| Term | Definition |
| Abrasion | Wearing, grinding, or rubbing away by friction. |
| Abrasion Resistance | Resistance to a form of wear, in which a gradual removal of a flooring surface is caused by the frictional action of relatively fine particles. Abrasion resistance generally depends on the toughness of the product or wearlayer, thickness of wearlayer, and existence of surface coatings. |
| Acclimation | The act of allowing wood moisture content to become at equilibrium with the environment in which it is expected to perform (see EMC, Equilibrium Moisture Content). |
| Acid | Chemical substance rated below 7 on the pH scale. |
| Acrylic Impregnated / Acrylic- infused | The generic name for wood-plastic composites using wood impregnated with acrylic monomers and polymerized within the wood cells by heat, pressure or radiation. |
| Acrylic Resin | A translucent synthetic resin that is resistant to discoloration, moisture, alcohol acids, alkalis and mineral oils. It is usually made by polymerization of acrylic acid and methacrylic acid. |
| Adhesion | The ability of a finish to stick to wood. |
| Air Dried | Dried by exposure to air in a yard or shed without artificial heat. |
| Alkalinity | A measurement of alkine rated above 7 on the ph scale. |
| Alligatoring | A finished that exhibits large segmented areas with the appearance of an alligator hide. May be caused by heavy coating, coating over non-cured coatings, use of fast drying thinners or the application of a finish over another with less elasticity |
| Amber | A yellowish color change within the wood or finish or both. See Color Change. |
| Aniline Colors | Colors made from aniline oils or coal tar derivatives and used in the manufacture of wood stains. Aniline dyes are made in different grades to be soluble in water, alcohol or hydrocarbons, and accordingly are called water colors, spirit colors and oil colors, respectively. |
| Anisotropic | Not possessing the same properties in all directions. Wood is anisotropic because the shrinking and swelling, from moisture loss or gain, are unequal in length, thickness and width. |
| Annual Growth Rings | The layer of wood growth, including spring- and summerwood, formed on a tree during a single growing season. |
| APA | Formerly called the American Plywood Association, it is now known as APA – The Engineered Wood Association. |
| APA Trademarked | Wood underlayments approved by APA – The Engineered Wood Association. |
| Applicator Marks or Streaks | Associated with partially cured finishes. When an applicator is drawn across the surface of half-set finish, especially when applying a new section of finish, the lapped area is deglossed leaving a streak. Usually caused by thin films which have faster curing times than the surrounding area. May also be caused by inadequate agitation of satin and semi-gloss finishes which allows “settling” of glossing agents. |
| Asphalt Laminated Felt Paper | A laminated paper that is used as a moisture retardant meeting Federal Specification UU-13-A |
| Asphalt Saturated Felt Paper | A moisture retardant paper saturated with asphalt meeting ASTM Standard D4869. |
| Bark | In wood anatomy, a non-technical term used to describe all the tissues outside the wood (xylem) cylinder. In older trees, bark is usually divisible into inner (living) and outer (dead). |
| Bark Pocket | Ingrown bark that becomes visible when the board is machined and sanded. |
| Base Shoe | A molding designed to be attached to baseboard molding to cover expansion space. |
| Bastard Sawn | See Rift Sawn |
| Beetle | A small insect, which, in the adult and larvae states, bores in the bark or between the bark and wood of living trees, fallen trees and logs. May degrade the wood products. |
| Beveled Edge | An angular edge and/or end treatment used on flooring. |
| Bird Peck | A small hole or patch of distorted grain resulting from birds pecking through the growing cells in the trees; it is usually accompanied by discoloration extending for considerable distance along the grain. |
| Bird’s Eye | Small localized areas in wood with the fibers indented and otherwise contorted to form few to many small circular or elliptical features remotely resembling a bird’s eye on the tangential surface. Common in redwood and in sugar maple. |
| Bit Ends (Nips) | Planer bites on the ends of a board. |
| Blank End Match | When either end of a piece of flooring is not end-matched. |
| Blister | A raised spot on the surface of a floor similar in shape to a blister on human skin. How soon after installation a blister develops can help determine the cause. Blisters which occur within a few hours are usually due to a concentration of trapped air. Blisters which occur at a later time often indicate the presence of moisture in the substrate, or delamination of materials or adhesives. |
