The better to insulate the floor. How to insulate floors in a private house

Even at the design and construction stage, it is necessary to think about how to insulate the floor in a private house. will create comfort and coziness. The health of the inhabitants of the house and the condition of the home interior depend on it.

Floor insulation can be carried out using several heaters. Each of these materials has its own laying technology. How to insulate the floor, you can decide after studying it and the possibility of using a heater.

As a floor insulation use:

• mineral wool;
• expanded polystyrene (polystyrene) or (polystyrene);
• expanded clay.

The better to insulate the floor, you can decide after you know all the advantages and disadvantages of each heater.

Styrofoam

A common material that is widely used for warming different areas.

Its use is due to a number of advantages:

• cheap material that can be bought at any hardware store;
• has a small weight;
• moisture-proof, as a result of which it retains its characteristics for a long time;
• has a porous structure, as a result of which it is easy to process. Can be cut to any shape and size;
• low thermal conductivity.

However, there are some drawbacks, due to which it is sometimes abandoned. These include:

• the material ignites quickly and burns well, emitting caustic gas. Difficult to extinguish;
• in case of violation of steam insulation and waterproofing, it begins to collapse during operation.

Penoplex is a subspecies of polystyrene. It is characterized by a denser shape than foam. Differs in the increased resistance to mechanical loadings and differences of temperatures. The disadvantages include the fact that the material, compared with polystyrene, is not cheap.

Mineral wool

For home insulation with your own hands, the most popular material is mineral wool. Mineral wool is a name for thermal insulation materials that are made from inorganic constituents and have a fibrous form. They are made from a mixture of rocks, glass and waste slag.

The mixture of these components, followed by heating and the formation of a thread, determines the process of obtaining mineral heaters. It can be glass wool, stone wool or slag wool. The name of the material depends on the filler that is used to produce the fiber.

To produce glass wool, boric salt, sand, lime and soda are combined in specific proportions. After iron is smelted, blast-furnace slag remains, which is added to produce slag. Basalt minerals predominate in stone wool. These materials have almost the same thermal performance, fire resistance, thermal conductivity and density. Mineral wool is inexpensive and is sold in building materials stores.

One type of mineral wool is ecowool. This is a more refined and high-quality type of glass wool, made from environmentally friendly components.

Warming the floor with mineral wool has several significant advantages. These include:

• ease of installation of the material;
• the insulation has a high fire resistance, does not burn and does not smolder;
• it is easily processed, as a result of which the plates can be cut into the desired shapes and sizes;
• after deformation, it can take its original size and shape. This is useful when filling hard-to-reach voids;
• has good noise absorption performance;
• high level of energy saving;
• light weight;
• long period of operation.

Despite significant advantages, the heat insulator has several disadvantages. These include:

• working with this heat insulator can sometimes cause allergies. Long-term operation turns the fibers into fine dust. This can be avoided by reliable insulation of the material during its installation;
• if the insulation is broken, the material absorbs moisture well. As a result, the original thermal insulation characteristics are lost and there is a need for unscheduled repairs;
• during the installation of mineral wool slabs, it is recommended to wear special protective equipment (respirator or cotton-gauze bandage for respiratory organs, eye protection glasses, gloves and clothing to protect the skin).

Despite the shortcomings, mineral wool insulation remains the most common method of thermal insulation. Proper floor insulation will avoid these shortcomings.

Expanded clay insulation

Expanded clay is called porous granules made from a mixture of clay, sand and fine natural stone, followed by firing.

A characteristic feature of this floor insulation is the ability to maintain its heat-insulating parameters in a humid environment. A few positive qualities made it popular:

• high level of thermal conductivity;
• resistance to temperature extremes;
• has a high fire resistance, does not burn;
• ability to withstand significant mechanical loads;
• long period of operation exceeding 40 years;
• environmentally friendly material;
• ease of use;
• light weight;
• strength.

The disadvantages include large volumes of material for insulation work. To forget about the cold floor, the expanded clay layer, according to various criteria, should be from 10 to 50 centimeters.

Features of insulation work

A private house can be built directly on the ground or it can be a complete house with a basement.

If there is soil below the subfloor, then low temperatures and moisture that seeps from groundwater act on the floor and bottom of the walls. Cold floors in a private house can cause mold and fungal wall diseases, regardless of the material from which they are made. The result will be a constant unpleasant smell, rotting and destruction of the material from which the walls are made. In winter, the degree of freezing of the soil increases, which further affects the indoor temperature and the condition of the floor, which will become icy.

Insulation of floors in a private house depends on many factors. These include: material, walls of the house (brick, concrete, logs, frames), number of floors, floor bases (soil, cement, wood).

An important role in the insulation of the floor of a private house is played by the height of the basement, the presence of external insulation and protection from moisture. The presence of a basement in the house is important. It takes heat from the floor. If there is a basement, it is necessary to insulate its ceiling.

basement ceiling insulation

Work begins with a thorough inspection of the entire surface of the ceiling. All cracks, delaminations are inspected and an assessment of the condition of the ceiling and the amount of necessary work is carried out.

The warming process includes:

• cleaning of all roughness and swelling;
• flooding with plaster of all cracks, voids, depressions. Ceiling alignment;
• using a perforator and mounting an "umbrella", installation over the entire surface of the foam boards;
• application of adhesive composition and, if necessary, finishing material.

Reinforcing mesh may not be installed, since mechanical loads are not provided for on the ceiling.

Floor insulation in a private house is carried out based on the material of the floor itself. It can be insulated on a concrete surface, on logs or on the ground.

Draft floor

What to do if the house has a dirt floor. It contains a high level of moisture, due to the presence of groundwater. Before insulating the floor with foam, it is necessary to cover the soil, create a subfloor.

