The structure of the balcony, its waterproof membrane and the railing are common property in almost every Australian strata scheme. The lot owner is usually only responsible for cosmetic finishes and any non-original additions they put in.
If your tiles or membrane are failing, report it immediately. Delayed balcony repairs are one of the most expensive issues a scheme can face — water damage can spread to multiple lots and the building structure within months.
Compare written fee proposals from strata managers covering your building — free for owners corporations, no obligation.