Wood Is Making a Comeback in Construction

As a construction technique, mass timber is defined by its use of columns, beams, and boards made not of a single piece of wood, but of multiple wood layers or pieces tightly laminated or otherwise bound together. The two mass timber types Pantelides works with specifically are mass plywood panel and mass ply lam. These “panelized” or “composite” wood products, as well as their production process, have a number of advantages, environmental and structural, over the usual building materials. 

“The timber that we’re talking about, it’s very strong. It can take the place of steel or concrete in many building frames, but it’s much lighter,” Pantelides explains. “A mass timber building is one quarter the weight of a concrete building too, requiring a much smaller foundation.”

Thanks to its super-compressed makeup, mass timber is effectively fireproof as well, resistant to moisture damage, and highly durable.

On top of that, with today’s sustainable forestry techniques, using wood is more sustainable and “renewable” than ever.

“It takes only seven seconds for European forests to grow enough timber required for a three bedroom apartment,” Pantelides explains. “Canada alone has enough timber to house a billion people in perpetuity, with forested trees replenishing faster than the population.”

And whereas concrete and steel production is highly carbon intensive, every ton of timber grown sequesters 1.8 tonnes of carbon dioxide from the atmosphere. Further cutting down emissions, and cutting costs, a mass timber building could be 25% faster to build compared to a concrete building, and result in 90% less construction traffic. 

According to Pantelides, once the structure is finished the wood goes from benefiting nature to having natural benefits. “People simply like to be in buildings that have lots of exposed wood,” He says. “The sense of being connected to nature, the biophilic design, makes for healthier living and working environments.” 

Yet despite all this, steel is still the go to for tall buildings, especially in areas with high risk of earthquakes or hurricanes; steel’s ability to bend and not break under pressure is key. Maintaining a building’s structural integrity relies on a deep understanding of such properties — an understanding we don’t have with the generally stiffer mass timber. This is where Pantelides’ research comes in. 

With its varied compositions, mass timber is far from one-size fits all; the type of wood used, the size and shape of the wood particles, how they’re stuck together, or even whether individual layers are stacked parallel or perpendicular to each other will greatly influence how the finished product reacts under stress.

Since he first started investigating mass timber, Pantelides has been troubleshooting and experimenting with different “recipes,” eventually arriving at one that calls for shaving dark fir wood into chips, tightly compressing the chips together into planks or boards, and then laminating those layers together with ultra-strong glue. The resulting plywood can then be securely fastened to other pieces of wood with joints made of steel dowels and plates. 

Using this formula, Pantelides and his team began to experiment with mass timber versions of earthquake-resistant architectural elements, including the Timber Buckling Restrained Brace (T-BRB) — the focus of Pantelides’ most recent publication.

Mark Helzen Draper is a videographer at the University of Utah College of Engineering. The story was originally posted to the website of the University of Utah College of Engineering,