| Term |
Description |
| Green
Certification |
Landowners
who actively manage their woods can apply for green certification. Two agencies
perform reviews and issue certification for the Forest Stewardship Council
(FSC): the non-profit Smartwood and the for-profit SCS (Scientific Certification
Systems). Both agencies charge to ensure that land is properly and sustainably
managed and that loggers employ best management practices (BMP) to cut wood
on certified woodlots. To maintain its green certification status from landowner
to consumer, lumber mills must also be certified in chain of custody arrangements,
that is, they ensure that certified logs are stored and milled separately from
non-certified logs. It was originally thought that certified logs would sell
at a premium but that has not been the case in New England. The Quabbin Reservoir
managed by the Metropolitan District Commission in Massachusetts was the first
publicly owned land to be green certified. |
| Green
lumber |
Lumber
with a moisture content in excess of 19%. |
| Green
Lumber |
Freshly
cut lumber that has not had time to dry. |
| Green
weight |
The
term green weight specifically refers to the weight of freshly harvested wood
that has the same moisture content (MC) as the standing tree. MC is defined as
the weight of water in the wood expressed as a percentage of the weight of the
oven-dry wood (wood from which all moisture has beensd removed). Also see "dry
weight." |
| Green
Wood |
Freshly
sawed or undried wood which still contains the moisture that was present in the
standing tree. |
| Grillage |
A
system of orthogonal elements, usually beams or trusses, acting together to resist
a common load. |
| Ground
wood chips |
Ground
wood is usually produced from a hammer mill or tub grinder and appears shredded
and fibrous with irregular sizes, depending on the screen or grate used. Ground
wood is easily disinguished by its geometry from wood chips produced from mill
chipper or a whole tree chipper (WTC). WTC and mill chips appear square and evenly
cut rather than fibrous and irregular. |
| Ground
wood paper |
Newsprint
and other inexpensive paper made from pulp created when wood chips are ground
mechanically rather than refined chemically. |
| Growth
Ring |
The
layer of wood growth formed by a tree during a single growing season. In many
tropical species, annual growth rings are hardly discernible. |
| Growth
rings |
Rings
of earlywood and latewood on the transverse section of a trunk or branch marking
cycles of growth. |
| Gum |
A
natural exudation, also called kino, produced in trees as a result of fire or
mechanical damage. |
| Gum |
A
generic term for non-volatile viscous plant secretions, which either dissolve
or swell up in contact with water. |
| Gum
Canal |
Tubular
intercellular cavities in hardwoods which may contain gums, mucilage, kinos,
resins, or latex depending upon the genus. |
| Gum
vein |
A
ribbon of gum between growth rings, which may be bridged radially by wood tissue
at intervals. Also known as kino. |
| Gusset
plate |
Plates
(1), often steel or plywood, fixed by nails, bolts or other means to connect
timber members in a truss or other frame structure. Gusset plates may be applied
to one or both sides of a joint. |
| Half-Blind
Dovetail |
A
dovetail joint where the cut does not go all of the way through the board. The
ends of a half-blind dovetail are concealed. |
| Hammer |
A
tool consisting of a metal head set perpendicular on a handle, used for driving
nails. |
| Hardboard |
A
type of manufactured board similar to particle board but with a much smoother
surface. A common brand of hardboard is Masonite. |
| Hardboard |
A
pressed homogenous fibreboard having a mean density of not less than 800 kg/sq
m. |
| Hardboard |
A
generic term used to describe a panel produced mainly from interfelted ligno-cellulosic
fibers (usually wood), consolidated under heat and pressure to a density of 31
pounds per cubic feet or greater, and to which other materials may have been
added to improve specific properties. |
| Hardness |
A
property of wood that enables it to resist indentation. It is measure in kN and
is often determined by the Janka hardness test. |
| Hardness |
The
property of wood that enables it to resist indentation by other materials. |
| Hardwood |
A
general term for timber of broad leafed trees classified botanically as Angiosperm.
The term has no reference to the relative hardness of the wood. |
| Hardwood |
Hardwood
comes from deciduous trees that lose their leaves during the winter. Hardwoods
have traditionally been used in making such products as furniture, strip flooring,
interior trim, cutting boards, novelties, and so forth. Wood used in making these
products is typically in the form of relatively small and defect-free pieces
which are subsequently glued together; it is also generally more costly than
wood from softwood species. Because of these factors, hardwood lumber is manufactured
to non-standardized length and width dimensions which will minimize trim waste.
