Roof cracking common in old flats?

I live on the top floor of an old flat in new territories, ~30-40 years old. When we bought the flat from the previous owners, it looked immaculate, but thick, ~8mm cracks were quickly appearing in the rooms. The cracked areas were “repaired” and I was told by our neighbor, it happens because the metal frame work that the block is made with is an old material, and any work on them, short of replacing the whole frame, including waterproofing the cracked regions, will only inevitably result in cracking elsewhere within ~ year. We were also told that the previous owners had only stayed here for a couple of years, and had to engage in two major roofing works, to no avail as the cracks reappeared. Obviously they had cosmetically touched up the flat before selling to us. Is this roof cracking problem common in old flats? or is it because we live on top floor of an old block? is any of this true? and anyone else experienced cracking on roof in a old flat?

There seems to be a rule of thumb here that nearly all roofs last about 10 years and then have to be stripped, waterproofed and then retiled. It's the summer heating and winter cooling that does the damage. It's not cheap to have this done properly but then you get another 10 years - and no neighbors living above you pulling chairs across uncarpeted floors, playing mahjong at 3 am etc etc