Roofing Glossary

Parapet Wall

A parapet is the low wall that extends above the edge of a flat or low-slope roof — the wall you see forming the roofline on commercial buildings and many rowhouses and additions. It hides the roof edge, provides fall protection, and anchors the roofing membrane.

Parapets are prime leak territory: the membrane must turn up and be sealed to the wall (base flashing), the wall's top needs a watertight cap (coping), and every penetration or joint in the wall is a potential entry point. Parapet flashing failures are among the most common flat-roof leaks.

Parapet caps and coping take the worst weather exposure on the building — full sun, driving rain, freeze-thaw — so their condition is a bellwether for the wall's overall health.

Why It Matters

When a flat roof leaks near the edge, the parapet flashing and coping are the first suspects. Include the parapets in every flat-roof inspection.

A Maryland Note

Baltimore's rowhouses and many Maryland commercial buildings have parapet flat roofs — aging parapet flashing is a routine source of leaks in the city's older stock.

Questions about your own roof? Request a free estimate or call Nucci Brothers Roofing at (301) 458-1003.