Monthly Update: November 2018

The proposals will now be subjected to an online government consensus vote, with final results due in mid-December. If approved, the proposals will allow for three new mass timber building types to be constructed in the United States:

Type IV-A – Wood buildings up to 18 stories tall

Type IV-B – Wood buildings up to 12 stories tall

Type IV-C – Wood buildings up to 9 stories tall

Mass timber includes any product currently permitted for use in Type IV construction, such as cross laminated timber (CLT), structural composite lumber, glued-laminated timber, and large section sawn lumber. The SLB estimates that up to 5.1 billion board feet (bbf) of annual demand exists for mass timber construction.

Reflecting on the likely impact, the SLB’s Cees de Jager noted that, “while formal adoption of these code changes won’t take place until well into the next decade, jurisdictions have the opportunity to incorporate the tall wood building provisions into their current code.” He noted that Oregon recently approved an addendum to its building code that allows timber structures to be built over six stories without having to acquire special permission. Code changes are seen as a turnkey intervention that will encourage more developers and architects to design projects in wood from the start, versus attempting to convert from steel or concrete to wood later in the process.

The SLB joins the industry in eagerly awaiting the outcome of the online vote and is committed to capturing the market share opportunities created by code changes.

nline vote and is committed to capturing the market share opportunities created by code changes.

Wood, Naturally recently teamed with three partner associations—the Southern Forest Product Association (SFPA), the Western Red Cedar Lumber Association, and the Southeastern Lumber Manufacturers Association—to promote the benefits of wood at the annual DeckExpo trade show, held in October in Baltimore. This is the second consecutive year that Wood, Naturally exhibited at this trades-only show, which attracts more than 5,000 design and build professionals annually.

Wood, Naturally’s 20×20 exhibit featured handcrafted projects constructed using pressure-treated southern pine and western red cedar, including a bulkhead/retaining wall, a privacy fence, a raised deck, a Japanese-style torii gate, and a pergola. The projects highlighted wood’s versatility and beauty in outdoor settings. The exhibit also hosted six demonstrations by carpentry expert Mark Clement to standing-room-only crowds and had on hand industry publications that offered additional outdoor building ideas and construction tips.

A recent op-ed published by the Mass Timber Building Coalition takes aim at the misleading claims of the concrete industry as it attempts to discredit the code compliance and performance qualities of mass timber despite a preponderance of evidence to the contrary. Concrete has gone so far as to suggest that the International Code Council (ICC) process for considering proposals is itself misguided.

In doing so, the concrete industry seeks to undermine the fact that the purpose of the International Building Code (IBC) is to provide code officials with the tools they need to ensure safety in the built environment, irrespective of the market position of any material or industry—including softwood lumber. Rather, the ICC code development process as applied to tall mass timber buildings and any other building system is predicated on science. In tall wood’s case, an ICC-appointed Ad Hoc Committee on Tall Wood Buildings undertook two years of research, including full-scale fire-resistance testing at a federal fire lab, to fully understand the science of mass timber and recommend code changes to ensure safety.

This rigorous process may not sit well with certain industry groups, but the public will be safer as a result while benefiting from the clear environmental and economic advantages of mass timber buildings.

For mid-rise projects especially, WoodWorks has observed more and more developers and contractors getting involved in structural material decisions alongside building design teams. Often these individuals have long histories of using steel or concrete, and lack both practical experience with and/or confidence in wood as a viable and potentially better choice for their projects.

To overcome this barrier, WoodWorks is going to new places and events to reach and build relationships with this new segment of its audience. In recent months, WoodWorks participated in one-on-one developer meetings during the MultiFamily Executive Conference, met with contractor associations and firms to discuss education needs related to mass timber installation, and started attending developer- and contractor-focused events run by organizations such as the Urban Land Institute and the Commercial Real Estate Development Association.

Big names like Amazon and Google are joining boutique firms like Katerra in rapidly entering the building sector as they realize the efficiencies and potential profitability of prefabrication and off-site construction. Both prefab and off-site construction have seen exponential growth in recent years as a nationwide construction labor shortage forces builders and developers to leverage process efficiencies at every stage of construction.

Prefabricated wood building systems in particular—which are no longer limited to single-family homes and small, temporary workspaces—have a unique value proposition with many benefits, including high quality control standards, material efficiency, reduced waste, safer working environments, and outstanding return on investment.

Think Wood is ensuring that the benefits of prefabricated wood building systems are continuously communicated to architects, engineers, and developers by

• Curating the latest high-impact research on prefabricated wood building systems.
• Educating architects and engineers on wood prefabrication.
• Highlighting thought leaders who are rapidly adopting and investing in softwood lumber technology and construction.
• Leading the narrative about wood’s advantages in prefabrication.

The AWC has released a new report on sound transmission, Technical Report 15 (TR15), Calculation of Sound Transmission Parameters for Wood-Framed Assemblies, to support building professionals in meeting stringent code requirements regarding sound in wood buildings.

TR15 describes how acoustics for floor-ceiling assemblies are regulated in the code and provides a code-recognized, calculation-based model that can be used to demonstrate compliance for wood-framed floor-ceiling assemblies. The acoustics model can also be used to quickly determine the effect of changes to basic assemblies or proprietary designs without needing to undertake further engineering analysis or costly physical testing of each new variation.

A free PDF version of TR15 can be found here. The AWC also developed a companion, ICC-accredited, free e-course that provides an understanding of the calculation-based analysis approach, which is available here.