A survey of more than 1,100 teachers and support staff has revealed that some teachers report even having to take a pay cut.
This is despite many private schools seeing increasing pupil numbers and rising school fees, the respondents say.
The Association of Teachers and Lecturers’ survey reveals a culture of long hours and “working until the job is done”.
Four in 10 of the respondents said they only got a 20-minute break for lunch each day, while anecdotally many said they felt obliged to work through their lunch.
A female teacher in the Midlands said: “I find it necessary to work most lunchtimes in order to prepare for the next lesson. I rarely take a break of more than 10 minutes during the day as there is so much to do.”
Another from the South East has to “take a club one lunch and is on duty another”. She added: “I work all through lunch breaks on other days as well.”
Having set contracted hours is not a common practice in the private sector and respondents reported working up to 14 hours a day.
A female teacher from the South East said: “We are expected to offer extra-curricular and student support as needed. We do not have any set hours apart from what is timetabled. I regularly work 60 hours a week and quite often more. Weekend working is a regular event.”
A male teacher from Sussex added: “Sport and co-curricular involvement mean that I regularly work a seven day week of 12-plus hours Monday to Saturday and four to five hours on a Sunday.”
Despite this, two-thirds of the respondents report not receiving any additional allowances or payments for extra work. Also, 19 per cent of the respondents received no pay increase for 2015/16, while a majority got a rise of between 1 and 2 per cent.
The survey reveals that 25 respondents actually had to take a pay cut in 2015/16.
Despite this, 45 per cent report that their school has more pupils this year compared to last, while 30 per cent say their school’s fees have gone up by more than two per cent.
The ATL is soon to launch a work-life campaign and general secretary, Dr Mary Bousted, said the findings were “disheartening”. She added: “Excessive workload is one of the most serious issues facing the education profession. It affects the quality of teaching and learning our members are able to deliver. It is driving experienced and valuable staff from the profession and is having a hugely detrimental impact on personal lives.”