Glossary

An additive used to modify the properties of hardened concrete, such as reducing the water content or accelerating the curing time. 

Drying by exposing to air without the use of artificial heat and within a yard or shed. 

Hardware used to mechanically fasten wood flooring to the substrate. 

The layer of wood growth, including spring and summerwood formed on a tree during a single growing season. 

The Engineered Wood Association’s classification of plywood, including span rating, bond classifications, panel grade, and various standards. 

Similar to quarter round in profile. It is a molding designed for attaching to a base molding to cover the expansion space. 

A pattern that you can achieve when installing parquet block flooring where planks are arranged into a pattern that resembles that of a wicker basket.  

Lumber, where the annual rings are at an angle of 30 to 60 degrees of the lumber surface. 

A chamfered or beveled edge of strip flooring, plank, block and parquet at approximately a 45-degree angle. 

A unit of measurement that is represented by a board 1 foot long, 1 foot wide, and 1 inch thick or its cubic equivalent. 

In lumber the distortion in which there is a deviation, in a direction perpendicular to the flat face as measured from a straight line from end to end. 

A swirl or twist of the grain of the wood that does not contain a knot but usually occurs near a knot. 

Ripple-like waves in finished flooring that become visibly pronounced in reflective overhead and/or natural lighting.
 

A lengthwise separation of the wood that usually extends across the rings of annual growth and commonly results from stress set up in wood during air-drying or kiln-drying.

A type of fastener specifically designed to prevent wood and tongue splitting. 

The condition where the extreme edges of the flooring appear bulged upwardly above the balance of the board face, giving rise to a “ripple-like” surface appearance. The appearance is similar to cupping except the surface is not truly concave.

Occurs when wood strips or parquet slats absorb excess moisture and expands excessively crushing the cells along the edges of adjoining pieces in the floor. 

A hard strong building material made by mixing a cementing material (such as Portland cement) and a mineral aggregate (such as sand and gravel) with sufficient water to cause the cement to set and bind the entire mass (creating a slab). 

General term that describes lumber produced from conifers. (Needle and cone bearing trees.) 

A design wherein a plywood surface is continuous across the top layer of the subfloor.  

The distortion that occurs within a board that has a deviation in a direction perpendicular to the edge, from a straight line from end to end of the piece. 

A condition that occurs at an end-joint with the ends of flooring strips pulled in opposite directions. 

A “convex” or “crowned” condition or appearance where the center of individual flooring strips becomes higher than the edges. (Opposite of cupping.) 

A “concave” or “dished” condition or appearance where the center of individual strips becomes lower than the edges. (Opposite of crowning.) 

The change of adhesives properties by chemical reaction (which may be condensation, polymerization, or vulcanization). Results in the development of maximum strength. Commonly accomplished by the action of heat or a catalyst, with or without pressure. 

Wood floor that is specifically made to order. Offers flexibility for design, grade, specie, etc. 

A location on a sports floor where ball rebound is markedly less than on the majority of the rest of the surface.  

Decomposition or wood by fungi. 

Commonly one of the botanical groups of trees that have broad leaves in contrast to the conifers or softwoods. This term does not refer to the actual hardness of the wood. 

The separation of layers in a laminate (such as plywood), through failure within the adhesive or at the bond between the adhesive and laminate. 

Certain hardwoods where the pores tend to be uniform in size and distribution throughout each annual ring. 

The ability to maintain the original planned dimensions when influenced by a foreign substance. 

Interior covering material, such as hardboard, plywood or gypsum board that is applied in large sheets or panels. 

 A chamfered or beveled edge of strip flooring, plank, block and parquet at approximately a 45-degree angle.

The place where two pieces of flooring are joined together end to end.

Plank or strip flooring milled using a uniform tongue and groove method of joining. 

The moisture content at which wood neither gains nor loses moisture when surrounded by air at given relative humidity and temperature.

Spaces installed at regular intervals across the floor surface to allow maple expansion as normal seasonal changes dictate. Intermediate expansion spacing (or "washer rows") is installed based on a dimensional calculation using the flooring moisture content at the time of installation and/or normal anticipated changes in moisture contents throughout the year. 

Areas in a sports flooring system that provide unobstructed space for system movement. usually found at the perimeter of a floor and at all vertical obstructions including volleyball inserts, floor electrical outlets, audio/video box hookups, threshold anchors, and bleacher anchors within the borders of the floor. 

Hardware used to secure wood flooring to the subfloor. See Cleats, Staples, and Nails. 

The manufacturer-specified spacing of fasteners. Fasteners are also typically installed near the end of each piece of flooring. 

A molding accessory for parquet floors utilized to separate squares into patterns larger than the individual parquet units. It is available in widths from 5/16” to 2”, the same thickness as the parquet, and is available in various lengths. The strip is flat and may have grooves on both sides to match the tongues of adjacent plank or parquet.

The stage in drying or wetting wood at which the cell walls are saturated with water and the cell cavities are void of water. It is usually taken as approximately 30% moisture content, based on oven-dry weight. 

