Re: New Insurance company - will they pay for old problem ??
There are 2 issues here:
1) is the damage covered at all?
Insurance policies are not maintenance policies. Unless the crack was caused by an event covered by your insurance policy (storm/impact/subsidence etc.), then there won't be cover. SO you need to get an engineer to assess the cause of the damage. Subsidence is the usual cause of serious cracks but it is relatively rare in Ireland except, I think, in parts of Cork.
2) which insurance company?
the vast majority of household policies are on a claims occurring basis so the cover would be provided by whichever insurance company you were with at the time the 'event' took place. Again, you'll probably need an engineer to assess when the damage occurred - if it was an event which occurred over several years then, subject to agreement by each insurance company's engineer, the bill would be split in some proportion deemed fair by the insurance companies.