| Term |
Description |
| Delamination |
The
separation of plies or laminations through failure of the bond, visible at
an edge. |
| Density |
As
applied to timber, density is the mass of wood substance and moisture enclosed
within a piece expressed in kilograms per cubic meter. As the mass will vary
dependant on the amount of moisture in the piece, density is often expressed
at a specified moisture content, usually 12%. |
| Density |
As
applied to wood, density is the mass of wood substance per unit of volume. It
is variously expressed as pounds per cubic foot, kilograms per cubic centimeter,
or grams per cubic centimeter at a specified moisture content. |
| Diameter
at Breast Height (DBH) |
Height
on the trunk of standing trees from the ground where measurements are usually
taken to determine the size of the tree. |
| Diaphragm |
1.
In a beam, an element at right angles to the span with the function of connecting
the beams so that they resist load as a unit. 2. A relatively thin, usually rectangular,
element of a structure that is capable of withstanding shear in its plane and
acts as a bracing elements. |
| Distortion
(warp) |
A
drying defect caused by the differential shrinkage along the three axes of a
piece of wood. Distortion may take the form of cup, bow, twist, spring or diamonding. |
| Dominant
trees |
Trees
with crowns extending above the general level of the canopy and receiving full
light from above and partly from the side; taller than the average trees in the
stand with crowns well developed. Also see codominant trees. |
| Dovetail
JointÊ - NEW! |
A
method of joining wood at corners by the use of interlocking pins and tails. |
| Dowel |
A
cylindrical timber rod or steel bar generally without nut or thread driven into
pre-drilled holes to make a joint. |
| Dowel
Center |
A
cylindrical metal pin with a raised point that is inserted into a dowel hole
and used to locate the exact center on a mating piece of wood. |
| Dowel
joint |
A
joint where the pieces of timber are joined by dowels running either longitudinally
or transversely through the joint. |
| Doyle
Log Rule |
In
use since about 1870, this scaling method deducts a full four inches for slabs.
It grossly underestimates the yield on small diameter logs (less than 14")
. Every fourth Doyle load could be considered free in comparison to International
rule, if the logs are within 14 to 20" inches in diameter and the prices
per MBF for both scales were identical. The variance between Doyle rule and other
rules is based on diameters, rather than lengths. (Also see Scribner and International
Rule.) |
| Dozuki |
A
type of Japanese woodworking saw that is used for fine joinery work such as dovetails.
Its Western equivalent is a back saw. |
| Drawer
StopÊ - NEW! |
A
device installed in a cabinet to limit the drawers travel. |
| Dressed
lumber |
Lumber
that has been trimmed and planed at the sawmill. |
| Dressed
timber |
Timber
finished to a smooth surface on one or more surfaces. |
| DressingÊ
- NEW! |
Shaping
the cutting edge of a chisel to correct the bevel. |
| Dry |
Seasoned,
usually to a moisture content of less than 19% (less than 15% for selects and
factory lumber). |
| Dry
kiln |
A
chamber in which lumber is dried by controlling the moisture, temperature and
air circulation. |
| Dry
lumber |
As
applied to softwoods, lumber sold as "dry" or "kiln dried"
is at 19% or lower moisture content, as specified by the American Softwood Lumber
Standards. Hardwoods are generally considered dry when at 10% or lower moisture
content, although there is no definitive standard as with softwood species. |
| Dry
rot |
A
generic term for the decay of timber by fungi that at an advanced stage leaves
the wood light and friable. The term is actually a misnomer as all fungi needs
considerable moisture to grow. |
| Dry
weight |
The
oven-dry weight, or simply dry weight, is the weight of wood after drying to
a constant weight at a temperature slightly above the boiling point of water
(215¡ to 220¡F). |
| Drying
defect |
A
feature developing during drying which may decrease the value of a piece of timber. |
| Drying
Defect |
Any
irregularity occurring in or on wood, as a result of drying, that may lower its
strength, durability, or utility value. The following are some commonly encountered
