Hardwood Flooring Glossary

A

Above Grade

This term indicates a flooring installed above ground level, with a minimum of 18 inches of well-ventilated space.

Abrasion

This is a term which refers to the wearing away at a hardwood floor finish.

Acclimation

Acclimation points out to the hardwood’s improvement to the environment it is in, in terms of moisture and humidity.

Acrylic-Impregnated Flooring

Refers to flooring which has had liquid acrylic (and stain) injected into and throughout the surface of the flooring. This adds more strength and durability.

Acrylic-Urethane

This is a clear wood finish famous for its ease of use, fast drying time, and low odor.

Aluminum Oxide

Aluminum Oxide is frequently used to finish flooring because of its strength. This serves as a hard protective coating for many hardwoods and bamboo and is second hardness to diamond.

Antique Flooring

Antique flooring uses recycled wood from buildings in order to manufacture the flooring. Either by the use of hand or machine, it is createed an antique look.

ASTM

ASTM is an acronym used for the American Standard Testing Methods.

B

Baby Threshold

Indicates a kind of molding used in areas where expansion is needed. For example, by sliding glass doors and to transition to carpet.

Baseboard

This refers to the molding installed at the base of a wall. Baseboard are designed to cover a portion of the wall and floor. It is generally seen as quarter round, though other styles are available.

Base Shoe

A type of molding created to attach to base molding to cover any expansion space.

Bastard Sawn

See “Rift Sawn”.

Below Grade

Flooring installed in below ground areas (for example basements). Solid hardwood cannot be installed below grade. Engineered hardwood care perfect for below grade installation.

Beveled Edge

Refers to a type of edge available in hardwood flooring. With a distinct and deep “v” shaped groove, the beveled edge hardwood is generally used in informal settings.

Bi-Level Reducer

This is a type of molding used to transition from a hardwood floor to a carpeted room.

Blind Nailing

Refers to the method of forcing nails into the grooves of tongue and groove flooring planks. The nail is put in at a 45 degree angle and made flush by using an electric flooring hammer. Most types of wood flooring (including bamboo) are too hard to be nailed by hand.

Border

A design technique that includes a pattern around the outside of the hardwood flooring.

Buckle

Warped and weakened hardwood resulted from excessive moisture.

Bull Nose

A type of trim installed on a wall.

Burl

A swirl or twist of the grain of the wood that generally happens close a knot, but does not contain a knot.

Butt Joint

A type of joint made by forcing two ends together. It is considered the weakest because there is no support other than glue to hold the joint together.

C

Ceramic Finish

Advanced finishing technology using ceramics in order to increase abrasion resistance.

Chatter Marks

Patterned markings on the floor caused by the use of a drum sander.

Conversion-Varnish Sealers

A type of sealer that is acid curing and resistant to stain and spotting.

Cross-Ply Construction

Engineered hardwood planks stacked on top of each other, in alternating directions. This creates a dimensionally stable flooring less affected by moisture or humidity change.

Crowning

A type of warping where the center is higher than the sides.

Cupping

Warping where the sides are higher than the center.

Cutting Method

Refers to how the solid hardwood veneer for an engineered floor is cut.

Cure

The process of allowing the finish to completely dry and reach its fullest hardness potential.

D

Dimensional Stability

The ability of the hardwood to retain its dimensions throughout its lifetime, avoiding warping, swelling and contracting in response to moisture and changes in temperature and humidity.

Distressed Hardwood Flooring

This indicates the intentional scratching, scraping and/or gouging of a flooring surface to create an antique look by hand scraping or machine use.

Drum Sander

A type of sander used in order to smooth the surface of hardwood before finishing.

Dry Solid-Sawn

A cutting method for the real hardwood veneer that is glued on the top of engineered hardwood flooring. It involves letting the wood dry out slowly with a low humidity level to keep moisture from inside the wood cells intact, reducing the risk of cupping.

E

Eased Edge

This indicates a type of edge available in hardwood flooring which is slightly shallower than a beveled edge and slightly rounded versus “v”-shaped.

Edge gaps

Distance to the wall, which has to be observed when laying hardwood flooring.

