We have an old (1957) concrete staircase at the entrance (outdoors) that is covered with colored plaster, 2-3 cm on the treads, thinner on the risers. The plaster has cracked in several places so we have now chipped away everything that is loose. In some places, there are also some damages to the underlying concrete. I would like the staircase to be completely smooth so that I can potentially cover it with tiles or other coverings if I want. I was thinking of using fine concrete, but when I was at Hornbach and told them about the staircase and its age, the salesperson recommended their regular mortar. Is that a good solution?
