Update 8.39pm: Western Building Systems says it remains available to meet the Education Minister, as assessments continue on buildings identified during the Government's recent schools safety alert.
The company said in a statement tonight that it has been engaging with the Department of Education across the weekend.
"We welcome that of the 42 schools identified by the Department, half have now been assessed," the company stated.
"We note that of the 21 schools assessed so far, two have been temporarily closed (as originally announced by the Department last Tuesday).
"We appreciate fully that this is an important matter, particularly for pupils, parents and teachers.
"In accordance with our contractual obligations, we are engaging constructively with the Department over the past number of days.
"We immediately offered to participate in the assessment process. We remain available to meet with the Minister for Education and Skills.
"We are committed to better understanding why schools previously certified for completion by the Department are now being assessed by the Department."
Serious fire and structural safety flaws have been uncovered at three more Celtic Tiger-era schools built by Western Building Systems as part of an ongoing urgent examination of 42 sites due to fears lives are being put at risk.
The Department of Education confirmed that one more school will only partially re-open after the Halloween break and two more will need immediate protections to remain open - bringing the total number of schools known to be affected to at least six to date.
Last week, new Education Minister Joe McHugh confirmed an urgent structural review of all Western Building Systems properties built for the State was underway due to serious fears people's lives are being put at risk.
Noting the fact in one school there was an 80% chance parts of the walls would dislodge and potentially collapse in storm force winds, Mr McHugh said the structural reviews were urgently needed.
The "urgent" reviews were launched on the back of further fire safety fears detailed in still unpublished audits which are now forming part of evidence for legal cases.
These audits were launched after an October 2015 Irish Examiner expose which revealed one school, Rush and Lusk Educate Together in north county Dublin, was warned by Dublin fire brigade and two architects reports the building would burn down in 20 minutes - far below the 60 minutes evacuate time.
While the Tyrone-based Western Building Systems has denied any wrongdoing and instead blamed Department inspectors for not finding flaws, the Department has been adamant the multi-million euro responsibility lies with the firm.
In a statement on Sunday afternoon, the Department said that of the 42 schools in danger, 21 have been assessed to date.
The latest school to be told it can only partially re-open after the Halloween break is Gaelscoil Eiscir Riada in Lucan, which follows Tyrrelstown Educate Together, St Luke's national school in Tyrrelstown and Ardgillan national school - all of which are in Dublin.
Gaelscoil Eiscir Riada officials were told yesterday "an internal and external intervention is required to facilitate the re-opening of the ground floor area after the mid-term break", a Department spokesperson said.
Two other schools were also informed on Sunday that fences and "protective decking" must be installed around parts of the buildings before they can re-open after the mid-term break due to similar but still unstated safety fears.
They are Scoil Chaitlin Maude in Tallaght and the Castlemills Further Education Centre in Balbriggan, both of which are in Dublin.
The Department said a further "analysis" of results at nine other schools "remains ongoing", but gave the all-clear to six other schools, namely:
All Western Building Systems sites are expected to have been fully examined by Tuesday.
Assessments have continued over the weekend in the school's structure controversy, including seven inspections which were conducted yesterday
The Department of Education says one school, Gaelscoil Thulach na nÓg in Dunboyne can reopen fully after the mid-term break.
In relation to five of the schools, information was gathered and will require further assessment.
Structural issues were identified at Castlemills Education Centre, Balbriggan and will be dealt with during the course of the mid-term break.
In total, 21 assessments of more than 40 schools constructed by Western Building Systems have been carried out to date.