Project Spotlight

This fall, our crew tackled a towering challenge at the Art Gallery of Ontario: remove an outdated stack buried deep in the gallery’s south shaft, and replace it with a brand-new 34” Ø, 164-foot stainless steel, double wall freestanding system.

Before the new could rise, the old had to go. The original stack was boxed in behind shaft walls and steam coils, access was minimal. Crews opened the shaft wall, removed the coils, and sent in the team to unbolt the base. Section by section, the stack was cut, tensioned, and lifted. Tag lines held swing in check while saws ran counterclockwise through steel and insulation. Each lift was carefully coordinated to keep workers clear and the site clean. Before demolition could even begin, however, a precisely measured temporary system had to be laid out, fabricated, and installed. This was done within a very narrow shutdown window, carefully coordinated with the AGO, to maintain service continuity and protection of the priceless artwork.

Once cleared, the shaft was ready. The new system was designed not only with a main 34" Ø boiler exhaust stack, but also with twin 8" round generator stacks all tied into a single vertical system exhausting above the building. Each section required multiple alignment points to be exact, ensuring bolting to the structure and to the previous stack section could be executed seamlessly.