Although there are no regulatory or regulatory documents, there are still certain rules associated with the work.

The installer must take into account the following:

1. The thickness of the screed under and above the heating cable.
2. Choosing a screed installation method.
3. Nuances associated with the preparation of the solution and the pouring process.

A properly made screed for a warm electric floor does not crack, ensures uniform heat distribution throughout the room, and maintains strength over a long service life.

What layer of screed for electric heated floors

A screed under a warm electric floor is not mandatory. It is often poured to level the surface before laying the cable. Manufacturers' recommendations should be taken into account.

According to the requirements of most manufacturers electric floors, a cement mortar screed cannot be thinner than 3 cm. When using special leveling mixtures, the thickness can be reduced to 2 cm.

The optimal thickness of the screed for electric heated floors is selected depending on the following factors:

• Base for pouring. The screed on the ground must be at least 10 cm. The thickness for the screed on the floor slabs depends on the unevenness of the surface. The resulting plane should be perfectly flat.
• Material. The cement-sand mixture is poured with a thickness of at least 3 cm, leveling solutions depending on the manufacturer’s instructions.

Laying the heated floor cable in the screed can be done strictly according to the ideal flat surface. Variations affect the uniformity of heating and often cause cable overheating.

What is the thickness of the screed above the electric floor?

Experts' opinions on this matter may vary. Therefore, it is best to refer to the recommendations of underfloor heating manufacturers. According to the instructions given in the operating instructions, minimum layer the screed should be 4-5 cm.

But the thickness may vary depending on several factors:

1. Cable thickness.
2. Type of floors.
3. Screed mortar used.

Thus, heating mats are laid out on the floor surface, after which they are immediately covered with floor covering. The cable in mats is attached to a reinforcing mesh. The design allows you to lay tiles using an adhesive composition without a screed.

The larger the volume of the cable, the greater the thickness of the concrete screed. To determine the minimum parameters, you should refer to the operating instructions. The minimum thickness of the screed over a warm electric floor cannot be less than 4 cm for cement mortar and 2 cm for special leveling mixtures.

The total height of the screed for an electric heated floor is from 5 to 8 cm. Provided that the installation is carried out on a flat base, the thickness of the cake can be reduced to 4 cm. Heating mats together with the floor covering reduce the height of the room by no more than 2 cm.

Which screed to choose for pouring

In addition to the traditional sand-cement composition, there are other types of screed recommended for pouring heated floors.

Each of existing options has its advantages:

• Wet screed. For preparation, take cement, sand and plasticizer. Be sure to add fiber fiber to avoid the appearance of cracks and deformation during the drying process and during operation. The advantage of the solution is that you can make it yourself. The components are inexpensive, which somewhat reduces the final cost of the work.
  The disadvantage of a wet screed is that the floor takes a long time to dry (28 days), there is a high probability of cracks, and the inability to make a perfectly level base.
• Semi-dry screed method. A small amount of water is used for production. Ready-made mixtures are popular. But if necessary, you can prepare the solution yourself, based on - river sand 120-140l/fiber fiber 130g/cement 1 m/water 14-17 l. /plasticizer 0.5 l.
  The advantage of the semi-dry composition is the complete absence of cracks in the screed after drying. There is no need for additional leveling of the floors after drying.
• Dry method. The composition of the screed mortar may vary depending on the manufacturer, but most often fine perlite or quartz sand, fine-grained slag, etc. are used. The advantages of the dry method include: quick installation and drying. Further work can begin after 12 hours.

The screed must be done carefully, preventing possible damage cable. The rupture of protective insulation or conductive conductor during floor pouring is the most common cause of floor failure.

How to reinforce the screed

In order for the installation of the heating cable into the screed to be successful, it is imperative to prevent deformation and cracking of the floor during the drying process. Cracks cause the appearance of cold zones and uneven distribution of heat over the entire surface of the slab.

What methods of screed reinforcement exist?

1. Additives. When preparing the solution, it is important to use fiberglass. This is a special additive based on polypropylene. After adding fiber fiber to the solution, the strength characteristics increase several times: resistance to mechanical damage, cracking, settling and spreading of the mixture. At the same time, frost resistance and fire resistance increases.
2. Reinforcing mesh. Recommendations for pouring screeds for heated floors indicate the need to use a plastic reinforcing layer. The manufacturer additionally provides special stands to raise the mesh above the floor.

In large rooms, cracking of the floor may occur due to the lack of compensation pockets. That's why mandatory measure is to install a compensating damper tape along the walls, as well as between sections of the slab.