For subfloor equipment you need:

• Prepare a pit, which should be 30-40 cm below the level of the intended finishing floor.
• Protect the base from moisture. To do this, you need to equip the substrate.

When equipping the drainage, it is necessary to lay a sandy layer, 5-10 cm thick, on the bottom of the pit. On top of the sand, a layer, 10-15 cm thick, of medium-sized crushed stone or broken bricks. Compact crushed stone or broken brick until it sinks into the sand. Lay another layer of sand on top of the rubble, 5-10 cm thick, and compact it.

• Make a mesh from the reinforcing wire and install it on top of the substrate. The reinforcing mesh is made of wire, 6-10 mm thick, with a mesh size of 10x10 cm. The intersections of the wires are fastened with knitting wire.
• Pour a layer of cement mortar. The layer thickness should be 10-15 cm.
• Leave the floor to dry.

After 5-7 days, the draft floor will gain initial strength and will be ready for insulation.

Foam insulation

Thermal insulation of the floor with foam plastic is carried out in the following sequence:

• A waterproofing membrane must be laid on the subfloor. The strips of the membrane should overlap each other by a width of 10 cm. The place of overlap is sealed with a wide adhesive tape.
• Styrofoam boards must be laid on the waterproofing material. Each new row should be shifted to the side in relation to the previous half. This will create a checkerboard pattern for stacking the tiles.
• It is necessary to make a mesh from the reinforcing wire and install it on top of the foam boards. The reinforcing mesh is made of wire, 6-10 mm thick, with a cell size of 10x10 cm. The intersections of the wires are fastened with knitting wire. The grid is recommended to be fixed at a height of 3-4 cm from the foam. After pouring, it will be inside the solution.
• It is necessary to stick nails into the foam plastic, 8-10 cm high. They determine the level of pouring the cement mortar.
• Pour the cement mortar and let dry. Completely the solution hardens from 4 to 5 weeks.
• The frozen floor must be covered with a vapor barrier membrane. The strips of the membrane should overlap each other by a width of 10 cm. The place of overlap is sealed with a wide adhesive tape.
• On top of the vapor barrier it is necessary to lay a wooden grate and install a floor covering on it.

The grate under the flooring acts as an additional ventilated space.

The floors of the lower floors and the floors that are the overlap between the floors are insulated according to the same principle, regardless of the insulation material.

Expanded clay insulation

The principle of insulation with expanded clay is absolutely identical with foam plastic. An important feature is the size of expanded clay granules and the thickness of the insulation layer.

For good insulation, it is recommended to use medium-sized granules, which should form a heat-insulating layer, at least 10 cm thick. The expanded clay layer should be even. For verification, the building level is used. The height of the layer is determined by pre-installed signal beacons.

Mineral wool floor insulation

In this case, the laying of a heat insulator is carried out between the logs that lie at the base of the house. If there is no lag, and we have a rough cement floor in front of us, then it is necessary to make a frame. It can be made of wooden boards or plasterboard. The dimensions of the frame cells are recommended to be made according to the size of the insulation boards. This eliminates the need to cut the insulation boards of the required size.

Thermal insulation of the floor is carried out in the following sequence:

• It is necessary to install a waterproofing film.
• Mineral wool must be laid between the lags or in the cells of the frame.
• After laying the insulation, the entire surface must be covered with a vapor barrier membrane. The strips of the membrane should overlap each other by a width of 10 cm. The place of overlap is sealed with a wide adhesive tape.
• A wooden grate must be laid on top of the vapor barrier
• Install a clean floor.

The vapor barrier membrane will additionally protect the room from microparticles that are released by the mineral wool.

Conclusion

One person is able to cope with the work on his own if he knows how to properly insulate the floor. The main criterion in the work is compliance with the technology of work. Therefore, the insulation of floors in the house is a complex process, but doable.

Living in the private sector, the owners themselves take care of the insulation of their own homes. It is not difficult, knowing the technology, having at hand step-by-step photos of the work or instructions on the video. The article will tell you how to make a warm floor in a residential building with your own efforts.

When choosing a material, pay attention to the following properties:

1. Flammability. The indicator G1 indicates that the substance will not ignite without direct exposure to fire.
2. Hydraulic resistance. The lower the percentage of water absorption, the less moisture the material absorbs, which means it retains heat better and longer.
3. Thermal conductivity. A low coefficient indicates good insulation.
4. Density. Indicates how much the material makes the entire floor structure heavier.

Floor insulation materials

Also, an important role when buying a heater is played by its quality, cost, durability (the service life should be at least 10 years) and ease of installation - which is especially important if you are going to make a warm floor with your own hands.

The most common materials for insulation:

Mineral wool. Her virtues:

• inexpensive;
• durable;
• withstands high temperatures, up to 1000°C;
• has low thermal conductivity;
• well isolates sounds.

Mineral wool

Disadvantages:

• high vapor permeability. If you do not take care of waterproofing, cotton wool will accumulate moisture over time and become useless;
• attraction for rodents. They need special protection.

Glass wool. It is similar in its properties to mineral wool, but has an additional disadvantage: you need to make sure that it does not get into your eyes and skin. Because of this feature, it is difficult to work with it, it is necessary that professionals do it.

Ecowool- non-toxic, environmentally friendly material with the same advantages and disadvantages as other types of cotton wool.

Sawdust. The cheapest material for floor insulation. They hold heat well, but have many disadvantages: they are highly combustible, attract rodents and insects, absorb moisture well, being a favorable environment for the development of mold and fungus.

Sawdust

The following materials are more often taken to insulate concrete floors than wooden ones:

Expanded clay. It has a clay base and is an inexpensive, environmentally friendly material. It has low thermal conductivity. Of the shortcomings: it absorbs and retains moisture well, although it does not lose its properties.

