If ‘strata’ doesn’t have the money then the fees need to be raised. If it’s for an essential repair then a levy needs to be struck.
An issue if you pay for it out of your own pocket is that you may never get the money back. Also, this repair sounds like something that must be done, meaning the Owner’s Corporation must do it.
And never forget the Owner’s Corporation, or as you’ve referred to it ‘strata’ is made up of the owners. You are as much part of the problem as part of the solution whilst you’re being adversely affected by the current fault.
PS the longer you wait, the more expensive it will be to repair.