The company that built more than 40 schools where structural defects have been discovered has accused the Department of Education of "distraction and secrecy".
In a statement issued this afternoon, Western Building Systems has said independent expert answers are needed.
It has repeated questions it has previously posed such as why the schools in question were certified by the Department's own professional assessors, but are now "suddenly deemed to have defects".
It has also questioned how schools built as lately as 2017 and 2018 are now subject to remedial works when a clerk of works appointed by the department was onsite at each school from 2017.
The company has also asked what criteria has been adopted for the remedial assessments and the completion of subsequent works identified.
It has criticised the Department of Education for failing to proceed with an independent review of its building programme that it promised ten months ago.
The Department of Education said it has commissioned a review and the procurement process is nearing completion.
However, it says any review will only be taken after a legal process currently underway against Western Building Systems is complete.
The company said it would continue to engage with the department to better understand the nature and severity of the issues.
Meanwhile SIPTU has called for a major reassessment of the procurement and tendering policy for publicly funded building projects.
SIPTU Construction Sector Organiser, John Regan, said: "The issues that have emerged in relation to 40 schools constructed by Western Building Systems highlights the need for change in the procurement and tendering policy in relation to publicly funded building projects.
"These issues have resulted in unnecessary stress, and in many cases expense, for parents of children attending these schools."