Attention! The expanded clay layer must be at least 10 cm, otherwise the floors will be cold.

Perlite. Similar to expanded clay, but has improved characteristics.

Styrofoam. Advantages:

• good thermal conductivity;
• moisture resistance.

• environmental friendliness;
• high flammability;
• fragility.

Styrofoam

Extruded polystyrene foam. This is an “improved version” of foam: it is stronger, lasts longer, retains heat better.

Cork. Natural material that holds heat well. Usually it is placed under the floor finish.

Polyurethane foam. Good for almost everyone

• resistance to moisture, temperature fluctuations and loads;
• durability;
• excellent thermal conductivity.

Of the shortcomings, it should be noted non-environmental friendliness.

Insulation with polyurethane foam

Foam glass. It has all the advantages of polyurethane foam, plus it is environmentally friendly. However, it is fragile, therefore it is not able to withstand heavy loads.

Advice. When purchasing insulation in slabs or rolls, press on a small piece of material. If it takes its original form, feel free to take it.

Warming methods. Options for wood and concrete floors

There are two main ways to insulate the floor:

Advice. These methods are good at the stage of building, repairing or renovating a house. If you plan to insulate an already lived-in room, you will need to disassemble the floors or put insulation on top of them, and then again “decorate” the floor covering.

Instructions for warming a wooden floor

• Before starting work, it is necessary to lay a subfloor. It is made from raw boards, they are mounted on beams. If we are talking about repairs, then first you need to dismantle the old floors.
• Lay the logs on the subfloor. Fasten them with screws. The distance between the bars is 0.6-1 m.
• Lay waterproofing material.

Wooden floor insulation

• Position the insulation so that it fits snugly against the lags. Lay waterproofing on both sides. If expanded clay is used, it just needs to be poured into the space between the bars.
• The next layer is vapor barrier. This is a special film or membrane that extends the life of the heat-insulating material. It should be laid with a smooth surface to the insulation.
• Installation of a finishing floor covering.

Attention! Ventilation is required between two levels of the floor. To do this, special holes are made in the upper floor covering - vents.

This version of the double floor, consisting of a "draft" and "clean" floor, is also suitable for a concrete base. However, it should be borne in mind that this design reduces the height of the ceiling by about 6 cm.

Concrete floor insulation instructions

For a concrete floor, you can use another, albeit less effective, technology, but it reduces the height of the room by only 3 cm. You need:

• Clean and level the concrete floor.
• Lay the substrate, on top of it - wood plates in 2 layers. They are laid like bricks, the seams of the layers should not match, they need to be smeared with sealant.
• Glue, and also connect wood plates with self-tapping screws.
• Lay floor covering.

concrete floor insulation

Heated floors

Such a system allows you to evenly warm up the housing. However, it has a significant drawback: high power consumption. Also, this option is not suitable for houses with wooden floors. Otherwise, they must be dismantled. The sequence of installation of the heating system:

• Clean and level subfloor.
• Lay waterproofing material.
• Place a heater on top, for example, foam.
• Lay the cable over the entire surface (in the form of a "snake").
• Connect the system and fill the floor with a screed. Its thickness is approximately 5 cm.

You can use the finished structure only after 3-4 weeks, when the concrete dries. The heating temperature should be increased little by little and gradually. Infra-red also works from electricity - a special film or rods with wires. Such a heater is mounted faster, but it costs more than a traditional electrical system.

Scheme of electric floor heating

Another option for underfloor heating is water. Comfort in the house is provided by pipes laid under the screed. This method requires significant financial investments, but is profitable in operation. It is advisable to install it in a house with autonomous heating. It is better to entrust the installation of a water-heated floor to professionals.

When insulating floors, we must not forget about other, no less components of the process. For example, if the house has a basement, you need to start with it first. It will not be superfluous to insulate the walls of the foundationso that they do not come into contact with freezing soil and moisture. Only with such an integrated approach can you achieve real warmth and comfort in the house.

Concrete floor insulation: video

Cold winters still take place, and you need to prepare well for them so that living in the house is 100 percent comfortable. Underfloor heating is the basis on which it depends how pleasant it is to be indoors when it is cool outside. There are convenient options for insulating this part of the building without removing the top layer - it's easy to do it yourself if you follow simple recommendations.

We insulate the floors from the basement - when is it appropriate?

Any wooden house quickly loses heat, this is due to the peculiarity of the material. Therefore, the insulation of all parts related to the external environment is mandatory. Walls are only part of the overall structure, which must undergo a thorough heat blocking procedure. The process of working with the floor will solve such problems as:

• excessive energy consumption for space heating;
• high humidity - relevant for the transitional seasons;
• rotting of wooden building elements;
• the appearance of fungus, mold, which poses a danger to the health of residents of the house.

Most often, in cottages, floors are insulated above a cold basement, because. in the cold season, they cool down quickly and have a low temperature even if the room is heated using their boiler system. Poor or no insulation means icy floors that are useless for carpeting. The problem is solved only by proper insulation, there are simple techniques that can be used without removing the old floor. It is better to spend money on such an event once than to constantly spend extra gas or electricity on double heating rooms.

In the event that the building has already been built, and there is a need for additional floor insulation, it is more expedient to do this from below, i.e. without removing floors. Benefits of the bottom technique:

• the ceiling height in the rooms will remain the same, because there will be no need to raise the floors due to insulation;
• no need to specifically spend money on insulating compounds of increased density and rigidity due to the load of furniture, appliances and other items in the house;
• you will protect not only the floor itself from freezing, but also all floor structures, which will extend their service life and generally make the home warmer;
• there will be a change in the location of the dew point from the inside to the surface of the floor - this will get rid of the decay of wooden elements.

