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
| Oct 20, 2011
LEED 2012 to require real-time energy, water use reporting
The LEED 2012 rating system, set to launch in November 2012, will contain features to make sure buildings function as intended, and improve over time.
| Oct 20, 2011
New York City moving to speedier, online design reviews
New York City is moving towards a development design review process that will let officials and developers review blueprints for new projects online in a virtual conference room rather than in person.
| Oct 20, 2011
Michigan bill would let private firms operate as a city’s building department
Michigan House Bill 5011 would change state’s building code to allow private companies to operate as a municipality's building department.
| Oct 20, 2011
Alabama’s strict immigration law drives away construction workers
Alabama's strict new immigration law is driving many construction workers and roofers from the state.
| Oct 20, 2011
Fed bill would allow school rehab funding via historic tax credits
Virginia Sens. Jim Webb (D) and Mark Warner (D) introduced a bill this month to rehab aging schools across the country through the use of historic tax credits.
| Oct 20, 2011
Process leads to new design values for southern pine and other visually graded dimension lumber
A summary of the process used to develop new design values will clarify many of the questions received by the SFPA.
| Oct 19, 2011
Another drop for Architecture Billings Index
Positive conditions seen last month were more of an aberration.
| Oct 18, 2011
Dow Building Solutions invests in two research facilities to deliver data to building and construction industry
State-of-the-art monitoring system allows researchers to collect, analyze and process the performance of wall systems.
| Oct 14, 2011
ACI partners with CRSI to launch new adhesive anchor certification program
Adhesive anchor installer certification required in new ACI 318-11.
| Oct 13, 2011
New Building Materials Label Focuses On Sustainability
Architectural products company Construction Specialities and design firm Perkins + Will have created a label for building materials to shed light on product content.