| Bleed Back | A condition in wood finish where the surface finish has dried and some stain that has penetrated the wood re-emerges to the face. It usually makes a pattern of small spots about 1/16″. Wiping with a dry, white towel normally identifies the presence of the problem which can be prevented by buffing with a red or white pad. |
| Bleeding | When the color of a stain or other coating material works up into succeeding coats, imparting to them a certain amount of color, it is said to bleed. A non-bleeding color is one that isn’t soluble in materials used over it. |
| Blistering | The formation of bubbles or pimples on the surface of finished work. It is caused by exposure to excessive heat, grease or other volatile material under the finish, by moisture in the wood or by the too frequent application of coats. Anything that causes a gas or vapor to form under the film may cause blistering. |
| Blushing | The formation of a white or grayish cast in a spirit varnish, shellac, epoxy or lacquer film during the drying period. It is caused by the partial or total precipitation of the solid ingredient as a result of condensed moisture in the film. This may be caused by excessive humidity or by use of an improper solvent. |
| Board Foot | A unit of measurement equal to a board 1′ long, 1′ wide, and 1″ thick; (abr. FMB.: bd. ft.) |
| Body | Often used to describe the consistency of viscosity of a finishing material. It’s also used to describe the fullness or thickness of film on the work. |
| Boiling Point | The temperature at which the vapor pressure of a liquid equals the air pressure, or the temperature at which a liquid begins to boil or become gaseous. |
| Bond | The adhesion between two materials. |
| Borders | Simple or intricate designs which frame and customize a flooring installation |
| Bound Water | In wood technology, moisture that is intimately associated with the finer wood elements of the cell wall by absorption and held with sufficient force to reduce the vapor transmission. |
| Bowing | A type of warping in which a piece of plank laid flat on a flat surface will be raised in the center or at the ends. |
| Boxed Heart ( Boxed Pitch or Heart center) | When the pith falls entirely within outer faces of a piece of wood anywhere in its length, it is said to contain boxed heart. |
| 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. Also affects drying rate. |
| Bright | The term is applied to wood that is free from discolorations. The term bright sapwood is sometimes used to describe sapwood of natural color or in which the stain or discoloration can be removed by surfacing to standard thickness. |
| Bright Sapwood | The term bright describes the natural un-stained color of sapwood. |
| Broken Corners | Broken corners consist of small pieces of wood being torn out during matching at the ends. Rough handling may cause them also. |
| Broken Edges | Broken edges consist of a small area of the wood being torn out or indented along the edge. |
| Broken Knot | A knot with a crack or check through the center. |
| Brown Streak | A streak that is brown in color |
| Brush Marks | Marks of the brush that remains in the dried film of a finishing material. They are caused by working the material after its solvents have evaporated to the point that the flowing power has been lost or by defects in formulation that prevent the material from leveling out after it has been brushed. May also be caused by the size of the bristle and its composition. |
| Brushability | The ease with which a material can be applied with a brush under practical conditions. |
| Bubbling | The appearance of bubbles in the film of finish while a finishing material is being applied. It is caused by any condition that causes air, vapors or gases to be trapped in the film while it’s soft, but after it has hardened sufficiently to prevent the gas from escaping. |
| Buckle | Adhesive failure when a floor is under compression. It is caused by subfloor movement or floor growth. |
| Build Coat | A finishing material, usually of a transparent nature, used over the sealer or color coats and under the finishing coats to increase the fullness of the finished work. |
| Bundle | A parcel of relatively small sawed, machined, or other wood products assembled and bound together to facilitate handling, e.g., lathe, molding, or split items. The bundle, usually bulk piled, may be bound with twine, wire, or strap. |
| 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 wood or veneer, a localized severe distortion of the grain generally rounded in outline, usually resulting from over growth of dead branch studs, varying from 1/2″ to several inches in diameter; frequently includes on or more cluster of several small contiguous conical protuberances, each usually having a core, but no appreciable amount of end grain (in tangential view) surrounding it. |
