| Balanced Construction | A construction such that the forces induced by uniformly distributed changes in moisture content will not cause warping. Symmetrical construction of plywood in which the grain direction of each ply is perpendicular to that of adjacent plies is balanced construction. |
| Bark Pocket | An opening between annual growth rings that contains bark. Bark pockets appear as dark streaks on radial surfaces and as rounded areas on tangential surfaces. |
| Bastard Sawn | Lumber (primarily hardwoods) in which the annual rings make angles of 30¡ to 60¡ with the surface of the piece. |
| Beam | A structural member supporting a load applied transversely to it. |
| Bearing | The contact area over which one structural element, such as a truss, is supported on another structural element such as a wall. |
| BEES | BEES measures the environmental performance of building products by using the life-cycle assessment approach specified in the ISO 14040 series of standards. All stages in the life of a product are analyzed: raw material acquisition, manufacture, transportation, installation, use, and recycling and waste management. Economic performance is measured using the ASTM standard life-cycle cost method, which covers the costs of initial investment, replacement, operation, maintenance and repair, and disposal. Environmental and economic performance are combined into an overall performance measure using the ASTM standard for Multi-Attribute Decision Analysis. For the entire BEES analysis, building products are defined and classified according to the ASTM standard classification for building elements known as UNIFORMAT II. |
| Bending, Steam | The process of forming curved wood members by steaming or boiling the wood and bending it to a form. |
| Biocides | An additive which will prevent growth of bacteria or fungi. Used in paints, floor coverings and sometimes in fabrics. They are toxic materials which are usually only safe in low concentrations. |
| Biodegradable | A material that will decompose into naturally occurring, harmless components with exposure to air, sunlight and/or moisture. |
| Bio-Mass | Biomass fuels are any plant or animal matter that may be used directly or indirectly as a fuel. In practice these fall into two main categories. The first is the dependent biomass resources (arising as by-products of other activities; e.g. wood residues and recovered wood waste, straw, poultry litter, forestry residues, livestock slurry, etc.). The second is the dedicated biomass resources (energy crops grown specifically for fuel; e.g. short rotation tree crops - single stemmed or coppiced, whole crop cereals, etc.). |
| Bioswale | A shallow trench planted with trees, shrubs, and ground cover that detains and filters stormwater before allowing it to infiltrate the groundwater system. |
| BIPV | Building integrated photovoltaic products such as solar roof shingles for homes and opaque glass PV facades are now available on the market. These replace conventional building materials while generating electricity, effectively reducing the cost of PV installation. (See Photovoltaic) |
| Bird Peck | A small hole or patch of distorted grain resulting from birds pecking through the growing cells in the tree. The shape of bird peck usually resembles a carpet tack with the point towards the bark; bird peck is usually accompanied by discoloration extending for considerable distance along the grain and to a much lesser extent across the grain. |
| Birdseye | Small localized areas in wood with the fibers indented and otherwise contorted to form few to many small circular or elliptical figures remotely resembling birds' eyes on the tangential surface. It sometimes found in sugar maple and used for decorative purposes, rare in other hardwood species. |
| Black Water | Waste water that contains organic matter - i.e waste water from kitchen sinks, toilets, etc. |
| Blister | An elevation of the surface of an adherend, somewhat resembling in shape a blister on human skin; its boundaries may be indefinitely outlined, and it may have burst and become flattened. (A blister may be caused by insufficient adhesive; inadequate curing time, temperature, or pressure; or trapped air, water, or solvent vapor.) |
| Bloom | Crystals formed on the surface of treated wood by exudation and evaporation of the solvent in preservative solutions. |
| Blow | In plywood and particleboard especially, the development of steam pockets during hot pressing of the panel, resulting in an internal separation or rupture when pressure is released, sometimes with an audible report. |
| Blue Stain | A bluish or grayish discoloration of the sapwood caused by the growth of certain dark-colored fungi on the surface and in the interior of the wood; made possible by the same conditions that favor the growth of other fungi. |
