Forget the threat of legal action. Take a look at this previous column here. Your Owners Corporation boss (is it the chairman of the executive committee or the strata manager?) needs to get this straight with an experienced strata lawyer right now. If there is no special resolution allowing the work to go ahead and apportioning the cost of repairs and maintenance then it falls to the OC to fix the common property and any damage caused by its failutre. Futhermore, if in doing so they damage your tiles, they have to pay for that too.
And somewhere at the back of my brain there's a thought that if the OC takes legal action against an owner and the action fails, the owner doesn't have to pay their share of the cost. Has anyone else heard of that one? Or was I dreaming?