A broad generic term inclusive of sheet materials of wisely varying densities manufactured of 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.

The inherent markings, designs, or configurations on a woods surface. Produced by the annual growth rings, rays, knots and deviations from the regular grain. 

Any substance used to fill holes and irregularities in planed or sanded surfaces. Used to decrease the porosity of the surface before applying a finish coat.  

A liquid applied to flooring to protect and extend the life of the floor.

The tendency of a clear protective finish to take on a yellow appearance as it ages. Typically, the greatest color change takes place between the sixth month and the end of the first full year of service. 

The property of a material or assembly, to withstand fire or give protection from it.

A chemical or preparation of chemicals used to reduce flammability or to retard spread of a fire over the surface.

Swelling at the ends of boards from short term exposure to moisture. 

A heavy dark mineral streak shaped like a banner.

One or more wormholes surrounded by a mineral streak.

The development of a flame away from its source of ignition such as across the surface of a liquid or a solid, or through the volume of a gaseous mixture. 

The broad irregular-distinct-figure in quarter-sawn flooring.

Paint designed specifically for graphics, lettering, logos, signs and marking lines on sports flooring. 

Standard used to classify wood flooring based on the variations in the wood. The five MFMA grades are First, Second and Better, Third and Better, Third, and Utility. 

A general term that describes the direction and alignment of the wood elements.

Increments of growth, which appear as figures in the floor. Seen in a cross section of a log as rings around the center of the log.

Commonly one of the botanical groups of deciduous trees that have broad leaves in contrast to the conifers or softwoods. This term does not refer to the actual hardness of the wood.

The wood extending from the pith of the sapwood, the cells of which no longer participate in the life processes of the tree. It is usually darker than sapwood.

Spots and streaks that are large enough to significantly affect the appearance of a wood. 

An instrument for measuring the level of water vapor (also known as relative humidity, RH) 

The ability of a substance to absorb and retain moisture or lose or throw off moisture. Wood as a hydroscopic material expands with the absorption of water and shrinks with the loss of moisture.

The amount of water vapor in the air as a percentage of the total amount that could be held at its current temperature. 

To expand with heat to provide a low-density film; uses in reference to certain fire-retardant coatings. 

The vertical and head frame of a door consisting of side jambs, a head jamb, and a mullion. 

Strip flooring that is manufactured with square edges and no tongue and groove and is usually end matched. Primarily used for areas subject to routine damage and where easy replacement is desirable. 

Parallel beam used in series to support floor or ceiling loads. Supported in turn by larger beams, girders, or bearing walls. 

A chamber that has air flow, temperature and relative humidity control for drying lumber, veneer and other wood products. 

Wood dried in a kiln.

The portion of a branch or limb, which has been surrounded by succeeding growth of a stem.

An assembly made by bonding layers of veneer or lumber with an adhesive. 

Defects or blemishes that develop during manufacturing. Includes such as chipped grain, tom grain, skips in dressing. Hit and miss (a series of surfaced areas with skips between them), machining variations, burns and mismatching. 

Rays of cells extending from the pith of the bark. These strips of cells extend in radial pattern within the tree. On quarter-sawn lumber, the rays form a conspicuous figure that is sometimes referred to as flecks.

Mike Niese began his hardwood flooring career in 1975 as a carpenter with the Cincinnati Floor Company. In 1982, Mike transferred to Robbins Sports Surfaces where he became the new Technical Service Manager. 

The accumulation of mineral matter, introduced by sap flow. Causes an unnatural color within the wood that ranges from greenish brown to black. 

A predominantly wood floor that incorporates the use of other materials such as stone, ceramic, metal or painted finishes. 

The amount of moisture expressed as a percentage of the weight of the oven dry wood.

The unwanted movement of water or vapor into areas where it can cause damage. 

A tool used to measure moisture content.

A parquet flooring arranged in designs using small pieces to form a double herringbone, bordered or other design. 

A type of fastener.

In lumber, the size by which the material is known or sold. May actually differ from the actual size. 

Trim used to cover the outside corner of a step.

A widely used, versatile engineered wood panel similar to particle board made using waterproof heat-cured adhesives and rectangularly shaped wood strands that are arranged in cross-oriented layers. It is similar in strength and performance to plywood, resisting deflection, warping and distortion.   

When several flooring boards bond together forming one large slab or “panel” of wood. 

tiles created by arranging small pieces of hardwood in repeating patterns 

Individual wood slats that are joined together to form a tile-like square. 

Joined units that consists of 3 to 4 tile squares.

A generic term for a material manufactured from wood particles or other cellulosic material and a binder. 

The measure of the ease of passage of water vapor through a material. Also referred to as a material’s permeance. A material with high permeability allows liquid to easily pass through it. 

A small round hole that is made by a small wood boring insect and not over 1/16” in diameter. Also called Pinholes. 

A small round hole that is made by a small wood boring insect and not over 1/16” in diameter. Also called Pinholes. 

