Engineers have identified structural flaws in 17 school buildings that will require temporary works to be carried out in coming weeks in order to ensure that they are safe for pupils and staff to return to in September.

The 17 school buildings, which house 18 schools, are in addition to 22 others where defects discovered last year required precautionary measures, such as scaffolding and protective fencing, to be put in place.

Two of the schools share a building - the Firhouse Educate Together National School and Firhouse Educate Together Secondary School.

Two of the 17 buildings newly identified with structural defects were constructed just last year, while several others were completed as recently as 2017 and 2016.

All were built by Tyrone-based company Western Building Systems.

Educate Together, the patron body of a number of the schools affected, has said the reopening of a number of its schools after the summer break is likely to be delayed as a result of the development.

Minister for Education Joe McHugh has confirmed a number of schools have already told his department they will be unable to open in time for the new term.

Speaking in Tullamore this morning he said he could understand the frustration of principals and parents and had been told that some schools would not be in a position to open for two or three days when the new term gets under way in September, but he said important remediation works had to be completed.

The 17 school buildings were cleared for use last October and November after limited assessments found no requirement for any precautionary measures to be put in place.

However, the Department of Education has said that detailed investigations carried out in recent weeks by engineers have confirmed flaws that require the measures.

It said: "Temporary engineering solutions and other precautionary measures will be put in place in some parts of these school buildings."

The schools affected include 17 primary and one second level. Ten are located in Co Dublin.

A spokesperson for the Department of Education said it was hoped that any temporary fixes put in place would not be as intrusive as those required last year at three schools in west Dublin, where work included the buttressing of school entrance areas with scaffolding tunnels.

Those schools were forced to close temporarily, and children had to be bussed or walk to alternative accommodation for several weeks while emergency works were carried out. These and other schools also had areas of their external walls fenced off.

The department spokesperson said work would take place at the 17 school buildings in coming weeks and it was expected that all of the schools would reopen as planned.

No breakdown has been provided as to the extent or kind of problems discovered in the 18 schools.

The department said that investigations at the schools, carried out last October and November, were based on sample opening up works only.

It said that detailed structural investigations were required to discover the full nature and extent of the issues.

It added that detailed investigations have identified the need for permanent remediation work at the additional schools, which will be undertaken over summer holidays in the next two years.

Permanent remediation work has been completed on 14 of the 22 schools initially affected, but fire safety work remains to be completed.

Work to permanently address deficiencies at eight of those 22 schools will begin in the coming months, the department said, however fire safety issues have been addressed in those eight schools.

One additional school building at Ardgillan Community College in Balbriggan was shut down as a result of safety concerns and remains closed.

The Department of Education has said the safety of pupils and staff is its priority.

The 18 schools affected are: Luttrellstown Community College, Gaelscoil Shliabh Rua, Broombridge Educate Together, Scoil Choilm Community National School, Scoil Aoife Community National School, Gaelscoil na Giúise, Firhouse Educate Together National and Secondary Schools, Rush and Lusk Educate Together, and Lucan Community National School, all in Co Dublin.

Gaelscoil Thulach na nÓg in Meath, Maryborough National School in Laois, Letterkenny Educate Together, St Joseph's Primary School in Gorey, Gaelscoil na gCloch Liath, in Wicklow, Galway Educate Together (below), Gaelscoil Mhic Aodha in Kildare Town, and Mullingar Educate Together.

Galway Educate Together

Of the 14 schools where the Department of Education says permanent remediation work has taken place, one has postponed its reopening after the summer break.

Parents at St Paul's National School in Ratoath in Co Meath were informed earlier this summer that the school would not reopen to pupils until 10 September. The letter said that this was at the request of the department to facilitate the remediation works.

The department has said it continues to liaise with the Chief State Solicitor's Office and the Attorney General's office in relation to an ongoing legal process in relation to the defects. The department has initiated legal proceedings against Western Building Systems in the High Court.

When the structural defects controversy erupted last year, Western Building Systems said that the schools had been previously certified for completion as being free from defects and suitable for use by the department and its employed professionals.

It also pointed out that some of the schools identified as now requiring remedial works were still in their defects liability contract period.

This provides for the contractor to remedy notified defects, which the department identifies under the contract.

The company stressed that it was "not walking away", and would honour its contractual commitments.

It said high standards had underpinned its business for 35 years and that it had been awarded the contracts based on continuous quality of delivery.

Luttrellstown Community College

The patron body of a number of the 18 schools affected has said that the reopening of a number of its schools after the summer break is likely to be delayed as a result.

Educate Together said it is concerned by the development and is seeking further information from schools and the department. It said that it was up to individual schools to decide what was best.

One school told RTÉ News that staff, including cleaners, have not had access to the schools over the summer as engineers carried out investigation works.

The school was told that the keys would be returned on 27 August. It is due to reopen on 29 August with two new classes of junior Infants and seven new members of staff.

The school said those new staff needed to familiarise themselves with the building, and issues such as fire drill procedures.