Roofing / Internal roof junction
Valley
/ˈvæl.i/noun
From Latin vallis, “a hollow between hills.”
Definition
The sloping inside corner where two roof surfaces meet, forming a channel that collects rainwater and carries it down to the eaves.
Fig. 85 — Valley: schematic studyNOT TO SCALE
Illustrative study — Valley · AI-generatedSAMPLE IMAGE
Photo study — Valley · AI-generated00:06
Structural & construction notes
Valleys carry more water than any other part of the roof, so they get extra protection: a waterproof underlayment plus an open metal liner or interwoven or cut shingles. A valley rafter supports the shorter rafters on each side.
An educational reference. Project-specific design requires professional guidance.