3 men needed to do it in 1 hit mate,i did one a few year back in a golf club house 100m2 x 4 separate celings with pillars fire escape lights down ligters everywhere sign hanging from ceiling the f**k**g lot
3 man reciperical laying (one on mixer).1 putting it on, one following with second coat
One flattening and washing edges (the guy thats mixing in between).
Then first man wet trowel second wet trowel 3rd man polish behind you.
Will take you 3 hrs once scaffold set up mate.
Make H shapes across tresles with planks so you dont need to roll the scaffold!