Water Infiltration Mitigation, 96th Street Station, Second Avenue Subway


Project Overview

92nd Street Station on the Second Avenue Subway Line was opened to the public in 2017, but the roof structure in the Mezzanine public zone was plagued by significant water infiltration. Several unsuccessful chemical grouting attempts were made by MTA C&D prior to tasking Sovereign to remediate leaks through the roof structure in the public zone. The area treated included the roof of the public area between the W30 Architectural walls from column line 15 to column line 22.  


Sovereign was tasked to design and implement an effective solution.  Following research and development, Sovereign designed a leak program using NOH2O® to create a new waterproofing membrane above the roof employing positive-side grout application. Several tests were then performed to confirm successful spread of grout over the treated area. 


Work was successfully completed on schedule, followed by a period of observation of the  treated area conducted jointly with MTA C&D. The treated areas were cleaned and painted before the final acceptance walkthrough and completion of the project. NOH2O® successfully formed waterproofing membrane above the roof structure, rendering the treated areas dry.