International Convention of Society of Wood Science and Technology
Mass timber is a category of framing components that can be built with a variety of materials. Engineered wood products have become the backbone of the mass timber movement. Some of the most common mass timber structural elements used in buildings are glue-laminated beams (glulam), laminated veneer lumber (LVL) and cross laminated timber (CLT). However, wood is a natural material which is susceptible to decay and termite attack...
American Wood Protection Association Annual Meeting
Cross laminated timber (CLT) is a relatively recent addition to the North American timber construction market. CLT has been successfully used for construction in Europe and, in the past few years, manufacturers have looked forward to expanding the use of this product into the North American market. However, no termite susceptibility experiments have been published for the product and no standards exist for testing of the CLT and other mass timber products against termites. It is extremely important to evaluate the resistance to degradation of CLT, especially if the manufacturers are trying to implement this product in areas where the occurrence of termite infestation is high...
The development of composite mass timber products in the late 20th century continues to generate new developments in the design and production of multi-layer wood products in a wide variety of orientations and for a wide variety of uses. In the US Congress’ Agricultural Act of 2014, provisions were specified in Section 7310 to establish a series of priorities for research into the needs of the forestry sector. Specifically, collaborative research efforts into the increased use of CLT in support of the expansion of this portion of the forest products industry were addressed. Cross laminated timber products have been included in updates to national and international building codes, and new production facilities continue to come online. WoodWorks (2019) reports that 105 CLT based construction projects are in construction or completed, and 200 are in the design process. These projects are scattered across the United States, including in the highest areas of decay potential (Figure 1). Mississippi State University Department of Sustainable Bioproducts has several ongoing projects to investigate the durability of CLT under various conditions. These are partnerships with other investigators, primarily with USDA Forest Products Lab personnel, and are housed at both MSU Department of Sustainable Bioproducts facilities in Starkville, MS as well as Forest Products Lab locations in Madison, WI, McNeill, MS, and Saucier, MS. CLT is being tested in several different formats and in test pieces of different sizes. In an ideal situation, CLT panels would be tested at their full size, however, the time it would take to do so, and the logistics of handling pieces of typical size is prohibitive for rapid assessment of the product. Assessments of CLT to date have focused on examining the durability of CLT when exposed to hazards that occur in the high hazard zones of deterioration, such as fungi, termites, and natural weathering. This report describes the collaborative testing of CLT against termite infestation and damage.