When choosing insulation you should consider:

• There are no absolutely sealed vapor barrier layers;
• moisture that gets inside the insulation will not be able to evaporate from it through the concrete layer;
• when wet, mineral wool and ecowool sharply lose their thermal insulation properties;
• foam glass and polystyrene retain their characteristics even when immersed in water;
• From these materials it is necessary to exclude foam plastic, the density of which is too low and does not provide a 100% guarantee against shrinkage of the screed.

Floor on the ground.

Thus, of the variety of insulation materials, the best option for flooring on the ground remains extruded high-density polystyrene foam XPS or EPS and foam glass.

In the absence of underfloor heating circuits, high heat losses remain. The soil under the ground floor has a stable temperature of +5 – + 8 degrees, which is significantly lower than the same parameter in a living room (+ 25 degrees). Therefore, it is necessary to properly insulate the foundation, plinth and blind area from the outside at a depth of 0.4 m to prevent freezing of the load-bearing structures in winter. Sound insulation in this case is not necessary.

With heated floor

The situation for these operating conditions is similar to interfloor slab floors. Thermal insulation is laid under the pipes of water or electric heated floors. Underneath there is a film, membrane or built-up roll material vapor barriers. It is better to use foam glass or extruded polystyrene foam as insulation here, since the possibility of moisture penetration remains.

Thus, when designing thermal insulation of a screed according to concrete base Different pie design schemes are used, taking into account specific operating conditions.

Advice! If you need repairmen, there is a very convenient service for selecting them. Just submit in the form below detailed description work that needs to be done and you will receive offers with prices from construction teams and companies by email. You can see reviews about each of them and photographs with examples of work. It's FREE and there's no obligation.

Concrete has good thermal conductivity, but does not retain heat well. Therefore, the floor covering laid directly on the concrete base produces a cold feeling. And if a room with such floors is located above an unheated basement, heat will escape through the ceiling.

In addition, due to temperature differences, condensation forms on the concrete and the humidity level increases. The concrete floor on the first floor of a private house standing on the ground is also a source of heat loss, especially in the cold season. That's why the concrete base must be insulated.

Insulation materials for thermal insulation of concrete floors

To insulate a concrete base, materials with good thermal insulation characteristics are required. If floors are insulated in apartment building on the second floor and above, that is, below is located warm apartment, you can use roll or sheet insulation of small thickness - chemically cross-linked polyethylene foam (PPE, penofol and analogues), technical cork.

For insulating floors in a private house or on the ground floor apartment building Insulation of greater thickness and density is required. The most common options are laying mineral wool or expanded polystyrene (EPS), filling with expanded clay. Sprayed thermal insulation is less commonly used - liquid polyurethane foam, penoizol.

Mineral wool is produced in slabs and rolls, EPS - in slabs of different thicknesses and densities. Ordinary expanded polystyrene (foam plastic) has the lowest density and the worst thermal insulation characteristics, therefore for thermal insulation of concrete, extruded (extruded) PPS is preferable.

When choosing insulation, you need to consider a number of factors:

• If a layer of cement-sand screed or leveling agent is applied on top of the insulation layer, you need to use materials with high density and mechanical strength
• If the screed is made from plywood and other sheet materials, it is permissible to use insulation of a lower density
• If the insulation will be exposed to moisture, a moisture-resistant and moisture-proof material is preferable - EPS or hydrophobized mineral wool
• In a private home where rodents live, it is better not to use polystyrene foam.
• Expanded clay insulation is not suitable for rooms with low ceilings, where it is extremely undesirable to increase the height of the floor, but is the optimal solution if the floor needs to be raised
• Special equipment is required to apply spray thermal insulation.

If in conditions of high humidity you use insulation that is not moisture resistant, it must be protected with a layer of waterproofing. It is also necessary to waterproof the slab insulation on top before performing a wet screed.

