Southern Yellow Pine cross-laminated timber (CLT) debuts in Texas
Wood, seemingly the humblest of building materials, has made a comeback. Stronger, safer and more beautiful than ever before, cross-laminated timber (CLT) eliminates concerns that formerly marked wood as a lesser building material.
Also known as engineered wood or mass timber, cross-laminated timber has captured the imagination of architects, engineers, and developers as a way to build with a fully-renewable resource while meeting the same safety and performance standards boasted by masonry, steel, and concrete.
Unlike other building materials, CLT provides carbon reduction, sequestration, and storage values that only wood products can offer. When trees are harvested to create forest products, they hold onto the carbon they have removed from the air.
“In Texas, timberland area has increased and tree growth has exceeded removal over the last 30 years,” said Texas A&M Forest Service Forest Resource Analyst Aaron Stottlemyer. “So, not only are harvest levels sustainable, there is room for additional development.”
CLT panels are created by layering three to seven sections of dimension lumber oriented at right angles and gluing them together to create large panels. The strength and size of these panels make CLT a viable option for walls, roofs, and floors, even full mass timber buildings.
While CLT was developed in Austria in the 1990s and used in Europe over the last two decades, the U.S. has been slower to adopt CLT. However, attitudes and building codes are shifting as businesses, governments and designers recognize the appeal of CLT.
Texas has welcomed innovation and forward-thinking in design with the construction of a new First United Bank building designed by Gensler and made with Southern Yellow Pine CLT panels. The bank is located Fredericksburg and set to open in July.
While Douglas fir is most commonly used for CLT in North America, the bank is the first building to feature panels and glulam beams made from Southern Yellow Pine, a tree species prevalent throughout the Southern region of the United States.
IB X-LAM USA, an International Beam’s Company in Dothan, Alabama, manufactured the PRG 320 certified Southern Yellow Pine CLT panels used in the bank.
Kerlin Drake, International Beams, Vice President of Business Development, stated, “Southern Yellow Pine timber and structural lumber is a readily-available, renewable resource that offers multiple benefits including strength, carbon sequestration. and aesthetic beauty.”
Michael Dupras, DCI Engineers, served as the bank’s structural engineer. “Southern Yellow Pine CLT offers architects, engineers. and developers a regionally-sourced building material that is safe, innovative and sustainable,” he stated.
Since the panels are assembled offsite, CLT panels help simplify and speed up the construction process. “Some site benefits include reduced construction noise, reduced construction traffic. and very limited on-site waste,” Dupras said.
Fire safety, once a major concern surrounding wood in construction, is no longer an issue with CLT since CLT panels produce a char layer that resists fire damage. During a fire, the outer layer chars, starving the fire of oxygen and preventing further damage to ensure the structural integrity of the building.
CLT has also been proven to withstand seismic events, blasts, and rigorous safety testing, making mass timber as appealing to building occupants for safety reasons as much as aesthetics and sustainable qualities.
“The South is the wood basket of the world,” said Stottlemyer. “There is substantial interest across the South and in Texas for establishing CLT manufacturing facilities, and we are excited about the prospect of new markets for landowners to sell their timber.”