Edge Type

Refers to the edge of the sides of the strips or planks. Square edge has squared edges. Beveled, eased, micro beveled and micro beveled edges have a “v”-shaped groove which help to hide imperfections in the subfloor as well as slight differences in plank thicknesses.

Emission classification

E1 means that the formaldehyde emission limit decreed by law of 0.1 ppm (= 0.12 mg/m3 air) is observed.

End Cap/Molding

See “Baby Threshold”.

End Joint

See “Butt Joint”.

Engineered Hardwood

Wood made of a thin layer of solid hardwood glued or laminated onto a core board such as plywood or high density fiberboard to make the planks of flooring. Engineered hardwood is more dimensionally stable than solid hardwood.

Environmentally friendliness

Factors that make it easy on the environment.

Exotic Species

More expensive species of wood found outside of North America.

Expansion

Changes in dimension due to swelling and contracting of the flooring as a result of moisture.

Expansion Gap

Area of perimeter left to account for expansion.

Expansion Spacing

Amount of space left at the baseboard to allow for expansion.

F

Face Nail

A nailing technique that secures flooring to the sub-flooring by using nails perpendicular to the surface of the floor.

Finish

Wax based or urethane coating over hardwood flooring.

Flat-Sawn

Plain-sawn wood cut in long planks where the rings run parallel to the board.

Floating Floor

A type of installation that does not require the flooring to be attached to the subfloor.

Flush Reducer

Used to level the height between a wood floor and another floor surface.

Flush Stair Nose

Allows a smooth transition between the stair edge and the riser.

French Bleed

Stained edges of hardwood floor planks.

G

Gloss Level

The reflection from the finish. Standard gloss levels are satin or matte, semi gloss and high gloss.

Gloss Meter

A device used to measure the gloss level of a floor’s finish.

Glueless Click-Lock

Easy do-it-yourself installation of engineered hardwood flooring. No glue is required to install the floor.

Grade

The appearance of wood used to create the flooring, generally based on the number of visible knots and mineral streaks.

Grain

The alignment of the fibers in the wood, which designates the pattern seen on the flooring.

H

Hand Scraped Hardwood

Today’s hand scraping is usually done at the factory to give the floor an antique or vintage look. No two hand scraped floors will look the same.

Hand Sculpted Hardwood

Similar to hand scraped hardwood, but a less distressed result.

Heartwood

Heartwood is mechanically strong, resistant to decay, and less easily penetrated by wood-preservative chemicals than sapwood.

Herringbone

Hardwood installed parquet style to create a herringbone pattern.

High-density Fiberboard (HDF)

HDF is a type of core board used to make engineered hardwood. It provides more dimensional stability than plywood.

Humidity

Amount of water vapor in the air.

Hygrometer

Device used to measure relative humidity.

I

Inflammability classification

Refers to the likelihood that the flooring will not burn.

In-Floor Radiant Heating

See Radiant Heating.

Inlay

Method involving laying multiple pieces down to create a pattern inside the hardwood.

Installation Methods

Methods used to install hardwood flooring. Options include: nail down, glue down, staple down, and floating.

J

Janka Hardness

A scale which determines the amount of force it takes to drive a .444 inch steel ball into a plank of wood .222 inches in diameter.

Joist

A parallel beam used to support flooring or ceiling weight loads.

K

Kiln Dried

Wood dried with artificial heat in a controlled environment as opposed to naturally air dried.

Knot

The dark marking where the branch jointed the tree trunk.

L

Lacquer

A varnish that dries by solvent evaporation.

M

M.S.D.S.

M.S.D.S. stands for Material Safety Data Sheet, a required sheet that lists any hazardous ingredients, safety precautions, and first aid information that a consumer should know about a product.

Medallion

A design or image meant to be inlaid into a hardwood floor.

Micro Bevel Edge

A type of edge available in hardwood flooring which is similar to a beveled edge, but has a shallower “v”-shaped groove than both the beveled edge and the eased edge.

Micron Bevel Edge

A type of edge available in hardwood flooring which is similar to a micro beveled edge, but with a shallower “v”-shaped groove. It can be difficult to distinguish from a micro beveled edge.

Mineral Streak

Mineral matter left in wood by sap, generally from injury during growth.

