In architecture, strength is something that is at the forefront of mind. Whether in terms of structural stability or durability, we select building materials with a view to them enduring and providing permanence. 

Louis Kahn, one of the great architects of the 20th Century, understood that the properties of different materials should dictate how they are used. A brick is immensely strong in compression. The arch allows the brick to use this property to its advantage in counteracting gravity, but try to create a square opening in a brick wall, and the apparent strength will quickly disintegrate without support from other materials.

Steel is also commonly viewed as having great strength, particularly when considering its relatively low weight. Skyscrapers were physically impossible before the advent of steel construction in the late 1800s. We utilise steel’s capability to act in tension, similarly to how timber has been for millennia, but to greater extremes. But steel too has its weaknesses, namely its susceptibility to corrosion.

Strong and flexible, timber structures are often designed to move with the forces imposed upon them, rather than steadfastly bracing against them the way brick or concrete does. Timber is commonly used in countries such as Japan for this reason – generations of experience has found that allowing a building’s skeleton to flex and absorb the impacts of earthquakes and typhoons is preferable to the potential catastrophic failure of heavy, more brittle buildings.

In some ways, concrete is an amalgam of the structural properties of stone and steel. Hard, dense and durable, concrete on its own behaves much like brick or stone – immensely strong in compression but lacking somewhat in tension. When reinforced with steel, however, it benefits from that material’s inherent qualities, while protecting the steel from corrosion and fire.

All of these considerations go into deciding the best choice of material for a building. Modern technology allows us to ‘force’ materials to do things they may not be ideally suited to, for reason of aesthetic, cost, practicality or availability. I always like to apply Louis Kahn’s questions to these decisions. 

Architect Tomas O’Malley designs buildings that reflect Central Queensland’s climate and lifestyle.