More schools are expected to close as a result of structural checks which are currently being carried out, Education Minister Joe McHugh has warned.
The Department of Education published the full list of schools which were constructed by Tyrone-based Western Building Systems (WBS) between 2003 and 2018.
The contractor's work is now being probed in relation to structural safety.
The crisis deepened as a scramble began to find alternative accommodation for potentially thousands of pupils who risk of having no school to return to after mid-term.
Tyrrelstown Educate Together and St Luke's National School in west Dublin were closed following structural checks, with 1,200 pupils affected. Tyrrelstown Community Centre, on the same campus, as the two primary schools also closed temporarily.
Ardgillan Community College, Balbriggan, Co Dublin already shut 18 classrooms on Monday because of "significant structural issues".
Mr McHugh said there were no indications that all 42 schools which are being checked will have to shut, but he does expect more to close. Inspections will continue next week over the mid-term break.
The minister revealed the technical analysis at Ardgillan, which led to its partial closure, found that if significant defects in a building led to a structural failure, such as in extreme winds, there would be a more than 80pc likelihood that any material would dislodge and fall outwards rather than into the building.
The technical analysis aims to find if material could be dislodged in the event that a wall is compromised.
In a positive development last night, it emerged that an examination at Gaelscoil Teach Giúise in Firhouse Dublin, which opened this year, did not present the same concerns as were evident in Tyrellstown and Ardgillan, meaning the school will not close.
Amid the developments, the Department of Education has now set up a dedicated communications team to ensure principals are kept informed, and a separate team to source alternative, temporary accommodation.
The cost of the assessments, remedial works and the provision of alternative accommodation where schools have to close, or partially close, will be extremely high.
Mr McHugh said: "There was a request that WBS come forward and ensure that if there are costs, [they] will be met by them. If that doesn't happen we are going down a different road."
Meanwhile, Taoiseach Leo Varadkar told the Dáil: "The target is to have interim accommodation in place for when the pupils return to school after the mid-term break next week.
"Everything will be done to find alternative accommodation for schools but it is going to be difficult."
WBS said in a statement: "In respect of the 30 fire safety inspections carried out by the Department, we have only received reports for 20 schools, responding to each in full. We continue to await receipt of the 10 outstanding reports. On the building structures, we have only received a draft report for one school."
It said that it welcomed being involved in an assessment process on the three schools that have been closed "as it allows for a better understanding of why these schools, previously deemed compliant by the Department, have now been closed".