Flat rate (which fair work Australia does not recognise)
It all depends on the type of employment and weather you are on and hourly rate or annual salary. Annual salaries are generally loaded with extra to compensate when you are not on site.
Casual employment (hourly rates), you only get paid for the hours you work. For example if you were on a 2/1 Roster, you would be paid for the two weeks on site but not the week spent at home on R&R. Keep in mind FIFO positions always pay a lot more which means you would still most likely come out on top.