For those who’re any shingles adjacent to flashing are free, prevent nailing the shingles to the facet that makes contact with the flashing. Instead, bond the shingles for the flashing using roof cement to prevent puncturing the flashing.[27] X Research source Ways to Waterproof a Concrete Roof Created by Doityourself https://roofwaterproofingservices90122.activablog.com/17034804/the-single-best-strategy-to-use-for-roof-waterproofing-services-company