Wood Flashcards
The tough, fibrous cellular substance that makes up most of the stems and branches of trees beneath the bark.
Wood
The tough external covering of a woody stem, branch or root, composed of a living inner layer called phloem and an outer bark or corky, dead tissue.
Bark
A layer of tissue that carries food from the leaves to the growing parts of a tree.
Phloem, inner bark
A thin layer of reproductive tissue between the phloem and xylem, which produces new phloem on the outside and new xylem on the inside of stems, branches, and roots.
cambium
The soft, central core about which first growth takes place in a newly formed stem.
Pith
The woody tissue of a tree that provides support and conducts water and mineral nutrients upward from the roots.
Xylem
An organic substance that, with cellulose, forms the woody cell walls of plants and the cementing material between them.
Lignin
An inert carbohydrate that is the chief constituent of the cell walls of plants and of dried woods, jute, hemp, and cotton, used in the manufacture of a wide variety of synthetic building materials.
Cellulose
The younger, softer, living portion of wood between the cambium and heartwood, comparable in strength to heartwood but usually lighter in color, more permeable, and less durable.
Sapwood, Alburnum
The older, harder, inactive core of a tree, usually darker, denser, and more durable than the surrounding sapwood.
Heartwood, duramen
A concentric layer of wood produced during a single year’s growth of a temperate tree.
Annual ring, growth ring
The softer, more porous portion of an annual ring that develops early in the growing season, characterized by large, thin-walled cells.
Springwood, early wood
The harder, darker, less porous portion of an annual ring that develops late in the growing season, characterized by compact, thick-walled cells.
Summerwood, late wood
The wood from a conifer. The term is not descriptive of the actual softness of the wood.
Softwood
Any of various predominantly evergreen, cone-bearing trees, such as pine, fir, hemlock and spruce.
Conifer
Having foliage that remains green and functional throughout the year or through more than one growing season.
Evergreen
A tubular, intercellular space in a woody stem that secretes resins, esp in conifers.
Resin duct, resin canal
A viscous, clear to translucent, organic substance exuded by certain pines, used in makng varnishes, adhesives and plastics.
Resin
The resinous sap that exudes from various conifers.
Pitch
One of the elongated, supporting and conductive cells in woody tissue, having tapering closed ends and lignified walls oriented parallel to the axis of a stem or branch.
Tracheid
A tubular structure of woody tissue for conducting water and mineral nutrients, formed by the fusion and loss of end walls in a series of connected cells.
Vessel
One of the vertical bands of transverse cells that radiate between pith and bark for the storage and horizontal conduction of nutrients.
Ray
One of the relatively large vertical cells for conducting sap, esp in hardwood trees.
Pore
The vital flud of water, nitrogen, and mineral nutrients that circulates through a plant.
Sap
One of the slender, thick-walled cells that, together, serve to strengthen plant tissue.
Fiber
The leaves and living branches of a tree.
Crown
The main stem of a tree apart from its branches and roots.
Trunk
The wood from a broad-leaved flowering tree, such as cherry, maple, or oak. The term is not descriptive of the actual hardness of the wood.
Hardwood
Shedding leaves annually or at the end of a growing season. The term is descriptive of most hardwoods and a few softwoods.
Decidous
The timber product manufactured by sawing, resawing, passing lenthwise through a planing machine, cross-cutting to length, and grading.
Lumber
Wood suitable for use as a building material.
Timber
A length of trunk or large limb of a felled tree, ready for sawing.
Log
Lumber that is sawn, edged and trimmed, but not surfaced.
Rough Lumber
Lumber that is surfaced with a planing machine to attain a smooth surface and uniform size.
Dressed lumber
Of or pertaining to dressed lumber having a moisture content exceeding 19% at the time of manufacture.
Surfaced Green
Of or pertaining to lumber that has been dried to reduce its moisture content and improve its serviceability.
Seasoned
Of or pertaining to lumber seasoned in a kiln under controlled conditions of heat, air circulation, and humidity.
Kiln-dried
Of or pertaining to lumber seasoned by exposure to the atmosphere.
