Gehry’s Signature on Toronto

Don Procter

April 2007

When Frank Gehry designs a building, heads turn. No matter where, or how big or small his commissions are, his work attracts international attention.

One of the Toronto-born architect’s latest projects making headlines is the $254 million (Cdn.) makeover under way at the Art Gallery of Ontario, Toronto’s flagship art museum. To dramatically change the outward appearance of the AGO and add 45 percent more exhibit space, the fanciful renovation will certainly make a bold statement when it is completed next year. It features a 425-foot-long glass and wood façade rising 70 feet, a 140-foot-tall tower adorned in titanium panels and a striking stainless steel "egg-shaped” Gehry-esque staircase.

Flynn Canada Ltd. is the contractor for the metal portions of the exterior wall system. At $6.5 million and 40,000 square feet, it is not a big job for the contractor, but it is an unusual one. The wall system on the 140-foot South Tower, for example, consists of custom-made S-lock titanium panels. Flynn’s Greg Stewart says it might be the first use of titanium panels on a high-profile building in North America; Gehry used titanium for Museo Guggenheim Bilbao in Spain.

Corrosion-resistant, strong and durable, titanium has the characteristics of a long-lasting cladding. But so does zinc and stainless steel—two alternatives Gehry didn’t want.

What is different about titanium is that it can be colorized, points out Mike Mahoney, senior project manager of the AGO. Through a chemical process, its natural "pewter-like hue,” can be changed. The panels at the AGO will be metallic blue.

The titanium wall system for the South Tower will be 3.5-inches thick. The zed bars (Z-bars) will be installed vertically, rather than horizontally, because of the size of the titanium panels—24 inches by 46 inches. Horizontal insulation straps will run between the zed bars at 24-inch centers. Covering the zed bars and insulation will be a 14-gauge aluminum backup sheet with a half-inch air space that gives the titanium space to breathe. Densglas and Blue Skin will be attached to the wall’s framing system.

Flynn’s Stewart says the installation process is a "white glove operation” because the natural oils on hands can "react” with the metal, resulting in indelible marks.

Jack Stelpstra, construction manager, EllisDon Construction, the project’s builder, says Gehry’s penchant for detail makes for a big challenge. The titanium panels incorporate an earthquake pattern that feature stepped vertical lines. It is a "very precise process” to install the infrastructure behind the titanium panels perfectly so the pattern is properly featured.

One of Flynn’s jobs calls for the fabrication and installation of a grand "egg-shaped” staircase made of stainless steel panels. No two panels are alike. Flynn will use CATIA, 3D modeling software, and AutoCAD to first create the shape of the stairway and then it will "flatten out” the shapes on the computer program to arrive at the precise dimensions of the panels required to make the curves.

Converting such a drawing to reality is no small feat. One issue is whether the calculations produced by the computer are practical and workable in the field. "Can traditional fastening methods work, and can standard fabricating equipment produce these unique shapes?” Stewart adds.

The interior look of the AGO will also change dramatically under Gehry’s tutelage. The prime drywall contractor, Cesaroni Contracting Inc., has had its work cut out for it. One of the wall systems specified is an acoustical plaster ceiling that uses Baswaphon, a proprietary emulsion of mineral particles that form a micro-porous membrane for noise reduction.

The AGO is not your everyday building challenge, but no one ever expects a Gehry design to be straightforward.

About the Author
Don Procter is free-lance writer in Ontario, Canada.