01
Read the roof shape
A valley is an inward junction where adjacent roof planes direct water toward a shared line. A hip is an outward junction between slopes. That distinction affects material detailing and quantity schedules. Calling both of them ridges can lead to a supplier or estimator answering the wrong question.
02
Label photographs and drawings consistently
When asking for help, include a wide photograph showing the roof shape and mark the particular line. Use separate labels for valley, hip, and ridge. Have the contractor confirm any uncertain labels. Clear terminology is especially valuable when ordering special pieces or comparing quotations, because a correct slate size alone does not identify the detail in which it will be used.