Isn't that true of any building though? Where I live most houses have ceramic roof tiles, and even though they are supposedly long-lasting, after 60-80 years they do need replacing (most home-owners replace them much more frequently, every 10-20 years). I've replaced tiles on my grandparents' house which was around 60 years old, because they became brittle and started cracking after hundreds of temperature cycles, hailstorms etc.