EPDM roofing is a popular choice for flat or low-slope roofs because of its durability and waterproof qualities, yet valley leaks can still occur. Valleys are where two roof surfaces meet, directing a significant amount of water flow. In EPDM systems, leaks here often happen due to poor installation or damage over time. Common causes include improper sealing around the valley, punctures, or seams that have loosened or worn out. Water can seep through these breaks, leading to leaks inside your home. Simple checks a homeowner can do involve visually inspecting for tears, cracks, or gaps in the EPDM membrane specifically in the valley area, and looking for water stains or damp spots on the underside of the roof deck. You can also test for leaks during a storm or by using a garden hose to simulate heavy rain, carefully observing any water intrusion points.
If your DIY inspection reveals visible damage or persistent leaks, it’s a good idea to call a professional roofer experienced with EPDM systems. They can better assess whether the membrane needs patching, fully re-sealing, or partial replacement of the valley flashing. When speaking with a contractor, ask how they plan to fix the leaks and whether they will use EPDM-compatible adhesive and seam tape to maintain your roof's warranty. It’s also smart to inquire about their experience with EPDM valleys specifically, and if they provide a written guarantee on the repair work. Ensuring the roofer understands how to preserve your original warranty and apply industry-approved materials will give you confidence in a lasting repair.