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No More Leaks
70-25 Yellowstone Boulevard
Plagued by leaks in its large underground garage, the board at 70-25 Yellowstone Boulevard, a 563-unit Forest Hills cooperative, was seeking solutions. The situation was simple but frustrating: an Olympic-size pool on the building’s ground floor was leaking into the garage below it. Not only was spalling occurring on the walls, but the water was harming the structural integrity of those walls – and damaging the cars as well. The situation had gone on for nearly a decade, with various stopgap remedies being employed to stem the tide, but a permanent solution eluded the co-op.
Then, Yvonne Marscheider, assistant treasurer of the board, came across CGI Northeast at a trade show. That isn’t a special effects film company – as in Computer Generated Imagery – but it does offer some special effects of a more practical nature. CGI in this case stands for Concrete Gel Injection, a relatively low-cost and low-impact waterproofing solution.
“I thought it was something we should look into,” Marscheider notes. “When you saw the sample it was so common-sense smart that you immediately took an interest in it,” remarks Tony Pelloise, the property’s executive manager, who works for Gerard J. Picaso Inc. Since 2004, CGI Northeast has successfully completed over 300 projects (both commercial and residential condominum/cooperative buildings) within the tri-state metro area.
This is how it works: CGI contractors come in, drill a hole on the interior side of the building where a crack has appeared. Then Aqua Loc Resin LV goes to work. That is a “two-component hydrophonic resin system,” explains George Doukas, executive vice president at CGI. The resin is injected and when water is added, a flexible, “rubber-like” water-sealing gel is formed. “Upon the calculated setting time (as fast as five seconds for active leaks), the two components will become a gel, occupying volume within the depth of the structure and forming a gel on the positive (exterior) side at the crack points of entry (between the wall and the soil),” he notes.
The gel is non-toxic, odor-free, and environmentally friendly. Because the Aqua Loc Resin LV and the additives are close to the viscosity of water, these fluids can migrate into the smallest of cracks, fissures, and water pockets within the depth of the concrete. The fluids will also travel full-depth to the membrane above to form a gel, if the membrane has been compromised.
Alternative methods (by other companies) would have been to work from the exterior, which would have meant tearing up the grounds outside to get at the leak. In Manhattan, you usually don’t even have that option, notes Doukas, who adds: “Unlike Grout injection (urethane expanding foam injection), our system does not require ports (i.e., hydrocarbon steel) that often times remain embedded within the points of injection and will eventually corrode and allow water to intrude again. Rather, after our injection procedure is completed, our twist-in tools are taken out and the bored holes are closed with hydraulic cement.” Doukas says a big plus of CGI is that it works from the inside.
The process was completed more quickly than a major construction job – it took about a month – and was cheaper ($25,000) and less intrusive. The co-op subsequently hired CGI Northeast for a $45,000 project to Aqua-loc all the other areas of the garage, a process that is currently under way.
Pelloise is pleased. “This repair prevents a million claims from happening where people get damages to the finish of their car, caused by leaks,” he notes. “We were able to address the worst of our leaks coming from the pool deck. It’s a tremendous alternative.”
The new job will take about three weeks, estimates the manager. “To replace the entire roof membrane of the garage would cost us about half-a-million dollars,” explains Pelloise. “The membrane project will have to be done down the road, but this [new product] allows us to put more money in the reserve to help us prepare for the membrane project. And, in the meantime, we’ve solved the more pressing problem.”
Habitat, June 2013