| Cambium | The thin layer of generative tissue lying between the bark and the heartwood. Cambium produces new layers of upward conducting tissue (xylem) on the inside and downward conducting tissue (phloem) on the outside thus increasing the diameter of the trunk. All cells of the wood and of the bark originate in the cambium and is therefore known as the “Seat of Tree Growth” of the tree. |
| Chatter Marks | Slight indentations causing a ripple effect on the surface of a wood floor. They are usually caused by sanding machines that have out-of-balance or out of round sanding heads, bad drive belts or foreign objects stuck to the wheels. The marks are most noticeable on gloss finishes, in direct-light areas or at eye level. |
| Check(s) | A rupture or opening along the grain of the wood, which develops in seasoning. |
| Checking Finish | Similar to alligatoring, except that the finish is broken into smaller segments. Crowfoot checking is the name given to the defect when the breaks in the film form a definite three-prong pattern with the breaks running outward from a central point of intersection. When the checks are generally arranged in parallel lines, the defect is known as line checking. Irregular checks without a definite pattern are known as irregular checking. |
| Chipped Grain | An area in which pieces of wood have been pulled or chipped away from the surface during machining. |
| Classification of Grain | In grading, grain can be defined as referring to the arrangement of direction of the annual rings. |
| Cleat | A barbed fastener commonly used as a mechanical device to fasten hardwood flooring. |
| Color Change | Visual changes in the color of the wood species caused by exposure to light, deprivation of light and air, oxidation or other chemical reaction. |
| Compression Set | Caused when wood strips or parquet slats absorb excess moisture and expand so much that the cells along the edges of adjoining pieces in the floor are crushed. This causes them to lose resiliency and create cracks when the floor returns to its normal moisture content. |
| Coniferous | See Softwoods. |
| Conversion Varnish |
See Swedish Finish. |
| Crazing | The appearance of minute, interlacing cracks or checks on the surface of a dried film of finishing material. |
| Crook | The distortion of a board in which there is a deviation, in a direction parallel to the edge, from a straight line from end to end of the piece. |
| Cross Direction |
Laying of material perpendicular or at an angle to the material below it. |
| Cross Pull | A condition occurring at an end-joint with the ends of flooring strips pulled in opposite directions by movement of the subfloor. |
| Crowfooting | A form of finish crystallization wherein small lines are visible coming together at a central point. |
| Crowning | A “convex” or “crowned” condition or appearance of individual strips, with the center of the strip higher than the edges. (Opposite of cupping) |
| Cull | In lumber grading, pieces or parts that conform to no grading standards. |
| Cupping | A “concave” or “dished” appearance of individual strips, with the edges raised above the center. (Opposite of crowning) |
| Cure | A chemical process in which a material reaches its functional state. Such as cured finish, paint, concrete, etc. |
| Cut | To sand a floor. As a noun, cut refers to one pass over an area of floor with sanding equipment. Usually, in sanding a floor two or more cuts with progressively finer grits of sandpaper are performed. |
| Dark Mineral | Large amounts of mineral and/or mineral streaks that prominently discolor the piece. |
| Decay | The decomposition of wood substance by fungi. Advanced stage decay The older stage of decay in which destruction is readily recognized because the wood has become punky, soft and spongy, stringy, ring shanked, pitted or crumbly. Evident discoloration or bleaching of the rotten wood is often apparent. Incipient stage decay The early stage of decay that has not proceeded far enough to soften or otherwise perceptibly impair the hardness of the wood. It is usually accompanied by a slight discoloration or bleaching of the wood. Intermediate stage decay A stage, in which some breakdown of the normal wood structure is noticeable, but which does not yet present the characters of the advanced stage of decay or effect the structural integrity of the wood in general. |
| Deciduous | See Hardwoods. |
