Cross-laminated timber, or CLT, is touted as a more sustainable option for building construction than concrete and steel. But is it really? The answer is complicated.
CLT is intended to replace concrete and steel whose production accounts for about 13% of global carbon dioxide emissions. Wood in CLT panels pulled CO2 from the atmosphere, and that carbon should remain locked up as long as the building stands.
Some forest scientists, climate modelers, and materials experts question how much of an environmental net gain results from using CLT to replace concrete and steel. Part of the concern relates to choices the lumber industry makes in forestry practices and manufacturing.
Lots of carbon gets dumped into the atmosphere when logs are transformed into CLT, they say. Sawmills and CLT plants typically burn bark, sawdust, and other wood wastes for heat, releasing carbon. Piles of branches, treetops, and smaller trees left behind after a harvest are often burned or left to decompose—releasing carbon into the atmosphere.
When it comes to combating global climate change, the mantra of “wood is good” may be simplistic.
Related Stories
Codes and Standards | Sep 29, 2020
New drinking water standard criteria further restricts lead leaching in plumbing products
Tightened standard applies to endpoint devices that dispense drinking water, and other plumbing components
Codes and Standards | Sep 29, 2020
Groups sue CDC over eviction moratorium
Natl. Apartment Assn. and New Civil Liberties Alliance want hearing by October.
Codes and Standards | Sep 24, 2020
Benefits of building enclosure commissioning include reduced costs
Savings achieved in less rework and fewer and shorter punch lists.
Codes and Standards | Sep 23, 2020
Intl. Code Council aims to stay ahead of new tech, efficiency trends, and resiliency
Passive survivability, social resiliency, and community health among the goals.
Codes and Standards | Sep 22, 2020
Air cleaners, chemical and UV treatments among tools to safeguard indoor air amid pandemic
Strategies augment social distancing, increased air flow to combat COVID-19 spread.
Codes and Standards | Sep 21, 2020
No ease of lumber price spikes in sight
Wildfires strike Northwest timber industry in wake of Covid-19 shutdowns.
Codes and Standards | Sep 17, 2020
Spate of energy code appeals could hamper efficiency progress
Construction and fossil fuel interests oppose portions of latest model energy code.
Codes and Standards | Sep 16, 2020
Heat pumps are the future for hot water
Sustainability policies will drive trend.
Codes and Standards | Sep 15, 2020
Taller timber buildings approved in National Fire Protection Association code
Ensures compatibility with the International Building Code.
Codes and Standards | Sep 14, 2020
Relocation of neighborhoods, the next step in U.S. flood strategy, is underway
Repeated rebuilding after successive floods now seen as bad policy.
