He then moves the pieces of osb to walk on, to get to his next destination.
While I'm showing you things that should have been done....
(As close as I can get, because I am not walking that plank!) See those supports (pieces of wood slanting to the left attached to a beam that goes across the top of the attic ceiling)
Did I mention it's a long drop?
Oh, and did you notice he is wearing, coat, hat, boots, gloves? It's very cold in this part of the house.