The term refers to a category of framing styles often using large panelized solid wood construction. These include cross-laminated timber (CLT), nail-laminated timber, glue-laminated timber, dowel-laminated timber or glulam panels for floor and wall framing, according to the website reThink WOOD (produced by the The Softwood Lumber Board, a Washington-based industry funded group that promotes uses of softwood lumber products in outdoor, residential and non-residential construction).
CLT typically consists of three, five or seven layers of dimension lumber oriented at right angles to one another and glued to form structural panels with exceptional strength, dimensional stability and rigidity.
“The desire to use mass timber was fundamental from the inception of the project to demonstrate a commitment to sustainability, to create a warm and inviting living environment, and to support the statewide agenda for forestry development,” said Andrea P. Leers, FAIA, principal at Boston-based Leers Weinzapfel Associates, which led a national design collaborative that also included Modus Studio (Fayetteville, Ark.), Mackey Mitchell Architects (St. Louis) and OLIN (Philadelphia).
The University of Arkansas project used CLT for its wooden columns, beams and cross-bracing, which are all visible in the interior of the facility. Likewise, the structural columns and beams are made of glulam, where layers of wood all facing the same direction are laminated together under pressure. The results are handsome, warm and quite the endorsement for the mass timber industry, especially with all the sustainability benefits the wood has to offer.