The Dáil has heard that half of houses dealt with under the defective blocks scheme will have to be redone.
Charles Ward TD with the 100% Redress Party said that of 144 houses, 70 received only outer leaf remediation where the blockwork was retained.
He said these would have to be redone "at great expense to the Exchequer."
Mr Ward made his comments during a Dáil debate on a motion which called on the Government to "declare the defective concrete crisis a national emergency, mobilising the full powers of the state".
Sinn Féin, Labour, the Social Democrats, People Before Profit and some other independents, including presidential candidate Catherine Connolly, also support the motion.
Mr Ward said the concrete blocks redress scheme had many flaws and was "broken by design".
He said more than 80 amendments had been proposed to fix the scheme and he added that appeals take years with families stuck in unsafe homes.
"Some homes are so toxic with damp and black mould that respiratory issues have now become normalised. We are making people sick. You're making people sick with this failure of this scheme," Mr Ward said.
In response, Minister for Housing James Browne told the Dáil that the scheme was beginning to deliver for many homeowners in the effected counties.
He said more than 3,000 homeowners were at various stages of the grant scheme and would receive funding up to the cap of €460,000.
This was an increase of 10% on the previous cap.
He said the Department was redoubling its efforts along with local authorities, the Housing Agency and homeowners to accelerate funding and works.
More than €193 million has been provided to date and he said €175 million had been allocated for 2026 reflecting the strong take-up of the scheme.
He said amendments to the scheme would be included in a new Bill to be brought forward shortly which would also legislate for the new cap.
