Plans to tell all parents affected by the schools safety crisis if the facility their child has fire and structural flaws have been delayed by a "day or two".
The Department of Education pushed back the deadline for informing families of what is happening. It also confirmed some children at affected schools will be sent to different facilities when they return from the mid-term break.
Education Minister Joe McHugh said while it had been hoped to confirm which of the 42 schools built over the past decade by Western Building Systems are safe to re-enter by Tuesday evening, the deadline would not be met.
Noting the fact "initial site-based structural assessments" must be followed by "detailed analysis by engineers and Department officials", he said clarity on the safety of the buildings will now not be fully known until Thursday evening at the earliest.
"I am pleased with the progress being made on the programme of initial assessments.
The Department said on-site work has begun on three schools - Tyrrelstown Educate Together, St Luke's national school and Gaelscoil Eiscir Riada - to allow the three-storey buildings' ground floors to re-open next week.
However, the scale of the problems at the Dublin facilities mean their remaining two storeys will stay shut, while less serious work is also "commencing" at Scoil Chaitlin Maude in Tallaght and the Castlemills Education Centre in Balbriggan.
The Department has appointed a contractor to "mobilise in the event of internal and or external interventions being required" in more schools over the coming days.
However, a spokesperson said even if no further problems are identified, "displaced classes" in affected schools will have to be sent to other facilities next week, with the Department now arranging space and travel for those affected before the mid-term break ends.
Both Taoiseach Leo Varadkar and Mr McHugh were adamant late last week that the inspections would all be concluded by last night, allowing a clearer picture to emerge over what is facing education authorities and affected families.
In a statement last night, the firm at the centre of the scandal - Western Building Systems, which is based in Coalisland Co Tyrone - repeated its claim that it is not responsible for safety errors at the schools it built for the State.
"We welcome the ongoing progress in the Department’s assessment of the 42 schools identified.
"It is crucial for everyone that we better understand why schools previously certified as substantially complete and suitable for occupation and which also had defects certificates subsequently issued by the Department's advisors are now being assessed by the Department," the company said in a statement.