Hi Rita C,
Will need further info;
1) How old is your building, the strata registration date will be fine.
2) does this issue form part of a bigger HOW claim
3) Have you an expert report/s and if so what did the report/s say
It may be difficult for the forum to help. If you want email me directly so we can communicate and I can get the full info I need to help. With your permission once I know the facts I can up date the forum. My email is below.