drying defects:
Drying Defect
Any irregularity occurring in or on wood, as a result of drying, that may lower
its strength, durability, or utility value. The following are some commonly encountered
drying defects:
Bow
The longitudinal distortion, flatwise, from a straight line drawn end to end
of lumber;
Casehardening
A term applied to dry lumber with nearly uniform moisture content but characterized
by the presence of residual compressive stresses in the outer layer of cells
(shell), and tensile stresses in the inner layer or core;
Check
A lengthwise separation of wood that extends along the wood grain. It develops
during drying and is commonly caused by differences in radial and tangential
shrinkage or because of uneven shrinkage of the tissues in adjacent portions
of the wood;
Chemical Stain
A chemical discoloration of wood that is believed to be caused by the concentration
and modification of extractives;
Collapse
The flattening of single cells or row of cells which occurs during drying of
some species with very wet heartwood; it is often evidenced by a caved-in or
corrugated appearance of the wood surface;
Cup
A distortion of a plank or board resulting in a troughlike shape with the edges
remaining more or less parallel to each other;
Honeycomb
Internal splitting, often not visible at the wood surface, that develops during
drying. It is caused by internal stresses or by the closing of surface checks;
Mineral Stain
An olive to greenish-black or brown discoloration believed to show regions of
abnormal concentrations of mineral matter in some hardwoods. It is common in
hard maple, hickory, and basswood. See also Mineral Streaks;
Shake
A separation along the the grain, the greater part of which may occur at the
common boundary of two rings or within a growth ring. It is usually considered
to have occurred in the standing tree or during felling;
Surface Checks
Checks that occur on the wood surface during seasoning; they may extend to varying
depths into the wood;
Twist
A distortion caused by the turning or winding of the edges of a board so that
one corner is no more in the same plane as the other three;
Warp
Any variation from the true or plane surface in a piece of wood that may occur
during seasoning. It includes bow, crook, cup, and twist, or any combination
thereof. |
| Drying
schedule |
A
sequence of kiln conditions which result in a gradual decrease in moisture content
of the wood. |
| Durability |
1.
The natural resistance of timber to biodeterioration due to fungi, insects and
mechanical break down caused by weathering, checking and splitting. 2. In building,
the efficacy of details in preserving or protecting the fabric of the building
from decay or deterioration. |
| Durability |
The
ability of wood to resist the attacks of foreign organisms, such as fungi, insects,
and marine borers under conditions that favor such attacks. The main reason for
the natural durability of some wood species is the presence of substances that
are toxic to decay causing organisms. In general, the heartwood of most species
is more durable than the sapwood because of the presence of a wide variety of
extraneous materials and phenolic substances in the heartwood. Durability ratings
usually refer to the heartwood, and are often based on heartwood samples in ground
contact under long-term outdoor exposure or on actual reports of in-use performance
under decay hazard conditions. The ratings below, which are based on the Princes
Risborough Laboratory, United Kingdom, classifications, follow a format that
is commonly used. Classification Approx Life in Ground Contact : Very Durable
>25 years; Durable 15 to 25 years; Moderately Durable 10 to 15 years; Slightly
Durable 5 to 10 years; Perishable. The Building Code of Australia (BCA) requires
building material in some building application to have particular characteristics
in the early stages of a fire. These are set out in three indexes: ignitibility
index (scale 0-20); spread of flame index (scale 0-10); smoke develop index (scale
0-10). |
| Durability
class |
Durability
is expressed as one of four classes. The value for each species is based on trials
of the resistance to both decay and termites of untreated heartwood in the ground.