The method of floor insulation from below has only one limitation - the subfloor is too low, in which it is impossible to be for work. Such cottage buildings are quite rare. If this is your case, choose the floor insulation option from above, i.e. with the procedure for opening it and filling it with a suitable insulating material.

Minvata - fiber insulator

Mineral wool is a building insulation made up of many fibers in three distinct types: glass; stone or basalt; slags. To work with the floor, basalt canvas is most preferable, because. it is easiest to mount it under the floor structure. Of the two options - rolled and mats in the form of plates - choose the second, because. it keeps its shape well. Advantages:

• good level of thermal insulation;
• simple installation technology;
• relatively low level of moisture absorption from the environment;
• moderate price;
• heat resistance and fire safety;
• bacteria, mold, fungus do not start in the material.

Disadvantages:

• when laying with your own hands, you must use special protection - gloves, clothing, a respirator, glasses, because. there will be many particles of fibers and dust in the air, causing irritation of the skin and respiratory organs;
• moisture protection is required, because the structure is susceptible to vapor absorption;
• if installed incorrectly, strong shrinkage is possible;
• when laying between the lags, you need to leave a gap to the main structure of 5 centimeters.

If you decide to choose mineral fiber, select the material of the desired thickness. Specific data depend on the climatic zone, for example, an indicator of 100-150 millimeters is suitable for central Russia. Basalt wool is suitable for all types of floors, including the attic.

Styrofoam - air material from granules

Styrofoam consists of foamed PVC granules containing a maximum of air inside, this gives it good thermal insulation qualities. Advantages:

• has strength, stability, rigidity;
• almost does not absorb moisture - the percentage is lower than that of mineral mats;
• has a light weight;
• easy to mount, because does not change shape;
• inexpensive;
• durable, does not mold, does not rot.

Disadvantages:

• subject to fire;
• brittle to break;
• ventilation of the base is required, because does not pass steam and air.

For floor insulation in an ordinary private house, foam boards of the PSB-S-15 brand ten centimeters thick are suitable. At the time of purchase, do not confuse them with granulated polystyrene foam, which easily crumbles into small PVC balls. The latter can also be used as a heater if the repair budget is very small. The material has good thermal conductivity, but has a relatively short service life - no more than ten years.

Polyurethane foam - do I need a device to work with it?

This building material is a foam of two types - light and hard. To work with the floor, the second option is used, because. it does not require special vapor barrier from the basement side and has the best thermal insulation characteristics. The first type is very similar to mineral wool - in the same way, when working with it, you will have to leave gaps for ventilation and waterproof the lower surface. PPU consists of two components:

1. 1. polyol or hydroacid with emulsifiers, polyesters and foaming agents;
2. 2. isocyanate or polyisocyanate and diphenylmethane diisocyanate mixed with each other, which are strong reagents in the complex.

Building material advantages:

• fills all cracks and corner spaces thanks to spraying technology;
• suitable for bottom mounting;
• does not shrink, fireproof;
• does not require vapor protection;
• durable - lasts up to 50 years;
• high level of adhesion to all materials;
• high installation speed;
• complete environmental friendliness;
• has no seams, because is a single sheet after drying.

Among the shortcomings, one can single out the high cost, the need for skill in applying and the use of special equipment - a high-pressure apparatus that can be rented.

Installation technology - how to keep warm quickly and efficiently?

Mineral wool and foam plastic, having the form of plates, are mounted on the "wrong side" of the floor from the basement side using the same technology. Attach bars with a cross section of 50 to 100 millimeters to the beams from below. Lay a layer of material for thermal insulation on top, like on shelves. The beams should be placed under the "top" floor at such a distance that a few centimeters remain between it and the top surface for ventilation. Hem the heat-insulating "pie" from below with boards, apply waterproofing to prevent vapors from penetrating into the material from the basement side.

The waterproofing function can be performed by ordinary polyethylene film - this is the cheapest and most convenient option. A moisture-proof membrane will cost more - it is stronger and does not prevent air movement, unlike cellophane. In order for the materials to last longer, the film will need to cover the upper surface of the main thermal insulation. The order of all layers from top to bottom will be as follows:

1. 1. flooring;
2. 2. concrete screed or expanded clay;
3. 3. overlap;
4. 4. vapor barrier from the side of the room;
5. 5. a layer of mineral wool or polystyrene;
6. 6. waterproofing from the basement;
7. 7. holding boards.

Application of PPU is carried out on a specially prepared floor surface, it is necessary to remove dust, debris from it and make sure that it is completely dry and free of grease. The foam does not adhere to polyethylene and greasy compounds. The procedure can be carried out at temperatures above 10 degrees, otherwise the material will not stick to the ceiling as it should.

For work, you will need a high-pressure apparatus - it is very expensive to buy it, you can rent it in specialized companies. It is connected to two containers with the first and second components. When the start button is pressed, the compositions are combined in a vortex chamber, then they are sprayed in the form of a fine and light mass. The pressure in the machine must be at least 140 atmospheres. When choosing a technique, pay attention to the current source - the required one must match your home network.

Apply PPU evenly, after putting on protective equipment - goggles, a respirator, gloves. The procedure for a professional is about an hour, if you are confident in your abilities, you can try it yourself, but it will take more time due to insufficient experience. Apply polyurethane foam not only to the space between the lags, but also to the lags themselves - this will protect them from rising steam from the ground.

After applying a layer of about 10 centimeters, turn off the machine and leave the room to dry. Complete hardening of the material and its perfect adhesion is achieved in two days. There is no need to specially process the bottom layer, because. it is not exposed to moisture and holds well to the top of the floor.

