This Special Issue brings together emerging innovations and practical advancements that are shaping the next generation of timber construction. From breakthroughs in material science to high‑performance structural systems, our goal is to highlight how wood can contribute to safer, more sustainable, and more efficient buildings.

We invite contributions across the full spectrum of research and practice, including:

• Original research on materials, systems, testing, modelling, and structural performance

• Comprehensive literature reviews that synthesize current knowledge and identify future research needs

• Research case studies demonstrating innovative methods, analytical approaches, or performance insights

• Practical/industry case studies showcasing real‑world applications, challenges, and lessons learned

This Special Issue aims to serve as a platform for researchers, practitioners, and industry partners who are advancing the science and practice of building with wood.

If your work aligns with these themes, we warmly welcome your submission. For more details, please visit the Special Issue page (https://www.mdpi.com/journal/buildings/special_issues/F5WJ269YMS), or feel free to contact me at zhiyong.chen@fpinnovations.ca. 

thanks for the help to pull together these data.

Part 1:

https://library.fpinnovations.ca/link/fpipub11016

Part 2:

https://library.fpinnovations.ca/link/fpipub11128

The slides from David Barber's presentation last week are available at https://www.woodworks.org/wp-content/uploads/presentation_slides_Barber_Fire_Design_Mass_Timber_Connections_09.2025.pdf

We will have a recording of the webinar available on https://www.woodinstitute.org/ in a few weeks.

Scott Breneman, PhD, PE (WA, CA), SE (CA)

WoodWorks – Wood Products Council 

The IBC states that all gaps must have caulk within them; however, the Fire Design Specification (FDS) provides a bit more information on varying char depths with different sized gaps (Section 3.2.3). These prescribed char depths can be used to evaluate if screw embedment depth and shear capacity of the beam are sufficient. However, most of the research shows that when the gaps are 3 mm and less, the char within the connections is quite small and the presence of caulk doesn’t influence the temperatures within the connections as much as when the gaps are greater than 3 mm (1/8 inch), and particularly greater than 6 mm (1/4 inch).

We did some fire tests on glulam beam-to-column connections, the goal was not to explore the influence of the gap though we did quantify it:

Fischer EC, Bhandari S, Sinha A (2025) Fire Testing of Glue-Laminated Beam-to-Column Connections. Journal of Structural Engineering 151:. https://doi.org/10.1061/jsendh.steng-13888

Recently we led efforts to study gap influences for CLT panel-to-panel connections:

Garrett W, Fischer E, Hasburgh L (2025) QUANTIFYING FIRE BEHAVIOUR IN GAPS IN CLT PANEL-TO-PANEL CONNECTIONS. In: Proceedings from the 14th World Conference on Timber Engineering: Advancing Timber for the Future Built Environment, WCTE 2025. World Conference on Timber Engineering (WCTE), pp 3684–3692

Rothoblaas did a study on gaps in CLT panel-to-panel connections all including fire protection and recently presented it at WCTE this year:

Brugnara P, Alice S, Sestigiani L (2025) FIRE AND CLT: LINEAR JOINTS. In: Proceedings from the 14th World Conference on Timber Engineering: Advancing Timber for the Future Built Environment, WCTE 2025. World Conference on Timber Engineering (WCTE), pp 4235–4241

Another study that is relevant: (more beam-to-column connections)

du Plessis M, Sulon D, Streicher D, Walls R (2024) Experimental testing on timber connections considering the influence of gap size and intumescent sealants. Fire Mater 48:39–61. https://doi.org/10.1002/fam.3164

The thesis/dissertations along with this work is here:

https://scholar.sun.ac.za/handle/10019.1/130182

https://scholar.sun.ac.za/handle/10019.1/130182

MTC has performed some research with this (beam-to-column connections) along with Christian Dagenais – he is presenting it at Woodrise next week, but they don’t seem to have a publication out yet. We just tested glulam beam-to-column connections this summer – and probably won’t have a paper out for a while. We are analyzing the data right now.

I hope that this is helpful!

Erica

Erica C. Fischer, PhD, PE

Below are two more references on the topic. I have also included Erica Fisher on this email chain in case she has more to share since OSU + REACTS + FPL are collaborating on a project that is digging into the fire dynamics within the gaps that occur at connections to evaluate the effect of various gap sizes (not caulked) on the charring/temperatures at those connections.

• IBC Section 703.7 (2021 and 2024 Editions) requires sealant or adhesive, unless not a required component of a tested assembly, be provided to resist the passage of air and they must meet either ASTM C920 or ASTM D3498, respectively.
• AWC’s Fire Design Specification (Section 3.10 from the 2024 Edition) details requirements for the design of protected connections.