Los Angeles apartment complex on fault line gets waterproofing solution.
A luxury multifamily apartment complex in the heart of Hollywood, CA, 1840 N. Highland Ave., is 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. The Alquist-Priolo Earthquake Fault Zone runs through the property boundary.
EPRO Services Inc. (EPRO), Wichita, KS, provided blindside waterproofing and building- envelope protection for the complex, using 70,000 sq.ft. of its E.Protect+ and E.Proformance below-grade solutions. Three stories of the structure sit below grade. The team had to install a 2-ft.-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.
E.Protect+ Underslab was used 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 the company’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 at 2-ft. 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 elevators and utilities.
“We collaborated with Terra-Petra (Los Angeles), the waterproofing consultant, regarding the usual qualifications, review of transitions, and fastening and drainage considerations,” said David Frymer, president, Frymer Construction, Santa Monica, CA, 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, with Terra-Petra, who was contracted to provide waterproofing consulting. “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.”
The E.Proformance Shoring blindside waterproofing system was used for the non-hydrostatic waterproofing system. E.Proformance was 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-yr., no-dollar-limit warranty to the developer. Providing such a robust warranty encouraged the entire project team to collaborate with the company to anticipate and overcome challenges in the field.
“My experience with EPRO has been outstanding,” said Mostafa Sobhi, president of BM Builders and BMG Roofing, Los Angeles, and certified EPRO applicator. “Their quick turnaround in answering any concerns and providing details due to changing field conditions has been a huge factor on how jobs like this can be successful, while also maintaining schedules. The EPRO team has always been there to support us from day one.”
EPRO’s E.Series systems features built-in layers of redundancy. The redundancy is achieved by combining different types of waterproofing materials to leverage the positive attributes of each and eliminate a continuous seam. The company calls this Redundant Field-Installed Composite Design. Founded on the belief that redundant systems provide the best protection, the company provides composite waterproofing and vapor-intrusion systems for all types of performance needs and project conditions.