It would seem, what kind of unseen - do-it-yourself floor insulation? He poured expanded clay or put foam plastic in a lath crate - that's all.

But it happens, and often, that winter comes, and something is not felt warming in the room. And then - spring, and mold or midges crawl from the floor along the walls. And then the floor starts to play, and then - to fail.

All this means that the floor was hastily insulated, thoughtlessly and without taking into account all the circumstances. The technology of floor insulation is based on the knowledge of floor thermodynamics, which is by no means simple. Let's try to understand it and we.

Heat transfer mechanisms and their importance for floors

As you know, there are three mechanisms of heat transfer: direct heat transfer, infrared radiation and convection. For the outflow of heat through the floor, the first two are of primary importance. Convection either does not take place at all, or is very weak. But if it has already appeared, then its smallness is more than “compensated” by its harmfulness: convective flows will find a way out somewhere, even a microscopic crack, and it will become a hotbed of rot and mold. In such cases, the floor is said to "whistle".

Heat transfer is reduced by using materials that conduct heat poorly, but it is more difficult to cut off thermal radiation: materials that are completely opaque to it most often either conduct heat well on their own (polished metals), or are not strong and short-lived (foamed materials and plastics). Meanwhile, the heat transfer through the floor by means of infrared radiation can exceed the direct heat transfer.

The most effective way to deal with infrared radiation is multilayer shielding. The principle is simple: the screen absorbs infrared radiation from one side, from the side of its falling stream, and re-radiates it in both directions. Even if the screen is an absolutely black body (reflection coefficient = 0), then it will pass through itself only half of the thermal radiation flux, and reflect half back.

Let's say the screen is plastic-coated aluminum foil; reflection coefficient is approximately 70%. Such a screen will keep these 70% in the room immediately, and of the remaining 30%, half, 15%, will be returned back. Only 15% will go outside, i.e. the screen will weaken the outflow of heat by 6.67 times. The second layer - another 6.67 times, total - 44.4 (6.67x6.67). If the initial heat flux was 1 kW/sq.m, which is more than from the Sun on a clear summer day in mid-latitudes, then only 22.5 W/sq.m will go outside, and the shielding efficiency will be 97.75%.

The matter is facilitated by the fact that many materials and substances reflect infrared radiation quite well. For example, soot photographed through an infrared filter looks light gray, and the almost black foliage of tropical trees looks silvery. But any granular and fibrous materials, on the contrary, absorb thermal radiation well: being repeatedly reflected in the cavities between the granules and fibers, the rays give off their energy to the material, heating it. At least half of the heat will still return back, but a lot of layers will be required for good screening of the layers.

Findings:

1. Any materials that are suitable in terms of strength and poorly conduct heat are suitable for thermal insulation of the floor.
2. Floor insulation should be layered.
3. Loose, porous and fibrous materials in the heat-insulating floor structure should be placed on the cold side so that the previous layers have time to return as much heat radiation back into the room.

Dew point

Recall that the percentage of humidity that the hygrometer shows is relative humidity. It shows how saturated the air is with moisture before it condenses and forms fog (100% relative humidity). Absolute humidity is the percentage of water vapor in the air by volume. For example, 1% absolute humidity means that in 1 cu. m of air contains 10 liters of water vapor.

The “moisture capacity” of air increases with increasing temperature, i.e. if relatively dry warm air is cooled, it can be saturated with moisture to the point that it condenses and falls out. That is why the hot, drying air of the desert, blown into the surrounding mountains by the wind, nourishes the local glaciers with moisture, and those, in turn, give rivers that moisten the desert oases.

The temperature at which, at a given absolute humidity, its condensation begins, is called the dew point. For thermotechnical calculations, it is convenient, on the contrary, to link absolute humidity to temperature. In this case, we talk about the dew point temperature.

The dependence of the dew point temperature on absolute humidity is described as a whole by a logarithmic function, but for the “conditional-room” temperature range it can be approximated by three straight line segments at four points:

• 0 degrees Celsius - 0.7% absolute humidity;
• +20 degrees - 1.8% absolute humidity;
• +32 degrees - 3% absolute humidity;
• +38 degrees - 4% absolute humidity.

Dew point and floor

If the dew point gets inside the insulated floor, even with microscopic voids, then condensation will fall into them. Due to the “empty bottle effect” (this is an interesting thing, but it would not be very appropriate to describe it in this article), condensate will accumulate in the floor, it will no longer insulate and become a source of dampness in the room. That is why it is strongly recommended to insulate the premises first of all from the outside, but there are no external floors.

Dew point and health

The dew point temperature is important not only and not so much for the floor. The comfort of the room and the health of its inhabitants depend very much on it:

• The dew point temperature of +26 degrees Celsius is deadly for asthmatics.
• At a dew point temperature of +24 degrees, physically strong healthy people breathe heavily and lose their ability to work.
• At a dew point temperature of +21 degrees, bed linen and clothes become damp, all objects seem sticky. For no apparent reason, colds begin.
• At a dew point temperature of +18 degrees, it is stuffy in the room, you want to open the window even in frost, which is fraught with the same colds.
• The dew point temperature of +12 - +16 degrees is a comfortable humidity range.

Findings:

1. When calculating floor insulation, first of all, you need to make sure that the dew point does not get inside the room.
2. Floor insulation should be made as thick as possible. Then the temperature gradient (temperature difference per unit thickness of the floor) will become smaller, "stretch", and the absolute humidity of the air in the microvoids of the floor will level out to insufficient for condensation due to the diffusion of moisture vapor.
3. Look again at conclusion 3 from the previous section.

