The Problem
The building owner contacted us after their roofer flagged serious mortar deterioration on the chimney and both parapet walls during a roof replacement. Mortar on the chimney was soft enough to scrape out with a fingernail. The parapet caps had cracked, allowing water to run directly into the wall cores from above.
This three-flat sits three blocks from the lake. The east-facing parapet takes the worst of the lake-driven moisture, and after 70+ years without repointing, the joints were well past due.
Our Solution
We erected scaffolding on the east and north sides to access the chimney and parapets safely. All deteriorated mortar was removed to 3/4 inch minimum depth by hand. The chimney required full repointing on all four faces - roughly 140 linear feet of joints.
Both parapet walls received full repointing on their exterior faces. We also replaced the cracked concrete parapet caps with new pre-cast caps set in flexible sealant to allow thermal movement without cracking.
Mortar was a standard Type N mix color-matched to the existing 1952 joints. Sand selection was critical - the original used a coarser river sand with a distinct gray-brown tone that finer modern sand cannot replicate.
The Result
The chimney and parapets are now fully sealed against water entry. The new parapet caps provide a proper first line of defense, shedding water away from the wall cores. The owner reported zero water staining on the top-floor ceilings through the following winter - the first dry winter in years.
