I’d immediately lodge a Conciliation case at NCAT because the Strata are failing to comply with the act
62 What are the duties of an owners corporation to maintain and repair property?
(1) An owners corporation must properly maintain and keep in a state of good and serviceable repair the common property and any personal property vested in the owners corporation.
You have to go to conciliation before Adjudication will rule in your favor (most likely outcome).
They obviously accept that it is a OC responsibility because they have repeatedly tried to fix it unsuccessfully a number of times over the last 12 months.
Also get an independent structural report to find out exactly what the problem is and how it should be fixed (ask the OC to do this within 7 days or you will get your own). Keep a detailed record of all your costs to present to the Adjudicator to enable you to be reimbursed.
Don’t blame the SM too much as he works for the OC and has to comply with their instructions, it’s the OC you need to target (sec and chairman).
I cannot find a procedure to bypass the conciliation stage for emergencies that your case obviously is. Cost of Conciliation and Adjudication is approx $200.