50-Foot CMU Walls Steal Show at John Burroughs

By on May 24, 2014

When John Burroughs School (JBS), an elite, college preparatory school in Ladue, was founded in 1923 masonry was the preponderant material for all structural construction. Over the years, various structural construction systems have supplanted that dominance.

But when the architect of a new $19,355,000 performing arts center, which was to be located in the middle of existing buildings on the 47.5-acre campus, looked for a building system with the necessary acoustic and structural properties, the structural CMU system won the day.

The performing arts center was part of a total $40,300,000 construction program. The project needed to be completed with minimal disruption to campus activities. This was rendered more difficult due to the fact that the building is located at the junction of several key campus buildings and needed to tie into those buildings structurally.

The Haertter Center for Performing Arts is a 76,000 sq. ft. facility. The major program elements include a 750-seat performance theater; a 125-seat black box theater; band, choral, and orchestra classrooms; a dance studio; a scene shop; a green room and dressing rooms; and a costume shop with laundry and costume storage.
“Load bearing masonry was chosen for the project so that we could achieve high acoustic values with a single material,” Tim Rowbottom, AIA, NCARB, LEED AP BD+C said. Rowbottom, principal with the Lawrence Group, design architects on the project, said that a steel frame and gypsum board system was considered as well as pre-cast panels.

“The project program required many large volume spaces. The large spaces required height and volume for sound dissipation within rooms, while containing and limiting sound transmission between rooms. The height of the walls required fully grouted cells for structural reasons. The performance of the rooms was enhanced by creating mass which limits sound transmission.

“In the audience chamber the design team determined that the structural masonry could provide both absorptive and reflective surfaces. For this reason we utilized both normal weight block and rough face block.”

While other materials could provide similar acoustic values, the use of load bearing masonry allowed the project to be more sustainable. Utilizing the same construction for the structure and to achieve acoustic goals was a key criterion in the sustainability of the project.

“An additional benefit of using the masonry as both a load bearing element and acoustical element was that it took less footprint for the structure as opposed to using a steel frame and then adding in non-load-bearing partitions for acoustics,” Robert Daugherty, P.E., associate with KPFF Consulting engineers, structural engineers for the project said.

Tight Building Team Coordination

The flexibility of the load bearing CMU system design accommodated the tight construction site, but also required coordination amongst the masons and the steel erectors. The project was constructed with 20 feet of laydown on the west side, 12 feet of laydown on the north and constructed adjacent to the existing field house. Additionally the existing auditorium rear wall was only 10 feet from the east façade. These constraints resulted in the use of a tower crane to move materials, scaffolding and rigging around the site. The project was constructed to allow the stage house and audience chamber to be constructed while the rest of the spaces were wrapped around the large masonry volume in clockwise fashion.

Tim Vaughan, project manager for Paric Corporation, general contractor on the project, said that the performing arts center was one of the most complex projects of his career. Because the structure of other Burroughs buildings had to tie into the performing arts center, Vaughn had to manage a complex schedule – creating masonry pockets for steel, then pulling the masons off the project and installing the steel. “We were able to start and stop at different levels and stages. It was a juggling act,” he said.

The Performing Arts Center construction began in May of 2012 and was originally scheduled to be completed in October 2013. The project was completed two months ahead of schedule in August 2013 in time for John Burroughs School to occupy the building on the first day of school.

“It’s a beautiful building… a complex building,” Vaughan said. This wasn’t like putting up a gym or a Walmart. I don’t think this building could have been built using any other system.”

50-Foot-Tall CMU Walls

The structural CMU walls of the audience chamber are 50 feet tall. These walls are 12-inch block with two #5 bars at 16 inches on center.

The stage house walls are tied to the concrete foundation at the stage level. The top of the stage house walls are 64 feet above the stage level. The walls are composed of two eight-inch blocks with two #7 vertical reinforcing steel at eight inches on center. Bond beams are used at 64 inches on center with two #5 bars and a header course above each bond beam.

“With the National Concrete Masonry Association’s help we’re trying taller, thinner walls that are more economical,” said John Smith, Jr., president of John J. Smith Masonry Company, mason contractor on the project. Smith, board chairman of the Mason Contractors Association of America, said “NMCA has been very helpful in revising the engineering.”

Smith noted that many younger architects, project managers, and engineers have never seen structural CMU walls on the scale of the JBS performing arts center. For that reason Smith and the Mason Contractors Association of St. Louis arranged a site visit for architects and other interested parties.
“What’s happening is that years ago we used load bearing masonry for everything, “Smith said. “The designs changed, to where they wanted to go to structural steel. Today, young engineering and project managers are all saying, “We can’t do it with concrete masonry,” Smith noted. “We ask them to run the numbers. When they do the calculations, they find out it works.”

Project Name: Haertter Center for the Peforming Arts

Location: Ladue, MO
Owner: John Burroughs School
Completed: August, 2013
Architect: The Lawrence Group
Structural Engineer: KPFF Consulting Engineers
General Contractor: Paric Corporation
Mason Contractor: John J. Smith Masonry Company
Block Producer: Midwest Block & Brick


This article was reprinted from Concrete Masonry Designs with permission from the National Concrete Masonry Association (NCMA)copyright 2014.  For technical information on the use of concrete masonry units, as described in the article, visit the NCMA website www.ncma.org, or call (703) 713-1900.


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