Scheduled to open later this month, a new retail and office building in downtown Des Moines, Iowa, will not only be the first mass timber building in the city but will be the first multi-story office building in the U.S. constructed with dowel-laminated timber, the Des Moines Register reported.
The unique, all-wood product that works without nails or other fasteners is pressed together using dowels, according to Canadian structural engineering firm and supplier StructureCraft. General contractor Ryan Cos. installed the "friction-fit" prefabricated 8-foot-by-20-foot DowelLam panels, which serve as floors and roof, within a spruce glulam beam-and-column frame, according to Neumann Monson Architects.
The mass timber system also allowed for quicker construction time, in conjunction with the precast concrete walls and buttresses used as an anchor at the south end of the building that make up the service core.
Mass timber is becoming more commonplace as a commercial construction material. While considered by some to be the greener choice over steel and concrete, its advocates are still trying to convince segments of the industry that it is safe, particularly when it comes to high-rise buildings.
Proponents scored a victory in that regard last year when the International Code Council voted to include mass timber provisions for tall buildings in its 2021 International Building Code. The next edition of the IBC will feature three new types of construction and will cover mass timber buildings from nine to 18 stories. However, although most states and many other jurisdictions incorporate the IBC into their own building codes, they're under no obligation to adopt the new mass timber regulations.
One city that has seemingly embraced the concept of tall wood construction is Milwaukee. Developer New Land Enterprises is planning to build what could be the tallest mass timber building in the Western Hemisphere, the 21-story Ascent. The design for the mixed-use, residential tower features a five-story, cast-in-concrete base topped off with an exposed, 15-story mass timber system that uses steel connectors.
Earlier this month, New Land, according to Urban Milwaukee, won a grant from the U.S. Department of Agriculture's Forestry Service to help further its work with mass timber. The 41 awards totaled almost $9 million with the average grant about $217,000.