Options for insulating concrete floors

In an apartment building on the ground floor, the floors must be insulated, on subsequent floors such a need usually arises if there is a noticeable cold draft from the floor. This situation is typical for older houses, where the finishing coating is laid directly on the concrete floor slab.

Also, thermal insulation of the base must be carried out when installing a floor heating system, so that the heat goes up and does not flow to the neighbors below. If the work is not carried out in a new building, where the finished floor is not laid, then insulation is usually preceded by the dismantling of the floor covering (with the exception of situations when a false floor is being installed).

Regardless of the chosen insulation and insulation option, the concrete base must first be inspected, cracks sealed, mortar deposits removed, and cleaned of dust and debris.

Insulation with foamed polyethylene

The main purpose of penofol is as a soundproofing and shock-absorbing substrate for complete thermal insulation of floors above unheated room it doesn't fit. But if you lay it on a concrete base in an apartment, the temperature of the floor covering will become more comfortable.

This is a moisture- and vapor-proof material, and no waterproofing is needed when laying it. Foil or metalized penofol is used as a substrate for heated floors, it must be laid with the reflective layer facing up.

The rolled material is rolled out on a prepared base, and the strips are laid end to end. Penofol is attached to the base with double-sided tape. If you use a material with a self-adhesive backing, you simply need to remove the protective layer. The joints are taped on top, and aluminum tape is used for the backing with a reflective layer.

Most often, foamed polyethylene is used as a floor covering that can be mounted directly on it. If tiles or an elastic coating such as a laminate are to be laid on top, it is necessary to make a prefabricated screed from sheet materials, and logs are placed under the plank floor.

Insulation under wet or semi-dry screed

The best insulation for cement-sand screed is extruded polystyrene foam. To insulate the floor, you need to choose EPS of maximum density with minimal hygroscopicity, for example Penoplex-35 or 45. Due to its light weight, in combination with the screed, it does not place excessive load on the floor.

Sequence of work

1. Prepared, strengthened and cleaned the base is primed deep penetration composition, if the concrete is porous, the application of the primer must be repeated
2. On the ground floor waterproofing of the base is carried out with approaching the walls using mastic or roofing felt; on other floors this step can be skipped
3. Along the perimeter damper tape is glued, its upper edge should be 5-7 cm above the surface of the future screed
4. If waterproofing work has not been carried out, the base is leveled using a thin (1.5-2 mm) layer of clean sand
5. Eps boards are laid close to each other, without gaps, with seams staggered. If sand bedding was used for leveling, then each slab before laying in place should be slightly moved back and forth along the sand layer, pressing from above
6. Waterproofing of insulation is carried out thick polyethylene film, its strips are laid overlapping, the joints are taped
7. Above reinforcing mesh is laid with mesh 80-100 mm
8. Screed in progress

Insulation by joists

This insulation is performed under. Wet processes are absent, and the load on the insulation is reduced due to the use of self-supporting sheet materials - plywood, chipboard, OSB, gypsum fiber board. Optimal choice for such insulation - mineral wool of sufficient density, expanded polystyrene is also suitable, and if you need to raise the floor level, you can use expanded clay backfill.

If the floors are located above an unheated room, the thickness of the mineral wool should be at least 50 mm; above a heated room, 30 mm is sufficient. It is better to determine the thickness of the layer based on the manufacturer’s recommendations, since it depends on the density of the mineral wool board. You can also use rolled materials.

If the floor is insulated above an unheated room, the mineral wool is covered on both sides with a waterproofing, vapor-permeable membrane. Diffuse membranes can be single-sided or double-sided; the details of their installation are described in the instructions for the specific product.

Covering mineral wool with a vapor-proof film is not recommended, especially when insulating the floor above a cold basement. Due to the temperature difference, condensation will form on the side of the film facing the insulation, and thermal insulation characteristics mineral wool is significantly reduced when it is moistened.