Now, having familiarized ourselves in principle with the physical processes in an insulated floor, let's move on to materials and methods that can ensure proper floor insulation in an apartment.

materials

Vermiculite

Vermiculite is an environmentally friendly and absolutely harmless product of the processing of mineral raw materials: burnt secondary minerals formed during the weathering of dark mica - biotite and phlogopite - pressed in a mixture with silicates (liquid glass) and carbonate (limestone, dolomite or marble flour) filler.

Vermiculite is produced in plates with a thickness of 20-60 mm, in the form of powder and paste for coating. Vermiculite boards can be cut with a hacksaw or a sharp mounting knife. Vermiculite is not very heavy: one person can do the work of laying the slabs. In terms of strength, it approaches foam concrete, and the drawing gives an idea of ​​​​its heat-insulating properties. The structure is dense, the microcavities are closed, convection and condensate accumulation are excluded. Durability - geological.

Unfortunately, this wonderful material, which literally does not have a single drawback as a heater, is quite expensive. And yet, for floor insulation in a private house of a fairly wealthy owner, it can be unequivocally recommended, and in other cases, the possibility of vermiculite insulation should be thoroughly considered, especially since granulated vermiculite is cheaper and quite suitable for making granulated concrete (see below).

Note: expanded vermiculite is also produced - loose slab material. It is excellent for expensive but highly effective wall insulation and finds use in pot gardening as an absorbent and irrigation moisture dispenser.

Mineral wool

Aluminized mineral wool

There are no conditions for the occurrence of convection in mineral wool: although the microcavities are open, they are too small, and air gets stuck in them due to its own viscosity, so direct heat transfer through mineral wool is negligible, but its cost is low. However, the health hazards of exposed mineral wool are well known. In addition, from a constant vertical load, even if insignificant, the mineral wool falls off and loses its heat-insulating properties, and it draws moisture into itself quite intensively and at the same time also falls off.

Nevertheless, mineral wool, due to its low cost, resistance to external influences and durability, is often used for thermal insulation of residential premises. There are cases (like the insulation of a wooden floor in a prefabricated panel house described below) when an alternative to mineral wool is only expensive vermiculite.

Floor insulation in residential premises with mineral wool is carried out with special mats, sheet or rolled, or slabs, closed on one or both sides with aluminum foil or metallized film (see fig.). Warming with open arrays of mineral wool is permissible only in non-residential premises or from the side of the basement. But still, aluminized mineral wool, with a slight increase in the price of it, has important advantages:

• Each layer of metal is a highly effective heat shield. One layer of mineral wool aluminized on both sides virtually eliminates heat transfer by radiation.
• Re-reflection of infrared radiation from the screens in combination with absorption in the mineral wool array equalizes the temperature gradient in the insulation. I put three layers - the dew point can be thrown out of my head.
• Aluminized mineral wool, subject to the technology of its laying (see below), does not require a separate vapor barrier.

Mats made of aluminized mineral wool are thinner than open ones - from 6 mm, therefore, in some cases they can be used without crates.

The laying of mineral wool should be carried out without fail in a petal respirator and protective gloves. Mineral wool is laid under a marmoleum or a floating cork floor in a continuous layer; between the lags - it is highly desirable with plates in the size of the crate cell. In any case, the joints and edges of the plates are carefully glued with special adhesive tape to prevent microneedles that are detrimental to the respiratory system from entering the air of the room. Over time, the adhesive tape will weaken, but the mineral wool will also stop peeling.

Styrofoam

When laying a finishing floor along the logs (you can talk about the device of such a floor) One of the best materials for insulation is foam. Its advantages in this case are as follows:

1. Convection is excluded - the material is dense.
2. Reflectivity in the infrared region is the same as in the visible - up to 90% and higher, so that shielding is not required.
3. Condensation does not form: the material is solid.
4. Styrofoam is cheap, environmentally friendly, harmless.

However, the foam is fragile and not resistant to external influences. And in every barrel of honey there is a fly in the ointment: just the “too good” insulating properties of the foam plastic do not guarantee that the dew point will not move inside the room in buildings built from aerated concrete, shell rock, cinder blocks, etc. Therefore, floor insulation with foam plastic can only be recommended as an additional measure in rooms that are sufficiently dry, and always with plywood for finishing decorative flooring.

Expanded clay

Expanded clay - pellets of aluminosilicate composition; simply - rounded pieces of baked clay. Environmentally friendly, harmless, cheap, conducts heat very poorly, strong, durable. The most common insulation under the screed (on the formation of all types of floor screeds).

The main disadvantage is its high hygroscopicity: its own moisture absorption is from 8% to 20% by weight, therefore expanded clay floor insulation requires a well-thought-out and carefully executed vapor barrier. It can be used both as a backfill and as a lightweight concrete filler instead of gravel.

The indisputable advantage of floor insulation with expanded clay is that in combination with a concrete screed, the dew point entering the room is excluded and, if the walls and ceiling are without gaps and not porous, you can safely use cheap and highly efficient foam plastic for final insulation.

Fibrous organic insulation

This kind of insulation is made from synthetic organic fibers, linen or jute fiber, often aluminized. Available in slabs or rolls, woven or loose. In terms of mechanical and thermal properties, they are identical to mineral wool and are completely harmless, but natural ones rot from moisture, and synthetic ones age and fall off over time (5-12 years).

Scope of application - additional insulation and damper cushion for laminate, floating cork flooring or marmoleum on plywood flooring without logs in rooms that meet sanitary standards. Advantages - ease of work: a room can be insulated in just an hour, using only a mounting knife and adhesive tape.

gypsum fiber

Gypsum fiber () is designed specifically for bedding under a warm floor. In itself, it is not applicable for insulation: after a year or two, it gains moisture and loses its qualities.

polyurethane foam

– a natural variation on the “theme” of polyurethane foam

Insulation with polyurethane foam is carried out by spraying. A good way for everyone, but it requires professional equipment with skills and expensive finishing.