Sawed from a hardwood log with annual growth rings making an angle less than 45 degrees with the surface. In ring-porous wood it produces a pleasing grain pattern. 

A groove cut in the surface of the wood piece deeper than intended by the planer knives.

Solid boards that are usually thicker than ¾” and 3” to 8” wide. 

Dowels that simulate the Colonial American plugged or pegged plank appearance. 

Drops of finish that has not fully cured that squeeze out from the side joints of the maple strips to the floor surface. 

A floor that is finished during the manufacturing process and requires installation only. 

A cover that offers an extra layer of protection and helps to keep your multipurpose floor looking its best. Covers come in a range of styles and thicknesses. 

Wood sawed from a hardwood log so annual growth rings make an angle of 45 to 90 degrees with the surface of each piece. 

A roughened or fuzzy condition on the flooring surface. Dense summerwood is raised above the softer springwood but is not torn or separated. 

Also called medullary rays or pith rays, are sheets or ribbons of cells running from the inside of the plant to the outside. 

A molding strip teardrop in shape. 

Usually a 2” x 4” laid flat side down and attached to a concrete subfloor to provide a nailing surface for tongued and grooved strip flooring or a wood subfloor.

The ratio of the amount of water vapor present in the air to the greatest amount that the air can hold at the same temperature.  

When drying, concrete slabs have lower moisture levels near the surface and higher levels towards the bottom of the slab. Concrete that contains excess moisture and high RH levels can lead to flooring failures. When flooring is installed and sealed too early, and not given enough time to dry, an excess of moisture is trapped inside the concrete. This water will try to evaporate, which can cause damage and deterioration of your wood flooring. Under normal drying conditions, a rule of thumb allows at least one month of drying for every 1 inch of slab thickness after closing the building. 

The capability of a strained structure to recover its size and shape after deformation caused especially by compressive stress. 

A synthetic or rubber pad acting much like a shock absorber, allowing compression under stress, which in turn creates shock absorption and relates to the area of deflection and the amount of vertical deflection.

Lumber (primarily hardwoods) in which the annual rings make angles of 30 to 60 degrees with the surface of the piece. (Also referred to as Bastard Sawn). 

Certain hardwoods where the pores at the beginning of each annual growth ring are comparatively larger than subsequent pores at the end of the season (or growth ring). This structure is mainly present in regions with contrasted seasons. 

Used to cover the transition between two different flooring types. Also known as threshold. 

Usually lighter in color than heartwood it is the wood near the outside of the tree.

(See bastard-sawn, plain-sawed and quarter-sawn.) 

Lumber (usually 2” x 4”) that is attached to a concrete subfloor. Provides a nailing surface for tongue and groove strip flooring or a wood subfloor.

A chemical solution that is applied to the surface of wood flooring to protect against stains and damage. Sealing may also help prevent panelization.

A separation along the grain, the greater part of which occurs between the annual growth rings.

Structural covering, usually plywood or other boards that are placed over the exterior studding or rafters. 

In hardwood cracks between boards that have developed from expansion due to excess moisture gain and loss of the moisture as it dries. Referred to as shrinkage.

A common structural element of modern buildings, consisting of a flat, horizontal surface made of cast concrete. 

Small solid hardwood pieces, which form mosaic, parquet squares.

Another name for screeds.

A spline or small strip of wood or metal. Used to reverse or change direction in installing standard tongue and groove strip flooring. 

General term that describes lumber produced from conifers. (Needle and cone bearing trees.)

Separations of wood fiber running parallel to the grain.

Wood flooring that is not tongue and groove.

Tongue and groove strips or plank flooring edges, neither eased nor beveled. 

Sections in parquet flooring, usually composed of an equal number of slats. 

A discoloration that develops in or on a floor and is other than the natural color. 

A type of fastener with two prongs, giving them extra gripping power. 

The term for shadowing or discoloration that occurs randomly on milled maple flooring as a result of lumber stacking that does not allow regular and even evaporation of maple sap prior to milling.

See Mineral Streaks 

Solid boards manufactured for installation in parallel rows. 

Structural unit used as supporting element in walls and partitions. 

The structural layer resting directly on the joists. 

Additional support to prevent deflection of subfloor systems from heavy loads imposed by bleacher systems, portable backstops, thresholds, etc. 

Used to cover the transition between two different flooring types. Also known as saddle. 

A joint made by a milled tongue on one edge of a board fitting into a corresponding milled groove on the edge of another board. 

A cover that tops the gaps that are incorporated into floors to provide for expansion and contraction. Also used to transition from the edge of a floor to doorways. 

Finish materials such as molding and baseboard.

A material used between the laminate flooring and the subfloor (e.g., foam padding).

A wood product that requires sanding and a finish application after installation. 

The “V” shape created between tongue and grove boards with chamfered edges when they fit together. (Also called V-Groove). 

A material with a high resistance to vapor movement, such as foil, plastic film, or specially coated paper that is used to control condensation or prevent migration of moisture.

A material that reduces the rate of water vapor movement.

Any distortion of a piece of flooring from its true plane that may occur in seasoning.