The logs are attached to the prepared concrete base covered with a membrane using anchor bolts. Their pitch should be 1-2 cm less than the width of the insulation boards. The logs are treated with antiseptic impregnation. If the membrane is not used, strips of roofing material must be laid under the joists on the concrete.

Insulation is laid between the joists. A layer of membrane is laid on top and secured to the joists with a stapler. After this, you can begin installing the sheet screed.

Insulation with expanded clay

If there is a monolithic concrete slab at the base of a private house, and a screed will be installed on top, you can insulate the base using expanded clay. One option is to fill in expanded clay and perform a rough lightweight screed with the addition of expanded clay to the solution.

1. The base is waterproofed, it is best to use mastic
2. Expanded clay is poured into a layer of at least 10 cm and leveled with a long lath. First, you need to make marks on the walls using a level to control the thickness of the expanded clay layer, rough and finishing screed
3. A reinforcing mesh is laid on top of the expanded clay
4. A layer of rough fixing screed 5-8 mm thick is applied and leveled over the beacons. For 1 part of standard concrete mortar, take 2-3 parts of expanded clay. Damper pads are pre-attached along the perimeter

After hardening the rough screed, which requires at least 7 days, a regular concrete screed is poured. In the future, it can be insulated from above using EPS, mineral wool, bulk or sprayed thermal insulation.

In a similar way, you can carry out insulation under the screed on the ground, you just need a well-compacted cushion of crushed stone and sand (covered in a 5 cm layer), and durable roofing material is used for waterproofing.

Video

Insulation of a concrete floor with extruded polystyrene foam

Insulation with mineral wool on joists

Insulation with expanded clay under dry screed

Bottom line

Insulation of concrete floors is necessary in private houses and on the first floors of apartment buildings, and preferably in apartments located above. The principles of insulating a ready-made concrete floor in an apartment and a private house are similar; the thickness of the insulation may vary depending on the temperature difference above and below the concrete floor. Also on the ground floor there are higher requirements for waterproofing.

Can be used as insulation various materials, the insulation technology depends on the selected material and the characteristics of the subsequent leveling of the base.

Under wet and semi-dry screed the best option is extruded polystyrene foam, and if a significant increase in the floor level is permissible - expanded clay. Mineral wool is suitable for sheet screed, and foamed polyethylene with a heat-reflecting layer is suitable for heated floors.

Floor insulation for concrete under screed is one of the most popular materials due to the fact that it provides high-quality and effective thermal insulation, helping to retain heat, which concrete is not able to retain for a long time.

When carrying out construction and repair work, many consumers think about how to insulate a concrete floor. They study the detailed description and technical specifications various insulation materials, choosing the highest quality. Insulation of a concrete floor guarantees effective heat retention in a residential or office space, especially if it is located on the ground floor.

Features of choice

Insulation of a concrete floor requires the right choice thermal insulation materials.

You need to pay attention to such technical characteristics as:

• density;
• strength;
• environmental friendliness;
• duration of operation;
• moisture resistance;
• water permeability.

Due to heavy loads on the coating, thermal insulation material it is worth choosing increased strength

The material chosen as insulation for a concrete floor must be quite durable, since it is the floor that is subjected to the highest loads, and, accordingly, the insulation for the floor under the screed will also have to withstand increased pressure.

The weight of the thermal insulation material depends on the density, and the quality of the thermal insulation depends on the level of porosity.

High-quality floor insulation under the screed must have low moisture permeability (the ability to absorb moisture) and high moisture resistance.

This quality has great importance, if the thermal insulation of a concrete floor is being constructed in a bathroom or on a balcony.

In cases where the insulation of concrete floors is carried out in the living room or bedroom, office or hallway, there is no need to pay special attention to this characteristic.

Great importance is attached to the environmental friendliness of thermal insulation, especially when carrying out the described work in children's rooms and bedrooms.

