Teachers do indeed get 13 weeks where school is closed to pupils. They are not technically paid for that time.
This is easily seen when you compare an employed teachers pay to a supply teacher's pay.
An employed teacher recieves much less per day, over 12 months, than a supply teacher.
A supply teacher takes home more money per day than the employed teacher. However the employed teacher does recieve the same per day wage, or thereabouts, but it is deivived into 12 eqiual payments and paid per month instead. So, there is no additional holiday pay - just that the hours they are contracted for are paid in equal payments per month.
Just because a teacher only has xxx contact hours doesn't mean they don't work outside of that time.
Infact it would be impossible to do the role of a teacher without working outside of that time.
PPA time is no where near sufficient to cover all the planning, prep, assessment, report writing, display work, meeting with parents or educational agencies, other admin, etc. It has to take place outside of those contracted hours.