ᐅ Schlüter Screed System – Renovation with a Low Screed Thickness?
Created on: 7 Sep 2022 14:08
L
LostWolfGood morning,
For my major renovation project (built in 1961), I need a replacement for the installed screed with a build-up of about 4.5-5cm (1.8–2 inches).
I have come across the Schlüter Bekotec system.
At first glance, it sounds quite interesting, but I also have a few questions.
It seems there is no thermal insulation between the system and the (concrete) ceiling itself, so I would be heating the entire ceiling and, of course, the adjacent masonry as well.
One advantage mentioned is that the underfloor heating can be controlled quickly. This makes sense since the screed itself is reportedly only 8mm (0.3 inches) thick.
This would allow me to implement a nighttime (and absence) temperature setback.
However, I wonder if the heat pump might have to cycle more frequently and therefore consume significantly more electricity due to the missing heat storage effect of the screed?
What about the load-bearing capacity?
Schlüter states high load capacities but does not specify how these loads need to be distributed.
I am particularly thinking about furniture feet here.
It is usually said that any type of floor covering is possible, but there is a constant reference to tiles.
How suitable is this system for glued parquet or laminate flooring?
Does anyone here have experience with this floor build-up from the manufacturer and can share insights?
So far, I have not yet contacted any company willing to install this system.
Should I continue looking for alternatives, or is this system recommended?
For my major renovation project (built in 1961), I need a replacement for the installed screed with a build-up of about 4.5-5cm (1.8–2 inches).
I have come across the Schlüter Bekotec system.
At first glance, it sounds quite interesting, but I also have a few questions.
It seems there is no thermal insulation between the system and the (concrete) ceiling itself, so I would be heating the entire ceiling and, of course, the adjacent masonry as well.
One advantage mentioned is that the underfloor heating can be controlled quickly. This makes sense since the screed itself is reportedly only 8mm (0.3 inches) thick.
This would allow me to implement a nighttime (and absence) temperature setback.
However, I wonder if the heat pump might have to cycle more frequently and therefore consume significantly more electricity due to the missing heat storage effect of the screed?
What about the load-bearing capacity?
Schlüter states high load capacities but does not specify how these loads need to be distributed.
I am particularly thinking about furniture feet here.
It is usually said that any type of floor covering is possible, but there is a constant reference to tiles.
How suitable is this system for glued parquet or laminate flooring?
Does anyone here have experience with this floor build-up from the manufacturer and can share insights?
So far, I have not yet contacted any company willing to install this system.
Should I continue looking for alternatives, or is this system recommended?
Becothec-EN and Becothec-Therm are special designs that have become well-established in practical use. In other words, they work.
When are such systems used? Well, on one hand, they are employed due to site-specific height restrictions, and on the other hand, they are used on problematic substrates that are unstable, prone to sand migration, or highly susceptible to cracking. In short, these are not surfaces suitable for direct installation.
In your case, it seems you have removed an existing screed, leaving a thickness of 45mm to 50mm (1.8 to 2.0 inches). The old screed, as I would call it, was installed in residential construction and certainly included an insulation layer.
If that insulation layer is still present and there is a height of 45mm (1.8 inches), there is nothing preventing the installation of a new standard screed (without underfloor heating).
If you want to replace the old, unheated screed with a heated one, we are actually facing the limits regarding build-up height. This requires a nominal thickness of 60mm (2.4 inches).
The Becotec system uses an embossed panel and a highly modified leveling screed that builds up 35 to 38mm (1.4 to 1.5 inches).
The problem with this type of hydronic underfloor heating is the small diameter of the heating elements. Typical systems use pipes with an outer diameter of 12mm (0.47 inches) and an inner diameter of about 10mm (0.39 inches).
With smaller inner diameters of the heating pipes, the water flow rate must logically be increased to achieve the same heat output as larger diameters. This can sometimes cause whistling noises, as the internal stress on the pipe walls around bends is quite high due to the increased media velocity.
What advice can I give you? I would accept the risk of flow noise, because otherwise this system would not still be available on the market.
Regarding the load you asked about, I have no concerns. In residential construction, a distributed load of 2 kN/m² (42 pounds per square foot) is assumed, and point loads can generally be disregarded unless unusual furniture, such as a piano, is expected. In those cases, load-distribution plates would be necessary under rollers.
In short: there will be no issues with the load-bearing capacity of the Becotec system under the typical traffic boxes used in residential construction, especially since the thickness of parquet or ceramic tiles provides additional load distribution that prevents point loads from acting directly on the leveling screed.
I hope this explanation has been helpful.
Regards, KlaRa
When are such systems used? Well, on one hand, they are employed due to site-specific height restrictions, and on the other hand, they are used on problematic substrates that are unstable, prone to sand migration, or highly susceptible to cracking. In short, these are not surfaces suitable for direct installation.
In your case, it seems you have removed an existing screed, leaving a thickness of 45mm to 50mm (1.8 to 2.0 inches). The old screed, as I would call it, was installed in residential construction and certainly included an insulation layer.
If that insulation layer is still present and there is a height of 45mm (1.8 inches), there is nothing preventing the installation of a new standard screed (without underfloor heating).
If you want to replace the old, unheated screed with a heated one, we are actually facing the limits regarding build-up height. This requires a nominal thickness of 60mm (2.4 inches).
The Becotec system uses an embossed panel and a highly modified leveling screed that builds up 35 to 38mm (1.4 to 1.5 inches).
The problem with this type of hydronic underfloor heating is the small diameter of the heating elements. Typical systems use pipes with an outer diameter of 12mm (0.47 inches) and an inner diameter of about 10mm (0.39 inches).
With smaller inner diameters of the heating pipes, the water flow rate must logically be increased to achieve the same heat output as larger diameters. This can sometimes cause whistling noises, as the internal stress on the pipe walls around bends is quite high due to the increased media velocity.
What advice can I give you? I would accept the risk of flow noise, because otherwise this system would not still be available on the market.
Regarding the load you asked about, I have no concerns. In residential construction, a distributed load of 2 kN/m² (42 pounds per square foot) is assumed, and point loads can generally be disregarded unless unusual furniture, such as a piano, is expected. In those cases, load-distribution plates would be necessary under rollers.
In short: there will be no issues with the load-bearing capacity of the Becotec system under the typical traffic boxes used in residential construction, especially since the thickness of parquet or ceramic tiles provides additional load distribution that prevents point loads from acting directly on the leveling screed.
I hope this explanation has been helpful.
Regards, KlaRa
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