Variety of thermal insulation materials

Expanded clay goes well under a rough screed

Insulation of a concrete floor is carried out in several options. Thermal insulation should be selected depending on which screed will be mounted on top of it. If it is a cement-sand mixture, then you will need slabs with high strength and density.

Concrete floors are associated with solidity, durability and reliability. But they also have a drawback - they are cold. The high thermal conductivity of reinforced concrete removes heat from residential and domestic premises. Therefore, high-quality thermal insulation is necessary for concrete floors. For this purpose they use different materials– fibrous, foamed plastics, bulk plastics, etc. Having general construction skills, the homeowner can cope with insulation on his own.

Why insulate the floor

Among the total heat losses, the floor occupies a prominent place - up to 15%. A cold floor not only “steals” kilocalories of heat - it significantly reduces the comfort for those living in the house. If your feet are cold, the general feeling of cold intensifies. Cold floors are especially dangerous for young children, who often play sitting and lying down, and the elderly.

Cold coming from the floor harms pets and indoor plants. Large heat losses have a number of other unpleasant consequences: moisture can condense on cold surfaces and the relative humidity will increase. This will lead to the appearance of mold and mildew, which are extremely harmful to human health. Therefore, in addition to thermal insulation, it will be necessary to take care of the vapor and waterproofing of the ceiling.

Determining heat leakage paths

Heat leaves rooms in two ways - by heat transfer through concrete and with drafts through joints with walls. Accordingly, when insulating the floor, you need to block both of these paths by selecting and installing suitable thermal insulation materials.

Selection of material for floor insulation.

The thermal insulation material must have a low ability to conduct heat. It is characterized by the coefficient of thermal conductivity. The lower it is, the better material insulates.

In addition, the material must:

• be durable;
• do not lose properties when moistened;
• easy to install;
• have a reasonable price.

Today the most popular thermal insulators are:

• Fibrous. Basalt, glass and slag wool.
• Monolithic. Foamed plastics in panels, plywood, OSB, etc.
• Sprayable. Polyurethane foam and ecowool, applied using the wet-adhesive method.
• Bulk. Dry ecowool and traditional - expanded clay, sawdust, shavings.

How to choose the most suitable material for thermal insulation?

Mineral wool

Basalt wool is made from volcanic rocks rocks. Its fibers are short and stiff, and its density is high. Kt= 0.034…0.039 W/(m*K).

Advantages:

• Strength. Withstands heavy loads, used for flat roofs and interfloor ceilings under the screed.
• Low hygroscopicity. When moistened, it does not lose its properties.

Flaws:

• Low elasticity. Difficult to install by surprise.
• Large mass of insulation. It is necessary to calculate the load-bearing capacity of the floor and, possibly, strengthen it.

Supplied in the form of mats 1200*600 mm.

Glass wool is made from glass production waste; its fibers are long and elastic. Density lower than basalt wool, Kt =0.032…0.041 W/(m*K)

Advantages:

• High elasticity makes cutting and installation easier.
• Low density makes it possible not to increase the load-bearing capacity of the floors.

The disadvantage of glass wool is its high hygroscopicity. When wet, the material loses its thermal insulation properties. Available in both mats and rolls, more convenient when laying over a large area

Expanded polystyrene

The common name for the material is polystyrene foam. It is foamed polystyrene, supplied in the form of sheets of different thicknesses. Kt 0.038-0.052 W/(m*K)

• very light;
• cuts well.

• Fragile.
• It's crumbling.
• The joints must be additionally sealed, for example, with polyurethane foam.

Polystyrene foamed using extrusion has best performance by thermal conductivity Kt = 0.029-0.032 W/(m*K). It is more durable and is available in tongue-and-groove sheets, which makes it easier to install joints. Does not absorb moisture at all and does not require additional vapor and moisture insulation.

Extruded polystyrene is often called “penoplex”, after one of the most common brands.

Foamed polyethylene

This insulation is very popular for insulating and waterproofing concrete floors; it is laid under laminate, parquet board, linoleum. Kt=0.035-0.037 W/(m*K).

