Such an indicator as the thickness of the screed under the warm floor determines many factors, but the fact that this surface should be perfectly smooth is the law. The whole process of arranging a warm water floor consists of several stages, including the organization of hydro- and thermal insulation, laying of reinforced mesh, pipes and arranging the screed itself.
At the last stage, special attention and responsibility are required, since any, even the slightest violation of the technology will lead to irreparable consequences. The protection of the warm floor and the preparedness of the surface for decoration with a decorative coating depend on how the norms are met. It is the optimum thickness of the screed of the warm water floor that provides strength and uniform heating of the surface throughout the room.
General principles of calculation and some details
A concrete layer is located above the warm water floor, but it is not just a cement mortar. This filling has an important effect on the quality of the floor, providing the pipes with the proper pressure for pressure testing and their reliable fixation, which in turn eliminates mechanical damage. Technologically correct installation with the thickness of a warm water floor that complies with all standards and requirements ensures high-quality long-term service and uniform heating. It is very important to carry out all the calculations correctly, including determining the thickness of the screed.
What to consider during the calculation
Do not forget about the main rules of calculations when planning work on arranging a warm surface under your feet. Note that:
- The presence of screed makes it possible to evenly distribute heat over the entire surface of the warm floor. When pouring too thick a layer, count on increased heat capacity, thin - on rapid heating. In the first case, the passage of heat occurs for a long time, and adjusting the level of floor heating is difficult. With a thin layer of concrete screed, heat approaches the top of the surface faster, but only a few centimeters of concrete in the kitchen or in the bathroom, where mechanical damage is possible, can play a cruel joke with the owners. A thinner layer of concrete is easily cracked and is not able to evenly conduct heat.
- The organization of a water floor involves the coating of absolutely all heating elements with concrete, and a thickness of a warm water floor of 65 mm is considered optimal.
- The thickness of the screed is determined, not based on the wishes of the owner of the apartment, but by a number of rather important factors - the structural features of the building. Among them are indicators:
- thermal power of the surface;
- overlap properties;
- type of facing material, etc.
How to organize the calculation of the thickness of the screed
This procedure is carried out so that the minimum thickness of the warm water floors is at least 10 mm. The thinner layer is easily cracked and leads to inefficient use of the heated floor.
Please note that the described actions in relation to the calculation are based on the diameter of the pipes purchased for the underfloor heating. When using products with a standard diameter of 20 mm, the best option is a screed with a thickness of 40 mm, where 20 is allocated to communications, and half of the remaining covers the laid pipes.
As the reviews confirm, with the right calculation, you don’t have to worry about the effectiveness and efficiency of the system. And, of course, you will not have to face problems during the operation of the system, such as deformation and uneven distribution of heat.
The most admissible indicator of thickness
When using pipes with a diameter of 20 mm, it is permissible to increase the thickness of the finish screed by 10-20 mm, but not more than 60 mm of the thickness of a warm water floor. Otherwise, the organization of such a heating system will be inappropriate in terms of efficiency, and most of the energy will simply go to heating a thick layer of concrete.
What determines the thickness of the screed
Please note that this indicator directly depends on the functional purpose of the room. For residential premises, the minimum flow rate of solution will do, but for trade pavilions, hypermarkets and industrial enterprises, where it is planned to equip a heated water floor, you will have to resort to the maximum thickness of the warm water floor. This can be explained by a different degree of load on the coating and the fact that in public buildings there is no need for such a level of heat transfer as in a residential building. The screed with the coating thickness above the pipes of 30 mm is considered the thickest and it is used in aircraft hangars.
What else to consider when organizing a warm floor underfoot
The screed can be reinforced if large objects are supposed to be placed in the room. For example, if a piano or piano is planned to be installed in a room, there is a need to additionally fasten the concrete in its upper part, above the pipes, and only after that perform decorative decoration. The fittings are positioned pointwise or over the entire area of the room, if necessary.
Additional structural strength will be added by special fractional fillings, which are actively used during this kind of work. Judging by the reviews, the use of such an alternative allows us to abandon the reinforcing fabric, which, in turn, allows us to make the thickness of the warm water floor slightly less.
Among the fractional particles include polypropylene chips and fiber, contributing to a good surface strength. These are one of the most common and frequently used materials in the field of pouring underfloor heating.
Therefore, in the standard calculation of the layer of screed over the pipes in the amount of 40-50 mm and the use of the above-mentioned additives, you can refuse additional strengthening and leave the thickness from 20 to 25 mm.
If you are doing repairs, then it is better not to save on organizing the final layer for the heated floor. As a result, this can result in a decrease in the strength and heat transfer of the heating system.
What is the thickness of the water floor heating resulting in
To calculate the volume of the screed, you will have to calculate the thickness indicators considered above. Based on the volume of the pipes, the concrete layer above them, the presence of a reinforcing mesh or fractional particles holding the solution together:
V screed = final screed thickness (30-60 mm) × per room area.
What else to take note when organizing a warm floor
Please note that there are a number of requirements and rules that should be taken into account in order not to violate the technology of organizing a warm floor in a house. Among the recommendations of experts, the following details:
- Starting directly to pouring, first of all, it is worth checking the quality of the installation of the tubes and their connection to the heating system. You can start pouring a concrete screed only after you have verified the operability and hydraulic density of the warm floor.
- The effectiveness and efficiency of the entire underfloor heating system depends not only on the thickness of the screed, but also on the quality of the materials used. This is especially true for cement, which has the property of caking. Therefore, the choice of materials should be approached with all seriousness and carefully monitor the certification of purchased products, and buy cement only before starting work.
- Excessive heat loss can be avoided by taking the matter seriously, rather than doing work negligently. This means that ignoring the laying of the heat-reflecting layer is highly discouraged. The presence of such a layer is mandatory under the pipeline system. At the same time, the thickness of the insulation under the warm floor (water) depends on the type of raw material and is:
- cork insulation boards - from 10 to 30 mm;
- profile systems with polymer-based guides - from 10 to 35 mm;
- heat-insulating roll filler - from 9 to 12 mm.
How much screed dries under a warm floor
After the solution is poured, it is worth waiting for a while, that is, let it dry. It takes an average of 6 weeks to dry a thick screed, and only after this period can you take on the next, no less important stage of work - laying a decorative decorative coating. Often these are tiled products that more than ever look appropriate on the warm floor in the bathroom, kitchen and hallway.
How to prevent screed cracking
To prevent cracking of the concrete layer, experts recommend the design, wetting the underfloor screed thickness under a tile or other decorative coating, moisten with water 2-3 times in 24 hours for ten days. Having ensured proper wetting of the surface during the drying period, you need not worry about cracking the concrete screed. Getting the proper amount of moisture, cement will acquire the necessary level of strength.
Now, having studied this material, you know what thickness of a coupler for a warm water floor is considered optimal, what indicators are not recommended to be exceeded and what to consider during the performance of work.
Following the advice of experts and having studied the reviews of those who have already tried to fill and equip the warm floor of the house with their own hands, you can easily determine the details, options and features of the heating system. Just before you start to do something, decide whether you can handle the expected amount of work yourself or whether it is better to give this task to the hands of specialists.