The multi-millennium history of engineered wood
How modern mass timber building materials are rooted in innovations that date back thousands of years.Given the amount of research today to measure the performance of mass timber products, it’s ironic to recall that engineered wood in some form has existed for thousands of years.
According to a history of engineered wood from APA – The Engineered Wood Association, archaeologists have found evidence of laminated wood in the tombs of ancient Egyptian pharaohs. Chinese societies glued wood together for furniture more than a thousand years ago, and early modern-era plywood was used to manufacture household items such as cabinets, chests, and doors.
The modern plywood industry was born in 1905 when the Portland Manufacturing Company used paint brushes as glue spreaders to laminate wood panels for a World’s Fair Exhibition. The product gained interest among fairgoers, and within two years, the company was producing 420 panels a day. Advancements in waterproof adhesives, performance testing, and industrialization eventually led to a massive national plywood industry.
Turn-of-the-century builders were also experimenting with tall timber construction. In 1908, the nine-story 500,000 square foot Butler Brothers Building in Minneapolis became the largest wholesale warehouse west of Chicago. The heavy timber post-and-beam construction – built with wood from the developer’s own tree farm – provided the 300-pound-per square-foot loading requirements of the warehouse. In 1974, owners added a central atrium and raised floors to preserve the exposed wood ceilings.
Ongoing innovation by wood product manufacturers has led to the rise of today’s mass timber building materials, including cross-laminated timber (CLT), nail-laminated timber (NLT), glulam, and dowel-laminated timber (DLT). Alongside those developments, engineers and building scientists have studied the performance of these materials to develop standards that allow designers to specify mass timber for ever-larger projects.
The historical context of engineered wood makes the achievements of today’s modern timber towers even more impressive. In the webinar, A Tale of Two Timber Towers, structural engineers dive deep into the design intricacies and the mass timber materials they used in designing INTRO, a nine-story mix of apartments and retail space in Cleveland, and Ascent Milwaukee, a 25-story residential/mixed-use building.
As you learn about the code requirements unique to tall wood buildings—and the data and testing the engineers used to gain approval for these projects—think back in appreciation of the early engineers performing their own laminated wood innovation that eventually led to the advanced materials we use today.