The Department of Environment has said homeowners in Co Mayo, whose properties have structural damage due to excessive pyrite, will not be eligible for Government compensation.
Less than a month after a scheme to assist homeowners affected by pyrite damage was opened, new problems have emerged at some properties in the Erris area of Co Mayo.
Cracks have been appearing in the walls of over 20 private homes and two local authority developments.
Mayo County Council says testing has revealed excessive pyrite levels in external block work and it is monitoring the situation at 15 houses. It is understood repair work will be carried out by the local authority in due course.
However, it has now emerged that private residents cannot avail of the Government's remediation scheme because the problem has not resulted from excessive pyrite in foundations.
The Department of Environment says the scheme is for a restricted number of homeowners whose properties have been significantly damaged by subfloor pyrite levels only.
Problems with bricks due to pyrite have not been identified until now.
In a statement, the Department said a total of 74 estates in five local authority areas had been identified as eligible for the scheme.
These do not include the one-off homes or developments with structural issues in Co Mayo.
Similarly, exemptions from the Local Property Tax will not apply to homeowners experiencing pyrite related issues outside the designated areas.