Mixed Media

Wood flooring that also includes other elements (for example slate or stone).

Moisture Barrier

See “Vapor Barrier”.

Moisture Content

The amount of moisture in wood.

Moisture-cured Urethane

A finish which indicates the moisture in the air before curing.

Moldings

A lot of different types of moldings (aka trim and transition pieces) that are installed to give a flooring project a finished look.

N

Nail Down

An installation process requiring nails to attach the wood flooring to the subfloor.

Natural Stain

A clear finish that allows for the natural look of the wood to show.

NWFA

An acronym for the National Wood Flooring Association.

O

Oil-modified Urethane

Most common finish for wood flooring, available in various gloss levels.

Oil-Treated Finish

An oil based finish for hardwood flooring.

On Grade

The ground level of a building as it is at the same level as the surrounding ground.

One-Sided Reducer

Has one sloped side and one flushed side and is used to transition from hardwood to other flooring types.

OSB

An acronym used to describe a type of subflooring material.

Overlap Reducer

Used to transition between hardwood and carpet.

Overlap Stair Nose

Function as the finishing transition for the edge of a stair on a floating floor system.

Oxalic Acid

A poisonous strong acid that occurs in various plants and is mainly used as a bleaching or cleaning agent and in making dyes.

P

Parquet Floor

A floor installed in a manner that creates a geometric pattern (for example herringbone pattern).

Particleboard

Building material created from wood fragments (for example chips or shavings) mechanically pressed into a sheet and bonded together with resin.

Paste Wax

Used to finish floors before the arrival of lacquers and varnishes. Since it never dries to a hard finish, it does not provide great damage protection, but can be used as polish to keep floors shiny and reduce the appearance of scratches.

Penetrating Oil Sealers

These oil based sealers are spread across the floor, allowing them to penetrate the surface, offering a stain and a finish to protect it.

Penetrating Sealers

As with penetrating oil sealers, without the use of oil.

Penetrating-Seal-Treated Finish

A finish treated with a sealer, applied by penetration into the floor.

Photo Sensitivity

Refers to the likelihood a wood floor’s color will change as it is exposed to light.

Pilot Hole

A small hole drilled into a material to assist in making the larger hole the right width.

Pin Knot

A knot no larger than ½ inch in diameter.

Plain-Sawn

Making a series of parallel cuts into a log known as the easiest way to make wood planks.

Plank Flooring

Boards that are 3 inches wide or more.

Plies

Thin sheets of wood bonded together with adhesive to form plywood.

Plugs

Dowels designed to mimic the Colonial “plugged” look.

Plywood

Wooden material made by pressing together plies, or thin sheets of wood.

Pneumatic Nailer

A power nailer that uses air pressure to operate, generally used to speed the process of nail down hardwood installations.

Polyurethane

Type of finish for hardwood that does not require waxing.

Prefinished

Flooring that is stained and sealed before installation.

Q

Quarter Round

Type of trim used for vertical walls and the floor.

Quarter-Sawn

The log used to create wood floor planks is first cut into quarters and then cut into boards using parallel cuts.

R

Radiant Heating

A heating system installed below the flooring designed to improve energy efficiency in the home.

Random Length

Some flooring is sold as random length, meaning that the boards are not all the same length.

Random Width

Some flooring is sold as random width, meaning the boards are not all the same width. Typically, the each box of random width flooring is comprised of boards of 3 or more different widths.

Reclaimed Wood

Wood that is salvaged from an old building or structure or from a lake or river and refinished for use in another project.

Recoat

See Screen & Recoat.

Reducer

Used to join wood floors to other flooring surfaces.

Refinish

The practice of sanding down a wood floor and finishing it again, to reduce the appearance of damage, wear, and tear.

Repairs

Replacing sections of hardwood with new material to avoid having to sand and refinish the entire floor.

Resistance to staining

Allows an insight as to how the wood flooring will resist staining when subjected to a number of potential staining agents.

Rift-Sawn

Cutting a log into boards that ensures each board has the same relation to the log, providing the same grain pattern. This is the most stable lumber. Also referred to as Bastard Sawn.

