01
Choose a valley appropriate to the roof
Open, closed and specialty valley arrangements create different appearances and drainage paths. Roof size, slope, climate, slate dimensions and expected water volume should guide the design rather than appearance alone.
02
Protect the drainage channel
Valley metal needs suitable width, laps, fastening and edge treatment. Cut slates should remain stable and should not crowd the centerline or leave vulnerable corners. Debris accumulation and ice can magnify a detail that is already undersized.
03
Treat failed valleys as an assembly repair
Coatings may obscure splits or corrosion without restoring concealed laps. Durable renewal usually requires enough slate removal to access sound metal termination points, followed by careful replacement of the surrounding units.