Snow and ice-free steps and landings
Heating cables are very well suited to keep concrete stairs free from snow and ice throughout the winter. To obtain an efficient snow melting installation, the recommended area power is in the range between 300W/m2 and 350W/m2. The area power in the steps may well be little higher than in the landing(s), as each step has a larger surface area (the front) and potentially greater heat loss.
The cables can be laid out on the concrete base and covered by screeds, or they can be attached to rebar / reinforcement nets if these follow the staircase profile. The cable strands shall be evenly distributed in each step, but it may be advisable shift the installation towards the edge of the step, so as to somewhat compensate the cooling which will take place at the front of the step. This is particularly important if there are steps with e.g. slates protruding beyond the edge of the step ("nosings"), as ice can easily build up in this area. In plain concrete staircases, the cable should be covered by 2-3 cm of concrete. In staircases with tiles, or similar, in the steps, the layer of screed may be reduced to about 1 cm. Nexans offers several products suitable for installation in staircases.
TXLP Single conductor
It is quite common to use single conductor heating cable (also called drum cable) in stairways installations. Since the cable should be laid in such a way that the "end" of the cable comes back to the starting point of the installation, it is usually necessary to install an even number of strings in each step
(2, 4 or 6 strings). Single conductor heating cable systems should be calculated by a person possessing experience with such systems.
DEFROST SNOW is a twin conductor heating cable element which yields 28W/m. The cable is equipped with a hidden splice and 10 m cold lead, and it is ideal for snow melting systems in stairs. When using DEFROST SNOW, there is no requirement for an even number of strings per step.
TXLP Heating cable elements
For particularly small stairs, and with climatic conditions permitting, "indoors" heating cable elements (17W/m) may be used. The cables are robust enough to be used in outdoor installations, but because of low linear power (compared to products that are intended for outdoor use) the highest achievable area power will be approximately 280W/m². In installation of some size, this implies a large installation job (many meters of cable to install). When using heating cable elements, there is no requirement for an even number of strings per step