I'm going to be installing an attic vent fan this weekend. The 15 step instructions make it seem pretty straight forward. However, they are written for a new installation and I'm replacing and existing fan.
My question is: do I need to worry about holes left from the old installation if the new fan/flashing covers them? I plan on only using roofing cement on new nails I put through or any holes not covered by the new flashing.