How to pour screed correctly

The technology for pouring screeds for electric heated floors is practically no different from that used when installing a conventional cement base. After execution preparatory work and laying out the cable for further installation in the concrete screed, proceed to the following steps:

1. Display of beacons. The surface must be extremely flat. In this regard, the step between the beacons is no more than 0.8 m. Although you can find recommendations that the distance between the beacon level should depend on the length of the rule, practice shows that the longer the step, the more irregularities appear during the stretching of the solution.
   Initially, we place the beacons along the edges of the room, so that there is 10-15 cm left to the wall running parallel to the plank. The fishing line is stretched, the rest of the guides are positioned under it. If the recommendations are followed, the result is a perfectly flat surface, leveled along the beacons, even when using ordinary cement-sand mortar.
2. Filling the screed. After the solution used to attach the beacons has dried, you can begin pouring the screed. If the floor thickness exceeds 5 cm, the work is carried out in several stages. First, apply the first layer of 2-3 cm. A day later, the second, finishing layer is pulled along the beacons. It is important to ensure that the rule does not scrape excess solution from the surface and that pits do not form after drying.
3. Drying the solution. Care should be taken to ensure that the room is not exposed to direct sunlight. The screed is covered with film and watered at regular intervals during the first 5-7 days.

Warm floors built into the screed can be turned on no earlier than 28 days after pouring the solution. According to SNiP, installation can begin at this time flooring.

How to make an electric heated floor without screed

It is possible to lay the underfloor heating cable without a screed. The following two methods are popular:

1. Grooving screeds for underfloor heating cables. In the stove or concrete screed cut grooves about 2 cm deep. To avoid a lot of dust, use a special tool with dust collection bags. The cable is laid in grooves. The top is laid with a solution with the addition of fiberglass or adhesive composition for tiles.
2. Laying heating mats- this method is also popular due to the ease of installation work. The design of the mats is quite simple. To connect, you need to spread them over the surface and plug them into a power outlet.

Many nuances and features that must be taken into account when installing an electric heated floor in a screed lead to the fact that more and more buyers prefer heating mats.

To lay an electric heated floor, it is important to perform the screed correctly, since the uniformity of heat distribution in the room, structural strength and heating efficiency depend on it. Arrangement of the screed is the most labor-intensive stage of laying a heated floor.

Its functions are as follows:

• protection heating elements from mechanical influences and negative influence air;
• uniform heat distribution over the surface of the floor radiator to heat the entire space of the room;
• creating a level base for the finishing coat.

Please note the following during installation:

• the thickness of the entire screed, as well as the upper and lower layers around the heating element;
• what manufacturing method to choose;
• taking into account the specifics of solution preparation and cable casting technology.

Most common wet screed, although dry is beginning to be widely used, which eliminates the need to waste time drying the solution, during which time the heating cannot be turned on.

Despite the apparent simplicity of the composition, the screed is made in several versions:

• Sandy- cement mortar with a component ratio of 3:1 it is suitable for electric heated floors.
• Concrete based on fine-grained filler is used in water floor systems. The slab is durable and does not crack.
• The self-leveling mixture is well suited for pouring electric heated floors when it is necessary to obtain thin layer.
• Mixtures for heated floors, produced in a wide range.
• used as a thin screed for electric heated floors.

The strength of the screed increases significantly if you use reinforcement mesh or microfiber.

Compositions are obtained with high durability and plasticity if plasticizers are added to them.

Thermal insulation

To prevent heat loss through the ceilings, thermal insulation is used. When choosing it, take into account the heat-shielding properties, on which the overall thickness of the screed depends. On the ground floor, slabs 5 cm thick are used as thermal insulation; if there is an apartment below with heating, insulating layers no more than 2-3 cm can be used.

The heat insulator is taken with a metallized coating. Aluminum foil does not withstand prolonged contact with the screed and is destroyed. It is necessary to use metallized coatings in the form of spraying with lavsan, etc.

The slabs are laid without gaps. The resulting cracks are filled with polyurethane foam, all joints are sealed with adhesive tape.

Laying heated floors

The best way to install an electric heated floor depends on the type of heating elements. For any underfloor heating, it is important to ensure that the heating elements do not touch the insulation. To do this, they are separated from it by reinforcing mesh.

Cabling

The location of the thermostat is selected. It is mounted at a height of more than 30 cm from the floor. If the device is a hidden type, grooves are made in the wall for it, as well as for the power and temperature sensor wires. In places with high humidity Thermostats are not installed. They are taken to adjacent rooms.

