I'm getting ready to install roofing shingles on an outdoor shed/office. The roof has a small/moderate incline. At the moment, the roof just has bare plywood on it. In several spots, I needed to remove/relocate nails so there are some old holes in the roof deck. Should I fill these in with something? If so, what compound should I use to fill in the holes?
Or is that not necessary considering that I'm going to place underlayment felt over everything and shingles over that?