In roofing terminology, what is a course?

• A. The surface, installed over the supporting framing members, to which the roofing is applied.
• B. A horizontal row of shingles or roll roofing running the length of the roof.
• C. A peaked saddle construction at the back of a chimney to prevent snow and ice buildup.
• D. The open portions of a strip shingle between the tabs.

Answer: (B)

A course is a horizontal row of shingles or roll roofing that runs the length of the roof. Shingles are laid in successive courses from the bottom edge up toward the ridge, with each course overlapping the one below to shed water. The idea of it running the length of the roof emphasizes that a course spans across the roof rather than being a single spot. This distinguishes it from the roof deck, which is the surface installed over the framing; from a cricket or saddle, which is a structure to divert wind and snow around a chimney; and from the exposed tabs of a strip shingle, which are the openings between the cutouts rather than the row itself.