Final answer:
Scuppers used for secondary roof drainage should have at least a 4-inch opening dimension.
Step-by-step explanation:
In engineering, the term 'scuppers' refers to drainage openings in roofs or walls that allow water to flow off the structure. Scuppers are commonly used for secondary roof drainage to prevent water buildup, leaks, and damage. According to standard building codes, scuppers used for secondary roof drainage should have an opening dimension of at least 4 inches.