Investigating the potential of cross-laminated timber panels made from low-grade hardwoods for building construction
Cross-laminated timber (CLT) is an engineered wood building material characterized by high strength and stability. Although scarce, existing research confirms that production of hardwood CLT is technically feasible. CLT made from low-grade hardwoods has the potential to become a building material that could be used as an alternative to concrete, masonry, and steel. In a recent study, scientists randomly selected low-grade yellow-poplar (Liriodendron tulipifera) logs from two sites in the Central Appalachian region of the U.S. The logs were imaged using the U.S. Forest Service high-resolution laser scanner to measure and record surface defects and then sawn to maximize the production of timber for CLT manufacture without respect to guidelines set out by the National Hardwood Lumber Association for grade. (Most common defects that reduce the value of the lumber are acceptable in CLT laminations.) By changing sawing parameters, scientists reduced the amount of wood residue and increased recovery. Overall yield of cross-laminated timbers from low-grade logs was 30 percent. Considering the low quality and low value of the material used, and potential value of the end product, these results are encouraging. Use of hardwood cross-laminated timber for building material is not well established yet. However, it has the potential to become a major application for low-value hardwoods from U.S. forests and generate economic opportunities in rural areas.
Forest Service Partners