For the same reasons, such lumber is measured relatively accurately, with rounding
of measurements in small increments. |
| Headsaw |
In
a sawmill, the large band saw or circular saw used to size the log into lumber. |
| Heartwood |
The
wood making up the centre part of the tree, beneath the sapwood. Cells of heartwood
no longer participate in the life processes of the tree. Heartwood may contain
phenolic compounds, gums, resins, and other materials that usually make it darker
and more decay resistant than sapwood. |
| Heartwood |
In
a cross section of a log, the heartwood is the center and dead portion where
growth rings appear. Also see bark and sapwood. |
| Heartwood |
The
dead inner core of a tree. Usually much harder and darker than the newer wood.
Also see sapwood. |
| Heartwood |
The
inner core of a woody stem or log, extending from the pith to the sap, which
is usually darker in color. This part of the wood contains dead cells which no
longer participate in the life processes of the tree. |
| Hectare |
A
metric unit of area, 100 metres by 100 metres (10,000 square metres) or 2.471
Acres. |
| Herringbone
Pattern |
In
veneering, a hearing bone pattern is formed when successive layers of veneers
are glued up so they form a mirror image. Usually this pattern slants upwards
and outwards, like a herringbone. |
| Hewn
timber |
Timber
with or without wane, finished to size with hand tools such as an axe or adze. |
| High-Grading |
The
practice of harvesting only the higher value trees and leaving the lower value
trees in the woods ("Take the best and leave the rest"). It is frowned
upon in this era of sustainability, and much effort is being made to find suitable
markets for lower grade logs. |
| Hobnail |
A
pattern of pin-holes left by insect attack. |
| Honeycombing |
A
drying defect which occurs when tensile stresses in the core (usually a result
of collapse) result in the formation of internal cavities. |
| Horizontally
laminated timber |
Laminated
timber designed to resist bending loads applied perpendicular to the wide face
of the laminations. For vertical loads, this means that the wide face runs horizontally. |
| Housed
joint |
A
joint where one piece is notched or grooved to receive the other piece. |
| Hygrometer |
An
instrument for measuring the humidity of air. |
| Hygroscopic |
Changes
its moisture content to be in equilibrium with the atmosphere. |
| Hyperbolic
paraboloid shell |
A
complex curved surface which has one line which is always straight. |
| Impact
Strength |
A
strength property of wood that essentially measures energy absorption or work
properties and toughness. |
| Improvement
cutting |
The
removal of trees of undesirable species, form or condition from the main canopy
of the stand, to improve health, composition and value of the stand. |
| Infeed |
The
direction a workpiece is fed into a blade or cutter. |
| Insulating
Board |
A
generic term used for a homogeneous panel made from wood or cane fibers characterized
by an integral bond produced by interfelting of the fibers, to which other materials
may have been added to improve certain qualities, but which has not been consolidated
under heat and pressure as a separate stage in the manufacturing process. The
board has a density that is less than 31 pounds per cubic feet (specific gravity
of 0.50) but greater than 10 pounds per cubic feet (specific gravity of 0.16). |
| Intensive
silviculture |
Refers
to the treatments carried out to maintain or increase the yield and value of
forest stands. Includes treatments such as site rehabilitation, conifer release,
spacing, pruning, and fertilization. Also, known as incremental silviculture.
Compare with basic silviculture. |
| Interlocked
grain |
Grain
where the angle of the fibres periodically changes or reverses in successive
layers. |
| Internal
Stresses |
Stresses
that exist within a member even in the absence of applied external forces. |
| International
Log Rule |
In
use since about 1906. Generally regarded as the most accurate of the three scaling
methods, International log rule deducts only 2.12 Inches for slabs and 1/4 inch
for kerf. (Also see Scribner and Doyle Rules.) It is the standard rule used in
Massachusetts. |
| Irregular
grain |
Grain
where the fibres contort and twist around knots, butts, curls and so on. Also
called wild grain. |
| Isotropic |
Exhibiting
the same properties in all directions. |
| Jamb |
The
side of a window or door opening. |
| Jig |
A
device used to make special cuts, guide a tool, or aid in woodworking operations. |
| Joinery |
Finished
timber fixtures of buildings such as doors, windows, panelling, cupboards, etc. |
| Joint |
A
prepared connection for joining pieces of wood or veneer. |
| Joint
group |
Species
of timber are classified into joint groups according to their mechanical properties.
