Valley detailing on a steel roof refers to how the metal sheets meet and drain water where two roof slopes intersect. There are three common valley styles for steel: woven, closed-cut, and open metal valleys. Woven valleys involve interlacing the metal panels from each side, creating a tight, overlapping seam that channels water smoothly. Closed-cut valleys use a single piece of metal running down the valley with adjacent panels cut to butt tightly against it, offering a clean, sealed look. Open metal valleys feature a metal flashing strip exposed in the valley, with the steel panels stopping short of the centerline. These designs prevent water pooling and leaks by properly guiding runoff off the roof. Valley issues often occur due to improper sealing, debris buildup, or incorrect panel alignment, which can cause water infiltration or rust.
For simple, safe DIY checks, visually inspect valleys after rain to see if water flows freely without pooling or leaks. Look for signs of rust, loose fasteners, or damaged sealant along seams. Clear away leaves or debris that might block drainage. You can gently run a garden hose over the valley to test flow but avoid walking on the valley metal as it can be fragile and slippery. If you notice standing water, leaks in the attic, or damaged metal, it’s time to call a professional roofer with steel roof experience. When interviewing contractors, ask if they are familiar with all three valley styles and which approach they recommend for your roof’s pitch and conditions. Also, inquire about what sealants or fasteners they use to ensure the warranty on your steel panels remains valid after repairs. Understanding these details will help ensure a long-lasting, leak-free steel valley installation.