jdonly1's correct but I don't think that this dough (at 60% hydration) should be spreading rather than rising even if made without improvers etc. I don't think that it needs a special flour either, at this hydration even a supermarket cheap bread flour should be fine.
I think that he's hit the nail on the head when he says, "make sure your dough is mixed enough". Knead it for 8 - 10 minutes in a Kenwood Chef (or similar) or 15 minutes by hand - and time it, 'cos 5 minutes seems like 15 when you're kneading dough by hand!
HTH
Phil