https://johnnylist.org/Stay-Dry-Roofing_323476.html">https://johnnylist.org/Stay-Dry-Roofing_323476.html. A high quality roofing system will have them installed all around the edge of the roofline, where vertical walls https://geraldozac560176.isblog.net/stay-dry-roofing-things-to-know-before-you-buy-56601167