Mounting tape is attached to the base at intervals of 50-100 cm and at a distance of 30 cm from the walls. Markings are made on the floor, taking into account the distances from the furniture. The distance from the walls is 10 cm, and from pipes and radiators - 15 cm. Then the heating cable is connected to the power cable using a coupling, and then attached to the mounting tape.

The power cable is routed through a groove prepared in the wall to the thermostat, and the heating cable is laid according to the diagram. In this case, the radius at the bends should not be less than 5 cm. The bends are made smooth, without unnecessary tension. Fixation is done with staples or mounting tape. Contacting or crossing of turns is not allowed. The convergence should not be less than 8 cm. All indents are strictly observed according to the scheme, which is developed in advance.

The temperature sensor fits freely inside the corrugated pipe along with the supply wires. The corrugation at one end is hermetically sealed with a plug to prevent cement mortar from getting inside. The pipe with the temperature sensor is located between the turns of the cable at a distance of at least 50 cm from the wall and is placed in the prepared groove, after which the wires are connected to the thermostat.

After installation and connections it is checked electrical resistance heating cable and sensor. The values ​​must differ from the passport values ​​by less than 10%.

The grooves are sealed with mortar or putty, and after hardening, the functionality of the heated floor system is checked.

Laying the heating mat

Heating mats are easier to install because the cable is already attached to a mesh base, which only needs to be spread on the base. At turning points, the mesh is carefully cut without compromising the integrity of the cable. Where obstacles are located, the mesh is removed and the cable is laid maintaining a distance of 6-8 cm from adjacent turns.

An important advantage of the heating mat is its small thickness, which makes it possible to pour a thin screed or lay heating elements in a layer of tile adhesive. Then the thickness of the fill will be only 8-10 cm, which will allow you not to take up excess space in the room.

Laying the core floor

Rod infrared heaters look like rope-ladder. They contain transverse heaters and 2 longitudinal connecting wires through which power is supplied.

The core roll rolls out across the floor, starting from the thermostat. At the turning points, the connecting wire is cut, after which it is necessary to reconnect the ends with a piece of wire. This reduces the reliability of the heated floor. It is advisable to select rolls of suitable length. Then you won't have to cut anything.

After laying the insulation, windows are cut out in a checkerboard pattern for better adhesion of the screed to the base. All connections must be carefully insulated.

Compositions and types of screed

A concrete screed for an electric heated floor will turn out to be of high quality if you select the correct proportions of materials and mix them thoroughly.

Cement and sand alone are not enough to prepare a screed. It requires plasticizers and additives that increase the plasticity and uniformity of the mass.

Dry screed

Advantages of dry screed over wet screed:

• no special equipment is required: mixers, containers for solution, etc.;
• less effort is spent on delivering the material;
• speed of work completion (in 1-2 days);
• there is no need to wait for the screed to mature;
• the possibility of stage-by-stage installation of heated floors divided into zones;
• absence of dirt and excess moisture;
• small specific gravity screeds;
• the floor acquires sound absorption and thermal insulation properties without using special materials, the price of which is sometimes high;
• the possibility of laying communications in the thickness of the material;
• the surface is smooth and ready for finishing floor coverings.

With all the advantages, the coating is quite light and durable. It will not withstand the load from interior partition from gypsum boards or brick, but frame structures plasterboard can be installed on it.

Dry screed is not used in the following cases:

• if there is a slope in the room;
• if there are large dynamic loads(vibration effects or high intensity of human flow);
• in rooms with high humidity or the possibility of water spills on the floor;
• in cramped spaces where it is not possible to compact and level the composition efficiently.

When preparing dry screed, the following materials are used:

• Waterproofing film.
• Damper tape around the perimeter to compensate for temperature deformation.
• Dry backfill made of fine gravel, expanded clay, slag pumice, perlite. Instead, insulation boards with high density, for example, etc.
• The top layer is sheets of moisture-resistant plywood, asbestos cement, chipboard, OSB. They are also used for large thicknesses. The best option is the use of waterproof gypsum fiber sheets suitable for any floor finish.

Manufacturers building materials They produce special complete and balanced dry floor systems. For indoors different types a whole line of dry screeds “Knayf” is produced. Among them, two-layer gypsum fiber boards with the possibility of assembly with locks are popular. For housing, “Vega” compositions are produced based on small expanded clay screenings in bags and other components.