| Defect | Any irregularity or imperfection in a tree, log, bolt, lumber or other wood product that reduces the volume of useable wood or lowers its durability, strength, or utility or visual value. Defects may result from knots and other growth conditions and abnormalities; from filling, drying, machining, or other processing procedures. Drying Defect Any irregularity occurring in or on wood, as a result of drying, that may lower its utility value. Drying Defect Chemical Action A discoloration of wood caused by chemical modification resulting in sticker stain or marking, brown stain, etc. Drying Defect Fungus Any deterioration in quality caused by the growth of fungi on the surface or in the interior of the wood such as blue stain, sap stain, decay, mold, etc. Drying Defect Shrinkage Any irregularity occurring in wood resulting from shrinkage during drying, such as surface checks, end checks, honeycombing, splitting, warp, loose knots, knotholes, etc. |
| Delamination | The separation of layers in an engineered/laminate through failure within the adhesive or at the bond between adhesive and laminate. Term is often used incorrectly to identify a failure of finish to adhere to the surface of the wood. See Adhesion. |
| Diffuse Porous Woods | Certain hardwoods in which the pores tend to be uniform in size and distribution throughout each annual ring or to decrease in size slightly and gradually toward the outer border of the annual growth ring. Hard maple is an example. |
| Dimensional Stability | The ability of a material to retain its original size and shape without appreciable shrinkage and/or expansion after temperature or humidity change. |
| Discoloration | Change in color of wood due to fungal and chemical stains, weathering and heat treatment. |
| Dispersed | In reference to finishing materials, finely divided or colloidal in nature. |
| Distressed | A heavy texture in which the floor has been scraped, scratched, or gouged to give it a time-worn antique look. (A common method of distressing is wire brushing). |
| Drier | A catalytic material that improves the drying or hardening properties of oils or varnishes when added in small amounts. They are usually organic salts of lead, cobalt, manganese, zinc and iron, such as naphthenates, resinates and linoleates. |
| Dry Kiln | A room, chamber or tunnel in which the temperature and relative humidity of air circulated through parcels of lumber, veneer, and other wood products can be controlled to govern drying conditions. |
| Dry Rot | In wood, any decay attacking both the cellulose and lignin producing a generally whitish residue that may be spongy or stringy or occur in pockets. |
| Dry Tack-Free | The stage of solidification of a film of finishing material when it doesn’t feel sticky or tacky when a finger is drawn lightly across it in a quick continuous motion. |
| Dry to Sand | That stage of solidification of an applied film of finishing material when it can be sanded without undue softening, sticking or clogging of the sandpaper. |
| Dry to Touch | That stage of drying of a film of finishing material when it has solidified sufficiently that it can be touched lightly without any of the finishing material adhering to the fingers. |
| Drying | The act of changing from a liquid film to a solid film by the evaporation of solvents, oxidation, polymerization or by a combination of these phenomena. |
| Drying Characteristics | Drying characteristics occur during the drying process. Examples include: Checks, Split, Warp (including cork, cup, bow, and twist) and Honeycomb. |
| Drywall | Interior covering material, such as gypsum board, hardboard or plywood, that is applied in large sheets or panels. |
| Durability | The ability of the wood species or finish to withstand the conditions or destructive agents with which it comes in contact in actual usage. |
|
Dust | Small particles of solid matter. Also, A grading or size of natural resin. |
| Dust-free | That stage of solidification of an applied film of finishing material when dust that settles on the coated surface won’t penetrate or stick to the film. |
| Eased Edge | The chamfered, or beveled edge, of strip flooring , plank, block, and parquet. |
| Electrodes | In testing wood for moisture content, devices made of electrically conducting material for connecting wood into the electric circuit of an electric moisture meter. Insulated Electrodes In testing wood for moisture content, special electrodes for use with resistance-type electric moisture meters that are coated with an insulating material to limit or control the point of contact between the electrode and the wood. |
| End Joint | The place where two pieces of flooring are joined together end to end. |
| End Matched | In strip and plank flooring the ends of individual pieces have a tongue milled on one end and a groove milled on the opposite end, so that when the individual strips or planks are butted together, the tongue of one piece engages the groove of the next piece. |