There are six joint groups for unseasoned timber (J1, the strongest to J6, the
weakest) and six joint groups for seasoned timber (JD1 to JD6). |
| Joist |
A
structural framing member used horizontally to support a ceiling or floor. |
| Joist |
One
of a series of timber beams used to support the floor boards or ceiling of a
building. |
| Just
in time (JIT) |
A
buying philosophy characterized by minimizing inventories and buying products
only as they are needed. |
| Juvenile
spacing |
A
silvicultural treatment to reduce the number of trees in young stands, often
carried out before the stems removed are large enough to be used or sold as a
forest product. Prevents stagnation and improves growing conditions for the remaining
crop trees so that at final harvest the end-product quality and value is increased.
See also commercial thinning. |
| Juvenile
Wood |
Formed
near the wood pith, it is characterized by progressive increase in dimensions
and changes in cell characteristics, and the pattern of cell arrangement. It
is also called core wood. |
| Juvenile
wood |
The
term juvenile wood refers to wood formed early in the life of a tree. By most
measures, juvenile wood is lower in quality than wood which forms later; this
is particularily true of the softwoods. Juvenile wood is of greatest concern
in lumber and other products in which wood is used in solid form. Juvenile wood
is of lesser concern in paper and fiber products and in products in which wood
is reduced to individual fibers, fiber bundles, or small pieces prior to product
manufacture. The two most troubling characteristics of juvenile wood are that:
1) It shrinks and swells along the grain as moisture content changes; 2) Strength
is lower, and in some cases much lower, than mature wood of the same tree |
| kerf |
The
cut made by a saw blade. |
| Kerf |
The
width of the sawblade (circular or band) and the source of sawdust. The more
traditional circular sawblades are wider (1/4" to 3/8") than the newer
band saw blades (1/8" to 3/16") and produce more sawdust, a waste byproduct
of sawmills. |
| Kerfing |
making
a series of parallel saw cuts part way through the thickness of a piece of timber
so that the piece can be curved towards the kerfed side. |
| Kickback |
When
a workpiece is thrown back, in the opposite direction the cutter is turning. |
| Kiln |
A
chamber used for seasoning timber in which the temperature and humidity of the
circulating air can be controlled. |
| Kiln |
A
heated chamber used for drying lumber, veneer, and other wood products and in
which air-flow, temperature, and relative-humidity conditions can be controlled. |
| Kiln |
Freshly
cut green lumber may be sold green or first dried in a kiln to accelerate removal
of the moisture in the wood. Drying wood in a kiln is an art to ensure that the
wood dries evenly to retain its strength and aesthetic properties. Different
species dry at different rates. Kiln dried lumber commands a higher price than
green or air dried lumber. |
| Kiln |
In
lumber drying, a kiln is a room or building where temperature, moisture, and
the amount of air circulating are controlled to dry wood. |
| Kiln
Dried |
Lumber
that has been dried in a Kiln. |
| Kiln
dried (KD) |
Describes
lumber that has been dried in a kiln (as opposed to being air dried). |
| Kiln
dried after treatment (KDAT) |
Refers
to lumber that has been kiln dried to 19% or less moisture content after being
pressure treated. |
| Kiln
wet |
Lumber
that has gone through the kiln drying process, but still contains more moisture
than is allowable for dry lumber. |
| Kiln-dried |
Dried
artificially in a kiln. |
| Kiln-Drying
Schedule |
A
stipulated set of dry- and wet-bulb temperatures and air velocities employed
in drying a kiln charge of lumber or other wood products. |
| Knee
brace |
A
diagonal corner brace fastened between a column and a beam or truss to provide
lateral restraint. |
| Knot |
A
part of the tree where a branch has been overgrown by the tree and incorporated
into its trunk. |
| Knot |
That
portion of a branch or limb that has been surrounded by subsequent growth of
the stem. The shape of the knot as it appears on a cut surface depends on the
angle of the cut relative to the long axis of the knot. |
| Knot |
That
portion of a branch or limb that is embedded in the wood of a tree trunk, or
that has been surrounded by subsequent stem growth. |
| Knots |
Areas
of the main stem of a tree in which the base of a branch has been overgrown through
diameter growth of the main stem are called knots. Knots in lumber or veneer
are cross sections of tree branches
Encased Knot
A knot whose annual growth rings are not intergrown with those of the surrounding
wood.
