The Government has admitted almost half of the schools found last year to have serious fire and structural safety problems will still not have the faults repaired by the start of the new school year.
Education Minister Joe McHugh said further repair work will be needed over the coming months to ensure the schools are brought up to standard.
Mr McHugh last autumn launched a detailed investigation into dozens of schools built during the Celtic Tiger era's rapid building programme by Western Building Systems.
After initial examinations, Mr McHugh gave the green light for a number of the schools to re-open, on condition various levels of repair work took place to ensure the buildings were safe for thousands of children.
It had been expected that structural remediation work on 22 of the 40 schools which needed further repairs would be concluded over the summer break, before a second wave of repairs takes place later this year.
However, while emphasising progress is being made, in a statement Mr McHugh said only 14 of the first group of 22 schools will be fully repaired by the start of the new school year.
"I am deeply conscious of the disruption and difficulties that this issue has caused since last autumn," the Minister said.
"It is a complex problem that has required intensive analysis and tailored solutions following detailed assessment by engineers.
“Safety has always been at the heart of our response to the structural deficiencies that were identified in these schools. It will continue to be.
Any permanent or temporary engineering solutions or precautionary measures that are advised by engineers as a result of detailed assessment and analysis of these buildings are being undertaken.
The delay in completing initial remediation work on all 22 of the first group of schools means eight of these facilities will see ongoing work on their sites in the coming weeks after schools return for the new academic year.
A further 18 schools will undergo further work after this point, in a bid to address less serious structural problems.
All of the schools which have been examined and are now in the process of repair work were built by Western Building Systems, from Coalisland in Co Tyrone.
The company won the rights to a series of rapid school build contracts a decade ago, including the schools that are being examined.
In addition, the company also won contracts to build other units at State facilities, including rapid build houses and hospital projects.
While WBS has insisted it is not at fault for any errors in the sites, the Department of Education is in the process of taking legal action against the firm, with court hearings expected later this year.
Mr McHugh has previously said there will be "no holding back" from the Government in terms of seeking compensation, and that officials are "pushing very hard" to ensure the taxpayer is not left with a multi-million euro repair bill.