Rotary-Peel Cut

Refers to a cutting method used to create a solid hardwood veneer for the top layer of an engineered hardwood floor. It involves boiling the log for a certain amount of time at a certain temperature to prepare the wood.

S

Sapwood

The wood near the outside of a tree which it is softer and lighter in color than heartwood.

Scratch resistance

Allows an insight how the laminate flooring will behave, when scratched. This is a very important quality criterion, which is derived from scratching the flooring with a diamond tipped instrument.

Screen & Recoat

The practice of adding another top coat of polyurethane to improve appearance of the floor, after abrading it slightly (using a mesh screen) so that the finish adheres better.

Sheen Level

See “Gloss Level”.

Shellac

A resin substance secreted by female lac bugs. Used to form a cocoon, the resin comes from India and Thailand. Processed as dry flakes, it can be added to denatured alcohol to create a liquid.

Shoe Molding

A type of molding that is humidity resistant and ideal for high traffic areas in a home.

Site Finished

The opposite of prefinished, unfinished hardwood is installed and then finished on site.

Sliced-Peel Cut

A cutting method used to create a solid hardwood veneer for the top layer of an engineered hardwood floor. It involves boiling the log for a certain amount of time at a certain temperature to prepare the wood.

Small Knot

A knot in the wood that is not over 1/2″ in diameter.

Solid Hardwood

One piece made from lumber, unlike engineered hardwoods which use other materials to form the planks.

Solvent Based Urethane

Uses an oil chemical base rather than water in the floor finish.

Sound Knot

A knot with an exposed section which appears elongated.

Species

Types of trees. Many species are available such as oak, pine, cherry, and hazelnut.

Spline

Also known as “slip tongues” these are used to reverse or change the direction when installing tongue and groove hardwood flooring.

Square Edge

The edges of the floor boards flush together to decrease the appearance of lines between boards. This creates a uniform and smooth surface and gives the room a contemporary, formal feel.

Square Nose

Trim used along the walls of floating floors.

Stain

Discoloration of flooring other than its natural color.

Stair Nose Molding

Used for transition when placing plank or strip on stairs, landings or step downs.

Strip Flooring

Thinner boards of wood, smaller than planks, 2 ¼” wide.

Stud

Support structure for walls and flooring.

Subfloor

A support surface below the flooring, such as plywood or concrete.

Surface-Sealed Finish

A finish which also serves to seal the wood to protect it, applied directly to the surface without penetration.

Swedish Finishes

See “Conversion-Varnish Sealers”.

T

T-Molding

A molding piece that finishes the space between two areas of wood.

Thickness

Refers to how thick the planks of hardwood flooring are.

Thin Profile Solid

Thin piece of solid wood.

Threshold

See “Baby Threshold”.

Tongue and Groove

Refers to the profile construction milled to the panels’ sides allowing the panels to be pushed together.

Transitions

Moldings used to transition from hardwood to another flooring type.

Trims

See “Moldings”.

Tung Oil

A type of oil used to finish wood. It is extracted from the seeds of the tung tree.

U

Underlayment

The layer of material that is laid loosely between the sub-floor and and the main flooring. It serves one or more of the following functions: vapor barrier, padding, sound barrier and/or insulation.

Unfinished Wood Floor

Flooring that has not been pre-finished at the factory. It has to be finished after installation.

Universal Edge

A transition used to join hardwood to carpet.

Urethane

chemical solvent used to seal and finish wood floors.

UV-Cured

Cured with UV light rather than heat.

V

Vapor Barrier

Type of underlayment that protects the flooring from moisture coming from the subfloor (e.g. a concrete subfloor).

Varnish

A finish containing oils with a slow curing time that can be decreased by heat.

Veneer

A thin layer of real, solid hardwood glued to the top of a core board to create an engineered wood floor.

W

Wall Base

See “Baseboard”.

Warping

See “Buckle”.

Water Based Urethane

Solvent which contains water.

Wax

See “Paste Wax”.

Wear Layer

See “Veneer”.

Whitewash

A cost effective finish option, a type of paint that takes a long time to cure.

Wire Brushed

The way to distress wood flooring by machine in order to achieve an antique look.

Wood Movement

The expansion and contraction of wood due to moisture content.