Blister formation on balcony floor

Hello first of all, since I am new here, first a compliment to this forum. I hope that I am also in the right section here. My problem: our house from the 70s has an uncovered balcony. Now I have noticed that on the underside, in the plaster, or paint, small bubbles are forming. Is that normal after a few years and just needs to be repainted, or is there a bigger cause? I hope to find one or the other expert here who can give me advice. Thank you very much and regards alsteff

Hello,

our house built in the 70s has an uncovered balcony. Now I have noticed that small bubbles are forming on the underside, in the plaster, or paint. Is that normal after a few years and just needs to be repainted, or is there a bigger cause?

It depends on the materials used at the time of construction; but I would instinctively answer "yes."

Get an expert from the masonry trade and have him inspect the balcony. Only then will you get reliable information on whether and how to address the efflorescence ;)

Kind regards