Precast Goes to School

New Jersey’s first precast concrete school creates a sound space for a growing student body.

By Leslie Lichtenburg

A burgeoning student population and a fast-track schedule for building classroom additions at two district middle schools led to the recent construction of New Jersey’s first precast concrete school facilities.

The $5.2 million contract with the Roselle Board of Education paved the way for a 21-classroom addition at the Grace Wilday Junior High School and a four-classroom structure at the Leonard Moore Middle School. These are two of the six schools that make up the Roselle Borough Public Schools in Roselle, N.J. The Wilday School, located in Roselle’s Union County, enrolls 217 students in grades 5 through 7. Nearby Leonard Moore Middle School houses 482 students, also in grades 5 through 7. Construction began in June 2004 and was completed two months later.

The building sections, comprised of 58 precast concrete modules, were manufactured off site at the same time the foundations were constructed. Designed and manufactured by Oldcastle Precast Modular Group of Telford, Pa., the four-sided building components – with a floor, ceiling and two walls (exterior and interior) in one “ring” – were cast using 5,000 psi reinforced concrete. Components for this type of modular building system are available in 8-foot, 10-foot, 12-foot, by 32-foot sections. For this particular project, the interior span was 32 feet, with the height and width of the modules measuring 12 feet each. The units were erected on a grade-beam foundation, bolted and then welded to create the classroom structure.

“There are cost savings across the board with this type of building system,” says Barbara Bogo of Oldcastle Precast Modular Group. “The two walls and ceiling are monolithic, requiring only one pour, and the exterior walls are completely finished. Also, there is a significant energy savings, owing to the thermal mass of the concrete and the fact that there is no thermal bridging.”

Once the wall and ceiling panels are removed from the mold, a second pour creates the base (floor), which is then welded to the first unit. The security and high strength of the reinforced concrete sections create a strong, quiet and durable floor, roof and wall system. In addition, the system’s multistemmed roof and floor structure design increases the overall structure’s load-bearing capacity while decreasing its weight.

“The product is very low maintenance,” says Bogo. Because there are no mortar joints at the corners, there is little opportunity for water to seep inside and create mold and other problems. In addition, concrete’s inherent fire resistance contributes to the structure’s safety, reliability and strength.

“These modular units are secure, durable structures, which are the primary reasons they are preferred over portable classrooms, trailers and other products typically used for school expansions,” says Todd McCoy, president and CEO of H. Wilden & Associates, Pennsylvania-based engineering consultants to the precast concrete industry. “They are engineered for hurricane loads and to hold up under seismic conditions,” he says.

Other features that added to the efficiency, strength and overall aesthetics of the Roselle school additions included an insulated exterior wall – comprised of a 6-inch interior wall, 2 inches of insulation and 4 inches of concrete – with preinstalled windows, door openings and electric components that were cast integrally into the concrete walls. In addition, the classroom additions feature a factory-painted, plain grade concrete finish designed to match the existing school building.

“Oldcastle offered us a quick and affordable solution to overcrowded classrooms,” says Darlene Roberto, superintendent of schools for the Roselle Public School District.

When compared with conventional construction, the precast concrete modular system offers several advantages. Building components install on a ground level foundation – slab or grade beam – and include integral insulation. The end result is a completely finished structure that is aesthetically pleasing and, more importantly, offers the same structural integrity and weather resistance as conventional classrooms. Designed to provide a life span of 50-plus years, this modular concrete system is also competitively priced when compared with conventional construction.

Oldcastle markets its modular building product as a “highly secure school construction system” that is fast and cost-effective.

“You don’t need manpower on site for construction of the modules and because the system is factory produced, you eliminate the risks of waste, vandalism and theft,” says Bogo, adding that for the Roselle project one module per day was produced in the plant. Finished sections were transported to the site on trucks and erected by an installation crew. “Once the units are erected, they create an enclosed space.”

With another school year at an end, the Roselle Public School District is already thinking ahead to September and the new crop of students that will spend their days in the busy classrooms.

“As you enter our modular additions, you can hear an educational buzz and a sense of renewed enthusiasm emanating from both teachers and students,” says Roberto. “Thanks to precast concrete, this venture has been a positive experience.”

Project Profile
Project Name: Roselle Borough Public Schools, Roselle, N.J.
Owner: Roselle Public School District, Roselle, N.J.
Engineer: H. Wilden & Associates, Allentown, Pa.
Precast Manufacturer: Oldcastle Precast Modular Group, Telford, Pa.