This video shows how you can properly install a roof valley. Properly installing valleys is essential in preventing any water leakage that can lead to roof damage. It would be wise to install a waterproof underlayment first to keep your roof deck from the harsh effects of weathering. You can then fasten the starter strips to protect your roof's edges from damage due to climatic elements.
Corner cutting is the next step after fastening your starter strips.
This step involves accurately placing your valley on the roof deck crease before cutting off any excess metal extending beyond the fascia board corners. You can then nail your valleys on the outer edges where water is unlikely to pass. The best roof installations incorporate this nailing technique to prevent leaking holes from forming at the valley centers.
Ensure you fasten starter strips along the length of your valley after nailing it in place. Such starters provide a base for correctly installing your shingles around the valley. It would be wise to align your shingle nail lines to the valley starter strips for a more functional and visually appealing finish. Cut off shingle edges extending into the valley to avoid interfering with the intended water flow.