The classes are: Class 1: Timber of the highest natural durability, expected
to have a life of at least 25 years and up to 50 years in the ground; Class 2:
Timber of high natural durability, expected to have a life of about 15 to 25
years in the ground; Class 3: Timber of moderate natural durability, expected
to have a life of about 8 to 15 years in the ground; Class 4: Timber of low durability,
expected to have a life of 1 to 8 years in the ground. The sapwood of all species
is regarded to be Class 4. |
| Earlywood |
That
portion of a growth increment that is formed at the beginning of the growing
season. Also called springwood, it is less dense and weaker than Latewood. |
| Earlywood |
The
less dense, larger celled, first formed part of a growth ring. Also called "springwood". |
| Earlywood
(Springwood) |
The
first part of the tree's rings to form after winter hybernation. Earlywood is
often characterized by larger cells and a lower density.Ê |
| Eccentric
load |
Loads
that are applied off the central axis of a structural member. |
| Ecology |
The
science that studies the interrelationships, distribution, abundance, and contexts
of all organsims and their interconnections with their living (biotic) and nonliving
(abiotic) environment, in addition to the processes that determine ecosystem
function, change over time, and response to disturbances. Ecology takes two main
forms: (1) systems ecology, which relies heavily on computer modelling and inventory
data; and (2) field ecology, which studies organisms and communities in their
natural settings. |
| Edge
guide |
A
straightedge that is used to guide tools, such as a circular saw or router, along
a workpiece. |
| Edge
joining |
Smoothing
and squaring the edge of a board so that it can be glued up squarely to another
piece. |
| Edger |
Lumber
cut on circular or band headrigs from the outside portions of logs does not have
square edges. These pieces must be passed through a machine called an edger that
can make two or more lineal cuts simultaneously. The edgings are chipped for
use in generating power or for use in paper production. Square-edged lumber must
be trimmed to length. |
| Electronic
data interface (EDI) |
The
transferring of information, invoices, payments, etc. Between companies via computer
rather than by mail or fax. |
| End
grain |
The
grain shown on a cross cut surface. |
| End
matched |
A
pattern run on both ends of pieces of lumber; one end has a tongue, the other
a groove. When butted together end to end, the alignment forms a joint. |
| Engineered
Wood Products |
A
composite wood product using glued fiber, lumber and/or veneer to meet specific
design criteria. Such products include laminated veneer lumber (LVL), parallel
strand lumber (PSL), and structural I-beams. Products under development include
various molded, extruded, and other structural and non-structural composites.
Although engineerred wood products have a number of advantages over solid lumber
(including the ability to make large-sized members from small diameter trees),
engineered wood products are more costly to produce than lumber and require the
use of more energy to manufacture. |
| Environmental
Profile or Conservation Status |
Ten
categories used to evaluate the degree of threat posed to the survival of plants
and animals within their natural boundaries. The World Conservation Monitoring
Centre (WCMC) and the Species Survival Commission (SSC) of the World Conservation
Union (IUCN) use the Red Data Book categories to indicate the degree of threat.
Although there is no worldwide agreement on a standard criteria for defining
the conservation status of plants and animals, the categories applied by IUCN
are widely accepted.
Extinct Rating
Species that are currently known to be out of existence in the wild after repeated
attempts to locate them in their natural habitats or other known or likely habitats
have failed.
Endangered Rating
Species whose extinction is imminent if the factors which are currently threatening
their survival persist. This category include species whose numbers have been
diminished to critical levels or whose natural habitats have been so reduced
that they are deemed in immediate danger of extinction.Vulnerable Rating
Species that will definitely move into the Endangered category if the conditions
which caused their Vulnerability continue. Included in the Vulnerable category
are species whose numbers are decreasing because of over-exploitation, extensive
habitat destruction or other environmental disturbances, species whose long term
security is uncertain because their numbers have been seriously reduced, and
species which currently exist in large numbers but are threatened by serious
destructive factors throughout their natural habitat.
Rare Rating
Species which naturally occur in small numbers and which are currently not Endangered
or Vulnerable but are at risk. Such species are usually confined to small habitats
or are scattered in very small numbers over a wide area.
Indeterminate Rating
Species that are known (after officially assessing its environmental status)
to be Extinct, Endangered, Vulnerable, or Rare but which cannot be placed in
a single class because of incomplete of information.
