Conceptual Reference Database for Building Envelope Research |
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Concept:wood, lumber, timberDefinitions Wood: the hard, fibrous substance that forms the major part of the trunk and branches of a tree. Hardwood and softwood Hardwood trees have broad-leaves and 'nuts' as seeds, softwood trees are coniferous (needle leaves) and naked seeds. Lumber: wood that has been cut and surfaced for construction use. Timber: lumber whose smallest dimension is not less than 5 in. Laminated lumber is commonly used when increased wood lard-carrying capacity and rigidity are required. Plywood is a panel product made from thin sheets of wood called veneers. Expand 0.2% from dry to saturation. Also see: OSB - Oriented strandboard, MDF, LVL
Specification on lumber and engineered wood products
"Canadian forest ¡ resource accounts for 15% of the world's softwood timber from which Canada produces 11% of the world's lumber. The bulk of Canadian softwood lumber is exported to the United States, where it represents 1/3 of U.S. consumption."¡ http://www.cwc.ca/products/lumber/visually_graded/intro.php
"Qu¨¦bec is impressive in terms not only of its land area but also of the quantity and diversity of its resources. Forests figure prominently among the province¡¯s resources, constituting a source of social wealth. Upwards of 90% of Qu¨¦bec¡¯s forests are publicly-owned, while private woodlots, located primarily in the south, account for 10% of the province¡¯s forested lands." -- http://www.cifq.qc.ca/html/english/index.php?PHPSESSID=1833766861bce501ab5c6aae0ac9375e
Dimensional lumber/studs: Employee productivity was near 2,125 m3 (900,000 bf) per worker per year for dimension and stud mills -- Spelter and Alderman, 2005, Profile 2005 : softwood sawmills in the United States and Canada
"With some 300 mills each processing more than 10 000 m3 of wood annually, the lumber industry is at the heart of the economic and social development of the regions of Qu¨¦bec. Indeed, this sector is the economic cornerstone of close to 250 of Qu¨¦bec¡¯s municipalities, generating approximately about 40 500 direct jobs. Qu¨¦bec ranks second, after British Columbia, among the Canadian provinces for softwood lumber production. As further proof of its powerhouse status throughout North America, it alone accounts for approximately 24% of Canada¡¯s production. As for hardwood lumber production, Qu¨¦bec takes first place among all Canadian provinces; weighing in at 78% of the country¡¯s output, the province again enjoys pre-eminence on the North American scene. In 2000-2001, shipments of lumber manufactured in Qu¨¦bec¡¯s primary processing mills, for all species, totalled 42 000 000 m3. The main supply sources were softwood species harvested on public forest lands, such as fir, spruce, grey pine, and larch. -- http://www.cifq.qc.ca/html/english/sciage/index.php tidbits: Embodied energy: "The complex molecules in a wooden beam contain 15 gigajoules of energy perf ton¡" Lippiatt, B.C., 2002, BEES 2.0, building for environmental and economic sustainability-Technical manual and user guide, E1557-02 standard classification for building elements and related sitework-UNIFORMAT II Timber engineering software: http://www.wwpa.org/pdf/TN8.pdfhttp://www.wwpa.org/pdf/TN8.pdf For joint designs see Erman, 2003, Timber joint design: the geometric breakdown method All about trees provides some snapshot info on US forestry by AF&PA - American Forest and Paper Association Journals: Wood Based Panels International Wood Science And Technology Journal Of The International Academy Of Wood Science Wood Technology Woodcut An Annual Good References: Fridley, K. J., 2002, Wood and wood-based materials: current status and future gives a good summary of existing technical resources Tsoumis, G., Science and technology of wood -- structure, properties, utilization, Van Nostrand Reinhold, NY, 1992. Wood properties, by JERROLD E. WINANDY, at FPL
Also see references related wood by Dr. Reddy Mallidi Mold growth on "green" lumber and other wood products Understand the requirements for the growth of fungi, and the differences that exist between mold and decay fungi. Be able to discuss the molds commonly found on green lumber, and how these differ from other molds commonly found on wood and wood-based products. FP339-Introduction to Wood Science course note (concise, good, 12 chapter+) An Introduction to the Behavior and Design of Timber Structures at Washington State University, "to aid in the understanding of wood as an engineering material and with the structural design processes used in timber design." US pulp capacity estimation 2000 by FPL
Others: Cell wall micropores "Wood is a complex porous material. The pores within wood exist at the macroscopic level (cell lumena, pits etc.), but there are also micropores, which exist within the cell wall having diameters of the order of 3 nm and lower. An understanding of the geometry of these microvoids is important in trying to understand processes such as the drying of timber, biodegradation, efficient penetration by preservatives, and pulp bleaching.". ?a mercury porosimeter and nitrogen sorption analytical equipment, Dynamic Vapour Sorption analyser, helium pycnometer and solute exclusion equipment.
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