When using industrial waste, for example, solid expanded clay or slag, for dry screed, the fraction size should not exceed 5 mm. Otherwise, the floor will begin to sag and creak.

The backfill thickness must be more than 30 mm, otherwise required quality can't achieve it. If the upper limit is higher than 60 mm, intermediate spacer sheets will be required. The top of the screed is additionally covered with a sheet covering, the thickness of which is about 20 mm.

The base for backfilling must be level.

Semi-dry screed

The screed is a cement-sand mixture with the addition of fiber fiber and plasticizers, but with a low water content. A distinctive feature is the large layer thickness of 70-100 mm. If the thickness is less, the layer may crack.

The advantages of semi-dry screed are its warmth, - and soundproofing properties, thanks to the porous structure.

The disadvantage is the need to use construction equipment, but in small rooms The screed can be laid manually.

The ratio of components, which include cement, sand and water, is 1:3:0.4, respectively. Fiber fiber is added to them in an amount of 600-800 g/m 3.

The screed is laid using beacons, similar to the wet method. A special machine is used for grouting, which can be rented. It is difficult to compact the screed manually.

Wet screed

A screed is a layer of mortar or concrete applied to the surface of the base.

It is laid in several layers, the functions of which differ:

• Leveling the base. The first layer is always used for uneven surfaces. It is necessary even when a dry screed is placed on top.
• A layer on top of thermal insulation for laying heating elements. If the cable touches the insulation, it may overheat at this point.
• The third layer covers the heated floor, evens out the temperature field and holds the floor covering in place. It is often combined with a second layer, if the thermal insulation is covered with a waterproofing film on top.

In all cases, it is advisable to reinforce the layers to prevent them from cracking and maintain the integrity of the heated floor. At the same time, the thickness of the floor increases significantly, which leads to a decrease in the height of the premises. It can be reduced through the use of leveling compounds.

The classic screed is cement-sand. But the composition is not limited to only two components. Plasticizers are added to it, as well as crushed stone or expanded clay. A mixture of 3 parts sand, 1 part cement and PVA glue, added in an amount of 1 kg per bag of cement, works well.

Using ready-made mixtures achieved high quality screeds. Each composition has its own preparation instructions.

Any heated floor must be installed on a flat surface. To obtain a level base, use regular cement-sand mortar, and leveling compounds are most often placed under the finishing coat. Their cost is high, but the filling is perfect.

The thickness of the tie depends on the diameter of the cable and is 3-5 cm. If it is made smaller, the required strength of the slab and uniform heating will not be ensured.

When cracks appear in the screed, the reliability of the heated floor decreases sharply. Due to the violation of the integrity of the layer, the heating of the floor becomes uneven. Areas with high temperatures appear, as a result of which the cable overheats and its service life is reduced.

The technology for laying the screed must be performed correctly. The strength of the cement takes 4 weeks; no work can be carried out during this period. It is important to ensure uniform fixation of the layer. To do this, cover it with film and keep the surface damp.

The main screed is installed after leveling the base and laying the cable. First, a damper tape 10 cm wide is rolled out along the perimeter of the walls from below and secured with tape in places adjacent to subfloor. It is also placed in places of transition to other rooms.

Cracks will not form in rooms larger than 40 m2 if they are divided into rectangular zones and T-shaped strips of porous material are laid between them. Damper tape is not suitable here because it is flexible. Thin foam sheets are usually used. Where the cable passes through expansion joints A short corrugated hose is put on the cable so that it does not break due to temperature deformations.

A reinforcing polymer mesh is placed under the cable. It should be rigid and located at a distance from the insulation.

The laid heated floor must be tested - apply voltage and check the uniformity of heating.

In order for the screed to be exactly horizontal, beacons should be installed at a given height. For this purpose it is used laser level. If it is not there, the usual one is used, but then the upper boundary of the fill should be drawn on the walls.

The first beacons are installed at a distance from the wall, and next rows are made at a distance slightly shorter than the rule. Beacons are made using a solution, after which you need to wait for it to set.

The heated floor is poured with careful leveling and filling of all voids manually. The solution is poured 1 cm above the level of the beacons and compacted with a hand tamper. Then another layer of screed is applied on top and pulled out using the rule. After this, you should immediately rub the surface with a trowel, making circular movements. At the same time, it is regularly checked horizontal level with adding solution to the holes and removing excess.

The work of pouring the screed is done within one day with minimal interruptions during manual mixing.

