Housing Complex Relies on Waterproofing System in Los Angeles, California
by Peter Grant, vice president of marketing & sales, EPRO Services, Inc.
EPRO Services, Inc., an innovator of composite waterproofing, methane mitigation, and vapor intrusion systems, provided blindside waterproofing and building envelope protection for a new, luxury multifamily complex in the heart of Hollywood, California, just steps away from the world famous Hollywood Bowl and Hollywood Boulevard. The 118-unit complex sits on an 8,144 sq.ft. lot, and presented several challenges, which 70,000 sq.ft. of EPRO’s E.Protect+ and E.Proformance below-grade solutions were able to mitigate.
The lot is zoned for a multifamily housing project, and the Alquist-Priolo earthquake fault zone runs through the property boundary. Subsequently, the team had to install a 2’-thick layer of geofoam between the shoring system and below-grade shotcrete walls, which were put in place to reduce and eliminate seismic movement impact on the building’s structure. Three stories of the structure sit below grade.
E.Protect+ Underslab was implemented to protect the building foundation and blindside vertical walls for water intrusion considerations. In addition, E.Protect+ transitioned to E.Proformance Shoring system above the design water table. Complexity increased as EPRO’s negative side waterproofing systems were applied directly to the Geofoam layers for below-grade waterproofing purposes. The transition between E.Protect+, hydrostatic, and E.Proformance, non-hydrostatic, was above the high historical water table level and extended to grade.
“EPRO helped us and the geotechnical consultant work through the issue regarding the north face of the building where the fault line divided the water table across the north and south sides,” said architect Ronald Rosell, AIA, with the project architect, Arquitectonica, Los Angeles. “The fault acted like a subterranean waterfall, and EPRO gave us recommendations for how best to prevent that hydrostatic pressure and constant flow of water from impacting the structure.” The waterproofing system was carefully detailed around many pipe penetrations and several pits for both elevators and utilities.
“We collaborated with Los Angeles-based waterproofing consultant Terra-Petra regarding the usual qualifications, review of transitions, and fastening and drainage considerations,” said David Frymer, president, Frymer Construction, Los Angeles, the project’s general contractor. “EPRO was with us every step of the way.”
“There were some real twists to the project, including two fault lines under the cantilever of the building and the water table, which sat at different levels. EPRO saved us a lot of work and was on the site a great deal of the time,” said Josh Heidt, CP, Terra-Petra. “EPRO was deeply involved with this, responded promptly, and have the kind of case history we were looking for from a manufacturer on a multi-faceted project like this.”
EPRO’s E.Proformance Shoring blindside waterproofing system was used for the non-hydrostatic waterproofing system. E.Proformance was also selected as a solution at grade level where it was transitioned to a hot rubber horizontal waterproofing system, a landscaping area for planters, and a stucco wall system. Despite the high level of complexity and the presence of hydrostatic conditions, working closely with the project team enabled EPRO to provide a 15-year no-dollar-limit warranty to the developer. Providing such a robust warranty encouraged the entire project team to collaborate with EPRO to anticipate and overcome challenges in the field.