The self-locking roof hanger is designed for on the roof deck installation. If you lack a fascia board, or have a steep roof pitch, a roof mounted hanger is recommended. With the galvanized steel being 1" wide and 1/5" thick, these hangers are super strong. You need to use a hanger bender to bend the shaft to the correct angle. You can also use a vice or press brake. It is a quick installation where you place the back edge of the gutter into the hanger, and simply push the bead in and down into place. The hanger is tested to the highest standards and strength classification available. Fasten the hanger with 2-3 stainless or exterior screws, min 1 3/4" long, per hanger. Calculate with one hanger per two feet of gutter.