Detailing valleys on Spray Polyurethane Foam (SPF) roofs requires careful attention to ensure water tightness and longevity. Valleys are the channel areas where two roof slopes meet, often prone to water accumulation and leaks if not properly managed. There are three common valley types: woven, closed-cut, and open metal. A woven valley involves alternating roof shingles from both sides over the valley, creating a continuous surface. Closed-cut valleys require one side’s shingles to be cut flush and covered by the opposing side’s shingles. An open metal valley uses a metal liner to channel water, which is then covered by shingles on either side. On an SPF roof, proper detailing involves embedding flashing material into the foam at the valley area to prevent water intrusion. The foam should be contoured to allow smooth water flow towards the gutters, avoiding puddling. Simple DIY checks include examining the valley for cracks, splits, or areas where the foam or coating might have pulled away from the flashing. Additionally, ensure there are no signs of rust or poor sealing around any metal components.
If you notice any splits in the foam or visible gaps in the valley flashing or coating, it’s a good idea to consult a professional roofer. Spray foam roofs respond differently to repairs than traditional roofing materials, as improper patching can lead to further water damage or void warranties. When calling a roofer, ask specifically how they will integrate the valley flashing with the SPF layering and what materials they’ll use to maintain warranty compliance. Another helpful question is whether they will apply a protective elastomeric or silicone coating over the valley area to improve durability and UV resistance. Ensuring the contractor understands SPF’s unique properties will help the valley perform well over time and avoid costly leaks or damage.