Responsible stage - laying the screed for the warm floor

Screed for underfloor heating is a very important step in its construction.

It is from the screed that the correct heat distribution depends.

Also, if the fill is incorrect, defects in the coating can form, which will negatively affect the whole system of the warm floor.

For laying works for a warm floor, you can contact a specialist or do all the work yourself.

When doing the work yourself you need to know everything about the correct device, the types of screeds, as well as the specific technologies for each type of warm floor.

Screed types

The screed for the warm floor can be of three types:

• cement-sand( wet);
• is dry;
• is a semi-dry one.

Dry

Dry is a layer of dry mixes and loose materials intended especially for warm floors.

The laying of the dry screed is carried out as follows:

1. , a waterproofing is laid on the cleaned concrete base, which can be made with a polyethylene film;
2. on it it is necessary to pour claydite;
3. lay heating pipes;
4. and from above put sheet material - plasterboard, plywood, etc.

Advantages of this type of coating are:

• Ease of implementation. All work can be done even by a novice builder;
• No time required for drying. All work can be continued immediately after installation;
• The claydite used has excellent heat and sound insulation;
• In the loose layer, you can put electrical wiring.

Despite the advantages of dry, the method has disadvantages:

• high probability of occurrence in the loose layer of rodents;
• used plasterboard does not withstand a partition of blocks or bricks, as a result of which the floor may be squeezed.

Semi-dry

The semi-dry screed differs from wet by a small amount of water. Due to this factor, the semi-dry screed quickly solidifies and is more durable.

Polymer modifiers and reinforcing layer are added to the composition.

Advantages of this type of coating include: a small amount of time for hardening and drying compared to a wet screed, and no shrinkage, so that cracks and voids are not formed.

For laying a semi-dry coating with your own hands it is necessary to prepare the surface, removing all irregularities, and laying the insulation, for which you can use cork foil and penofol.

The next step is to make holes for each square meter of thermal insulation.

Also on the perimeter you need to leave a free strip with a width of not more than 15 cm, which will preserve the strength and heat of the entire system.

After that, laying pipes or cable of the warm floor, then you need to apply the prepared solution.

For maximum strength, it is recommended to use fibrefiber.

The final step is to grind the top layer of the coating to a level surface.

To check the preparedness of the solution, you need to take a handful of your fist, and if a jet of water is released, then there is too much moisture.

With a properly prepared solution, a tight, non-decaying lump should form during compression.

Wet

Wet screed is the most common type of covering under the warm floor.

However, for laying your own hands you need to have some knowledge and experience, since wet casting has many features and is the most difficult of all kinds of screeds.

The solution consists of cement, sand and water.

For mortar it is necessary to use cement of mark not lower than M-300 and fraction 3-5 mm.

The plasticizer for the screed of the warm floor is mandatory.

Special plasticizers in solution will make the screed much stronger and more plastic. They are added to the composition in the calculation of 0.6-1 liter per 1 square meter.

Without the use of such an additive, the thickness of the coating should be at least 5 cm. The solution should not be liquid, as severe shrinkage and damage to the underfloor heating system can occur.

When laying a coating in a room of more than 40 square meters, additional fiber should be added to the solution, which will increase the strength of the floor.

Concrete screed requires long drying and hardening. This period is about 30 days.

It is not possible to switch on the underfloor heating system until the floor is completely dry. On the second day of laying the surface should be watered and covered with a plastic wrap.

To prevent the formation of cracks every three days, you need to water the floor with water.

laying technology The technique of installing the screed with your own hands is different for each kind of warm floor, which is divided into water and electric.

Consider the technology of laying a concrete screed, since it is the most difficult.

water floor technology The screed for the water floor begins with the installation of the process gap using a damper belt. The technological gap prevents the movement of the coating when heated.

The damper gap is produced between individual contours, the maximum area of ​​which is 40 sq.m.

The next stage is the thermal insulation of the substrate. A common option for warming the water floor is a foam, the thickness of which should be at least 5 cm.

After the layer of thermal insulation, the heating circuit is laid according to a certain scheme. To do this, you can use special plates of expanded polystyrene, which have special fasteners.

Video:

After laying pipes, you need to set up beacons and pour a concrete solution over them. The thickness of which is 45 - 65 mm above the pipe.

However, upgraded special mixtures designed for the warm floor make it possible to pour the solution 20 mm above the pipe. Before using such mixtures, you should carefully read the instructions.

A very important point is that after the concrete pouring of the screed of the water floor, the system must be under pressure until the screed hardens completely.

Electric floor technology

Electric floors are divided into systems with a cable heating element and on systems with infrared film.

A warm floor with an infrared film is forbidden to be mounted under a concrete screed.

When using the infrared floor, certain types of finishing coatings are used, which must be laid directly on the infrared film or the sheets are laid on the film, and the top coat on top.

Video:

The electrical floor tie with the hands starts with the preparation of the base on which the individual heating cable or cable mats are laid.

Cable mats are different in that they have reinforcing mesh, and when using an individual cable, you first need to lay the mesh, which will be attached to the cable.

The next feature of installing an electrical floor is that the heating elements should be located only in places where people walk.

No heating elements are placed under furniture.

All other actions are similar to laying the water floor.

It is necessary to leave the technological clearances, then lay a layer of thermal insulation, make reinforcement, lay the cable and pour the solution.

The thickness of the coating for a living room is not more than 100 mm, for commercial premises the thickness should not exceed 200 mm.

Thickness of concrete over 300 mm is used only in aviation hangars.

It is not difficult to make a screed for a water or electric floor with your own hands, the main thing is to choose the composition, which is the main step in the screed device, and, of course, know the technology.

The entire process must be approached with the utmost responsibility, since high-quality laying of the screed under the warm floor is the guarantee of long operation of the entire system.