An owner cannot willy-nilly make changes to common property, such as repairs, and expect to be reimbursed by the OC without showing that you have behaved reasonably. The fact that you may sell is not relevant to your rights to have the damage fixed.
Consider taking the following steps:
1. Get 2 quotes from tradesmen for the job;
2. Write to the strata committee and strata mgr exactly what the problem is;
3. Make clear how long the problem has persisted;
4. Remind them how you have suffered;
5. Remind them that you have brought this to their attention on XXX and again on YYY and to date the have failed to act;
6. Their failure is a breach of their duty under s. 106 SSMA;
7. Include the quotes in your correspondence to the SC and strata mgr;
8. Tell the SC and strata mgr that they have, say 2 weeks to fix;
9. Tell the SC and strata mgr that you have applied for mediation on the matter as a prelude to taking the matter to NCAT, as you are not confident the property will be repaired by the strata. If the damaged property is rectified by them before mediation is to take place, you will withdraw your mediation application. Otherwise you look forward to seeing them at mediation;
9. Call 13 32 20 (NSW Fair Trading), select the option of STRATA and they’ll tell you how to go about lodging a mediation application. Have the quotes from licensed tradesmen ready to attach to your application. Note attempting mediation is a prerequisite to applying to NCAT. Whether an agreement is struck at mediation between you and the strata or no agreement is struck or the strata doesn’t turn up (they don’t have to), the fact that you attempted is enough to apply to NCAT.
Good luck!