INSTALLATION AND COMMISSIONING
The pipes foreseen by the standard for water systems are made of cross-linked polyethylene (PE-X), polybutylene (PB), polypropylene (PP), copper; the use of steel has been abandoned, although the very first systems were made with this material. The laying pitch is variable, even inside the same room: the designer can choose to thicken the steps where greater thermal emission is required, i.e. near the external walls. For systems made with specific electrical conductors, the installation system does not vary, but since they are easier to work with, the construction of a system is simpler and faster.
For water systems, plastic pipes, particularly those in PE-X, are the most common: being flexible and light, they are easier to install; they must be equipped with an oxygen barrier layer to protect the system from corrosion. Although less common on the market, copper pipes are also installed. The advantage of these is their very high thermal conductivity (390 W/(m*K)), which allows an efficiency that would otherwise not be achievable; copper has wider pitches (generally 20-25 cm), is impermeable to oxygen and has a thermal expansion closer to that of the screed in which it is immersed.