What is a seal cap?

What is a seal cap?

• A. The mortar cap around the top of a chimney
• B. A decorative ridge cap for the roof edge
• C. The metal flashing around chimney openings
• D. A vent cap for roof penetrations

Answer: (A)

A seal cap is the mortar cap that sits on top of a masonry chimney. It’s a concrete or mortar crown that covers the top surface of the chimney and slopes to shed water away from the bricks and mortar joints. This protects the chimney from water intrusion, which can cause deterioration and leaks over time. It’s not the decorative ridge cap along the roof edge, not the metal flashing around chimney openings, and not a vent cap for roof penetrations—the seal cap’s job is to seal and shed water from the top of the chimney itself.

A seal cap is the mortar cap that sits on top of a masonry chimney. It’s a concrete or mortar crown that covers the top surface of the chimney and slopes to shed water away from the bricks and mortar joints. This protects the chimney from water intrusion, which can cause deterioration and leaks over time. It’s not the decorative ridge cap along the roof edge, not the metal flashing around chimney openings, and not a vent cap for roof penetrations—the seal cap’s job is to seal and shed water from the top of the chimney itself.