Theatres are often among the more demanding commercial projects to build and the recently completed Tom Patterson Theatre in Stratford, Ont., is no exception.
The 77,000-square-foot theatre along the banks of the Avon River in the southwestern Ontario city has presented the building team not only with the challenge of meeting the stringent acoustical specifications expected of a theatre, but also with how to construct its unusual serpentine form.
For Tom Shean, a site superintendent for project manager EllisDon, the contract has been “one of most challenging projects” of his construction career.
“The foundation follows the profile of the glass and brick walls, which wind and curve,” Shean says of the building which cost close to $50 million to construct.
To round or curve the walls in some sections of the curvilinear-shaped building involved taking a straight four-foot form and “nickeling (bending) it to form a curve,” he says.
It was critical that the foundations were placed with pinpoint accuracy to ensure that the walls would precisely meet the form or shape of the intended design.
“As I did the finishes, I found the curvature of the concrete foundation to be very accurate,” Shean says. “The formworkers did a good job keeping the walls on line.”
Much of the foundation work was done over the winter, with tarps to protect the concrete and blowers to maintain temperature.
EllisDon self-performed the concrete work.
Shean says the irregular-shaped building has “multiple choke points” which made for tight space for construction. “It was a logistical challenge to schedule subs and to place equipment and materials.”
To meet the demanding acoustical specifications, the building team had to go above and beyond standard construction methods. For example, a neoprene bond break was installed between concrete walls to prevent vibration transfer into parts of the building.
Mechanical room floors also had to be isolated. “We poured a slab on top of another slab, jacked it into the air to be supported on rubber isolators.”
The 600-seat auditorium is a self-contained concrete, “360-degree bowl” that required isolation from sound and from vibrations resulting from other parts of the theatre, Shean says.
To achieve the STC (sound transfer class) rating specified by Toronto-based acoustical consultant Aercoustics, the interior of the auditorium is covered in fabric and two layers of wood slats connected to a steel stud frame. Behind that wall structure are two layers of 5/8-inch drywall on an acoustic channel system connected to the concrete structure.
In some parts of the ceiling, the tapering wood slats are about 30 feet long. Precision cut on a CNC machine, the walnut boards fan out to meet the shape of the room.
“Not only is this radiused from the floor to the ceiling, but it is also radiused from side to side,” Shean says.
The millwork contractor was Architectural Millwork & Door Installations Inc. of Komoka, Ont.
The exterior is clad in lime-washed brick imported from Denmark. The straight and curved glass was imported from France and Italy and is supported by hundreds of bronze mullions.
Hurdles aside, the project was completed without any major hitches in the schedule or budget. At peak of construction, the site had 100 to 120 workers.
“We all had our piece of the puzzle that we were taking to the finish line,” says Shean. “It was a collaborative effort.”
An architectural design of the building by Hariri Pontarini Architects was completed in February. The consulting team includes structural engineers Thornton Tomasetti, mechanical-electrical engineers Arup Canada Inc., landscape architects Holbrook & Associates and The Planning Partnership.