'Insufficiently Known' Rating
Species that are suspected but are not definetely known to be Extinct, Endangered,
Vulnerable, or Rare. The specific category cannot be determined, even after environmental
assessment, due to inadequate information.
Candidate Rating
Species whose environmental status is being assessed, and which is suspected
to be Extinct, Endangered, Vulnerable, or Rare. The actual conservation category
has not been definitely determined.
'Out of Danger' Rating
Species which used to belong to one of the above classes but which have now deen
determined to be relatively secure because of effective conservation measures,
or because of the removal of previously existing conditions that threatened their
survival.
'Not Threatened' Rating
Species that do not belong to any of the above conservation categories.
No Information
Species for which there is no information regarding their current conservation
status.
|
| Epoxy
dowel joint |
A
joint in which the parts are joined by dowels that have been set in oversized
holes with epoxy resin. |
| Epoxy
resin joint |
A
joint in which the parts are bonded using an epoxy resin adhesive. |
| Equilibrium
moisture content |
The
moisture content at which timber neither gains nor loses moisture from the surrounding
atmosphere. |
| Equilibrium
moisture content |
When
the level of moisture in a board is equal to the moisture in the surrounding
air. |
| ESLP |
Englemann
Spruce Large Pole pine |
| exterior
plywood |
Plywood
of naturally durable or treated veneers bonded with waterproof adhesive and capable
of withstanding prolonged exposure to severe exterior conditions without failure
of the glue-lines. |
| Extractive |
Substances
in wood, which can be removed by solution in hot or cold water, ether, benzene,
or other solvents that do not react chemically with wood components. The odors
and colors in heartwood are usually derived from extractives. Extractives may
also affect other physical and mechanical properties of wood, such as resistance
to insect attack, permeability, specific gravity, hardness, and compressive strength. |
| Exudates |
Secretions
such as resin, gum, oil, or latex over the surfaces of timber, sometimes exacerbated
by drying certain species at high temperatures. Excessive secretion of such exudates
can adversely affect some machining properties of the timber; saws may gum up
and there may be increased difficulty in gluing and finishing operations. |
| Face
Veneer |
High
quality veneer that is used for the exposed surfaces on plywood. |
| Factory
lumber |
Lumber
intended to be remanufactured after it leaves the sawmill. |
| Fascia |
A
vertical board nailed to the lower ends of rafters. |
| Fb |
The
designation for the bending strength design value. |
| FBM |
Feet,
board, measure. |
| Featherboard |
A
piece of wood with thin "fingers" that hold a board against a fence
or down against the table of a power tool, usually a table saw or router.. |
| Feller-buncher |
A
harvesting machine that cuts a tree by shears or a saw and then piles it. |
| Fence |
A
straight guide used to keep a board a set distance from a blade or other cutters. |
| Fiber,
Wood |
A
wood cell that is comparatively long. |
| Fiberboard |
A
broad generic term covering panels of widely varying densities produced from
refined or partially refined wood (or other vegetable) fibers. Bonding agents
and other materials may be added to increase strength, resistance to moisture,
fire, or decay, or to improve some other property. |
| Fibre
saturation point |
The
point in the seasoning or wetting of timber at which the cell cavities are free
from water but cell walls are still saturated with bound water. It is taken as
approximately 25-30% moisture content. |
| Fibreboard |
A
generic term including sheet materials of widely varying densities manufactured
from refined or partially refined wood or vegetable fibres. Bonding agents and
other materials may be added to increase strength or to improve other properties. |
| Fiddleback |
Figure
in timber or veneer produced by small, regular undulations in the grain. |
| Figure |
The
pattern produced on the cut surface of wood by annual growth rings, rays, knots,
deviations from regular grain such as interlocked and wavy grain, and irregular
coloration. |
| Figure |
Design
or distinctive markings on the longitudinal surface of wood produced by annual
growth rings, rays, knots, deviation from regular grain such as interlocked and
wavy grain, and irregular discoloration. It may also refer to such decorative
designs in wood that make them highly desirable in the furniture and cabinetmaking
industries.
