Distinguish step flashing from counterflashing.

• A. Step flashing is folded segments installed with shingles at walls/penetrations; counterflashing is installed over base flashing to seal seams
• B. Step flashing is installed over base flashing; Counterflashing is the folded segments installed with shingles at walls/penetrations
• C. Step flashing and counterflashing are the same thing
• D. Counterflashing is used on metal roofs only

Answer: (A)