What do all of those strange flooring terms really mean?

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The act of allowing wood moisture content to become at equilibrium with the environment in which it will be installed. [top]
Air Dried
Dried by exposure to air in a yard or shed without artificial heat. [top]
A yellowish colour change from either the wood or the finish. [top]


Base Shoe
A molding designed to be attached to baseboard molding to cover expansion space. It is the alternative to a quarter-round in profile. [top]
Simple or intricate designs which frame and customize a flooring installation. [top]
The distortion of lumber in which there is a deviation, in a direction perpendicular to the flat face, from a straight line from end to end of the piece. [top]
A swirl or twist of the grain of the wood that usually occurs near a knot, but doesn't contain a knot, commonly found in the stump of a tree and where limbs branch out from the tree. [top]


A lengthwise separation of the wood that usually extends across the rings of an annual growth and commonly results from stress set up in wood during air or kiln drying. [top]
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. [top]
A barbed fastener commonly used as a mechanical device to fasten hardwood flooring. [top]
Colour Change
Visual changes in the colour of the wood species caused by exposure to light, deprivation of light and air, or some chemical reaction. [top]
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. [top]
Cross Direction
Laying of material perpendicular to the material below it. [top]
A convex or crowned condition or appearance of individual strips with the center of the strip higher than the edges. The opposite of cupping. [top]
A concave or dished appearance of individual strips with the edges raised above the center. The opposite of crowning. [top]
To change the properties of a product by chemical action as opposed to drying when the product has reached its optimum state. [top]


The separation of layers in an engineered / laminate through failure within the adhesive or at the bond between adhesive and laminate. [top]
Dimensional Stability
The ability to maintain the original intended dimensions when influenced by a foreign substance. Wood is hygroscopic ( readily takes up moisture ) and isn't dimensionally stable with changes in moisture content below the fiber saturation point. Engineered wood flooring, however, is more dimensionally stable than solid wood. [top]
A heavy artificial 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. [top]
The ability of the wood species or finish to withstand the conditions or destructive agents with which it comes in contact in actual usage, without an appreciable change in appearance or other important properties. [top]


End Joint
The place where two pieces of flooring are joined together end to end. [top]
In tongue and groove strip and plank flooring, the 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 fits into the groove of the next piece. [top]
An assembly made by bonding layers of veneer or lumber with an adhesive so that the adjacent layers have their grains going in opposite directions to increase dimensional stability. [top]
Equilibrium Moisture Content
The moisture content at which wood neither gains nor loses moisture when surrounded by air at a given relative humidity and temperature. [top]


The loss of colour do to exposure to light, heat or other destructive agents. [top]
Feather Edge
The tapering of the edge of a 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. [top]
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 colour or species. [top]
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. [top]
Flatting Agent
A material added to a normally glossy coating to reduce luster and produce a flat appearance. [top]


The luster, shininess or reflecting ability of a surface. [top]


The property of the wood species or dried film of finishing material that causes it to withstand denting or being marked when pressure is exerted on its surface by an outside object or force. [top]
Generally, one of the botanical groups of deciduous trees that have broad leaves, in contrast to the conifers or softwoods. The term has no reference to the actual hardness of the wood. [top]
The wood extending from the pith to the sapwood, the cells of which no longer participate in the life processes of a tree. It is usually darker than sapwood. [top]
The amount of water vapor in the air. [top]
An instrument for measuring the degree of humidity or relative humidity of the atmosphere. [top]
A substance that which can absorb and retain moisture, or lose or throw off moisture. Wood and wood products are hygroscopic. They expand with an absorption of moisture and their dimensions become smaller when moisture is lost or thrown off. [top]


Janka Wood Hardness Scale
The Janka hardness test is a measurement of the force necessary to embed a .444-inch steel ball to half its diameter in wood.

To view some ratings, please visit Janka Wood Hardness Scale. [top]


A chamber having controlled air flow, temperature and relative humidity for drying lumber, veneer and other wood products. Kiln is often pronounced like “kill”. [top]
Dried in a kiln with the use of artificial heat. [top]
The 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. In hardwood strip flooring, small and pin knots aren't more than one-half inch in diameter. A sound knot is a knot cut approximately parallel to its long axis so that the exposed section is definitely elongated. [top]


Mineral Streak
Wood containing an accumulation of mineral matter introduced by sap flow, causing an unnatural color ranging from greenish brown to black. [top]
Mixed Media
A wood floor that is predominately wood, but also incorporates other materials, such as slate, stone, ceramic, marble or metal. [top]
Moisture Content
The amount of moisture in wood expressed as a percentage of the weight of oven-dried wood. Hardwood flooring is usually manufactured at 6 to 9 percent moisture content, with a 5 percent allowance for pieces up to 12 percent moisture content. Five percent of the flooring may be outside of this range. [top]


