A ridge board is a horizontal structural element used in roof construction. It is typically installed at the peak of a roof, where two sloping roof sections meet. The ridge board provides support for the roof rafters, helping to maintain the shape and stability of the roof structure. In addition to its structural role, the ridge board also serves as a reference point for aligning the rafters during installation. It is usually made of wood or engineered lumber and is an essential component in various roofing styles, including gable roofs and hip roofs.