Material Flaws Often Don’t Portend Catastrophe

Brief 

Cracks and warping that become evident over time in structures built with either wood, steel or concrete don’t necessarily suggest failure that might lead to something like the recent partial condominium collapse in Surfside, Fla., according to Sense Engineering founding principal Brennan Vollering. Speaking last week at Buildex Vancouver, Vollering noted different types of flaws and said, “People get concerned and we explain, that’s just normal, it’s shrinkage.”

Insight

he collapse of the Surfside condominium complex in Florida spurred new concerns in the construction industry about the reliability of commonly used materials such as wood and concrete, but one expert’s message is simple.

“Everyone, take a deep breath,” Sense Engineering founding principal Brennan Vollering said.He made the remarks as part of a session titled Is My Building Going to Collapse? The Difference Between Normal and Dangerous Building Movements at Buildex Vancouver on March 23.

He explained while it is prudent to be cautious and investigate possible faults, Canada has not seen very many building collapses.“In the case of Surfside, work was identified as not having been done, and some think that’s what caused the collapse,” Vollering said.

Different materials exhibit different behaviours and are used in different contexts, he said.Wood is used primarily in residential projects, while steel is employed for commercial and highrise structures as it is non-combustible. Concrete is used for most highrises in Canada especially in a residential context, he added.

“Masonry is not used as much in the Lower Mainland, but is much more predominant in Ontario,” Vollering added.Wood, he said, tends to deflect especially over time.Because of its light weight it performs well in earthquakes but “because of that light weight it tends to form alternate and unintended load paths.”

Other problems with wood include its tendency to rot when exposed to moisture and that it tends to shrink more than other materials.By contrast, structural steel has the most predictable set of behaviours due to consistent material properties but “if built wrong, it can be prone to catastrophic failure,” he said.