The material has undeniable advantages:

• Easy.
• Elastic.
• Easy to install.
• Insensitive to moisture.
• Perfectly isolates sound and vibration.

The disadvantage of insulation is its high price. Available in the form of mats (thick) and rolls, sometimes foil. The canvases are glued together with double-sided tape.

Spray polyurethane foam

Polyurethane is sprayed onto the heat-insulating surface in liquid form, foams and hardens on it, forming a continuous layer. The texture resembles a construction one polyurethane foam. It has excellent heat-insulating properties - its Kt = 0.023 W/(m*K).

Advantages:

• Low thermal conductivity.
• No joints or seams.

The following disadvantages limit the widespread use of insulation:

• High price of equipment. Very tall.
• High requirements for the qualifications of the spraying plant operator.
• Requirements for air temperature during application.

Plywood, fibreboard, chipboard and others

Such materials are used as insulation only for thermal insulation of the second floor, above heated rooms. Kt =0.12...0.15 W/(m*K), which is three to four times higher than other popular materials. When using chipboard as a thermal insulation material, it is necessary to perform vapor and waterproofing especially carefully. When wet, chipboard swells and can warp the finish coating.

Ecowool

The increasingly popular insulation for concrete subfloors is made from recycled or recycled cellulose fibers. Kt=0.032-0.041 W/(m*K)

The composition of ecowool contains a bioprotector that suppresses the development of mold, fungi and microbes, and a substance that prevents combustion.

Advantages:

• does not burn;
• light;
• does not emit harmful substances, including in case of fire;
• is blown into the narrowest cracks, openings and voids of insulated structures.

The disadvantages of ecowool include:

• high cost of spraying equipment;
• the need for highly qualified workers.

To insulate concrete floors, you can also use the manual method of applying the material - grinding it with a construction mixer in a vat and simply pouring it onto the insulated surface. Material consumption at manual way 20-30% higher, but no expensive equipment is required.

Traditional materials

Thermal insulation properties natural materials, such as:

• shavings;
• sawdust;
• reed mats;
• peat slabs;
• pressed flax and hemp fiber.

cannot compete with insulation materials industrial production. Although they saved our ancestors from the cold for thousands of years.

Their advantage will be environmental friendliness and low cost.

The disadvantages are the following:

• poor thermal insulation;
• hygroscopicity;
• susceptibility to rot, mold and mildew;
• flammability.

When building a log house from imported logs, a large amount of sawdust and shavings are formed on the site. It is reasonable to use this waste for floor insulation. You will only need to take care of their impregnation with a fireproof and bioprotective solution, as well as steam and waterproofing.

Bulk materials for thermal insulation

This is also cheap way insulation. The most popular material of this type is expanded clay, obtained by firing a clay mixture. Its porous granules are inexpensive and provide Kt=0.1 W/(m*K).

The advantage of expanded clay is its environmental friendliness, non-flammability and ease of use. The disadvantage is the high thermal conductivity and the need to perform labor-intensive cement screed, which significantly increases the cost of the solution.

Less commonly used by others bulk materials- foam glass, vermiculite, foam or expanded polystyrene crumbs. They are better for insulation in conditions of a limited budget.

How to insulate a concrete floor

The technology for thermal insulation of floors is simple, but all the requirements technological process must be followed strictly. An attempt to save time will lead to ineffectiveness of the entire insulation. When choosing a method of insulation, you should take into account the method and degree of thermal insulation of the foundation, ground floor and blind areas. How to properly waterproof and insulate a concrete floor? The technology depends on the selected material.

Fibrous materials

The main thing when working with mineral wool is not to forget about steam and waterproofing, joints and fits. The layer thickness is selected depending on climate zone, in regions with a mild climate, 50 mm is enough; in frosty places it is better to use 150.

