What length of wood shingles is commonly used alongside 16" and 18" variations?

The length of wood shingles that is commonly used alongside 16-inch and 18-inch variations is 24 inches. This specific length is part of the standard sizing for wood shingles, which are typically available in increments that allow for consistent and aesthetically pleasing overlaps when installed on roofs or walls.

Using shingles of the same actual exposure length ensures a uniform appearance and maintains effective water drainage. When shingles are 24 inches long, they are designed to provide ample coverage when installed with appropriate overlaps, which is particularly important for preventing water infiltration and ensuring the durability of the roofing or siding material. Variations like 20 inches, 22 inches, or 26 inches are less common and may not fit seamlessly with the more widely used sizes, potentially leading to complications in installation and performance.