When it comes to underfloor heating, the quality and thickness of the screed play a fundamental role in how the system performs.
Key principles to keep in mind:
In underfloor heating systems, the long-term durability of the tiled surface does not depend solely on the quality of the tile itself or the adhesive used. One of the most important factors is the construction of the esztrich concrete layer.
The role of the esztrich is to transfer the heat released by the heating pipes evenly toward the tiled surface. If the thickness or quality of the concrete is not appropriate, it can affect:
When it comes to underfloor heating, esztrich is therefore not just a subfloor layer. It´s one of the key structural elements that determines how the entire system performs.
In practice, indoor underfloor heating systems typically use a esztrich thickness of 6–7 cm.
It is important to note, however, that this refers to the minimum thickness. If the subfloor is uneven, the esztrich may be thicker in certain areas.
During installation, it is essential to aim for the most even thickness possible.
A uniform esztrich thickness is important for several reasons:
In underfloor heating, the entire floor structure is made up of multiple layers. Together, these ensure proper insulation, load-bearing capacity, and efficient heat transfer.
A typical underfloor heating floor build-up includes:
1.base concrete layer
2.waterproofing layer (GV membrane)
3.thermal insulation
4.protective foil
5.underfloor heating pipes
6.Esztrich concrete
7.final floor covering
The waterproofing layer prevents ground moisture or vapor from entering the floor structure.
Thermal insulation reduces downward heat loss, allowing a greater proportion of the heating energy to be directed into the living space.
The esztrich concrete then acts as a heat-distribution layer, transferring warmth evenly to the floor covering above.
Tilers often blame the adhesive or the tile material itself when problems begin to appear over time.
In reality, however, the underlying base layer is often the true cause of the issue.
With underfloor heating, the concrete is constantly:
This is why properly planned expansion joints are especially important, as they allow the concrete to move where needed.
If these are missing, that movement can eventually appear through the tiled surface.
Good esztrich work begins long before the concrete is actually poured.
Important steps during the process include:
– on-site assessment
– laser level setting
– determining the required insulation thickness
– planning the expansion joints
This helps ensure that the concrete is installed with the most even thickness possible, something that is especially important in underfloor heating systems.
Creating the right subfloor is essential for the long-term durability of the tiled finish. More detailed professional information about esztrich installation can be found on the Esztrichbetonozas.hu website:
Esztrich betonozásról
Proper drying and aftercare of esztrich concrete are essential for the long-term durability of the tiled surface.
Fresh concrete is especially sensitive to rapid drying during the first few days. If it loses moisture too quickly, it can:
For this reason, it is important after installation to carry out what is often referred to as curing. In other words, protecting the concrete from drying out too quickly.
Fresh esztrich concrete should be kept in a draft-free environment for at least one week.
In practice, this means:
Without the use of additives, concrete needs moisture in order to cure properly.
For this reason, during the first few days:
Once the active curing period has passed, usually after about one week, the drying phase can begin.
At this point:
Tiling is only recommended once the esztrich surface has dried properly and has been fully prepared.
The required amount of esztrich can be calculated quite easily.
Formula
Concrete volume (m³) = floor area × thickness
(professionals can help account for compaction and other practical factors)
| Area | Thickness | Concrete Volume |
|---|---|---|
| 100 m² | 6 cm | 6 m³ |
| 100 m² | 7 cm | 7 m³ |
| 120 m² | 6 cm | 7,2 m³ |
Before tiling over esztrich with underfloor heating, it is important to check:
This can significantly reduce the risk of future tiling problems.
In underfloor heating systems, esztrich concrete is not just a base layer.
This layer determines:
This is why the correct thickness, a well-planned floor build-up, and professional installation are all essential.
For indoor applications, a esztrich thickness of 6–7 cm is generally typical.
Full drying usually takes several weeks, but the first week is especially critical in terms of proper curing and aftercare.
Tiling can begin once the concrete has dried properly and the moisture level is within the appropriate range.
An even esztrich thickness ensures consistent heat output and helps reduce the risk of cracking.
Have you grown tired of your bathroom, kitchen, or perhaps your living room and would like to have it retiled, but feel that the possible costs of a tiling project of this size are getting out of hand? In this article, I’d like to talk to you about why it makes such a big difference when you entrust this job