Repair a deteriorated parapet wall, addressing coping, through-wall flashing, and freeze-thaw exposure specific to parapets

Steps

1. Inspect the parapet coping (cap) for cracked units, open joints, missing sealant at coping joints, and inadequate slope/overhang, since a parapet's exposed top is its primary vulnerability to water entry
2. Check for through-wall flashing at the parapet base (where the parapet meets the roof membrane) and confirm it is continuous and properly tied into the roofing membrane; missing or failed through-wall flashing is a common root cause of parapet deterioration even when the visible masonry looks intact
3. Assess freeze-thaw damage (spalling, cracked coping, bulging or delaminated wythes) which is often more severe on parapets than the rest of the facade because parapets are exposed on both faces and at the top to weather and lack the thermal buffering of an occupied building behind them
4. Repair or replace damaged coping units with proper slope, overhang, and drip edges, and reset with a mortar or sealant system appropriate to expected joint movement (see sealant-vs-mortar joint guidance)
5. Coordinate through-wall flashing repair or replacement with a roofer where the parapet interfaces with the roof membrane, since this is a shared trade boundary similar to chimney flashing work
6. Reassess and repoint parapet field mortar separately using appropriate mortar matched to the wall's masonry, since parapets often need more frequent repointing cycles than the main facade due to their harsher exposure