The Government is supporting thousands of home owners affected by defective blocks with a new repair or replace scheme.
The rescue will need legislation but its hoped work will start next year.
The scandal sparked a major campaign in the Irish Mirror, and after Taoiseach Leo Varadkar paid an emotional visit to families in Co Donegal last month, he said: This has to be fixed, its only fair.
Eileen Doherty who helps run the Mica Action Group from Co Donegal, said: We are beyond delighted. Weve been battling for five years to have this situation and our needs recognised. Today the Cabinet has signed off on an agreement to get the redress scheme up and running.
No cap has been placed on the expenditure and with 5,000 homes in Donegal and more in Co Mayo affected, the final bill could be in the billions. Some families affected by the defective block scandal have tried to patch the damage on their properties only to watch it fall apart.
Others have had to leave after their homes after they were condemned as unsafe.
Many more with no choice to leave, are living surrounded by scaffolding and in fear of their home collapsing with them inside.
And tragically for one family, the stress and despair of living with Mica defective blocks in their home proved so devastating that it led to suicide.
Eileen said: Our hearts have been utterly broken, families have been pulled apart and that is not something that can be repaired or rebuilt with bricks and mortar.
Leo Varadkar was deeply moved by what he witnessed and heard in Buncrana. He had read the reports in the Irish Mirror and then saw first hand the distressing, devastating effect on families living in homes that are literally crumbling around us.
Today we can say that our voices have been heard at last.
More than 900 people have formally registered with the Mica Action Group but 4,000 more have not.
Eileen explained: The moment the house is registered as being affected by Mica it becomes worthless. The house insurance is invalidated and no money can be raised against it.
Family homes on heritage land, holiday homes built by locals for retirement, schools, libraries and other public buildings have been affected by defective blocks.
Families have been put out of their homes because theyve been unsafe, families have split up, people have been devastated and left to fend for themselves. Some have managed, others have not. Mr Varadkar wanted to know everything from how many people had registered to how many people we believed where affected but had not yet registered.
He wanted to know how much money we thought it would take to fix and he assured us any company who sold the defective blocks would not benefit from the repair scheme.
The announcement today has given us hope.
Ann Owens, who chairs the Mica Action Group said: This is the day we have been waiting for, for a long time.
It is a day for celebration of that journey, it is a day to take a minute to think of the insurmountable task that was undertaken and to celebrate that we have achieved our aim. We were finally listened to and homeowners can now get the homes that they bought and paid for.
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Government Chief Whip Joe McHugh announced on Tuesday the Government signed off on the scheme. He was joined at a Cabinet meeting by Housing Minister Eoghan Murphy who reported to colleagues on the potential scale of the programme.
Mr McHugh said: I have always been committed to this cause and I am delighted we have now secured approval for a scheme.
This has been a long road for the many families living with this scandal and we hope now that this gives them some peace of mind and assurance that we are aiming to begin work early next year.