Fire Lab Science Team
Every year, both structure and wildland fires result in personal injuries, loss of life, and damage to property and infrastructure. Prevention and mitigation are key in saving lives and reducing the impact of these events. The Forest Products Laboratory fire science team understands the challenges that arise when quantifying complex fire behavior and incorporating wood-based materials in the built environment.
The unique experimental capabilities of the fire laboratory allow researchers to assess solid timber, engineered wood products, and wood-based composites in simulation of built and natural environments. We conduct cutting-edge research utilizing non-standard techniques and assist with the development of testing methods and material regulations in the following research areas:
- Char formation in wood products
- Fundamental fire science
- Wildland-urban interface
- Wildland fire acoustics
- Material properties at high temperatures and flammability/fire growth
- Standards development
Tall Wood Buildings
In 2015, an ICC Ad Hoc Committee was formed to study the science and feasibility of tall wood buildings and develop pertinent building code changes. In support of the code changes, Forest Products Laboratory researchers, in collaboration with Engineers at the Alcohol, Tobacco, and Firearms Fire Research Laboratory, conducted five full-scale fire tests to simulate aspects of the proposed code changes. The tests evaluated contribution of mass timber to a fire, integrity of structural members, performance of connections, performance of through-penetration protection, and conditions for responding fire personnel. Ultimately, the results of the tests showed the proposed code changes were conservative and the ICC adopted a comprehensive set of changes to the 2021 IBC for the safe construction and use of mass timber buildings up to 18 stories.
Ascent Building in Milwaukee
Understanding char rate is essential for structural designers to estimate the loss of load-carrying capacity of wooden beams and columns during a fire. We are advancing the understanding of char rates under several different fire exposures for a variety of engineered wood products to ensure structural wood members are design to safely withstand structural design loads during a fire. Working with the design team of Ascent Milwaukee, Forest Products Laboratory researchers evaluated the effect of a three-hour fire exposure on structural calculations for glulam columns.
Fire Behavior of Gaps in CLT Panel-to-Panel Connections
Cross Laminate Timber (CLT) test specimen with plywood spline connection instrumented with thermocouples to monitor temperatures within the wood during fire test.
The Forest Products Laboratory, in collaboration with Oregon State University and the Research on Engineering, Architecture & Construction of Timber Structures (REACTS) Consortium, assessed the fire performance of typical connection assemblies and potential gap distances that may occur in timber construction. The approach involved a series of fire tests conducted on the intermediate scale furnace at Forest Products Laboratory and included the first-of-its-kind measurements on the propensity for connections to smolder during a cool-down phase. The results advance the scientific basis for design recommendations on timber-to-timber connections and give a relative indication of the risk of failure due to fire and the propagation of smoldering combustion in connections. The final findings impact the construction of timber structures by understanding what sized gaps are acceptable in exposed mass timber construction and can be incorporated into International Building Code.
Fire Performance of Penetrations in Glulam Beams
Glulam beam specimen with horizontal penetrations being removed from furnace post-fire test.
Glue laminated timber (glulam) is an engineered wood product that offers designers highly predictable structural and fire performance when used in accordance with design specifications. However, field modifications, such as notching and drilling to route piping and ductwork through, are common practice. Forest Products Laboratory researchers are evaluating the effects of these field modifications on the structural capacities of glulam in the event of a fire to ensure safe designs are implemented.
Weathering and Fire Testing of Exterior Fire-Resistant Coatings
Over 32% of homes in the U.S. are in the Wildland Urban Interface, the areas where human development meets natural spaces. These areas are more vulnerable to wildfire damage. To fire-harden individual structures, Forest Products Laboratory researchers evaluate the use of treatments and coatings applicable to exterior wood products, including the effect of weathering on fire performance.
Detecting Infrasound Emissions from Wildland Fires
Current monitoring techniques of wildland fires capture snapshots of either a moment in time or continuous observations that are restricted in space where not everything can be viewed. Though wildland fire practitioners have learned how to work well with these tools, they still leave critical information, like the time-evolution of the fire and the characteristics of the fire’s growth completely out. Remote detection and monitoring of wildland fire dynamics using Infrasound emissions is an entirely new technique that has strong potential to yield new metrics about the fire that are irretrievable by traditional means. In particular, the growth and fluctuation of the fire, both in space and time, are attainable with the use of Infrasound emissions monitoring, making it a great complement to existing tools.
Left: a single infrasound sensor deployed on recently burned ground. Right: Scientists and practitioners watching a prescribed fire where infrasound emissions were collected.
Identifying Sound Sources in Wildland Fire
Through collaborations with Blue Ridge Research and Consulting as well as the University of Mississippi and University of California San Diego, the Forest Products Laboratory fire research team and researchers from the Northern Research Station is investigating the use of acoustical inverse techniques, like acoustical holography and beamforming, to locate and model the sources of noise and fire-atmosphere flow structures in wildland fires. This work will provide critically needed information to help to validate fire behavior models and improve training and safety resources for fire practitioners.
WOODWISE: Wood Optimization for Occupant Safety, Design, Wood Innovation, Smoldering, and Emissions
Through a partnership between Forest Products Laboratory, Oregon State University, U.S. EPA and other organizations, a multi-scale and multi-disciplinary research program is underway to study fire behavior in mass timber. This project consists of three activities: large-scale compartment fire testing, intermediate-scale compartment fire testing, and small-scale fire testing of mass timber. The intermediate- and small-scale tests will verify if the data collected in the large-scale compartment fire tests, including emissions, can be scaled. Scaling the data is critical for the broader applicability of the experimental results to a wide range of compartments and buildings that are being constructed globally. By applying the results from the large-scale tests, the strengths and limitations of scaled approaches regarding fire performance and emissions can be further evaluated and assessed.
