As mass timber projects have proliferated across the U.S., many developers, building owners and contractors have found that insurance companies unfamiliar with these types of buildings are reluctant to provide insurance. Their questions to WoodWorks are typically:
- Who has faced this issue before?
- How did they address it?
- What information is available to alleviate insurance company concerns about building safety and performance?
- What is the best path forward?
While mass timber is relatively new in the U.S., it is also experiencing tremendous growth—as of December 2020, there were 1,060 mass timber projects completed, under construction or in design—and much can be learned from successful projects.
The insurance challenge tends to present itself in two forms: builder’s risk insurance (or course of construction) and fixed property insurance (after the building is complete and occupied). Relative risks are assessed differently for each type of insurance, and each requires a unique approach. For example:
- Construction-phase risks associated with fire are different in mass timber buildings than with most other framing systems. Since the timber elements have inherent fire-resistance capabilities, a building has a certain level of fire-resistance as soon as the frame is erected. Protection doesn’t rely on (and wait for installation of) materials such as spray-applied fire proofing. The potential for faster construction can also mitigate several risks. Less time under construction means less time for potential hazards such as theft, arson, etc.
- In addition to safety, fixed property insurance for mass timber buildings requires an understanding of performance related to things like moisture, durability and building enclosure detailing. Much of the fixed property insurance discussion is also site-specific—e.g., Is the area prone to flooding, earthquakes or high winds? Mass timber has been rigorously tested against potential natural disasters as demonstrated in the test and research reports linked below.
WoodWorks offers two avenues to assist project teams who face insurance issues:
Individual project support (at no cost) – We regularly engage in building-specific discussions on insurance issues. In addition to providing design and construction-related technical support, we can also interact with brokers and insurers to answer their questions related to mass timber’s performance. To request assistance on your project, contact your local Regional Director using our Project Assistance Map or email the WoodWorks help desk at .
Published resources – Because insurers often have similar areas of concern, WoodWorks maintains a growing list of resources that demonstrate mass timber’s safety and durability, including the results of testing, research and ongoing monitoring. WoodWorks is also developing a white paper, to be released in the Spring of 2021, which will take an in-depth look at the insurance industry, including its history, what affects premiums, how risks are analyzed, and how project teams can navigate coverage for mass timber projects.
Mass Timber Building Trends and Project Maps
- WoodWorks mass timber project trends; quarterly update of projects in design, under construction or built across the U.S.
- WoodWorks Innovation Network (WIN) interactive mass timber project map
- North American Mass Timber State of the Industry Report – The Beck Group, Forest Business Network, Treesource, Kaiser+Path
Testing Data and Results
- Inventory of Fire-Resistance Tested Mass Timber Assemblies & Penetrations – WoodWorks
- Compartment Fire Testing of a Two-Story Mass Timber Building: full report and summary videos – U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives/USDA Forest Products Laboratory (FPL)
- Tall mass timber-related fire test reports – Multiple sources via the American Wood Council (AWC)
- Fire Resistance of Structural Composite Lumber Products – White, R., USDA FPL
- Glulam Connection Fire Test Summary Report – Softwood Lumber Board, ARUP
- Calculating the Fire Resistance of Wood Members and Assemblies – AWC
