Heating cables in concrete floors

Varmekabler i støpte gulv

Direct heating
Concrete floors are very suitable for electric underfloor heating. The power requirement varies with the type of room to be heated. Normally, heating cables are installed in the lower part of a 30-50 mm thick layer of screed (concrete), atop thermal isolation with high insulation properties. It is always advisable to install insulation under the concrete floor, so as to avoid heat loss downwards.

In renovation projects or when, for other reasons, it is necessary to keep the building height of the floor at a minimum, special low profile screeds, which provide a thickness down to 10-15 mm, are used.

Pouring of concrete/screed
In all types of concrete floors, it is important with good mixing, proper mixing ratio (follow the vendor’s user manual carefully), and good compacting of the screed so as to avoid air pockets and to ensure that the screeds thermal conductivity is as good as possible.

Screeds of concrete shall dry and cure naturally, and the heating cable can be connected and carefully put to use after 6-8 weeks (normally).

NB! It is advised not to use so-called fast-drying screeds. This is very dry type of screed, and will easily assume a porous structure with a lot of air inside. If this type of screed is still required, it is very important with good mixing, using an electrical mixer, and thorough compacting. Especially approved low profile systems require very short curing and drying. Consult the manufacturers installation instructions.