Too many bricks
Les Terrasses de la Chaudière is a complex of government office buildings built in 1978 on the Quebec side of the Ottawa river across from Canada’s capital.
One of my favourite engineering courses at Carleton University was taught by a project manager on the Chaudière project. Unfortunately I don’t remember his name, but he had a passing resemblance to Sean Connery – surely the compliment outweighs the slight. We’re talking 1990 or thereabouts.
My memory is clearly suspect, but here’s the story as I recall it. The Chaudière was such a large project that its brick cladding would have taken far too long with manually laid masonry. Even with all the masons in Eastern Canada, said the prof, it would have delayed the project.
Unceasing parade of details
The conclusion was that the only workable option was to prefabricate brick panels offsite and apply them to the building.
This was a formative anecdote for me. I have used it to justify the time and effort of project management to myself and others. It’s not just an unceasing parade of details – it is a way to assess a project, find bottlenecks and apply innovative problem solving to remove them.
To fabricate the brick panels, the construction company set up a jig into which went bricks, reinforcing bars, mortar, windows etc. The story was that authorities were leery of this prefabrication technique which was still not common in the 1970s. To prove the strength of these panels, the construction company sent a sample to Florida and used a jet engine to drive water at the panel, simulating a worst-case storm.
Strong now, weak later
Alas, the Chaudière complex is famous in the present day for dropping bricks onto pedestrian walkways below.
“Since the construction of the complex, the exterior brick-cladding has undergone advanced deterioration, presently creating potentially serious safety issues.”
Government report: Les terrasses de la chaudière: preliminary risk assessment of existing brick-faced wall panels
The brittle mortar used; the different expansion rates of the bricks and the rebar; coupled with the constant expansion and contraction caused by seasonal changes and alternating hot sun and darkness, all conspire to compromise the strength of the panels.
I was researching the bricks on the Chaudière expecting to use them to illustrate innovation in the face of project bottlenecks. Instead I found that the innovation had in fact backfired.
My takeaway is that the innovation was sound – prefabrication was an appropriate time saving approach to cladding such a large complex with bricks. The failure was in implementation and overlooking the fact that a structure that is strong today may fail in time.
Prefabrication is an application of Principle 10 – Prior Action.