Air-dried
Of or pertaining to dressed lumber having at a moisture content of 19% or less at the time of manufacture.
Surfaced Dry
Of or pertaining to lumber dried to a point at which no moisture can be extracted when exposed in a kiln to a temperature of 214d to 221dF (101d to 105dC).
Over-dry
The stage in the drying or wetting of wood at which the cell walls are fully saturated but the cell cavities are void of water, ranging from moisture content of 25% to 32% for commonly used species. Further drying results in shrinkage and generally greater strength, stiffness and density of the wood.
Fiber-saturation point
The moisture content at which wood neither gains nor loses moisture when surrounded by air at a given temperature and relative humidity.
Equilibrium moisture content
The amount of water contained in a wood piece, expressed as a percentage of the weight of the wood when oven-dry.
Moisture content
The dimensional contraction of a wood piece occuring when its moistre content falls below the fiber-saturation point. Shrinkage is very slight along the grain but significant across the grain.
Shrinkage
Wood shrinkage in a direction tangent to the growth rings, about double that of radial shrinkage.
Tangential shrinkage
Wood shrinkage perpendicular to the grain, across the growth rings.
Radian shrinkage
Wood shrinkage parallel to the grain, about 2% of radial shrinkage.
Longitudinal shrinkage
The alternate swelling and shrinkage of seasoned wood occuring with changesin moisture content caused by changes in relative humidity of the surrounding air.
Working
To store wood products, such as millwork and flooring, in an interior space until the materials adapt to the moistre content and temperature of the new environment.
Acclimatize
A unit of quantity for lumber equal to the volume of a piece whose nominal dimensions are 12in square and 1 in thick.
Board foot
Lumber measurement in board feet.
Board measure
The dimension of lumber before drying and surfacing, used for convenience in defining size and computing quantity. Nominal dimensions are always written without inch marks.
Nominal dimension, nominal size
The dimension of lumber after seasoning and surfacing, from 3/8 to 3/4” (9.5 to 19.1mm) less than the nominal dimension. A dressed size is always written with inch marks (“).
Dressed size, dressed dimension.
The diretion, size, arrangement and appearance of the fibers in a piece of dressed wood.
Grain
Wood grain resulting from quartersawing, having the annual rings forming an angle of 45d or more with the broad faces of a piece.
Edge grain, vertical grain
To saw quartered logs approximately at right angles to the annual rings.
Quarter sawn
Wood grain resulting from plain-sawing, having the annual rings forming an angle of less than 45d with the broad faces of a piece.
Flat grain
To saw a squared log into boards with evenly spaced parallel cuts.
Plain-saw, bastard-saw
Any deviation from a plane or true surface of a board or panel, usually caused by uneven drying during the seasoning process or by a change in moisture content.
Warp
A curvature across the width or face of a wood piece, measured at the point of greatest deviation from a straight line drawn from edge to edge of the piece.
Cup
A curvature along the length of a wood piece, measured at the point of greatest deviation from a straight line drawn from end to end of the piece.
Bow
A curvature along the edge of a wood piece, measured at the point of greatest deviation from a straight line drawn from end to end of the piece.
Crook
A warp resulting from the turning of the edges of a wood piece in opposite directions.
Twist
A separation along the grain of a wood piece, usually between the annual rings, caused by stresses on a tree while standing or during felling.
Shake
A well-defined opening between the annual rings of a softwood, containing or having once contained solid or liquid pitch.
Pitch pocket
A lengthwise separation of wood across the annual rings, caused by uneven or rapid shrinkage during the seasoning process.
Check
A check that extends completely trough a board or wood veneer.
Split, through check
The presence of bark or absence of wood at a corner or along an edge of a piece.
Wane
An area of the surface of a board or panel missed by a planing machine.
Skip
A surface charring caused by overheating of the cutting blades or abrasive belts during shaping or finishing of a material.
machine burn
Any combination of edge-grained and flat-grained lumber.
Mixed grain
Wood grain resulting from a cut across the grain.
End grain
A cut made across the grain of wood.
