High Safety Ratings and Installation Efficiency Makes Hollowcore Plank Material of Choice in Luxury Apartment Complex

High Safety Ratings and Installation Efficiency Makes Hollowcore Plank Material of Choice in Luxury Apartment Complex


Brooklyn Park, MN


Doran Companies


Doran Companies

Hollowcore plank proved itself as an efficient construction material for the 610 West Apartment development in Brooklyn Park, Minn., after the erection process was completed two weeks ahead of schedule. The four-story complex is part of a multiphase project with the goal of creating luxury living for its suburban residents. County Materials Corporation supplied phase 1 and 2, which includes a 279-unit complex, with 119,000 sq. ft. of hollowcore plank. The 610 West development is owned by Doran Companies, who oversees their own project development, architecture, construction and property management.

The early planning stages called for an underground parking garage as a key feature to the luxury apartment complex. Parking garages demand careful planning because of their many challenges and requirements. Doran Companies needed a building material that would minimize support columns, accommodate ventilation and lighting fixtures, and meet safety regulations. Doran Companies turned to hollowcore plank from County Materials as their material of choice to create the roof and floor separating the garage from the upper living areas. Hollowcore was an easy choice for this application because of its high fire ratings, sound reduction, and its ability to span long stretches without the need for additional support columns.

Shortened Construction Schedule

The project’s general contractor began the construction process by excavating the site, building the foundations and constructing masonry piers for the precast columns. Doran Companies then turned the site over to County Materials for hollowcore erection. County Materials made 385 deliveries during phase 1 and 2. The subcontractor, Zachman Precast mobilized a single crane, which installed 1,400 ln. ft. of columns, 4,000 ln. ft. of beams and 119,000 sf. ft. of hollowcore plank. Coordination between County Materials and Zachman Precast along with safe and efficient procedures led to the erection process ending two weeks ahead of schedule.

County Materials manufactures hollowcore inside their Roberts, Wis. production facility, which enhances quality and prevents the extra work of moving forming equipment to the sight, which is necessary in cast in place projects. Each plank was custom made and sawed in their climate controlled building to meet the project’s dimensions. By delivering every plank to the site ready for erection, the construction schedule was dramatically shortened compared to alternative construction materials. Additionally, hollowcore provided Doran Companies an immediate working platform, allowing for work to begin the moment they arrived back on site.

After the erection process was completed, Zachman Precast grouted the seams between each plank and closed the hollow ends.

Unprecedented Strength

Hollowcore offered this project an inherently strong material that met design needs and safety regulations. The parking garage’s location below living spaces meant that high fire ratings were needed. Hollowcore is manufactured with high-strength, steel-reinforced concrete, which maintains its structural integrity through extreme conditions. County Materials’ hollowcore is manufactured to meet fire ratings up to three hours. Additionally, concrete does not burn, eliminating lethal fumes and smoke. Residents and building owners appreciate the sense of security and permanence offered by the solidly built structure.

Residents began moving into the building 1 immediately after its August 2016 opening. In April 2017 County Materials was selected as the supplier for the project’s fourth and final phase. County Materials expects to deliver an additional 80,000 sq. ft. of hollowcore plank for the last building, which is scheduled to open in fall 2018.

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