| Board | Lumber that is less than 38 mm standard (2 in. nominal) thickness and greater than 38 mm standard (2 in nominal) width. Boards less than 140 mm standard (6 in. nominal) width are sometimes called strips. |
| Board Foot | A unit of measurement of lumber represented by a board 12 in. long, 12 in. wide, and 1 in. thick or its cubic equivalent. In practice, the board foot calculation for lumber 1 in. or more in thickness is based on its nominal thickness and width and the actual length. Lumber with a nominal thickness of less than 1 in. is calculated as 1 in. |
| Bole | The main stem of a tree of substantial diameter-roughly, capable of yielding saw timber, veneer logs, or large poles. Seedlings, saplings, and small-diameter trees have stems, not boles. |
| Bolt | (1) A short section of a tree trunk. (2) In veneer production, a short log of a length suitable for peeling in a lathe. |
| BOMA Go Green | Green retrofit program administered by Building Owners and Managers Association BC targeting resource consumption, water reduction and recycling, building materials, interior environment and tenant awareness. |
| Bond | (1) The union of materials by adhesives. (2) To unite materials by means of an adhesive. |
| Bond Failure | Rupture of adhesive bond. |
| Bond Strength | The unit load applied in tension, compression, flexure, peel impact, cleavage, or shear required to break an adhesive assembly, with failure occurring in or near the plane of the bond. |
| Bondability | Term indicating ease or difficulty in bonding a material with adhesive. |
| Bondline | The layer of adhesive that attaches two adherends. |
| Bondline Slip | Movement within and parallel to the bondline during shear. |
| Bow | The distortion of lumber in which there is a deviation, in a direction perpendicular to the flat face, from a straight line from end-to-end of the piece. |
| Box Beam | A built-up beam with solid wood flanges and plywood or wood-based panel product webs. |
| Boxed Heart | The term used when the pith falls entirely within the four faces of a piece of wood anywhere in its length. Also called boxed pith. |
| Brashness | A condition that causes some pieces of wood to be relatively low in shock resistance for the species and, when broken in bending, to fail abruptly without splintering at comparatively small deflections. |
| Breaking Radius | The limiting radius of curvature to which wood or plywood can be bent without breaking. |
| BREEAM | British Research Establishment Environmental Assessment Methodology is a performance rating system for buildings. |
| BREEAM Greenleaf | Hybrid system comprising BREEAM's set of environmental issues with the Green Leaf Eco-Rating procedure. |
| Bright | Free from discoloration. |
| British Thermal Unit (BTU) | The quantity of heat required to raise the temperature of one pound of water 1 deg. F., equal to 252 calories or the heat given off by a match. Used to measure heat output or the energy contained within a material. |
| Brown Rot | In wood, any decay in which the attack concentrates on the cellulose and associated carbohydrates rather than on the lignin, producing a light to dark brown friable residue-hence loosely termed "dry rot." An advanced stage where the wood splits along rectangular planes, in shrinking, is termed "cubical rot." |
| Brown Stain | A rich brown to deep chocolate-brown discoloration of the sapwood of some pines caused by a fungus that acts much like the blue-stain fungi. |
| Brownfield Site | A site that has been previously developed and likely to contain soil contamination. |
| Building Related Illnesses (BRI) | Illnesses caused by toxic off-gassing from building materials or moulds, bacteria, etc. that can accumulate in HVAC systems and carpeting. |
| Built-Up Timbers | An assembly made by joining layers of lumber together with mechanical fastenings so that the grain of all laminations is essentially parallel. |
| Burl | (1) A hard, woody outgrowth on a tree, more or less rounded in form, usually resulting from the entwined growth of a cluster of adventitious buds. Such burls are the source of the highly figured burl veneers used for purely ornamental purposes. (2) In lumber or veneer, a localized severe distortion of the grain generally rounded in outline, usually resulting from overgrowth of dead branch stubs, varying from one to several centimeters (one-half to several inches) in diameter; frequently includes one or more clusters of several small contiguous conical protuberances, each usually having a core or pith but no appreciable amount of end grain (in tangential view) surrounding it. |
| Butt Joint | An end joint formed by abutting the squared ends of two pieces. |
| Buttress | A ridge of wood developed in the angle between a lateral root and the butt of a tree, which may extend up the stem to a considerable height. |
| By-Product | Anything produced in the course of making another product. |