Crosscut
Wood grain having the annual rings at an angle to the length of a piece, resulting from sawing at an angle to the axis of a log,.
Diagonal grain
Wood grain having the cells and fibers running transversely or diagonally to the length of a piece as a result of sawing, or irregularly as a result of a growth characteristic.
Cross grain
Wood grain characterzied by narrow, inconspicuous annual rings with little difference in pore size between springwood and summer wood.
Close grain
Wood grain characterized by wide, conspicuous annual rings with considerable contrast in pore size between springwood and summerwood.
Coarse grain
Wood grain having large pores.
Coarse texture, open grain
Wood grain having small, closely spaced pores.
Fine texture
A dressed wood surface having the denser summerwood rising above the softer springwood.
Raised grain
A knot having annual rings intergrown with those of the surrounding wood. Live knots are allowable in structural timber within certain size limits.
Live knot, intergrown knot
A knot that is solid across its face, at least as hard as the surrounding wood, and undecayed.
Sound knot
A knot held firmly in place by growth or position.
Tight knot
A knot having annual rings not intergrown with those of the surrounding wood. Encasement may be partial or complete, but a dead knot is considered to be a defect since it can easily loosen or be knocked out.
Dead knot, encased knot, loose knot
The decomposition of wood by fungi and other microorganisms, resulting in softening, loss of strength and weight, and often a change of texture and color.
Decay
A decay of seasoned timber caused by fungi that consume the cellulose leaving a soft, brittle skeleton readily reduced to powder.
Dry rot
Having isolated spots of incipient decay from fungi, as in pecky cypress or pecky cedar.
Pecky
To saw wood in the direction of the grain.
Rip, ripsaw
The base of a woody branch enclosed by a subsequent growth of wood in the stem from which it rises. In the structural grading of a wood piece, knots are restricted by size and location.
Knot
lumber sawn or selected primarily for use as a finish material rather than for strength, graded according to natural characteristics and manufacturing imperfections.
Appearance lumber
Softwood lumber intended for general building purposes,. including boards, dimension lumber, and timbers.
Yard lumber
Yard lumber less than 2 in (51mm) thick and 2 in or more wide.
Boards
Yard lumber from 2 to 4in (51 to 102mm) thick and 2 in or more wide.
Dimension lumber
Dimension lumber and timbers graded either by visual inspection or mechanically on the basis of strength and intended use.
Structural lumber, Framing lumber
Yard lumber 5 in (127mm) or more in the least dimension.
Timbers
Structural lumber of rectangular cross section, from 2 to 4in thick and more than 4in wide, graded primarily with respect to bending strength when loaded either on the narrow face as a joist or on the wide face as a plank.
joists and planks
Dimension lumber 2 to 4in thick and 2 to 4 in wide, intended for use where high strenght values are not required.
Light framing
Dimension lumber 2 to 4in thick and 4in or more wide, graded primarily with respect to bending strength when loaded on the wide face.
Decking
Structural lumber of rectangular cross section, at least 5in thick and a width more than 2in greater than the thickness, graded primarily with respect to bending strength when loaded on the narrow face.
Beams and stringers
Structural lumber of square or approximately square cross section, 5x5 in or larger and a width not more than 2in greater than the thickness, graded primarily for use as columns carrying an axial load.
Posts and timbers
Lumber sawn or selected primarily for further manufacture, graded according to the amount of usable wood that will produce cuttings of a specified size and quality.
Factory lumber, shop lumber
Lumber having edges dressed and shaped to form a toungue-and-groove joint when laid edge to edge or end to end.
Matched lumber
Lumber dressed and shaped to a pattern or molded form./
Patterned lumber
The width of the face of a piece of dressed and matched or shiplapped lumber, excluding the tongue or lap.
Face width
A stamp applied to each piece of lumber indicating the assigned stress grade, mill of origin, moisture content at time of manufacture, species or species group, and the grading authority.
Grademark
Any of the grades of structural lumber for which a set of base values and corresponding modulus of elasticity is established for a species or group of species by a grading agency.