Loose Knot
A knot that is not held firmly in place by growth or position and which cannot
be relied upon to stay in place.
Pin Knot
A knot whose diameter is less than or equal to 1/2".Sound Knot
A knot that is solid across the surface, at least as hard as the surrounding
wood, and shows no indication of decay. |
| Kraft
paper |
Heavy
brown paper sometimes treated to be water repellant. |
| Laminate |
A
thin plastic materiel used to cover a board. The most common use of laminate
is for counter and table tops. It is often referred to by the brand name Formica. |
| Laminate,
Paper-base |
A
panel composed of multilayered resin-impregnated paper sheets compressed together
into a coherent solid mass. |
| Laminated
timber |
A
built up product made of layers or laminations of wood, all with the grain laid
parallel and glued or otherwise fastened together. Laminating timber allows large
and structurally reliable sections to be built up from small, high quality pieces |
| laminated
veneer lumber (LVL) |
A
structural lumber manufactured from veneers laminated into a panel with the grain
of all the veneers running parallel to each other. |
| Laminated
Veneer Lumber (LVL) |
A
structural lumber manufactured from veneers laminated into a panel with the grain
of all veneers running parallel to each other. |
| Laminated
Veneer Lumber (LVL) |
Structural
grade timber veneers glued together under pressure to form a dimensionally stable
and uniform product. An engineered (man-made) wood product that is a substitute
for dimensional lumber. LVL is glued such that the grain direction of all veneers
is parallel; this is different than plywood in which the grain directions of
adjacent veneers is perpendicular to one another. LVL and other composite lumber
products have a number of advantages over solid lumber, including the ability
to make large-sized members from small diameter trees. Such products also allow
the dispersion of gross defects such as large knots. |
| Landing |
That
part of a wood lot to which fresh cut logs are skidded or forwarded, accumulated,
cut to length (if not cut to length in the woods) , stacked, and loaded onto
trailers for delivery or chipped and blown into trailers. |
| Lap
joint |
A
joint made by placing one member partly over another and bonding the overlapped
portions. |
| Latewood |
The
denser wood formed during the later stages of growth of each annual ring. Also
called "summerwood". |
| Latewood |
That
portion of an annual ring that is produced after the earlywood formation has
ceased. It is usually denser and mechanically stronger than the earlywood. |
| Latewood
(Summer Wood) |
The
portion of a treeÕs rings that forms after the earlywood and is often
characterized by smaller cells and a higher density. |
| Level |
Perfectly
horizontal |
| Light-induced
color change |
The
change in heartwood color caused by light during internal (indoor) use. |
| Lineal
Measurement |
Refers
to the sum of the lengths of boards or mouldings with the same dimension. |
| Linear
Foot |
A
measurement of the length of a board. |
| Linerboard |
The
inner and outer layers of paper that form the wall of a corrugated container. |
| Live
load |
The
total variable weight on a structure. It includes the weights of people, furnishings,
snow, wind and earthquake. |
| Load |
Measurement
term for log and lumber volume: 40 cubic feet of logs equals 1.13 Cubic meters,
and 50 cubic feet of lumber equals 1.416 Cubic meters. |
| Log
defects |
Defects
affect the log scale and value for which the log may be sold or bought. Deductions
for defects are subjective depending on the scaler and a source of confusion
in the buy-sell transaction. Defects may include red knots, black knots, rot,
burned area of a log, crook, sweep, or doglegs. |
| Log
scales |
Determines
the value of a log by estimating number of board feet of lumber it will yield
(less allowances for bark, slab and kerf). Helps log sellers understand what
they are getting for the product of their labor. Log buyers can usually predict
the actual yield of board feet from a log depending on the log rule used. Three
major log scales are used: Scribner Log Rule, Doyle Log Rule and International
Log Rule, although there are others (Maine and Roy). It is vital that sellers
understand the differences between the scaling methods so as not to be taken
advantage of. Savvy buyers are flexible in the rules they use. A common rule
of thumb is that International is always 25% better than Doyle, and Scribner
is always 15% better. Doyle and International are dramatically different for
small diameter logs, yet very similar for large diameter logs. If the average
diameter range of logs is 14" to 20", you can convert Doyle to International
by multiplying 1.2 And Scribner to International by multiplying 1.11. For example,
if logs for a particular site scaled about 5,000 board feet in Doyle, this
would convert to 6,000 board feet in International and 5,500 board feet in
Scribner. |
