Underfloor heating is a surface heating system, in which the heating surface is the floor of the heated space. The basic devices used are the same as those of conventional systems: burner, boiler, circulator, while any fuel can be used (electricity, oil, gas, etc.). The difference lies in the fact that the final recipients of hot water are not the radiators but the floor itself, which acts as a radiator.

The floor heats up slowly and radiates heat into the air. In this way a uniform heating of the air is achieved, from bottom to top. The low operating temperatures of the underfloor heating, get rid of the dryness of the air of the space and give a really healthy environment. In addition, due to the low temperatures, this system does not create air currents and so there are no phenomena such as tanning on the walls or transport of particles and germs.

An issue that arises after the installation of the underfloor heating is how we will cover the system. Our company recommends to make screed 20/25C reinforced with polymeric structural macro-fibers iScree 24 specially designed for addition to cementitious substrates and SikaPlast 250 reusable superplasticizer.

The advantages of using iScree 24 fibers are, first of all, the effective structural reinforcement of the concrete and the replacement of the steel reinforcement.They will also prevent cracks in the substrate. They are particularly suitable for flooring with underfloor heating systems, as they eliminate the risk of damage to the pipes due to the good dispersion in the concrete.The recommended dosage is 1.2-2kg/m³ and can be added directly to the concrete mixer, at the construction site.

By using the Sikaplast 250 superplasticizer we will achieve high water reduction, which results in high density, high strength and reduced permeability. It offers high mixture plasticity, which results in improved fluidity, placement and condensability. It will also offer reduced shrinkage during curing and reduced creep on hardened concrete. Consumption of the material is 1% by weight of cement.

Then, if it is to be coated with ceramic tiles, the weldingshould be done with tile adhesive which has the possibility of transverse deformation (elasticity), ie it should be of category C2TES1. We recommend SikaCeram 243 Ultraflex which is certified to be used on substrates with underfloor heating according to EN 14891. Another option is the Starflex Diamond where it is also suitable for underfloor heating.

Another final decorative coating that can be used over an underfloor heating screed is the Novamix microcement system. More information about this system can be found in the article Planocolor microcement system.