Stress grade
A base value for a species or group of species of structural lumber, adjusted for cross-sectional size.
Size-adjusted value
Any of the allowable unit stresses for a species and grade of structural lumber obtained by modifying the base value by factors related to size and conditions of use.
Design value
Any of the allowable unit stresses for bending, compression perpendicular and parallel to grain, tension parallel to grain, horizontal shear, and corresponding mdulus of elasticity, established by grading agency for various species and grades of structural lumber. Base values must be adjusted first for ssize and then for conditions of use.
Base Value
The angle of grain relative to a line parallel to the length of a wood piece
Slope of grain
A coefficient for modifying the base values of a species and grade of lumber according to the cross-sectional size of the piece.
Size factor
A coefficient for increasing the size-adjusted values of repetitive members, since the sharing of the load by the pieces enhances the strength of the entire assembly.
Repetitive member factor
Any of a series of three or more light framing members, such as joists or rafters, space not more than 24in on center and joined by sheathing, decking, other load-distributing members.
Repetitive member
A coefficient for increasing the size-adjusted values of a wood member subject to a short-term load, since wood has the property of carrying substantially greater maximum loads for short durations than for long durations of loading.
Duration of load factor
A coefficient for increasing the size-adjusted horizontal shear value of wood member having shakes, checks, or splits when their length is known and any increase in length is not anticipated.
Horizontal shear factor
A coefficient for increasing the size-adjusted bending value for planking having a face width of 4in or more.
Flat use factor
A coefficient for decreasing the size-adjusted values for wood members when their moisture content will likely exceed 19% in use.
Wet use factor
Wood impregnated with chemicals applied under pressure to reduce its resistance to decay and insect infestation.
Pressure-treated wood
A process for pressure–treating wood in which a vacuum is first drawn to remove air from the wood fibers and allow the preservative to be absorbed by the cell walls, after which pressure is applied to force additional preservative into the cell cavities. The full-cell process leaves the maximum amount of preservative in the wood.
Full-cell process
A process for pressure-treating wood in which the pressure of the entering preservative entraps air in the wood fibers, which expands when the pressure is released to expel excess preservative from the cell cavities. The empty-cell process yields a drier product while ensuring deep, uniform penetration of the preservative.
Empty-cell procedures.
Any of various substances for coating or impregnating wood in order to protect it against wood-destroying fungi and insets.
preservative
An inorganic, water0soluble copound, such as ammoniacal copper arsenite (ACA), or chromated copper arsenite (CCA), used as a wood preservative. ACA and CCA affix chemically to the wood cell walls and are resistant to leaching. The copper acts as a fungicide while the arsenate is toxic to wood-destroying insects. Wood treated wit hACA and CCA is odorless and paintable.
Water-borne preservative
An organic chemical dissolved in a petroleum oil carrier, such as pentachlorophenol or copper naphthenate, used as awood preservative. Pentachlorophenol, the most commonly used oil-borne preservative, has a persistent odor, is insoluble in water, and is highly toxic not only to fungi and insects but also to humans and plants.
oil-borne preservative
An oily liqued of aromatic hydrocarbons obtained by the distillation of coal tar, used as a wood preservative for marine installations or for severe exposures to wood-destroying fungi and insects. Creosote and creosote solutions have a penetrating odor and render wood unpaintable.
Creosote
A metal ring or cap placed around the end of a wooden post or handle to prevent splitting.
Ferrule
A wood column consisting of a single piece of solid-sawn or glued-laminated timber, usually square or rectangular in cross section.
Solid column
An eccentric load applied at some point below the upper end of a timber column, the static effect of which is assumed to be equivalent to the same load applied axially plus an additional side load applied at midheight.
Bracket load
A horizontal timber on a post for enlarging the bearing area and reducing the free span of a beam.
Bolster
A wood column having a cross section that diminishes along its length. In determining the slenderness ratio for a tapered column, the least dimension is taken as the sum of the minimum diameter or least dimension and one-third the difference between the minimum and maximum diameters or lesses and greater dimensions.
Tapered Column
A biult-up column having a hollow, square or rectangular cross section.
