Western Building Systems is insisting there were no "short cuts or penny pinching" involved in its school construction projects.
Assessments of the company's 42 schools were completed yesterday - with more than half needing some form of remedial work.
19 out of the 42 schools built by Western Building Systems are having safety measures like fencing and protective decking installed.
19 other schools were given the all clear following assessments.
While the vast majority of the schools will re-open after the mid-term, four schools in Dublin will only partially re-open - including one building being closed at Ardgillan Community College.
Meanwhile, Western Building Systems has criticised the Department of Education for giving the impression at the start of the controversy that all 42 schools could be facing closure.
The company said: "It is our view that shortcomings in the regulatory system have once again been exposed.
"Provisions within the existing regulations can be further utilised, and additional reforms warrant consideration.
"Our company works in the UK and Northern Ireland where school building projects are monitored and certified by a wholly independent entity with no Departmental and contractor involvement."