May 25, 2007

Variety of finishes adds complexity to art centre

DON PROCTER

correspondent

The $2 million wall and ceiling contract Toronto’s Select Drywall & Acoustics recently completed at the Brampton Performing Arts Centre hardly ranks in comparison with some of the contractor’s work at Toronto’s $4.4 billion international airport makeover.

But while it pales in size to the airport job where the contractor installed a near mile-long metal ceiling, the arts centre was big on challenges. In fact, it was one obstacle after another.

The airport was repetitive work; the performing arts centre was the opposite.

“We used many different construction methods to deal with the walls and ceilings,” explains Select’s project estimator Marcello Salvato.

That is no surprise. Theatrical centres often present unusual construction wrinkles. The Brampton Arts Centre was more complex than most because of its design. Sitting squarely on top of a parking podium and adjacent to high-speed rail tracks, the building is at a noisy crossroads.

To keep sound out, the building – more specifically the auditorium within the centre – is engineered to “float” above the parkade podium on massive sound-absorbing bearing pads.

The exterior of the building is a combination of precast concrete and red sandstone, imported from England.

Behind it is a structural steel skeleton isolated from the precast concrete to prevent outside noises passing into the building.

Although it may not be the largest project tackled by drywallers, the Brampton Performing Arts Centre may be among the most complex, including the main lobby above.

The unusual engineering had a significant impact on how it was built.

“We had to take into account deflection and isolation issues for every steel stud, sheet of drywall and finish that we did so as to eliminate all sounds from the outside.”

At the same time, the contractor had to meet architect Page Steele Architects Planners’ esthetic specifications for the ceiling. Combining the two elements successfully was a daunting task.

For example, an “undulating drywall ceiling that almost looks like an accordion” specified for the secondary hall had to be isolated from the structure to eliminate sound transmission. To meet the Level 5 finish required, a plaster skim coat was used at the curves in the drywall. “Our challenge was to pinpoint the high and low points on this ceiling with a laser level and then isolate everything.”

A bigger challenge yet was constructing the domed ceiling in the performing arts centre’s rotunda. It required an acoustical plaster finish. Select contracted out the job to Donalco Inc.

Several options for a substrate were reviewed for the plaster (including a ¼” flexboard product) before Select chose conventional metal lath and plaster.

Before creating the 18-metre high by 13-metre diameter dome, stationary engineered scaffolding supplied by Peri Formwork Systems Inc. was installed. A metal framework was built to install the flexible metal lath.

To find applicators with old-world plaster and lath experience techniques, the contractor had to turn to elder and former workers – bringing some out of retirement – to get the job done.

The main lobby of the arts centre threw a whole set of curves at the drywaller. Approximately 110 linear feet with a slight curve, the ceiling required 10 sections of coffers and cove surrounds built from scratch and secured to metal stud framing. “It was tricky to produce each of the 10 units to follow the radius of the exterior of the building.”

The lobby also called for three metal cast column covers and fabric panels, the latter was also installed on vomitory ceilings.

Another hurdle was the stage enclosure. Its walls, up to 22 metres high, required sway bracing. The bracing served as a sound isolation and structural support for a wall assembly specified to be three layers of 5/8-inch sheets of drywall.

The idea was to help eliminate sound passage from outside. To board the tall stage walls, the drywall was transported by hand because there was no room for a hydraulic lift.

The ceiling construction in some areas is isolated from the building’s steel skeleton, hung on a network of spring isolators.

By comparison, the installation of the auditorium ceiling was straightforward.

One hurdle was detailing and installing a bulkhead around a catwalk surrounding the ceiling, says Salvato. Covering an area of about 25 metres by 25 metres, the maze of scaffolding was “quite a sight to see”.

Select’s contract, which started March 2005 and wrapped up recently, also called for some “pretty spectacular finishes”.

For example, fabric faced acoustic panels and large GRG (glass reinforced gypsum) mouldings in the main lobby, rotunda and auditorium.

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