A roof valley lies at the inward meeting of two sloping roof planes and forms part of their drainage route. Its geometry differs from an eaves gutter along the lower edge, even when both are casually described as gutters.
Connections with tiles and underlying layers deserve their own assessment. A moisture report near a valley should therefore identify the location and surrounding roof planes clearly. A detail photograph without an overview may conceal the relationships between the components involved.
Ask which components a proposal will assess, expose, repair or reinstate. The term roof valley establishes neither the material present nor the extent of the intervention. Removing components yourself to inspect the assembly is not part of this preparation process.
Worth asking
Frequently asked questions
Is a valley an ordinary eaves gutter?
No. It lies between converging roof planes and has different geometry.
Does the name establish the material?
No. The actual arrangement needs separate identification and assessment.