A protest has taken place outside the offices of Homebond in Dublin calling on the insurer to pay pyrite damage compensation claims.
It is estimated that more than 20,000 homes are affected by the problem which is caused when under-floor infill used in the building of properties expands.
The Government is setting up a working group to examine the issue, but the Taoiseach Enda Kenny has said the State will not be bearing the cost of repair work.
Homebond said it will not be accepting liability for pyrite problems saying it is the responsibility of quarries who provided the infected material.
Peter Lewis, the Chairman of the Pyrite Action Group, said: "The purpose of today's protest is to follow up on recent announcement by Homebond that they're not going to honour any claims that have been related to pyrite-affected properties.
"This is just unbelievable from the point of view of the people we represent - it's an absolute disgrace".
"They've set a precedent by honouring these claims for a number of years now; and they've now made the decision not to go forward with it."