Simpson Strong-Tie’s Greg Bundy, Senior Branch Engineer in Columbus, Ohio, recently led a training webinar on mass timber advancements. The workshop covered topics like the NHERI TallWood Project and a new guide for cross-laminated timber diaphragm design. The hands-on session featured installation of innovative products for structural engineers.

What’s new with mass timber construction? On Thursday, October 19, 2023, a group of structural engineers found out. The Northeast branch of Simpson Strong-Tie (SST) hosted a mass timber workshop at their Columbus, Ohio, training center. This free workshop for structural engineers was titled “What’s New with Mass Timber?” Steve Pryor, PE, SE, with SST, and Scott Breneman, PhD, PE, SE, with WoodWorks – Wood Products Council, presented virtually while I, Greg Bundy, Senior Branch Engineer with the SST Columbus office, had the pleasure of facilitating the event and presenting in person. The workshop focused on the most current and innovative research/testing, design aids and products related to mass timber.

Steve discussed the National Hazards Engineering Research Infrastructure (NHERI) TallWood Project, in which he and SST were closely involved. The TallWood Project, a seven-year project funded by the National Science Foundation, was a collective effort by academia and the construction industry that culminated in 88 seismic tests during May of 2023. Steve covered the design, construction and testing of this 10-story full-scale building, including an in-depth summary of the lateral force-resisting system – ingenious post-tensioned mass timber rocking shear walls. Steve’s technical knowledge of the project was only overshadowed by his contagious enthusiasm for it! See the following link for additional information (and some great videos) of this wonderfully collaborative endeavor: NHERI TallWood Project.

Scott provided an overview of the brand-new guide for cross-laminated timber (CLT) diaphragm design that was published in July of this year. He explained the analysis, design and constructability of CLT diaphragms based on the newest version of the American Wood Council standard, Special Design Provisions for Wind and Seismic (SDPWS 2021). It was a real honor to have one of the primary authors present on this groundbreaking publication and Scott did not disappoint. Follow this link to download a FREE copy of the guide: CLT Diaphragm Design Guide. (And while you’re there, check out all the other great mass timber resources WoodWorks has to offer!)

I presented on Simpson’s latest and greatest products for the mass timber industry. Since publishing our Connectors and Fasteners for Mass Timber Construction Catalog in 2020, we have been diligently researching and developing new products for mass timber. Three of the new products we shared with attendees were the Strong-Drive® SDCFC Timber-CFC screw, the HSKP™ heavy seated knife plate hanger and the MTWS™ mass timber washer strap (which is used in tandem with the MTW™ mass timber angled washer). These and many other mass timber products may be found on our website at https://www.strongtie.com/solutions/mass-timber.

We also held a hands-on session for the structural engineers attending to “practice what they specify”. Attendees installed the following products into CLT panels that were donated by our good friends at Sterling Structural:

• The LDSS48 light diaphragm spline strap using our Quik Drive® PRO300SG2 delivery system and the collated Strong-Drive WSV Subfloor screw
• Strong-Drive SDWS Timber screws using the Timber Drive™ structural screw fastening system with its built-in nose plate for wood-to-wood applications
• The MDCST medium-duty diaphragm chord strap using our Strong-Drive SDS Heavy-Duty Connector screw

Experienced SST personnel were available to answer questions and demonstrate these products. By the time the hands-on session ended, it was obvious the structural engineers in attendance had gained an appreciation for these new cutting-edge products that will make mass timber installers’ lives easier.

So, what’s new with mass timber for 2024 and beyond? Who knows for sure what the future holds, but now that the 2021 IBC permits up to 18 stories of mass timber, it’s almost as if “the sky’s the limit”!