Schools are expected to close next week as members of Northern Ireland's five teaching unions plan a half-day walkout.
In total, five dates of strike action have been planned in response to a long-running dispute over pay.
The Education Authority (EA) said due to the large number of staff involved, significant disruption is expected.
Last week, non-teaching education staff held a day of strike action over failed pay reform and education budget cuts.
A half-day strike will be held on Wednesday 29 November, with a further four days planned for after Christmas.
Head teachers will join strike action for only the second time in their union's 126-year history.
The National Association of Head Teachers (NAHT) previously joined four other unions in a full-day walkout in April.
'We have run out of patience'
Liam McGuckin, NAHT's NI president, said the action was "the last resort" for school leaders after "a year of dispute with no progress".
"The system is failing our schools, our workforce and, most importantly, our young people," he said.
"We have simply run out of patience.
"We need immediate investment, without which the profession that holds together much of the fabric of society will be irreparably damaged."
Teachers are represented by the Northern Ireland Teachers Council (NITC) which includes five unions - the NASUWT, Irish National Teachers' Organisation (INTO), Ulster Teachers' Union (UTU), National Education Union (NEU) and NAHT.
Members of NASUWT in Further Education colleges will also take part in the strike action.
The pay dispute has been ongoing for 18 months.
In February 2022, unions rejected a pay offer from employers for the years 2021-2023, describing it as "inadequate".
Dr Mark Browne, the department's permanent secretary said the trade unions are "fully aware" a pay offer "can only be made if it is affordable within the allocated budget".
"The department fully understands the frustration of teachers and school leaders over the ongoing absence of a pay offer," he said.
Dr Browne added: "It is regrettable that the department has been unable to offer teachers a pay award for the past three years similar to other jurisdictions, but it is simply unaffordable within an inadequate education budget".
Continued strike action, he said, "serves only to cause disruption to the education of those who least deserve it, our children and young people".
NITC recognise that our members are resolute and determined to secure a fair pay settlement, which both properly reflects their value and also takes account of the soaring cost of living.#PayParityInEducation #TradeUnionThursday #InvestInEducation pic.twitter.com/JffDGPYEZB
— NASUWT N. Ireland (@NASUWT_NI) October 19, 2023
Ongoing pressures around Stormont's education budget means it is not clear how much money is available to make teachers a pay offer the unions would accept, but the Department of Education has previously said their demands are "unaffordable".
'Our children will pay the price'
Jacquie White, UTU's general secretary, said that the profession has never faced such a "parlous situation".
"We are truly in unchartered territory now," she said.
"Our education system here in Northern Ireland, once the envy of the UK and beyond, is in the jaws of a once-in-a-lifetime crisis and unless something is done to address that, it is our children who will pay the price."
The stalemate over a pay deal means schools are "haemorrhaging teachers" with many leaving for teaching jobs elsewhere, Ms White continued.
"It is downright shameful that this has had to happen and displays a morally bankrupt attitude on the part of the powers that be."
Justin McCamphill, NASUWT's Northern Ireland official, described it as a "crisis situation" for members, who have no option to strike.
The union's general secretary, Dr Patrick Roach, called for teachers to be "properly rewarded" for the work they do.
"At a time when teachers and lecturers are facing the biggest squeeze on their finances in a generation, the prospect of a further real-terms pay cut is simply unacceptable," he added.
"Our members are not prepared to stand by while their pay dwindles and their living costs rise."
The EA said in a statement: "The full impact will not be known until the strike action has concluded."
She said the management side of the Teachers' Negotiating Committee (TNC) - a body made up of the EA, the Department of Education and a number of other education sector employers - is "considering the potential implications of this action".
Guidance will be issued, the spokeswoman added, to support schools with managing the affect on pupils.
The spokeswoman added: "Parents, children and young people will be informed of any disruption through their normal school channels".