The drying surface is covered with a film and moistened for a month until the concrete matures. If you hurry and turn on the heated floor earlier, it will will crack and all previous work will be done in vain. In addition, removing a frozen screed will not be easy.

Video: installation of heating cable

The screed is important element warm floor, on which its quality depends. At correct installation she will provide comfortable conditions and durability of the heating system. Great importance has the thickness of the screed. If the surface is uneven, it can be improved with a leveling layer. The base must be strong and durable, since it is subject to constant alternating temperature influences. It should be erected according to certain rules, maintaining the thickness, ratio of screed components and the time of its maturation.

Warm floors are a popular system for primary and alternative heating of rooms. The design promotes uniform heat distribution and preserves natural humidity air and does not clutter up the space.

Features and device

The screed is a layer of special mortar or concrete. It serves as a base for decorative coating and is the place where the heating elements of the heated floor structure are located. The screed also performs leveling and stabilizing functions, on which the service life and presentable appearance of the appearance floor covering.

The advantages of this installation system for heating devices include the absolute fire and environmental safety of the structure, complete autonomy and the ability self-regulation temperature regime, long term service and efficiency.

The downside is the reduction in the height of the room due to raising the floor level.

The “warm floor” design can have different designs:

• cable;
• water;
• thermomat;
• infrared.

The water system is a network of tubes connected by a manifold responsible for movement hot water through a pipeline, equipped with temperature sensors and relays.

Cable heating is presented in the form of electric wire laid in rows, working on the principle of converting electrical energy into heat.

The thermomat system is a thin film with heating elements laid and fixed inside, and has a roll design. The infrared heater is also made in the form of a thin sheet, being the most effective and durable heating system.

However, it is not poured into the screed, but is placed on top of it, immediately under the decorative coating.

The heated floor in the screed is a layer cake, where the two lower layers are hydro- and thermal insulation. Next is a reinforcing mesh and a thermal element, and the structure is completed with a solution of concrete or a special leveling mixture. Layers may vary depending on the condition of the subfloor and the need for waterproofing. So, for the system electric heating there is no need for it, and if there are a large number of defects in the lower floor, an additional leveling layer is poured under the thermal insulation.

Special attention should be given to the thickness of the applied solution. It should be the same throughout the entire area of ​​the room. This will ensure uniform heat distribution and high-quality heat transfer. A layer that is too thin will lead to poor heating of the screed, faster heat transfer and cracking of the surface. A thick layer is also unacceptable. It will retain heat and not let it out.

For heated floors of water construction optimal thickness the screed is 6-7 cm, and 3-5 cm of them should be above the pipeline.

When laying a thermal cable, the thickness should be three centimeters, and for a thermomat system, one and a half centimeters will be enough.

Types and composition

Screeds can be dry, semi-dry and wet. Dry screed consists of plywood, plasterboard sheets and particle boards. To place the heated floor system, wet and semi-dry types are used.

Wet screed is made from a mixture of cement with sand and crushed stone, diluted with water to the desired consistency. Sometimes a little expanded clay and gravel are added to the solution. The brand of cement for preparing the mortar must have a quotation of at least M300. Instead of sand, it is better to use screenings: it will provide higher adhesion and prevent peeling and cracking. When preparing the composition, it is necessary to use a plasticizer at the rate of one liter per square meter area to be poured, which will reduce the final thickness of the screed to three centimeters. Cement screed is suitable for all types of heated floors.

Semi-dry screed is performed using dry mixtures and does not require prior leveling of the subfloor. When drying, there are no cracks and no shrinkage or deformation occurs. This composition hardens much faster than concrete, and a short setting period and a small amount of the required liquid will prevent the solution from leaking to the lower floor.

Semi-dry and wet screeds are floating and stationary. The first type is used when it is necessary to install heat and waterproofing. As a result, the layer has no direct adhesion to either the floor or the wall. The thickness of such a floor must be at least 3.5 centimeters and have a multi-layer structure. Floating screed is also used for pouring over soundproofing material, which consists of mineral wool and covered with a waterproofing film on top.

Stationary screeds are formed without the use of insulation.

Tile adhesive is used as a screed when installing an electric floor under the tiles. It levels the surface well and dries quickly. If repairs are necessary, opening such a screed is much simpler than a concrete one.

Which is better?

