An expert group examining the Enhanced Defective Concrete Blocks Grant Scheme has warned that it "appears inevitable" that it will have to be extended to other counties.
Last November, the Government unveiled its plan to support homeowners in Co Donegal and Co Mayo affected by Mica.
Work is also under way to determine if homes in Clare, Sligo, Limerick and Tipperary should be included.
However, an expert report published today warns houses in other counties may also be affected.
It states that members of Engineers Ireland have carried out tests that indicate "the problem may be far more widespread than feared".
According to the report, "it appears inevitable that the scheme will have to be extended to additional counties" beyond those already mentioned.
However, the extent of the problem is difficult to determine, and the experts say that if only a small number of homes are ultimately affected it should not have "significant financial implications on current cost projections for the scheme".
It highlights efforts under way in Clare, Sligo, Limerick and Tipperary to be included in the Defective Concrete Blocks Grant Scheme "with immediate effect" and that the legislation should allow for the possible extension of the scheme to other counties.
The Department of Housing is currently drafting legislation to give effect to the Defective Concrete Blocks Scheme.
This report and its findings will feed into that process.