Bird's-eye Figure
Figure on the plain-sawn and rotary cut surface of wood showing many small circular
or elliptical areas resembling a bird's-eye. It is caused by local fiber distortions
and is usually present in hard maple.
Dimple Figure
Indentations, caused by localized fiber distortions, that produce a figure resembling
dimples on the tangential surface of sawn lumber or rotary-cut veneer.
Herringbone Figure
A figure produced by matching two quarter-sawn pieces of wood together so that
their rays meet at an angle.
Mottled Figure
A disjointed stripe figure interrupted by irregular, horizontal waves in the
wood grain.
Quilted Figure
Blister-like figure sometimes found in bigleaf maple (Acer macrophyllum).
Ribbon Figure
Figure consisting of light-induced interchanging darker and lighter bands. It
is obtained when wood with Interlocked grain is quarter-sawn or sliced. It is
also referred to as stripe.
Roey Figure
Figure formed by relatively short stripes ( 1ft long) on the quarter-sawn face
of wood containing interlocked grain. |
| Filler |
In
woodworking, the term refers to any substance that is used to fill holes and
irregularities in planed or sanded surfaces to decrease the porosity of the surface
before applying finish coatings. |
| Finger
joint |
An
end joint in which wedge shaped projections in one piece of timber fit matching
recesses on the other piece and are bonded together by an adhesive. |
| Fire
Resistance |
The
property of a material that allows it to withstand or protect it from fire. In
terms of elements in a building or structure, it is the ability of an element
to contain and prevent fire from spreading to other elements or the ability to
perform a given structural function, or both. |
| Fire
Retardant |
A
chemical or preparation of chemicals used to reduce flammability or to impede
fire spread over the surface of a material. |
| Firm
offer |
a
promise to buy or sell a product if certain specific conditions are met. |
| Flame
Spread |
The
propagation of a flame from its ignition source across the surface of a solid
or liquid, or through the volume of a gaseous mixture. |
| Flange |
In
beams, the longitudinal ribs (a) of a built up member primarily intended to resist
flexure. (Figure 14) The flanges are joined by a web (b). |
| Flatbed
trailer |
Used
to haul lumber. Flatbed operators may haul logs if they carry portable stakes.
The number of stakes, stake height and distance between stakes determines the
number of log tiers and length of logs in each tier a flatbed may carry. Flatbed
operators will carry sawlogs before they will carry pulp logs, because the higher
value of sawlogs ensures they are more likely to receive an acceptable rate.
Lower value pulp logs may require quibbling over nickels and dimes in the rate. |
| Flat |
sawn
Lumber In softwoods, a method of sawing lumber where the log is cut tangential
to the growth rings. Also called plain sawn. |
| Flexural
strength |
The
resistance at failure of a beam subjected to bending. |
| Flitch |
A
large piece of log, sawn on at least two surfaces, intended for further cutting. |
| Flitch |
A
log sawn on two or more sides from which veneer is sliced. |
| Floor
board |
Boards
dressed to standard thickness and generally finished with a tongue and groove,
fixed to floor joists or a substrate to provide a floor. |
| Folded
plate |
The
configuration of flat sheets, such as plywood, into a folded form to produce
a beam of considerably higher strength and stiffness than is possible with the
flat sheet alone. |
| Forest
management |
The
practice of applying scientific, economic, philosophical, and social principles
to the administration, utilization and conservation of all aspects of forested
landscapes to meet specified goals and objectives, while maintaining the productivity
of the forest. Forest management includes the subset of all activities known
as timber management, but also involves planning and managing forested landscapes
for fish and wildlife, biological diversity, conservation measures, parks, wilderness
recreation, and aesthetic values. Forest management is an all encompassing activity
and is not to be confused with the more restrictive activities associated with
timber management. |
| Forest
Products Society (FPS) |
An
international organization comprising forest products firms, trade associations,
researchers, academics, landowners, government, consultants, and other stakeholders
with approximately 2,700 members in North and South American, Asia, and Europe.