When choosing the type of screed, you need to be guided by the type of subfloor, the purpose of the room and the type heating system. Concrete screed is suitable for all heated floor designs. The advantage of such a screed is moisture resistance, durability and the ability to be used in any type of premises. The concrete composition can be applied either to an existing subfloor or to the ground. The disadvantages include the risk of cracking, delamination and separation of the concrete floor from the base, as well as the need for regular wetting with water for 3 weeks until it dries completely. Finish coating can only be laid after the screed has completely cured.

Plaster screed It belongs to the semi-dry type due to the small amount of liquid required to prepare the solution. It is a self-leveling mixture that dries and hardens very quickly. The advantages of such a screed are that there is no need to lay reinforced mesh or pre-prime the surface. The coating layer can be less than three centimeters. Thanks to its porous structure, semi-dry screed provides high heat and sound insulation of the room.

Self-leveling mixtures are easy to prepare, are environmentally friendly and have a smooth and glossy surface after completely dry. Suitable for all types of heated floors. To improve ductility and prevent cracking, dry mixtures contain additives in the form of fiber fiber and modifiers. The disadvantages include the solution setting too quickly.

As a result, the composition should be prepared in small portions that can be used within an hour.

Laying technology

The first stage of floor installation work should be preparation work surface. To do this you need to seal it with a solution large gaps and chips, and clean the subfloor of debris and dirt. Next, it is advisable to cover the surface with a layer of primer. This must be done when pouring a concrete floor. If heavy furniture is to be installed in the room, then it will be necessary to use reinforcing mesh and additives from large fractions. This must be done to prevent the surface of the self-leveling floor from sagging or cracking in the future.

If a floor with a water heating system is being poured, then it is necessary to form expansion joints. If the area of ​​the room exceeds 10 sq. m, then the seams are made according to the fencing structures. The perimeter of the room should be laid with a damper tape, which is designed to absorb the expansion of the drying layer. Then you need to conduct a test run of the “warm floor” system and check the tightness of the pipeline. Next, a reflective layer is installed to prevent heat loss.

Reinforced mesh can be laid either on top of a reflective screen under pipes or mounted in top layer screeds in case large thickness concrete. Next, you should begin preparing the solution. For work in residential premises, you need to use grade 150, and for industrial buildings, 300 is suitable. The composition for a water floor should be made on the basis of screenings and contain a mixture of fine-grained crushed stone with sand.

This composition has best performance strength and heat transfer compared to cement-sand mixture.

When preparing the solution It is necessary to strictly observe the proportions of the components. This will prevent the dry floor from cracking, peeling or staining. The optimal ratio is 1 part cement and 6 parts screenings. When using sand and crushed stone, take 4 parts crushed stone and 3.5 parts sand for 1 part cement. It should be noted that if there is an excess of crushed stone, the surface of the dried floor will not be smooth enough.

To improve the plasticity of the composition, a plasticizer is added to the solution during mixing, which can be liquid soap. The finished solution has a consistency similar to sour cream. Fiberglass or reinforced wool is often used. They are added to the solution and make it possible to avoid the use of reinforcing mesh.

Filling should be done from the far corner of the room. The solution must be leveled in a timely manner using a shovel, and excess must be removed as necessary. Before leveling the screed, you need to tug the reinforcing mesh. This will remove any air pockets.

The maximum thickness of the screed for a warm water floor should not exceed 11.5 cm, of which 5 cm is for the heat insulator, 1 cm of the solution is under the pipes and 3 cm is above them. When pouring, concrete must be compacted using a rake or a special vibrator. This will help release air bubbles, which will further prevent voids from forming. The thickness of the pipe itself is 2 cm. After complete drying, which occurs in at least 30 days, you can turn on the heating.

The filling of the floor with cable and thermomat heating is carried out using a reinforced mesh, which is laid down and is needed to secure the cable to it. Otherwise, there is a risk of the wires floating up. The cable layout should be done evenly, avoiding sharp bends and creases in the wires. The cable and thermomat should not come into contact with the thermal insulator. The thickness of the screed is less than that of a water floor, which is explained by the small thickness of the cable or thermomat, it ranges from 5 to 10 cm.

The optimal thickness is considered to be 7 cm. This is explained by the fact that a layer that is too thin retains less accumulated heat, which is why the heater will need to be turned on more often. The thermomat can be laid either on top of the screed or in it, but the thickness of the layer above the heating element cannot exceed 2 cm.

The floor should be poured using beacons. They are necessary to guide the height of the pour and can be either alabaster columns or factory products. After the initial setting, the beacons are carefully removed from the concrete using a spatula, the holes from them are wetted and filled with solution. As the concrete floor dries, it undergoes regular wetting and leveling, which is carried out using a scraper. After removing all excess and uneven terrain, the surface is leveled with a special trowel. The damper tape is removed using a knife.