Box column
A wood column formed by fastening or gluing cover plates to two or more parallel planks, or boing planks around a solid core. A built-up column is never equal in strength to a solid column of comparable material and overall dimensions.
Built-up column
A wood column consisting of two or more parallel members separated at their ends and midpoints by blocking, and joined at the ends by timber connectors capable of developing the required shear resistance.
Spaced column
A vertically laminated wood beam made by fastening together two or more smaller members with bolts, lag screws, or spikes, equal in strength to the sum of the strengths of the individual pieces if none of the laminations are spliced.
Built-up beam
A beam having a hollow, rectangular cross section, made by gluing two or more plywood or oriented strandboard webs to sawn or laminated veneer lumber flanges.
Box beam
A joist made by gluing sawn or laminated veneer lumber flanges along the top and bottom edges of a single plywood or oriented strandboard web.
I-beam, I-joist
A vertically laminated beam consisting of timbers set on edge and bolted side by side to steel plates or sections.
Flitch beam, flitch girder, sandwich beam
A structural lumber product made by laminating stress-grade lumber with adhesive under controlled conditions, usually with the grain of all plies being parallel. The advantages of glued-laminated timber over dimension lumber are generally higher allowable unit stresses, improved appearance, and availability of various sectional shapes. Glue-laminated timbers may be end-joined with scarf or finger joints to any desired length, or edge-glued for greater width of depth.
Glued-laminated timber, glulam
A wood panel product made by bonding veneers together under heat and pressure, usually with the grain at right angles to each other and symmetricaly about the center ply.
Plywood
A number of identifying one of five groups of species used for the face and back veneers of a plywood panel, the species being classified on the basis of bending strength and stiffness, with Group 1 containing the stiffest and Group 5 the least stiff.
Group Number
A number specifying the maximum recommended center-to-center spacing in-inches of the supports for a structural wood panel spanning with its long dimension across three or mre supports.
Span rating
A classification of a wood panel product according to its ability to withstand exposure to weather or moisture without weakening or warping.
Exposure durability
An exposure durability classification for structural wood panels manufactured with a waterproof glueline for use as siding or other continuously exposed applications.
Exterior
An exposure durability classification for structural wood panels manufactured with an exterior glueline for use in protected construction subject to repeated wetting.
Exposure 1
An exposure durability classification for structural wood panels manufactured with an intermediate glueline for use in fully protected construction subject to a minimum of wetting.
Exposure 2
A trademark of the Americal Plywood Association (APA), stamped to on the back of a structural wood panel product to identify the panel grade, thickness, span rating, exposure durability, classification, mill number, and National Research Board (NRB) report number.
Gradestamp
The grade of a wood panel product identified by the face and back veneer grades or by its intended use.
Panel Grade
The grade of a structural wood panel based on its intended use as sheathing, subflooring, or in the fabrication of box beams and stressed-skin panels.
Engineered grade
An exterior wood panel having a resin-fiber overlay on both sides providing a smooth, hard, abrasion-resistant surface, used for concrete forms, cabinets and countertops.
HDO, High-density overlay
An exterior wood panel having a phenolic or melamine resin overlay on one or both sides providing a smooth base for painting.
Medium-density overlay, MDO
Any of various wood panel products, such as grooved or rough-sawn plywood, intended for use as siding or paneling.
Specialty panel
An exterior plywood panel having grooves 1/4” deep and 3/8” wide, spaced 4 or 8in on center.
Texture 1-11
A smooth softwood veneer of all heartwood or all sapwood, free from open defects with only a few well-matched repairs.
N-grade
A smooth, paintable softwood veneer with a limited number of neatly made repairs parallel to the grain.
A-grade
A softwood veneer having a solid surface with circular repair plugs, tight knots, and minor splits permitted.
B-grade
A softwood veneer having tight knots and knotholes of limited size, synthetic or wood repairs, and discoloration and sanding defects that do not impair the strength of the panel.
C-grade
An improved C-grade softwood veneer having small knots and knotholes, some broken grain, and synthetic repairs.