Bulk insulation

An extremely simple way, and you can immediately lay a decorative coating without a lag. But the ThermoPlast mixture used for this is very expensive. Insulated in this way, mainly floors in private housing of the elite class.

Foam concrete and aerated concrete

Foam concrete is, in essence, “boiled” and immediately frozen soda in a suddenly opened warm bottle. This is achieved either by preparing a cement-sand mortar in gas-saturated water and heating at the beginning of setting, or by setting the mortar under reduced pressure in a vacuum chamber. Aerated concrete is prepared not in air, but on nitrogen, which gives it additional durability and strength. Blocks and slabs of aerated concrete can be used in the load-bearing structures of low-rise buildings.

As a heat insulator, foam and aerated concrete is somewhat inferior to vermiculite, but stronger than it. For the price - it's cheaper, but for a heater it's still expensive and quite hygroscopic, just like expanded clay. For floor insulation, it can be used in the presence of residues from construction and battle as a substitute for expanded clay when filling under a screed.

granular concrete

Foam plastic concrete

Granular concrete is in some way a terminological contradiction, since any concrete is granules with a binder. Granular concrete is usually called a cement-sand mortar with "unusual" granules: foam, vermiculite, expanded clay, marble chips, etc. Granuloconcrete with light crushed stone substitutes is called lightweight concrete.

For thermal insulation, granular concrete with foam or vermiculite granules is most often used. You can cook it yourself, with a concrete mixer in a bucket or trough. The heat-insulating properties are high, convection and moisture condensation are excluded. Strength - slightly higher than that of foam concrete. Foam concrete is also inexpensive.

The preparation and use of granular concrete requires a full cycle of concrete work, so it is advisable to use it for thermal insulation in difficult cases, such as floor insulation on the first floor in a house with a wet basement, etc. as the top layer of a two-layer screed.

About vapor barrier

Vapor barrier of the floor should be carried out together with thermal insulation, since comfortable temperature and humidity in the room are inextricably linked. The vapor barrier film is laid either under the bottom of the insulation, or on top of it, or between its layers. Its exact location requires a heat engineering calculation according to the parameters of a particular room, we will give further only general instructions. In any case, the vapor barrier must be laid in a single layer, carefully gluing the joints of the pieces of the film with building (not household!) Scotch tape, and wrapped on the walls 10-15 cm above the level of the base floor.

About the insulation thickness

The best way to maintain a safe temperature gradient in the floor is to stretch it in height. Therefore, floor insulation should be made as thick as possible. If the height of the room and thresholds, taking into account the finishing flooring, allow you to lay insulation of 12 cm or more - excellent, there will be no problems. To increase the thickness of the insulation, it is better to increase the thickness of the bedding, and make the thickness of the concrete layer normal. Otherwise, under the finishing floor, a pad of fibrous aluminized insulation should be provided; in extreme cases - from cheaper mineral wool with the most scrupulous observance of technology.

Floor insulation methods

First floor

Warming the floor of the first floor is the most difficult type of work of this kind: heat transfer is high, and the likelihood of dampness from the basement as well. If there is access to the ceiling from the basement, it’s very good: you must first of all insulate yourself with mineral wool from there. The basement is non-residential, so you can use the cheapest mineral wool. It is necessary to lay mineral wool mats in a crate of galvanized U- and C-profiles, arranged in the same way as the plasterboard ceiling frame (cm. ), with vapor barrier. A wooden frame in a damp basement will quickly rot and cost more.

You will have to work in two or three: when attaching profiles to the ceiling (which in this case is under your floor), you need to hold the film; profiles fall on it. The mats in the cells are held either by a galvanized metal mesh slipped under the frame shelves, or by a fishing line stretched in the form of a mesh - it does not rust or rot.

At the beginning and at the end of the heating season, it will be necessary to revise the insulation: correct sagging mats and replace unusable ones. With this method, further warming of the floor in the apartment is carried out by conventional methods.

Covering the ceiling with insulation in the basement - this is where it is worth starting work on warming the floor of the 1st floor (why - it was said at the beginning of the article)

If it is impossible to get to your floor from under the bottom, then it all depends on the condition of the base floor: if its screed is cracked and crumbles, it is necessary. If the base floor is in satisfactory condition, the recommended methods of insulation are as follows:

1. Remove the flooring and lay aluminized mineral wool (strictly according to technology!), Or vermiculite, into the cells of the crate and lay it again. If the base is dry, only cold, and there was no moisture condensation in the room, you can use organic insulation or foam.
2. Remove the flooring with the crate, lay additional vapor barrier directly on the base and pour the second layer of foam concrete screed 30-40 mm, then completely re-lay the floor; possible without lag, as described below. This will require more work, but will solve the problem once and for all.

upper floors

Insulation of the concrete floor in the apartments of the upper floors is easier – it is made according to item 1 of the list in the previous paragraph, or as follows:

• We remove the old flooring.
• We lay aluminized insulating mats in the crate.
• We lay plywood 12-16 mm on the logs; with a crate step of 600 mm or more - 18-20 mm.
• Restoring flooring.

Note: if the new flooring is self-adhering (cork, marmoleum), then the mats can be laid on plywood. This is convenient if the plywood pillow on the crate was made earlier.

Under floor heating

Under the warm floor on any floor, additional vapor barrier will be required, above it a layer of warm screed of 20-25 mm and insulation with aluminized mats in two layers. The reasons are more economic: not a radiator, why heat the neighbors for their money from above. Also, this method of preparing a room for installing a warm floor does not require expensive gypsum fiber and is available for self-fulfillment.

