Hertsmere Jewish Primary pupils will enjoy an extra week's holiday after the start of the new academic year was postponed because of flood damage repairs.
Parents were informed by headteacher Steven Isaacs this week that the extent of the damage caused by flash floods in Hertfordshire in June had only recently become clear.
Restoration consultants had advised earlier this month that September 12 would be "the most realistic school re-opening date".
The school is examining the possibility of off-site events during the week and optional project work may also be emailed by staff.
A Hertsmere parent accepted that the delay was "not the school's fault. But it's a nightmare for working mothers. I may have to take the week off. There aren't any summer camps for them to go to."
Even after September 12, some pupils may have to be housed in Portakabins and packed lunches served until the kitchen and hall are operational.
Nursery children had been relocated to the library for the last month of summer term after the school building was affected by the overspill from drain pipes.