https://www.pubpub.org/user/stay-dry-roofing">https://www.pubpub.org/user/stay-dry-roofing. A top quality roofing system will have them mounted around the edge of the roofline, where upright walls fulfill the roof https://brianehve943318.digitollblog.com/39456120/stay-dry-roofing-things-to-know-before-you-get-this