Two Dublin schools have shut with immediate effect after problems were discovered during structural checks being carried out at 30 schools built by Western Building Systems.
More than 1,200 children go to Tyrrelstown Educate Together and St Luke's National School in Mulhuddart, which have both closed today.
Earlier this week, serious structural issues forced Ardgillan Community College in Balbriggan closed one of its buildings.
A statement from Educate Together said: "The Department of Education and Skills has announced that Tyrrelstown Educate Together National School is to close with immediate effect, following a safety assessment conducted at the school today.
"Consultant structural engineers appointed by the Department have today identified significant structural issues with the Tyrrelstown ETNS building, similar to the structural problems discovered at Ardgillan Community College which closed last week. Educate Together also understands that nearby Saint Luke's National School, Tyrrelstown is also to close with immediate effect.
"This safety assessment was organised as part of a series of investigations being carried out on schools built within the past ten years by Western Building Systems.
"For safety reasons, the Tyrrelstown ETNS building cannot be occupied whilst remedial works are being carried out. Educate Together expects that all students will be accommodated by the Department of Education after the mid-term break with interim accommodation solutions. These solutions are the responsibility of the DES. However Educate Together will assist the DES in any way it can in finding and sourcing suitable temporary accommodation for the school community.
"Speaking on Morning Ireland this morning, Minister McHugh stated: “if today shows up that there are issues in that school [Tyrrelstown ETNS], certainly we are going to be anticipating that there will be more. That doesn’t mean there will be issues in all of them.” Educate Together is anxious that structural assessments take place at all other affected schools as a matter of urgency to ascertain the facts in the case of each individual school.
"Educate Together acknowledges and reflects how inconvenient and frustrating this will be for the Tyrrelstown ETNS school community, and any other Educate Together school communities that may be affected by these structural issues. Educate Together is in ongoing communication with these schools and the DES."
The Taoiseach, Leo Varadkar, says it's clear to him that corners were cut while schools were built during the Celtic Tiger.
"It certainly does appear to me that corners were cut back in the Celtic Tiger period when it comes to the building of some of these schools, which is truly disgraceful in my view," he said.
"Prior to 2014/2015, and during the Celtic Tiger period, schools were built without proper oversight."
In a statement, a spokesperson for Western Building Systems said: “We are responsible, solutions focussed professionals operating for 35 years. We place considerable emphasis on delivering high quality work on each of our projects, always ensuring compliance with regulatory requirements. These include projects which have met the Department of Education and Skills compliance standards.
“We fully recognise that this is a very important matter, not least for the pupils, parents and teachers of the schools involved.
“Until now, our integrity has never been questioned. Each of our Department of Education and Skills’ projects, both before and since the amendments to building regulations in 2014, were subjected to inspections during construction. Every time, each was certified as meeting compliance standards.
“We are interested in getting to the bottom of this and that starts with establishing the facts. We are moving to intensify our engagement with the Department and other relevant bodies to better understand the issues which have now arisen and to work to resolve them.
“We have received some rather than all of the individual school fire audit reports. Of those we have received, we have responded with two exceptions which have only recently been issued to us.
“We are writing to the Minister for Education and Skills on the matter and remain available to meet with him and his officials.”