This is tricky, given the numbers. But these are repairs, even if that means a new roof. The OC is legally obliged to “maintain and repair” and if the roof is beyond repair, that doesn’t mean they do nothing. It’s a shame that you have a strata manager prepared to split hairs over this, and come up with the wrong answer.
Section 106 of the Act says:
(1) An owners corporation for a strata scheme must properly maintain and keep in a state of good and serviceable repair the common property …
and …
(3) This section does not apply to a particular item of property if the owners corporation determines by special resolution that: (a) it is inappropriate to maintain, renew, replace or repair the property, and (b) its decision will not affect the safety of any building, structure or common property in the strata scheme or detract from the appearance of any property in the strata scheme.
Look at section 3. You have to pass a special resolution to NOT fix common property, and even then only if it doesn’t affect the safety or appearance of the structure.
If your strata manager remains unconvinced, even by a simple majority vote of your owners, the simplest way to resolve this may be to seek orders at NCAT under section 232, requiring the Owners Corporation to fulfil its duties under the Act.
Now, I know this could seem like taking yourself to NCAT, but at the obligatory prior mediation, Fair Trading might just counsel the strata managers that they are misinterpreting the law, so you won’t need to proceed any further.
Otherwise you are just beating your head off a brick wall of ignorance, incompetence and indifference.