• Lay a vapor barrier membrane and connect the joints of the panels with metallized adhesive tape.
• Install logs. Their height should coincide with the selected thickness of thermal insulation, the pitch should match the dimensions of the slabs or rolls of mineral wool. Plates or rolls must fit between the guides without gap.
• Lay insulation. Special attention joints and abutments to walls.
• Place a vapor barrier membrane over the slabs, smooth side up. The membrane will remove moisture.

• Lay tongue and groove or thick plywood. Secure to the joists with self-tapping screws.
• Next, you can lay the final finish: laminate, parquet board, cork or linoleum.

Expanded polystyrene

Foamed polystyrene is often used under cement screed. The material is not hygroscopic, it can be used in damp rooms - kitchens, bathrooms, bathrooms, saunas.

• Prepare the concrete surface. Seal cracks, crevices and potholes, and level out protrusions.
• Clean from oil and grease stains and other contaminants.

Important! Alignment requires more careful than in the previous case. It is necessary to either concrete the insulated floor with a leveling solution, or fill the surface with fine sand and carefully level it.

• Lay the insulation boards end to end over the entire floor area.
• Tongue and groove slabs are laid using protrusions. The joints of the foam boards are sealed with polyurethane foam.
• Lay and glue damper tape along the entire wall line, allowing the screed to expand and not break during temperature fluctuations. The tape can also be nailed to wall blocks in aerated concrete houses.
• Roll out polyethylene over the insulation layer no thinner than 0.5 microns, with an overlap of 10-20 cm, and glue the sheets with double-sided tape. This layer will prevent moisture from leaking out of the cement screed.
• Place the fittings. If the room has a water-heated floor, install pipes, fittings, etc. on top of the reinforcement system.

• Fill the screed.

Sprayed materials

This method will require purchasing or renting expensive equipment. Most owners only rent out units with qualified operators. Manufacturers also produce disposable, non-rechargeable kits for self-use.

• Prepare the concrete surface. Seal cracks, crevices and potholes, and level out large protrusions.
• Clean from oil and grease stains and other contaminants.
• Careful alignment may not be necessary.
• Install a joist system on which the floor will rest. Secure with self-tapping screws and dowels or nails from a construction gun.
• Wet the concrete so that the foam adheres better.

• Spray insulation for the concrete floor. The volume of foam when hardened increases by 5-10%. This needs to be taken into account.
• Wait until the foam dries completely.
• If the floor will not be laid immediately, cover the foam layer with light-protective material.

Other methods of thermal insulation of the floor are also used, such as filling with expanded clay followed by installation of a cement screed. This method also does not require careful leveling of the floor. If added to cement mortar sufficient quantity special polymer additives, the screed itself will acquire thermal insulating properties.

Before you start

For thermal insulation work in most cases (except for sprayed coatings), only the usual set of construction tools is required, first of all:

• circular saw or jigsaw;
• screwdriver;
• roulette;
• corner;
• level;
• construction knife.

Almost all floor insulation work can be done alone. But with an assistant, the time will be significantly reduced, especially if the screed is done.

One of the weakest places for retaining heat in a house is the floors. This is especially true for apartments on the ground floors and private houses. Therefore, it is imperative to insulate the concrete floor. For this, various thermal insulation materials are used. The insulation technology depends on the selected material.

Concrete floor insulation scheme.

Basic properties of insulation

Various thermal insulation materials can be used to insulate a concrete floor. Each has certain properties and operating conditions. When choosing, it is necessary to take into account the following material indicators:

Scheme of floor insulation with polystyrene foam.