| Engineered | An assembly made of adhesive bonded layers of wood in which adjacent layers are normally at right angles to the adjoining layers which increase dimensional stability. |
| Epoxy, Epoxy Ester | A varnish that, with the addition of epoxy, creates a hybrid with the advantages of both products. Ambers well with quick build and high gloss but can be difficult to repair. Enhanced working characteristics make this finish a preferred choice for athletic surfaces. Dries to tack free in 8-24 hours, reaching full cure in 30 days. |
| Equilibrium Moisture Content | The moisture content at which wood neither gains or loses moisture when surround by air at a given relative humidity and temperature. |
| Face | The wide surface of rectangular shaped pieces of flooring. Often the surface that determines the grades. |
| Face Wrinkling | Wrinkle appearing on the surface of adhered flooring. This is normally caused by severe compression of the flooring, normally associated with hard set, firm bonding adhesives over shrinking substrates. |
| Fading | The loss of color due to exposure to light , heat or other destructive agents |
| Feather Edge | The tapering of the edge of film of dried material either by the method of application, sanding or rubbing the dried film, resulting in a gradual progression of the film thickness from little or no material at the edge to a normal coating at the center. |
| Feature Strip | A strip of wood used at a threshold or to border a room or to otherwise serve as an accent. Usually of a contrasting color or species. |
| Fiber Saturation Point | The stage in the drying or wetting of wood at which the cell walls are saturated with water (bound water) and the cell cavities are free of water. Most species reach reach their fiber saturation point at 28-30% moisture content, based on the weight when oven dry. wood neither expands nor contacts at its fiber saturation point. |
| Figure | Inherent markings, design, or configurations in the surface of the wood produced by the annual growth rings, rays, knots and deviations from regular grains. |
| Filler | Inherent markings, designs, or configurations in the surface of the wood produced by the annual growth rings, rays, knots and deviations from regular grain. In woodworking, any substance used to fill the holes and irregularities in planed or sanded surfaces to decrease the porosity of the surface before applying finish coatings. Wood filler used for cracks, knotholes, worm holes, etc. is often a commercial putty, plastic wood or other material mixed to the consistency of putty. A wood filler may also be mixed on the job using sander dust from the final sanding, or other suitable material, mixed with sealer or finish. |
| Fillets | The small components which comprise parquet. Also called fingers or slats. |
| Fills | Openings in the surface of the flooring, which would be filled with wood putty. |
| Fine Pin Worm Holes | Fine pin worm holes are 1/32″ or less in diameter. |
| Finger- block | Parquet made from small strips of wood assembled together. See Fillets. |
| Flag | A heavy dark mineral streak shaped like a banner. |
| Flag WormHole | one or more worm holes surrounded by a mineral streak. |
| Flame Spread | The propagation of a flame away from the source of ignition across the surface of a liquid or solid, or through the volume of a gaseous mixture. Note: Most wood species are Class C Flame Spread unless the wood floor has been treated and marked. |
| Flatting Agent | A material added to a normally glossy coating to reduce luster and produce a flat appearance. |
| Flecks | The wide, irregular, conspicuous figure in quarter sawn oak flooring. Also known as ray flecks. |
| Floating Hardwood Flooring | Flooring that adheres board to board at edge and end joints, without direct attachment to the subfloor. |
| Flow | The characteristic of a coating that allows it to level or spread into a smooth film of uniform thickness before hardening. |
| Ford Cup | A type of viscosimeter originally used by the Ford Motor Company, but now used extensively in testing laboratories. It consists of a cup with an overflow device to ensure a standardized volume, in the bottom of which is a standardized orifice. The number of seconds required for the cup to empty itself at a standardized temperature gives a numerical expression of the viscosity of the material. |
| Fungi | Low forms of plants consisting mostly of microscopic threads (hypea) that traverse wood in all directions, dissolving materials out of the cell walls that they use for their own growth. |
| Fuzzy Grain | Roughening of the surface of the wood, resulting from absorption of moisture sufficient to expand the wood cells at the immediate surface. The result is a fuzzy feel when touched. |