Wooden floor

The wooden floor should be insulated not only in a private house with a prefabricated panel structure, but also in the country: equalizing the temperature and humidity gradient along the thickness of the lower flooring will prevent fungi from roaming. In this case, the main condition: the vapor barrier is laid OVER the insulating material, freely and with sinuses - the tree must breathe (see fig.).

The only suitable material is aluminized mineral wool. Vermiculite, of course, is even better, but such a luxury for buildings with a service life of no more than 20 years is hardly justified. The floor of a country house can be insulated in the fall with ordinary mineral wool - it is cheaper. During the winter, the peeling of the material will stop, and the CNU (the number of solid particles per unit volume of air) will drop to a safe value for rooms of this class.

When choosing how to insulate a wooden floor in a private house, they proceed, first of all, from financial possibilities. So, expanded polystyrene is the most economical option, expanded clay is more expensive, but the most environmentally friendly, and mineral wool is easy to install and unattractive to rodents.

Warm basement - a guarantee of a warm floor

Before proceeding with floor insulation, you need to make sure that the basement is thermally and waterproofed. At the same time, one should not forget about ventilation, which will prevent the development of fungi and mold in the underground. After all, this destroys the wooden base and the floor will last very little.

Basement floor insulation

If the house has a basement or basement, you need to take care of their insulation and waterproofing. This will keep the basement from freezing in the winter and keep it cool in the summer. After all, the basement non-residential floor is often used specifically for storing food, and if it is above the freezing level of the soil, such measures are mandatory. But underground, an unheated basement does not need to be insulated.

The basement is insulated from the outside with extruded polystyrene foam, since it is not hygroscopic, unlike ordinary foam. Insulation must be laid on waterproofing, such as bitumen and roofing material. The base is dug out for a meter and EPPS is attached to a special glue.

After that, the soil is poured back in layers.

On the ground part of the basement floor, the insulation is laid on glue, and fixed on top with dowels and reinforcing mesh. The final stage is the lining of the basement. The material can be anything - from decorative stone to PVC panels. But it is better to choose a damage-resistant and water-repellent material.

If the base is low, about 50 cm, it is better to fill up the space under the subfloor. This option will turn out to be much warmer - there is no cold air under the floor of the house, there is no need to arrange ventilation that will have to be closed for the winter.

Backfilling is done with ordinary soil, and the last 10 cm to the floor are filled with sand. Both soil and sand must be rammed separately when wet.

It is economically unprofitable to fill up a higher base. In this case, it will have to be insulated according to the same principle as the basement, but to organize ventilation ducts that remain open in the summer and close in the winter. Special attention should be paid to the insulation of the basement for a house on a columnar or pile foundation.

Freely "walking" cold wind significantly increases the heat loss of the floor.

Common features of wooden floor insulation

When the base is in order, you can proceed directly to the floor. Regardless of the stage of work (during construction or in an already inhabited house), do-it-yourself insulation includes:

1. Laying or checking and replacing the lag.
2. Laying waterproofing on the logs (or under them if the logs lie on the sand).
3. Laying insulation between the lags.
4. Layer of vapor barrier on top of the insulation.
5. The device of a counter-lattice for the gap between the finishing floor and the vapor barrier.
6. Finished flooring.

For waterproofing, you can use any rolled material - from thick polyethylene to innovative, but expensive, materials.

For vapor barrier it is best to use polyethylene foam with aluminum coating on one side.

This will provide both additional floor insulation and prevent condensation from entering the insulation. If the winters are not very cold, sometimes only a layer of polyethylene foam is enough without additional insulation. But it is better to insulate the floor as well as possible, because then you will have to remove the coating again if the insulation is not enough.

The vapor barrier is laid with the “shiny” side to the finished floor. Both hydro and vapor barriers are overlapped with an allowance of at least 10 cm, and the joints are sealed with metallized adhesive tape.

Insulation with roll and tile materials

Even at the lag device stage, you need to decide what material will be used for insulation. Depending on its width and length, a lag step will be selected, between which a heater is laid very tightly and without gaps.

Ideally, the height of the log should correspond to the thickness of the mineral wool layer, but given the need for an air gap between the vapor barrier and the finished wooden floor, you can simply not make a counter-lattice. In this case, the vapor barrier is attached with a construction stapler to the sidewalls of the log so that it lies on the mineral wool without an air gap between them.

It is important to remember that the sides of the plates have different hardness. Such a heater is laid with the hard side up. For convenience, the right side is already marked with a blue stripe, so it's hard to make a mistake.

It is best to use plates with corrugated edges - this will provide the best grip. Lay the plates as tightly as possible, starting from the corner. The next row starts with an offset of half the plate. The last plates should enter with effort. Possible gaps are sealed with construction foam.

Thermal insulation with bulk and sprayed materials

There are more "exotic" ways to insulate the floors in the house. For example, sawdust is increasingly being used as a natural and environmentally friendly material.

The technology is not very different:

• on the plates fixed under the logs, a vapor-permeable material is laid, and not polyethylene;
• sawdust is poured out between the lags and poured from a watering can with a weak lime mortar;
• as soon as the material dries and sits down, a finishing floor is laid - vapor barrier is not needed.

But here you need to pay special attention to hydro and vapor barrier, as well as the dryness of the expanded clay itself. Because of the pores, it is very hygroscopic, but practically does not release moisture. Therefore, with improper installation, expanded clay accumulated moisture will only aggravate the situation.

Warming the floor of the house with sprayed materials - polyurethane foam, ecowool or penoizol, is practically inaccessible for self-implementation, and in some cases it is dangerous. This will require special equipment, and buying it to insulate a small house is extremely unprofitable.

The process of installing a wooden subfloor, its insulation, hydro and vapor barrier is detailed in the video: