在香港是很多的舊樓(唐樓)的，為什麼舊樓(唐樓)是不會倒下的?設舊樓(唐樓)是最至少50樓齡。?

There is no answer to your question.

The major reason is your assumption has been set incorrectly, which you assume aged building (tong lau) will eventually collapse.

1. Buildings are usually built to be long-lasting. When a building is used as designed, it can stand forever.

2. Age can weaken the structure. This is why periodical monitoring and repair is crucial.

3. Building collapse is usually the result of misuse or abuse of the building.