C-plugged grade
A softwood veneer having large knots and knotholes, pitch pockets, and tapering splits.
D-grade
Hardwood-faced plywood manufactured for use as paneling or in cabinetry and furniture.
Decorative plywood
A thin sheet of wood rotary cut, sliced, or sawn from a log or flitch and used as asuperior facing to inferior wood or bonded together to form plywood.
Veneer
A layer of veneer immediately adjacent to and at right angles to the face plies in a plywood panel.
Crossband
The center of a plywood panel, consisting of veneers, sawn lumber, or composition board.
Core
The solid wood stock extending around the sides of a veneered panel, concealing the core and facilitating the shaping of the panel edges.
Banding
The natural pattern on a sawed wood surface produced by the intersection of annual rings, knots, burls, rays and other growth characteristics.
Figure
The rotating of a log against the curring edge of a knife in a lathe, producing a continuous veneer with a bold, variegated ripple figure.
Rotary Cutting
The longitudinal slicing of a half-long parallel to a line through its center, producing a veneer having a variegated wavy figure.
Flat slicing, plain slicing
The slicing of a flitch mounted off-center in the lathe, slightly across the annual rings, producing characteristics of both rotary cutting and flat slicing.
half-round slicing
A longitudinal section of a log to be cut into veneers.
Flitch
The slicing of oak and similar species perpendicular to the conspicuous, radiating rays so as to minimize their appearance.
Rift cutting
Arranging sheets of veneers so as to emphasize the color and figure of the wood.
Matching
Arranging veneers from the same flitch alternately face up and face down to produce symmetrical mirror images about the joints between adjacent sheets.
Book matching
Book matching in which the figures in adjacent sheets slope in opposite directions.
Herringbone matching
Arranging adjacent sheets of veneer from the same flitch side by side without turning so as to repeat the figure.
Slip matching
Arranging four diagonally cut sheets of a veneer to form a diamond pattern about a center.
Diamond matching
Arranging veneers to intentioanally creaete a casual, unmatched appearance.
Random matching
A nonveneered wood panel product commonly used for sheathing and as subflooring, made by bonding three or five layers of long thin wood strands under heat and pressure using a waterproof adhesive. The surface strands are aligned parallel to the long axis of the panel, makng the panel stronger along its length.
Orienter Strandboad, OSB
A nonveneered panel product composed of large, thin wood flakes bonded under heat and pressure with a waterproof adhesive. The planes of the wafers are generally oriented parallel to the plane of the panel but their grain directions are random, making the panel approximately equal in the strength and stiffness in all directions in the plane of the panel.
Waferboard
A wood panel product consisting of two face veneers bonded to a reconstituted wood core.
Composite panel
A nonveneered wood panel product made by bonding small wood particles under heat and pressure, commonly used a core material for decorative panels and cabinetwork, and as underlayment for floors.
Particleboard, chipboard
A structural lumber product made by bonding long, narrow wood strands together under head and pressure using a waterproof adhesive. Parallel strand lumber is a proprietary product marketed under tra trademark Parallam, used as beams and columns in post-and-beam construction and for beams, headers and lintels in light frame construction.
Parallel Strand lumber, PSL
A structural lumber product made by bonding layers wood veneers together under heat and pressure using a waterproof adhesive. Having the grain of all veneers run in the same longitudinal direction results in a product that is strong when edge loaded as a beam or face loaded as a plank. Laminated veneer lumber is marketed under various brand names, such as Microlam, and used as headers and beams or as flanges for prefabricated wood I-joists.
Laminated Veneer Lumber, LVL
A building material made of wood or other plant fibers compressed with a binder into rigid sheets.
Fiberboard
A very dense, compressed wood fiberboard.
Hardboard
A hardboard impregnated with a drying oil or other oxidizing resin and baked to improve its hardness and moisture resistance.
Tempered hardboard
Trademark for a brand of tempered hardboard.
Masonite
Trademark for a brand of tempered hardboard having regularly spaced perforations into which hooks may be inserted for the storage or display of articles.
Peg-Board