- Fire Design of Mass Timber Members – McLain, R., Breneman, S., WoodWorks
- CLT Adhesive Tests in Support of Mass Timber Buildings – AWC
Post Fire and Sprinkler Remediation:
- Post-Fire Restoration of Cross-Laminated Timber (CLT) – Smartlam
- Solutions for Upper Mid-Rise and High-Rise Mass Timber Construction Rehabilitation of Mass Timber Following Fire and Sprinkler Activation– Ranger, L., FPInnovations
- Wind-Induced Vibrations in Timber Buildings – Parameter Study of Cross-Laminated Timber Residential Structures – Edskär, I., Lidelöw, H., Structural Engineering International
- Tall Timber Buildings – A Preliminary Study of Wind-Induced Vibrations of a 22-Storey Building –Johansson, M., Linderholt, A., Jamerö, K. Landel, P., 2016 World Conference on Timber Engineering
- Wind-induced vibrations of a multi-storey residential building in cross-laminated timber in the serviceability limit state – Kryh, M., Nilsson, M., Chalmers University of Technology
- Dynamic Performance of Tall Mass-Timber Buildings – Pangavhane, S.A., MagarPatil, H.R., Journal of Engineering Sciences
- Performance of Cross-Laminated Timber as a Residential Building Material Subject to Tornado Events – Stoner, M.W., Clemson University
- Wind and Earthquake Design Framework for Tall Wood-Concrete Hybrid System – Tesfamariam, S., Bezabeh, M., Skandalos, K., Martinez, E., Dires, S., Bitsuamlak G., Goda, K., University of British Columbia
- Development of a Ready-to-Assemble Tornado Shelter from Cross-Laminated Timber: Impact and Wind Pressure Testing – Falk, R.H., Bridwell, J.J., Williamson, T., Black, T., USDA FPL
- Risk-based wind design of tall mass-timber buildings – Bezabeh, M., Bitsuamiak, G.T., Tesfamariam, S., Canadian Society for Civil Engineers Annual Conference (2018)
- Wind-Induced Motion of “Treet” – A 14-Storey Timber Residential Building in Norway – Bjertnaes, M.A., Kjell, A.M., 2014 World Conference on Timber Engineering
- Seismic Performance Factors for Cross-Laminated Timber Shear Wall Systems in the United States – van de Lindt, J.W., Amini, M.O., Rammer, D., Journal of Structural Engineering
- Full-Scale Shake Table Testing of Cross-Laminated Timber Rocking Shear Walls with Replaceable Components – Blomgren, H., Pei, S., Jin, Z., Powers, J., Journal of Structural Engineering
- Experimental Seismic Response of a Resilient 2-Story Mass-Timber Building with Post-Tensioned Rocking Walls– Pei, S., van de Lindt, J.W., Barbosa, A.R., Berman, J.W., Journal of Structural Engineering
- Feasibility Study of Mass-Timber Cores for the UBC Tall Wood Building – Connolly, T., Loss, C., Iqbal, A., Tannert, T., University of Northern British Columbia
- Solutions for Upper Mid-Rise and High-Rise Mass Timber Construction: Seismic Performance of Braced Mass Timber Frames – Year 1 – Chen, Z., Popovski, M., Symons, P.D., FPInnovations
- Expanding Wood Use Towards 2025: Seismic Performance of Braced Mass Timber Frames – Year 2 – Chen, Z., Popovski, M., FPInnovations
- Basis of Design – Performance-Based Design and Structural CD Drawings for Framework Office Building in Portland, OR – KPFF Consulting Engineers
Construction Phase Moisture Protection
- Moisture Risk Management Strategies for Mass Timber Buildings – RDH Building Science, Inc.
- Nail Laminated Timber: U.S. Design and Construction Guide – Fast + Epp Structural Engineers, Perkins & Will, RDH Building Science, Inc., Seagate Structures Ltd., Holmes Fire, GHL Consultants Ltd.
- On-Site Moisture Management of Wood Construction – Wang, J., FPInnovations
- Monitoring Moisture Performance of Cross-Laminated Timber Building Elements during Construction – Schmidt, E., Riggio, M., Oregon State University
Building Enclosure & Related Long-Term Moisture Topics
- Mass Timber Building Enclosure Best Practice Design Guide – RDH Building Science, Inc.
- Moisture Monitoring and Modeling of Mass Timber Building Systems – Kordziel, S., Glass, S.V., Pei, S., Zelinka, S.L., Tabares-Valasco, P.C., 2018 World Conference on Timber Engineering
- Can Exposed Wood Framing be Used in Buildings Such as Aquatic Centers and Pools? Are there Durability Concerns? – WoodWorks