The FPS publishes the Forest Products Journal 10 times a year. URL: http://www.Forestprod.Org |
| Forestry |
A
profession embracing the science, business, and art of creating, maintaining,
and managing forested landscapes and their many component parts to produce consumptive
and/or nonconsumptive outputs for use by humans or other species in a manner
that does not cause ecosystem degradation. |
| Foundation |
The
soil, subsoil or rock upon which a structure is supported. |
| Frame |
1.
The main timbers of a structure fitted and joined together. 2. A three dimensional
self contained structural system of interconnecting members which functions with
or without the aid of horizontal diaphragms or floor bracing systems. |
| Framing
timber |
Timber
used to form the basic structure of a building, such as studs and joists. |
| Free
moisture |
Moisture
which is present in the cell cavities of wood. |
| Free
Water |
Moisture
found in the cell cavities of wood. |
| Full
sawn |
Lumber
cut, in the rough, to its full nominal size. |
| Girth |
The
distance around a tree; the circumference. |
| Glue |
An
animal, mineral or vegetable adhesive. |
| Glue |
The
term is now used synonymously with Adhesives but originally, it refers to a hard
gelatin obtained from certain parts of animals such as, hides, tendons, cartilage,
and bones. |
| Glue
Joint |
A
special interlocking grooved pattern that is used to join two pieces, edge to
edge, securely. |
| Glue
laminated beams |
Beams
made of lumber glued together. Replacements for solid wood timbers and steel
beams. |
| Glue
laminated timber |
Laminated
timber where the laminations are joined with adhesive. |
| Grade |
The
designation of the quality of a piece of timber or other manufactured wood products
in accordance with standard rules. |
| Grade
stamp |
An
inked marking put on lumber to show its important characteristics and mill information. |
| Grademark |
a
stamp or symbol applied to a piece of lumber, by the grader at a sawmill, to
designate grade. |
| Grain |
The
size, alignment, and color of wood fibers in a piece of lumber. |
| Grain |
1.
The general direction of the fibres or wood elements relative to the main axis
of the piece. 2. The direction, size, arrangement, appearance, or quality of
the fibres in wood or timber. |
| Grain |
The
overall dimension, size, appearance, arrangement, and direction of alignment
of the fibers in wood or lumber.
Closed Grain
Wood with narrow, barely visible annual rings. It is also used to describe wood
with small and closely spaced pores.
Crossed Grain
Wood in which the direction of alignment of the fibers deviate from a line parallel
to the sides. Crossed grain may be either diagonal or spiral or a combination
of the two.
Curly Grain
Wood with distorted fibers resulting in a curly appearance as in bird's-eye wood.
The area covered by each curl may vary up to several inches in diameter.
End Grain
The grain as seen on the cross-section of a piece of wood.
Fiddleback Grain
Figure produced by a type of fine and wavy grain found in certain species such
as, maple. Wood with such figure is traditionally used for violin backs.
Interlocked Grain
Grain in which the direction of the fibers follow first a left- and then a right-
handed spiral, and then alternate the spiral direction every few years. Such
wood is very difficult to split radially, although it may split fairly easily
in the tangential direction.
Irregular Grain
Figure produced by the contortion and twisting of fibers around elements such
as knots, in a piece of wood.
Spiral Grain
Wood in which the fibers follow a regular spiral direction (right-handed or left-handed)
around the trunk of the tree instead of the normal vertical course. It is a form
of cross grain.
Straight Grain
Wood in which the direction of fiber alignment is parallel to the main axis of
the piece.
Wavy Grain
Wood in which the collective appearance of the fibers presents a regular form
of waves and undulations.
|
| Green |
unseasoned
timber, with free moisture present in the cell cavities. |
