4 Things to Know About Mass Timber

Fire resistance, structural integrity and environmental attributes make new tall wood buildings among the most innovative structures in the world.

Wooden staircase by Martin Tessler

The International Code Council (ICC) Ad Hoc Committee on Tall Wood Buildings has recommended code proposals to ensure that the 2021 International Building Code remains relevant and provides local officials with the tools they need to ensure future mass timber buildings meet the highest standards.

The Committee’s work was informed by multiple fire performance tests on mass timber structures conducted at the federal Alcohol, Tobacco, Firearms and Explosives (ATF) Fire Research Laboratory, the world’s largest fire investigations lab. The fire tests confirmed that mass timber structures meet and generally exceed the fire resistance requirements in the current code.

Here are 4 things the Mass Timber Code Coalition wants you to know about Mass Timber:

Charred glulam beam, Arup fire testing

Photo: Arup

1. Mass Timber is Fire Resistant

During a fire resistance test of a 5-ply cross-laminated timber (CLT) panel wall, the panel was subjected to temperatures exceeding 1,800 Fahrenheit and lasted 3 hours and 6 minutesfar more than the two-hour rating that building codes require.

During fires, exposed mass timber chars on the outside, which forms an insulating layer protecting interior wood from damage. Additionally, when the code requires mass timber to be protected with gypsum wall board, the mass timber can achieve nearly damage-free performance during a contents-fire burnout event.

UCSD Shake Table Test, 2017 | Photo: Jacobs School of Engineering / UC San Diego

2. Mass Timber is Strong

Recent mass timber buildings weigh approximately 1/5th  that of comparable concrete buildings, which in turn reduces their foundation size, inertial seismic forces and embodied energy. High strength-to-weight ratios enable mass timber to perform well during seismic activity.

3. Mass Timber is Sustainable

Replacing steel with mass timber would reduce carbon dioxide emissions by between 15% and 20%.

By some estimates, the near-term use of CLT and other emerging wood technologies in buildings 7-15 stories could have the same emissions control effect as taking more than 2 million cars off the road for one year.

The fire tests confirmed that mass timber structures meet and generally exceed the fire resistance requirements in the current code. Studies have shown that building with wood produces fewer greenhouse gas emissions than building with other materials.

Choose the right material for a sustainable, safe and resilient project. Mass timber buildings can be 25% faster to construct than concrete buildings.

4. Mass Timber Makes Construction Cost-efficient

Mass timber buildings are roughly 25% faster to construct than concrete buildings and require 90% less construction traffic.

Since mass timber panels are prefabricated and then assembled on site, buildings made from mass timber have much shorter project timelines and safer construction sites.

Want to know more than 4 things about Mass Timber?

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