1. Density. The lower this indicator, the less weight and the more pores in the material. Accordingly, it has better thermal insulation properties.
2. Strength. When insulating a concrete floor, the strength of the insulation plays an important role, since significant loads are placed on it.
3. Moisture resistance. The higher this indicator, the better. Otherwise, the insulation will quickly absorb moisture and lose its properties.
4. Thermal conductivity coefficient. The indicator characterizes the ability of insulation to transmit heat through itself. Low values ​​of this value indicate good thermal insulation properties of the material.
5. Moisture permeability. This parameter must have minimum values, otherwise the material will absorb moisture from the air and concrete and lose its properties.
6. Durability. Everything is clear here, the greater the durability, the longer the material will last.
7. Environmentally friendly. This indicator is very important, because insulation is carried out indoors, and, accordingly, the material must be safe for humans.

Materials for thermal insulation

Among the most common home insulation materials, the following materials should be highlighted:

Scheme of thermal insulation of the floor with polystyrene foam.

1. Mineral wool. This material is one of the most common insulation materials. It has low density and thermal conductivity, good sound insulation, and is relatively inexpensive. However, mineral wool absorbs moisture well, which is why it loses its thermal insulation properties. Therefore, when using such a material, it is necessary to provide a vapor and waterproofing layer. In addition, mineral wool is not environmentally friendly; it must be used with extreme caution.
2. Polystyrene foam or polystyrene foam. This material is also very often used for thermal insulation of concrete floors. Polystyrene foam retains heat perfectly, does not absorb moisture and is completely indifferent to it, and is the cheapest insulation material. The negative properties of the material are not environmentally friendly and increased fragility.
3. Extruded polystyrene foam. This material is a derivative of conventional polystyrene foam, but has better performance characteristics. It is much stronger, more durable, and has better thermal insulation properties. At the same time, it is also resistant to water.
4. Polyurethane foam. This material is waterproof, has high thermal insulation properties, resistance to temperature changes and mechanical loads, and a long service life. The disadvantage is, again, not environmentally friendly.
5. Expanded clay. The material is most often used as a substitute for crushed stone in concrete mortar. Thanks to this, the thermal conductivity of concrete floors is significantly reduced, and the material itself is environmentally friendly. However, expanded clay has such disadvantages as larger total weight, high moisture permeability.
6. Cork. This material is natural and, accordingly, environmentally friendly. It has durability and excellent thermal insulation. However, it is better to use cork as insulation material raised floor or as a substrate for finishing floor finishing. The cost of cork is an order of magnitude higher than that of other insulation materials.
7. Perlite. According to the method of application, the material is similar to expanded clay, but many of the performance characteristics of perlite are better.

Related article: Choosing fabric for roller blinds

Thus, we examined the main materials used for insulating concrete floors and their properties.

Features of insulation

Before you start insulating a concrete floor, you should select not only a thermal insulation material, but also decide on the method of insulation.

Scheme of thermal insulation of the floor with expanded clay.

Let's look at the main methods:

1. Installation of thermal insulation under a concrete screed. This method is used only at the stage of building a house. Otherwise, the finished screed will have to be completely destroyed, to the very foundation. With this method of insulation, it is necessary to use materials that can withstand significant mechanical loads, are durable and moisture-resistant.
2. Installation of a "warm floor" system. This method allows you to heat the entire floor surface. The system is mounted on top of the insulation and filled with concrete screed. For heating you will have to use a third-party energy source ( hot water or electricity). The most commonly used are water or electric heated floors. However, in lately Infrared heated floors, which are laid on top of the screed, are increasingly being used.
3. Adding special fillers to the concrete solution. If you add materials such as expanded clay or perlite to the concrete solution, the floor will conduct much more less heat. As a result, heat loss will be significantly reduced.
4. Raised floor installation. In this case, logs are placed on top of the concrete floor, between which insulation is laid. A wooden flooring made of boards is attached on top of the logs. With this method, it is worth considering that the height of the room will decrease significantly.
5. Laying flooring. IN finished house The easiest way to insulate a concrete floor is by installing a special insulated floor covering. For example, by laying carpet or linoleum with a thick base. You can additionally insulate the base by laying a substrate, which also increases the thermal insulation properties of the concrete floor.