The water seeped through the shingles because of a missing nail, and the plywood has also started to rot. Roof repairs will involve removal of the entire section of plywood and replacement. The shingles would then have to be replaced over top of the new plywood. The video will explain the process and also explain how it was possible for the water to create so the amount of damage with only one missing nail. Once each stage has been completed, you will be able to see all of them. cptafbe65q.