The rules for pouring self-leveling gypsum mixtures are the same as when applying concrete mortar, but the alignment technology is somewhat different. Immediately after pouring, the entire surface must be treated with a needle roller. This will release air bubbles and prevent voids from appearing. Beacons should be removed quickly, before the solution sets. To do this, use a special attachment on shoes in the form of long spikes. After drying, the gypsum surface does not require moistening or sanding. Gypsum mixtures have a very short drying time, so the decorative coating can be laid within two days after completion of the work.

Laying a heated floor in a screed is a responsible process that requires a high-quality approach. It is on the correct execution of all actions that the final result depends, expressed in the uniformity of heat distribution, reliability and safety of the structure, as well as in saving consumed resources. Despite the difficulties, all the work can be done with your own hands, without the involvement of specialists.

The screed for heated floors has numerous functions, among which the following stand out:

1. Complete protection of the heating system from various types of influences that can lead to damage to the structure.
2. Proper distribution of the generated heat over the surface, as well as increasing the efficiency of heating the entire room.
3. Obtaining the required level of base for laying decorative facing materials.
4. There is no need to use bulky heating elements, which significantly reduce the area of ​​the object or spoil the appearance.

The efficiency of underfloor heating compared to a traditional radiator system is an order of magnitude higher

Thus, a warm floor located in a screed is rational decision, helping to create comfortable living conditions. But a number of conditions should be taken into account:

• Thickness of the poured layer. Placing the heating system at the wrong depth will negate the desired effect and create numerous problems. That is why all work is divided into two successive stages: the formation of a rough and finishing surface, between which the electrical element will be located. But when minimal deviations Only one layer of base is poured.
• Type and type of screed used. The technology used depends on this.
• Accurate adherence to all nuances when preparing the mixture and the stages of pouring it. The created structure can have several different layers: insulation, waterproofing, reinforcement.
• Safety. Electric floors and water systems require great care and attention. Important has the correct installation of elements.

The combination of all conditions is the key to a high-quality, reliable and durable result.

Having basic knowledge of electrical safety at the level high school, any House master will be able to install a modern electrical underfloor heating system

Varieties of compositions for laying the system

To install heated floors in screeds, they are used different kinds compositions that are used in different situations, based on their characteristics.

The most popular options:

• Concrete with the addition of fine filler. This solution is suitable for installing a subfloor or for pouring thermal systems using water heating.
• Cement-sand compositions. They allow you to install electric heated floors. To give the solution additional properties, special plasticizers are added.
• Mixtures with a self-leveling effect. They are used to obtain a thin coating, which is necessary for low room heights, as well as when installing a screed on a fairly level base.
• To simplify the process, special products for heated floors have been developed. Such mixtures have all the necessary characteristics and qualities.

Bulk special mixtures are considered to be of the highest quality, but for budget option Cement-sand mortar is quite suitable

Currently greatest distribution received a wet screed that allows you to achieve optimal results. But it has a number of significant disadvantages, in particular, the inability to quickly dismantle without damaging the structure. Also, if the technology is incorrect, there is a high probability of numerous cracks and deformations, which is why the dry version is gaining more and more popularity.

Features of installing an electric floor

Laying an electric heated floor directly depends on the characteristics of the selected elements.

Cable technology

This option is a system where a cable laid according to a certain pattern is used as a heating element.

Principle of work:

Installation of such a system requires strict adherence to the drawn up diagram and connection order.

The installation diagram of electric heated floors may change as the number of circuits increases, as well as depending on the type of connection (two and three phase)

Laying heating mats

The technology of laying heated floors on heating mats is a simpler procedure that does not require precise cable placement. This is due to the fact that they are already fixed into a single structure, which must be correctly spread on the surface.

Installation features: rolls of mesh are rolled out on a prepared base; to rotate the cells, they are carefully trimmed so as not to damage the cable. If it is necessary to bypass an obstacle, the mesh is cut off and the heating elements are placed at the required distance from each other. The thermostat is connected and the system is checked.

Mats, compared to other electrical systems, are considered one of the most convenient options arrangement

It is the mats that make it possible to fill the screed with a minimum thickness, which significantly reduces the height of the floor.

On a note! Currently, there are infrared electrical systems that are located not deep in the screed, but directly on its surface, under the decorative cladding.

