651 Coney Island Avenue

HLZAE was retained to investigate the intrusion of water into several apartments of a newly constructed 6-story residential complex located in Brooklyn, New York. Built in 2007, 651 Coney Island Avenue is a 21-unit residential building located along one of the busiest throughways at the heart of Ditmas Park. The forensic team conducted a preliminary walkthrough to assess the extent of probes and testing that would have to be performed. According to the property manager and the tenants, there were several areas of water infiltration that potentially stemmed from the roof/bulkhead and traveled down to the 5th floor. In addition, there were leaks from a unit on the 5th floor that were associated with the exterior façade and balcony areas.

After surveying the roof and a few units, we drafted a schedule comprised of flood testing with watertight dams, spray bar testing of exterior windows, and isolated water testing at “suspicious” roof penetrations. After 3 weeks of testing, we exposed multiple probes in 2 units, which were all linked to independent sources of leaks. The infiltration of water into the apartments at the Penthouse level were traced to compromised waterproofing applied at penetrations, improper flashing around the roof drains, and an inadequate roofing system. We also discovered several deficiencies with the exterior waterproofing installed at the head of the windows from spray bar testing a window at the 5th floor.