Plastic roof edging is also commonly called vinyl roof edging, or it is also known generically as drip edge. Roof edging serves two purposes: It adds a finishing touch to any roof; and most important, it channels water either into rain gutters or off the side onto the ground. By installing plastic roof edging, you can ensure water will flow away and off the edges of the roof, preventing it from flowing beneath flashing and shingles, where it would cause roof leaks and very expensive future repairs.
Installation on new or torn-off roofs
Place the plastic roof edging along the edge of a new or torn-off roof, directly onto the bare roof boards or plywood underlay sheathing. Roof edging is pre-bent to fit perfectly against the 90-degree roofing edge, so push and hold it in place firmly.
Nail the roof edge in place, using a hammer to pound the galvanised nails in at approximate 15 to 20 cm (6 to 8 inch) intervals. Nail the entire strip in place.
Add the next edge by overlapping it onto the nailed edge by 3.7 cm (1 1/2 inches). Nail it in place.
Overlap the edging at corners, making sure each edge is flush against the roof edge and nailed down. Trim as needed with shears.
Place felt or tar paper over the plastic roofing edge, and then shingles over the paper for a completed roof.
Installation on pre-existing roof
Tuck the plastic roofing edge beneath the last layer of shingles, but over the felt or tar paper.
Nail the edging to secure it through the shingles with 3.7 cm (1 1/2 inch) galvanised nails set at approximately 15 to 20 cm (6 to 8 inches) apart.
Nail the first piece on, then overlap the second piece about 3.7 cm (1 1/2 inches) over the first piece. Nail it in place.
Overlap at the corners, nail it in place, and continue around the entire roof edge in this manner. Trim the excess edging with your shears to fit.
Never add plastic roof edging in cold weather. Plastic edging has a tendency to crack if it is nailed onto a roof when it is cold.
Always wear safety glasses when using a hammer and nails.