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Ulf T. Runesson

Faculty of Natural
Resources Management,
Lakehead University

955 Oliver Road,
Thunder Bay, Ontario,
Canada P7B 5E1

     (807) 343-8784

     (807) 346-7769


Laminate, Wood A product made by bonding layers of wood or other material to a wood substrate.
Laminated Veneer Lumber (LVL) A structural lumber product manufactured from veneers laminated so that the grain of all veneers run parallel to the axis of a member.
Latex A synthetic resin used in the manufacture of water soluble paint coatings. PVA and acrylic are two types of latex resins used to make latex coatings.
Level or Soffit Return Lumber filler placed horizontally from the end of an overhang to the outside wall to form a soffit.
Light Framing The use of dimension lumber, trusses, and other small cross- section members to provide support and enclosure for a building.
Lignin The second most abundant constituent of wood after cellulose. It is the thin cementing layer between the wood celIs.
Limit State A condition of a structure at which the structure ceases to fulfil the design function as applied in Limit States Design.
Live Load Any loading that is of a temporary nature such as snow, wind, earthquake, and construction loads.
Load Combination Factor A factor applied to the factored loads in Limit States Design, other than dead load, to take into account the reduced probability of a number of loads from different sources acting simultaneously as applied to Limit States Design.
Load Duration The period of continuous application of a specified load, or the aggregate of periods of intermittent applications of the same load.
Load Factor A factor applied to a specified load that, for the limit state under consideration, takes into account the variability of the loads and load patterns as applied to Limit States Design.
Lumber The product of the saw and planing mill not further manufactured than by sawing, resawing, passing lengthwise through a standard planing machine, cross- cutting to length, and grading.
Lumber, Boards Lumber that is less than 38mm (2" nom.) thick and 38mm (2" nom.) or more wide.
Lumber, Dressed Sized The dimensions of lumber after being surfaced with a planing machine.
Lumber, Machine Stress-Rated (MSR) Lumber which has been mechanically evaluated to determine its stiffness and bending strength.
Lumber, Matched Lumber that is edge dressed and shaped to make a close tongue and groove joint at the edges or ends, when laid edge to edge, or end to end.
Lumber, Nominal Size The size of lumber after sawing and prior to surface finishing by planing.
Lumber, Patterned Lumber that is shaped to a pattern or to a moulded form in addition to being surface planed.
Lumber, Rough Lumber that has not been dressed (surfaced) but which has been sawed, edged, and trimmed.
Lumber, Shiplapped Lumber that is edge dressed to make a lapped joint.
Lumber, Sizes of For metric measure, lumber size is based on actual size rounded to the nearest millimetre. For Imperial measure, lumber size is usually expressed in terms of nominal size which is the size before surfacing. The dressed size is usually 12 to 19mm (1/2 to 3/4") less than the nominal or rough size. For example, a 2" ö 4" stud after dressing measures about 1-1/2" ö 3-1/2".
Lumber, Structural Lumber which has strength in relation to the anticipated structural end use, as a controlling factor in grading or selecting.
Lumber, Visually Stress-Graded Lumber that has been graded for strength based on visual appearance, as opposed to MSR lumber which is evaluated mechanically and checked visually.
Lumber, Dimension Lumber 38 to 102mm (2" to 4" nom.) in smaller dimension.

Medium Density Fibreboard (MDF) A panel product, widely used as a substitute for plywood, particleboard and solid lumber; manufactured in a process where wood fibres, resin and wax is compressed under high pressure to form a panel.
Millwork Planed and patterned lumber for finish work in buildings, including items such as sash, doors, cornices, panelwork, and other items of interior or exterior trim, but not flooring or siding.
Mineral Spirits A petroleum derived solvent similar to gasoline, used primarily for thinning alkyd and other oil based coatings such as paint, stain, and varnish.
Moisture Content The amount of water contained in the wood, expressed as a percentage of the weight of the oven-dry wood.
Moulding A wood strip having a curved or projecting surface used for decorative purposes.

Noncombustible Construction A factor applied to factored loads, other than dead load, to take into account the consequence of collapse as related to the use and occupancy of the structure, as in Limit States Design.

Oriented Strandboard (OSB) A panel product, used for sheathing, made from strands with the face wafers oriented in the long direction of the panel to provide additional strength in that direction.
Overlay A thin layer of paper, plastic, film, metal foil, or other material bonded to one or both faces of panel products, or to lumber, to provide a protective or decorative face, or a base for painting.

Paint A coating containing enough pigment to create an opaque solid film after application as a thin layer.
Paint, Enamel A coating product characterized by ability to form a uniform hard film used for flooring and other high wear applications. Enamels may be obtained in a full range of colours and usually in gloss or semi-gloss.
Panel Point The point of intersection where the web or webs of a truss meet a chord.
Parallel Strand Lumber (PSL) A structural wood product made by gluing together long strands of wood which have been cut from softwood veneer.
Pith The small cylinder of primary tissue of a tree stem around which the annual rings form.
Pitch The accumulation of resin in wood.
Pitch Pocket An opening between growth rings which usually contains or has contained resin or bark or both.
Panel, Exterior A general term for plywood or OSB/waferboard, bonded with a type of adhesive that by systematic tests and service records has proved highly resistant to weather.
Panel, Interior A general term for a panel made from a type of adhesive which is not resistant to moisture and is therefore limited to uses where protection from moisture is provided.
Plywood A glued wood panel made up of thin layers of veneer with the grain of adjacent layers at right angles, or of veneer in combination with a core of lumber or of reconstituted wood.
Plywood, Standard Construction Panels constructed of pairs of plies that are balanced as to grain direction and thickness about the central ply or panel centreline, in which the grain of each ply is at right angles to at least one other ply.
Plywood, Modified Construction Panels which are not standard thickness or which have an even number of plies.
Plywood Stressed-Skin Panel A form of construction in which outer skins of plywood are applied over internal frame members to form a rigid structural element.
Polyurethane A paint and varnish resin which imparts good abrasion resistance and marketed under several trade names such as varathane, urethane, and durathane.
Post A timber with larger dimension not more than 51mm (2") greater than the smaller dimension and usually graded for use as a column.
Preservative Any substance effective in preventing the development and action of wood-rotting fungi, borers of various kinds, and harmful insects that cause the deterioration of wood.
Pressure-Treating The process of impregnating wood with preservative or fire retardant chemicals by placing the wood and chemical in a pressure chamber.
Pressure-Treating, Empty-Cell Process Pressure treating process in which back pressure from air drives out part of the injected preservative or chemical to leave the cell walls coated but the cell cavity mostly devoid of chemical.
Pressure-Treating, Full-Cell Process Pressure treating process in which a vacuum is drawn to remove air from the wood before admitting the preservation, resulting in a heavy absorption and retention of preservative due to the cells being almost filled.
Primer One or more preliminary base coats of paint system, applied prior to the application of finishing coats.

Rafter One of a series of structural members of a roof designed to support roof loads.
Raised Grain A roughened condition of the surface of dressed lumber in which the hard latewood is raised above the softer earlywood but not torn loose from it.
Rays Strip of cells extending radially within a tree and varying in height from a few cells in some species to 100mm (4") which cause an appealing grain pattern.
Resin An ingredient of coatings which acts as a binder and gives the coating physical properties such as hardness and durability.
Resin (natural) Inflammable, water- soluble, vegetable substances secreted by certain plants or trees, and characterizing the wood of many coniferous species.
Rip A cut made lengthwise in a wood member, parallel to the grain.

Last Modified: January 20, 2014 15:01:06. 
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