New Zealand to Build First Timber Bridge in 50 Years With Glulam

Construction on the first state highway bridge built from timber in 50 years in underway in New Zealand, Wood Central reported (12-16-24).

Known as the Onetai Bridge, the 9-meter (approximately 30-foot) bridge represents a major shift in bridge design with low-embodied carbon materials. While small in stature, it is the first bridge built by Waka Kotahi NZ Transport Agency (NZTA) out of wood and not steel or concrete since at least the 1970s—a push that could have major implications for more than 4,200 bridges across the country’s road network.

Last year, Rob Campbell, NZTA’s regional manager for maintenance and operations, said the use of timber in the new bridge distinguished it from conventional bridge replacements. “Road bridges in New Zealand generally utilize concrete or steel. This will be the first to herald a return to a more sustainable design, incorporating timber beams and a deck.”

According to Campbell, mass timber—and not steel or concrete—could become the new standard for bridge construction, turning an ostensibly minor project into a ground-breaking shift in design for future state highway bridge replacements. The key is in glulam, which Campbell asserts is twice as strong per kilogram compared to steel and specifically designed for durability and resilience.

“The new Onetai Bridge is designed to last at least 100 years, linking the greater Waikato region with the Coromandel Peninsula and providing a small but vital part of our state highway network,” Campbell said. “The replacement will add to the resilience and safety of this route, as the new design will be stronger and wider than the old bridge.”