I have a balcony that is also the roof over part of the house. Previously, there was an old thick 'asphalt mat', under that tiles, and beneath that a concrete slab. I have now removed the mat which was hard with cracks in it. It turned out that the tiles underneath were also bad and in some cases loose due to moisture seeping in. In some places, the concrete was also damp when the tiles were removed. The house is 80 years old, so it has been around for a while, and I can't trace any moisture indoors under the balcony.
My question is, how do you renovate this? I was thinking of casting a new layer of concrete or cement, then self-leveling compound, and then tiles.
Should I apply a moisture barrier? I'm worried about trapping moisture if I do that.
Is it a problem to cast on the existing slab if it is not completely dry?
Grateful for tips and advice.
