Limited Common Element Issue/Roof Decks

I live in an eleven unit building where the 4th floor (top) have limited common element roof decks. The roof is leaking in multiple spots and the roof must be repaired, but in order to do so, the decks have to be removed and replaced.

The Association has offered to pay for the deck demolition, and of course, roof repair, and will pay for the tiny portion of the deck that is open to all residents, but does not feel responsible for replacing all of the private decks.

With all of the rain we have been getting this problem is not going away, and the 4th floor unit owners want resolution to this issue.