Infrared heaters differ good quality and are quickly installed, but are not suitable for every room and floor covering

General procedure for installing heated floors

Exists traditional scheme laying electric heated floors and pouring screeds. When carrying out work on an unprepared base, the process is divided into three stages:

The middle layer is not always an appropriate solution, so sometimes it is skipped and the insulation is covered with waterproofing. But be sure to place the heating system at a distance, securing it to the fittings.

Thermal insulation is not a mandatory option in the insulation cake, but it significantly increases the efficiency of the system.

Pouring the screed and installing the system

The full range of installation work is a sequence of actions depending on the specific situation.

Technology for pouring screed and laying heated floors into it:

Tile adhesive can replace the screed, but this option is only suitable for tiling

Thus, general technology laying the structure is not very difficult if the stages are correctly developed.

A training video will help you understand the process of laying heated floors in a screed:

Some nuances

To obtain a high-quality result, it is advisable to adhere to some rules:

• reinforcement is a mandatory procedure to avoid subsequent cracking;
• heated floor needs careful preparation base, it is placed exclusively on a flat surface;
• The thickness of the tie is affected by the diameter of the cable that is used for electrical system, optimal parameter a layer of 30 to 50 mm is considered;
• large rooms are separated by special expansion joints;
• when pouring cement mixture you need to wait for it to dry completely, after which you can carry out other work and use a warm floor.

According to the screed technology under a heated floor, it is most often necessary to pour concrete mortar on top of the heating elements. This is necessary not only to create a level surface for the flooring, but also to protect all components. At the same time, the thickness of the fill layer will differ in different situations. Even the manufacturers themselves avoid this issue in their instructions for installing screeds under heated electric floors. It is the thickness that should be determined in the process of laying the components.

Purpose of the screed

Next, remove all unnecessary debris from the surface and, if possible, dust. This might help you get the job done construction vacuum cleaner. A layer of thermal insulation is laid on top of the rough screed and the subsequent distribution of the underfloor heating cable or heating mat. In some cases, a floor screed under a warm floor is installed with your own hands and on top. True, this slightly reduces its efficiency during operation.

Laying heated floor components

In order for the underfloor heating system to function fully, before pouring it is necessary to determine the mounting locations of the main sensors and components. The thermostat is installed on the wall surface and, if possible, close to an existing outlet. The distance from the floor should be at least 30 cm, since the temperature from the base will somewhat distort the transmitted information.

The temperature sensor is placed in the base of the floor, onto which the prepared solution will subsequently be poured. It is worth noting here that if the solution comes into direct contact, it may fail. To avoid this, the temperature sensor is placed in corrugated pipe, which leads from the thermostat on the wall. All open areas of the corrugation are sealed with sealant so that the solution does not get into them during installation. It would not be superfluous to additionally install a special plug at the end of the tube at the base.

The heating elements are laid based on the drawn diagram, where the step of their installation will also be displayed. You should not deviate from the drawing, since all the little things are pre-calculated on it. After completing work with the underfloor heating components, you need to check their functionality by connecting them to the electrical network. The resistance of the cable is measured, which must correspond to the data specified in the passport for it. At positive result You can proceed directly with the concrete solution.

Screed device

The best option for making screeds is to use special ready-made screeds for heated floors. They contain all the necessary components, including a plasticizer. This significantly increases the quality ready solution. It should be distributed carefully so as not to damage the heating cable. In addition, the mixture should be distributed evenly over the entire surface.

When pouring the solution, no matter how much screed there should be above the heated floor, air pockets must not be allowed to form. This will help reduce heat transfer from the heating elements to the base.

As mentioned earlier, the optimal thickness of the screed for heated floors should be from 30 to 50 mm. There may be cases when the minimum screed thickness for electric heated floors is reduced. But then you will have to add appropriate additives (plasticizer) to the solution.

Until it dries, you cannot start the heated floor. Otherwise, the solution will not be able to gain the necessary strength and set. After a period of 28 days, you can begin trimming the protruding elements of the damper tape and thermal insulation, as well as turn it on after the screed. The heated floor after screed is covered with the selected flooring option.

There may be cases when the area of ​​the room is more than 20 m2 or one of the walls in the room is more than 5 meters long. In this case, you should not only create different circuits from the heating elements, but also fill the screed in two stages. Temperature joints must be created between the contours of the heated floor so that the integrity of not only the heating system, but also the floor covering is maintained.

All these subtleties allow us to get an answer to the question of how to properly make a screed under