In radiant floor systems the screed It is a functional component of fundamental importance: in addition to receiving the final covering and distributing the loads applied to the floor, it has the important function of conveying heat from the pipes to the floor.
Therefore it is necessary to realize it correctly to guarantee the maximum plant performance radiant and exclude damage to the flooring.
Traditional and self-leveling screeds: characteristics and critical issues
Il traditional screed it is obtained by mixing cement, water and sand of different granulometry. In the case of radiant screeds, part of the water functional to the mixture is replaced by specific additives that maintain the fluidity of the dough unaltered but allow a more conductive screed to be obtained and less exposed to shrinkage phenomena. body of the screed a layer of electro-welded mesh.
All components are mixed on site so that the experience of preparing the dough is decisive for the performance of the screed. The quality of the laying and the compaction of the screed instead affect the adhesion between the screed and the pipe.
The thickness adopted is generally of 45 mm above the heating tube for which long drying times are required, on average 4 weeks. Drying is also an important step for success: if it is too rapid or altered by uncontrolled temperatures, it can lead to boat damage or breakage.
Main critical aspects of a traditional screed:
- high thickness
- greater possibility of human errors
- not optimal adhesion of the screed to the heating pipes
- long processing times
Il self-leveling screed it is packaged with premixed and prepacked material to which only clean water should be added: it is sufficient to follow the manufacturer's specifications. The performance of the material is certain and declared by the manufacturer and the conductivity value is always high.
The mixture has a very fluid consistency that allows an easy leveling and produces a total adhesion of the screed to the heating tubes as well as a high compactness of the resulting layer.
It is not affected by shrinkage phenomena for which it is not necessary to use an electro-welded mesh. The thickness is variable depending on the solution adopted, but is usually less than 20 mm above the tube: this greatly shortens the processing and maturing times. The high dimensional stability that characterizes it means that joints that interrupt the floor are not necessary: this is an important advantage from an aesthetic point of view.
Advantages of a self-leveling screed:
- low thickness of application
- high thermal conductivity
- high dimensional stability
- total adhesion to the plant
- quick drying and steady state
Why choose a self-leveling screed
Today we are more and more aware of how much the choice of the screed is important for the good performance of a radiant floor: a high conductivity and a low thickness produce high thermal yields. In addition, the efficiency of the building park has reduced the thermal requirements and has favored radiant systems with low thermal inertia, able to immediately go to full capacity and respond quickly to the inputs of the regulation.
By virtue of these aspects, self-leveling screeds are gradually supplanting traditional ones.
We see 5 good reasons to choose a self-leveling screed.
1) It is perfect for renovations
Self-leveling screeds are particularly suitable for renovations where the screed level is constrained by several previous fixed dimensions, such as the entrance door or the French windows towards terraces or balconies.
A low thickness radiant system can also be installed directly on the existing floor, saving on the costs of demolition and disposal of the old floor.
2) Construction times are faster
The drying of the self-leveling screed is very rapid and allows the first start up on average within a few days. The works can be completed well in advance of a traditional screed.
3) Increases the yield of the radiant system
Self-leveling screeds have a very high conductivity, on average higher than 1,4 (W / mK):
by combining this property with the low thickness, the thermal performance of a radiant floor system is significantly increased. The heating flow temperature can be lowered by about 2-3 ° C compared to radiant floors with traditional screed, to the advantage of the efficiency of low temperature heat generators (heat pumps, condensation boilers, etc.).
4) There is a better diffusion of heat in the environment
The self-leveling screed has a low viscosity that allows an easy leveling and a fluid consistency that makes it incompressible and extremely compact.
For this reason it is possible to obtain a practically total coverage of the surface of the radiant pipes in contact with the screed, while in traditional screeds it is rarely possible to reach 70%.
This allows better heat exchange and a more even temperature of the floor.
5) The reaction of the radiant system is faster
The radiant floor heating with low thickness screeds takes place in about an hour, unlike traditional radiant systems that employ up to 5 hours. This reaction speed improves radiant system regulation and increases user comfort.
The EcoFloor Tech ultra-reduced system
Rossato, always specialized in the production of radiant systems, presents the new Ecofloor Tech ultra-reduced system with self-leveling screeds.
Ecofloor Tech is the latest generation system designed for the realization of radiant floors in 30 mm.
This makes the system the ideal solution for renovations with little available space and in existing floor applications.
ECOFLOOR TECH is synonymous with high comfort and energy efficiency.