Virtually all teachers now say they are working harder than ever to keep pace with developments, a survey of 354 Scottish NASUWT members concludes.
Secondary teachers are six times more likely than colleagues in primary to report increased workload and working hours.
As MSPs and pundits challenge the success of the pound;2.15 billion investment in the post-McCrone deal, the NASUWT is the second union in successive weeks to argue that school managers and local authorities are getting more than a fair return for higher pay.
The Scottish Secondary Teachers' Association last week insisted standards were rising for pupils, and teachers were working well beyond their official 35-hour week.
Mary Howard, senior assistant secretary of the NASUWT at UK level, told Scottish members: "The jewel in the crown of the McCrone agreement was the 35 hours' contractual limit but for most teachers it is not being met. A tiny minority of teachers - 5 per cent - said they had on average a workload of 35 hours or less a week."
Teachers wanted action on cutting paperwork and bureaucracy and on guaranteeing preparation and correction time. They also wanted a limit on the number of new initiatives, smaller class sizes and more support staff.
"Teachers' views on job-sizing were overwhelmingly negative, with 80 per cent of primary teachers and 90 per cent of secondary teachers indicating that it has had an unsatisfactory outcome for teachers in their schools,"
Ms Howard said.
As for continuing professional development, two-thirds of teachers said the time allocated had not increased. Around one in five secondary teachers had no access to plans and records of their CPD.
Bill Cook, Scottish president, said he was "a great believer McCrone can work", although he accepted it was being implemented differently across the country. "It will deliver the goods for Scottish teachers," Mr Cook forecast.