Permit Approved For Nation’s First All-Wood High-Rise In Oregon

Officials in Oregon have approved construction permits for the first all-wood high-rise building in the nation. Construction on the 12-story building, called Framework, will break ground this fall in Portland’s trendy and rapidly growing Pearl District and is expected to be completed by the following winter.

The decision by state and local authorities to allow construction comes after months of painstaking testing of the emerging technologies that will be used to build it, including a product called cross-laminated timber, or CLT.

To make CLT, lumber manufacturers align 2-by-4 boards in perpendicular layers and then glue them together like a giant sandwich before sliding the resulting panels into a massive press for drying. The resulting panels are stronger than traditional wood because of the cross-hatched layers; CLT can withstand horizontal and vertical pressures similar to those from a significant earthquake with minimal damage. They also are lighter and easier to work with than regular timber, resulting in lower cost and less waste.

For this project, scientists at Portland State University and Oregon State University subjected large panels of CLT to hundreds of thousands of pounds of pressure and experimented with different methods for joining them together. The project materials also underwent extensive fire safety testing and met fire codes.

State officials hope the building will stir greater interest in high-rise construction using mass timber and help revitalize the state’s lagging logging industry. Logging, once a major source of revenue in Oregon, has dropped sharply in the past few decades because of greater environmental protections for salmon and the spotted owl. The loss of the industry has devastated some of the state’s rural communities.

From The Register-Guard: https://registerguard.com/rg/news/local/35651365-75/portland-approves-permit-for-nations-first-all-wood-high-rise.html.csp

Portland State University Tests CLT’s Seismic Strength

When the 12-story Framework building planned at Portland’s Northwest 10th Avenue and Glisan Street is complete, it may look to passers-by like any other Pearl District condo tower.

But it will hold a special distinction in the sustainable building world: the nation’s tallest building made primarily from mass timber (long pieces of timber, glue-laminated together).

Designers and engineers across the country are chasing an innovative style of mass timber construction pioneered in Europe, which they believe will go a long way to reduce the carbon footprint of large buildings.

The breakthrough came with the development of cross-laminated timber or CLT: Large, layered flat panels used as floors and walls (rather than just beams as vertical posts).

As Oregon moves on multiple fronts to take the national lead in all-wood construction for tall buildings, Portland State University stepped up early to do basic research. PSU won a three-year, $400,000 National Science Foundation grant to study two aspects of mass timber construction: its sustainability and how well it resists earthquakes.

From Sustainable Life: https://pamplinmedia.com/sl/337694-214716-psu-tests-new-green-woods-seismic-strength