A hardwood molding used to cover the outside corner of a step, milled to meet the hardwood floor in the horizontal plane, to meet the riser in the vertical plane. It is usually used on landings. [top]


Oriented Strand Board commonly used as an underlay material. [top]
A flooring condition in which some wood pieces are raised above adjacent pieces leaving a slightly uneven surface. [top]


A tile composed of individual slats assembled together. A square may or may not possess tongues and grooves to interlock and isn't necessarily square or regular in dimension. [top]
A generic term for a material manufactured from wood particles or other ligno-cellulosic material and a synthetic resin or other suitable binder. Flakeboard is a particle panel product composed of flakes. Oriented Strand Board is a type of particle panel product composed of strand-type flakes that are purposely aligned in directions that make a panel stronger, stiffer and improves dimensional properties in the alignment directions over a panel of random flake orientation. Waferboard is a particle panel product made of wafer-type flakes. It is usually manufactured to possess equal properties in all directions parallel to the plane of the panel. [top]
A defect in a dried film manifested by large pieces becoming detached from the under surface and coming loose in sheets or large flakes. [top]
Penetrating Stains
Stains that penetrate into the surface of the wood. They are usually made of dyes dissolved into liquids that easily penetrate the wood. [top]
The property of some wood species which causes them to lighten or darken when exposed to light. [top]
Pin-Worm Hole
In hardwood flooring, a small round hole not more than 1/16-inch (1.5626mm) in diameter, made by a small wood-boring insect. [top]
Plain Sawn
The annual growth rings make an angle of less than 45 degrees with the surface of the piece. This exposes the pores of the springwood and dense summerwood of the annual growth rings in ring-porous woods to produce a pronounced grain pattern. [top]
Solid or Engineered/Laminated boards 3" and wider designed to be installed in parallel rows. Edges may be beveled to simulate the appearance of Colonial American plank floors. [top]
Factory-finished flooring that only requires installation. [top]


The annual growth rings of wood form an angle of 45 degrees to 90 degrees with the surface of the piece. In quartersawn strips, the medullary rays or pith rays in ring-pourous woods are exposed as flecks that are reflective and produce a distinctive grain pattern. [top]


Raised Grain
A roughened or fuzzy condition of the face of the flooring in which the dense summerwood is raised above the softer springwood but not turn or separated. [top]
Reducer Strip
A teardrop-shaped molding accessory for hardwood flooring, normally used at doorways, but sometimes at fireplaces and as a room divider. It is grooved on one edge and tapered or feathered on the other edge. [top]
Sanding a previously finished floor to bare wood and applying new finish. [top]
Rift Sawn
Lumber ([primarily hardwoods) in which the annual rings make angles of 30 degrees to 60 degrees with the surface of the piece. Also known as bastard sawn. [top]


The wood near the outside of a tree. It is usually lighter in color than heartwood. [top]
Slight incisions, breaks, tears or indentations on the surface caused by abrasive friction. [top]
Any finishing material that is applied with the primary purpose of stopping the absorption of succeeding coats. [top]
The degree of luster of the dried film of a finishing material. It is usually used to describe the luster of rubbed surfaces or of flat-drying materials. [top]
A spline or small strip of wood or metal used to reverse or change direction in installing standard tongue-and-groove strip flooring. It is sometimes used in laying 3/4-inch (19mm) solid tongue-and-groove parquet. [top]
Strip Flooring
Solid or laminated boards to be installed in parallel rows, produced in various thicknesses and widths. The strips are side-matched and end-matched (tongue-and-grooved). They are for nail-down installation directl6y to wood or plywood sub-floors, or over wood screeds on concrete slab construction. Some types can also be glued directly to a concrete sub-floor. [top]


In strip, plank and parquet flooring, a tongue is milled on one edge and a groove cut on the opposite edge. As the flooring is installed, the tongue of each trip or unit is engaged with the groove of the adjacent strip or unit. [top]
The finish materials in a building at the floor of rooms (baseboard, base show, quarter round for example). [top]
Trowel Fill
Method to fill an entire floor or large area. [top]
Tri Sodium Phosphate, commonly used to remove surface contaminates from flooring. [top]


A product that must have stain and/or a finish applied after installation. [top]


Any distortion of a piece of flooring from its true plane that may occur in seasoning. [top]
Wire Brushed
A method for imparting an artificial texture or distressed appearance to the surface of hardwood flooring. [top]