Self-leveling floor for heated floors under tiles: what thickness, how to make

Warm self-leveling floor is one of the types of obtaining a flat surface above the heating circuit. For this purpose, special mixtures are used, for example, polyurethane and epoxy. The pros and cons of such compositions, as well as how to properly fill, are described in detail in the presented article.

Types of self-leveling floors

Self-leveling floors for heated floors under tiles come in 2 main compositions:

• polyurethane;
• epoxy.

Polyurethane consists of an organic polymer of the same name. This is a unique finishing material that is suitable for concrete, metal and wooden surfaces. This type of poured heated floor has several undeniable advantages:

• strength and wear resistance (retains original properties for 10-15 years);
• resistance to aggressive chemicals;
• antistatic (does not accumulate electrical charge);
• withstands both static (constant) and dynamic (periodic) loads;
• the thermal conductivity of the self-leveling floor is about 0.96/(m*oC), which approximately corresponds to wet sand;
• easy to install;
• water resistant;
• withstands temperatures down to -25 degrees.

But if you plan to install a heated floor of this type, you need to keep in mind its disadvantages:

• it is necessary to very carefully prepare the base, which will take up to 1.5 months;
• high mixture consumption;
• maintainability is low - after removing chips and scratches, traces will remain;
• the composition may contain harmful substances.

The thickness of the self-leveling floor for heated floors is usually from 2 to 6 mm - it is this range that you need to focus on when planning the mixture consumption. More economical in this regard is the epoxy composition. It consists of a resin with the addition of a solvent, hardener, plasticizer and other components. The main advantages of this mixture are as follows:

• attractive appearance;
• greater durability (up to 30-40 years);
• resistance to aggressive chemicals;
• resistance to water;
• completely safe in composition;
• does not accumulate dust;
• high coefficient of adhesion to the base (the composition is not prone to peeling);
• You can use it already on the 4th day.

There is no need to doubt whether a heated floor can be filled with self-leveling flooring. Both of the described types are suitable for this. However, its disadvantages should also be taken into account:

• the material is inelastic, so it is placed only on a stationary, rigid base;
• if the premises are for industrial purposes and there are frequent vibrations, such a coating will not be suitable;
• does not consist of a ready-made mixture - you will have to make it yourself immediately before installation;
• dries in 30-40 minutes, so all work must be done promptly.

Preparation of materials and tools

Self-leveling floors for heated floors are purchased in the form of a ready-made composition, which is mixed with water according to the instructions. For work you will need the following tools and materials:

• bucket;
• tile adhesive or mounting foam;
• primer that penetrates deeply into the material;
• needle roller;
• spatula with a wide working surface;
• drill and mixer attachment;
• brush or regular roller;
• construction level;
• construction tape;
• damper tape;
• construction stapler;
• vacuum cleaner for cleaning;
• wet shoes (put on feet).

When planning to make a self-leveling floor for heated floors, you also need to take into account the consumption rate. It is determined in practice - the average value is from 1.6 to 1.8 kg per square meter, provided that the layer thickness is 1 mm.

But usually the liquid heated floor is made at least 3 mm high. Then you can make a simple calculation using the example of a large room (hall) with an area of ​​18 m2: 1.8 * 18 * 3 = 97.2 kg. It is clear that it is better to take the composition with a reserve, so for such a room you will need at least 100 kg, and for a small room of 12 m2: 1.8 * 12 * 3 = 64.8 kg, i.e. actually 70 kg.

Step-by-step instruction

The self-leveling floor for a warm water floor is manufactured in several stages:

1. First, prepare the base. Since the pipes have already been laid, the main surface is not touched. All that remains is to vacuum it and remove the debris. If there are gaps between the floor and the walls, go over them with polyurethane foam or tile adhesive.
2. Since the self-leveling floor for a house with a heated floor must be level, a damper tape is glued along the entire perimeter. Often they make a low screed (up to 10 mm) - then this stage can be skipped.
3. Now you need to make markings. Despite the fact that the self-leveling floor does have good fluidity, it will not level itself, so first you need to mark any horizontal line on the wall (with a laser level).
4. Determine the zero level, for example, 143 mm and subtract the layer thickness from it, for example, 3 mm. The result will be 140 mm - a horizontal line is drawn along this height and the boundary of the screed surface is determined along it - i.e. the maximum level that the filling of underfloor heating pipes will reach.
5. Now you need to prepare the mixture according to the instructions. First, cold water is poured into a bucket, after which the powder is added and stirred with a drill with a mixer attachment.Let it sit for a few minutes and stir again, after which they immediately begin to work. The heating floor must be covered within half an hour from the moment of mixing.
6. Then the floor is poured under a warm water floor. It is worth starting work from the farthest end of the room, from where you pour the liquid in approximately equal strips. A needle roller is used for leveling.
7. In some areas, level with a wide spatula.

Next, you need to wait until the solution dries in natural conditions (without draft). After about 5 hours it will be possible to step on it; at this moment it is permissible, for example, to trim the damper tape. But finishing work is allowed to begin in at least a week.