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Wood Flooring Glossary





Above Grade

Any floor lying on above ground surfaces.

Acrylic Impregnated

Acrylic is injected into the wood’s cellular structure to increase hardness and strength.

Acrylic Urethane

A urethane solution made with acrylic to produce the same benefit as a polyurethane coating.


Glue used to secure tongue and grooved boards together. Certain adhesives may expand as they dry to fill the bond between the subfloor and flooring, to avoid a hollow sound when the floors are walked on.

Aluminum Oxide

A chemical agent added to the urethane finished used to seal wood floors. It is typically added to increase resistance to abrasion, wear, and tear on a higher grade floor.



Below Grade

Any cement slab lying below ground ready for a flooring surface to be attached.


A grade of oak: high quality featuring few knots and little to no dark graining.

Beveled Edge

Products with a beveled edge have an easily identifiable groove in them. These types of floors are typically used to pull off a country or informal look to a room. When the floors are installed, the bevels are sealed so dirt, dust, and grime are easily removed during cleaning.


During high humidity times of the year, excessive moisture in the air will cause the wood to swell and cracks to vanish. When the wood dries and shrinks, it may warp and buckle.




A grade of oak: high quality featuring no visible knots or graining. This grade of oak is very expensive.

Click-Lock Planks

Wood floor planks that can be snapped together using a series of steps. While these are easier to install than other methods, these planks cannot be taken apart once they are put together.

Cross-Ply Construction

Cross-ply construction comes from planks of engineered hardwood flooring being placed on top of each other in alternating directions. This results in a more dimensionally-stable flooring, not as easily affected by moisture when compared to a 3/4″ solid wood floor. This type of construction does not expand and contract with changes in humidity, and it is versatile because it can be installed anywhere in a home, including over concrete slabs.


Warping that occurs when the sides of the boards are higher than the center.



Damp-Proof Membrane (DPM)

A plastic sheet that serves as a moisture barrier to help prevent warping. DPMs should be used when wooden boards or laminate flooring is laid over a concrete or sand and cement floor. Visqueen Heavy Duty DPM is the professional grade option.



Eased Edge

Also known as micro-edge beveled, this type of edge on a wood plank is used to hide small irregularities in the boards. It may be applied to the length of the board, as well as the joints of the board.


Engineered wood flooring is one of three types of wood flooring. They are typically made with anywhere from two to five plies of wood compressed together to form a plank. Most of these types of floors can be installed in a number of ways including: nail down, glue down, floated over other floors, or stapled down.

Expansion Gap

This is the 10 to 12 mm gap left around the edge of the floor to allow for natural expansion and contraction as wood swells when humidity is high.



Finish in Place

Finish in place refers to wood floor installations that are finished in the home. The wood is installed, sanded, finished, and coated with a urethane protectant. The floor finished can be screened and reapplied to revitalize the look of the floor.

Floating Floor Installation

A floating floor installation occurs when the wood floor is not attached to any subfloor. Instead, the wood floor is attached to a pad used as a barrier between the floor and the subfloor. The pad serves as a moisture barrier, reduces noise when walked on, and is more comfortable on the feet. Not all wood floors can be installed using the floating method, so it is important to ensure the floor you choose will work this way.



Glue Down

This refers to a wood floor installation method. The planks are glued to the subfloor using an adhesive. Not all types of wood floors can be installed using a glue-down method.


All wood species have grain patterns based on how they are cut. There will be natural variations in color and graining as no two pieces of wood are ever the same.



Janka Hardness Test

This is the test to determine how hard (and less likely to damage) the wood is. It is determined by the amount of force required to insert a .444 inch steel ball to half its diameter in a piece of wood.




This is a cross-section of the area of a tree where the branch joins the trunk. It is generally darker in color.




Laminate is a type of flooring material developed to mimic the look of many different materials including wood and stone.

Long Strip Plank

Long strip plank is one of the three types of wood flooring. Similar to engineered wood floors, it is made by compressing plies of wood together to make the individual planks. It uses a soft core, and attaches a variety of hardwood surfaces to the top to provide the appearance of real hardwood flooring. When the planks are damaged, they are easily replaced.



Moisture Cured Urethane

A specific type of urethane finish that requires moisture in the air in order to cure and finish.


Are used to cover expansion joints and to enhance the performance and appearance of the hardwood floor. In many cases, moldings and baseboards need to be removed for hardwood installation.



Nail Down

This is a wood floor installation method used on solid wood floors. The method works on floors of a certain thickness, and adaptations are available for thinner planks.

Number 1 Common

A grade of oak: featuring more knots and more dark graining.

Number 2 Common

A grade of oak: featuring knots and more dark graining.




Flooring installed on the same plane as the level ground around it.




This refers to the size of the boards used to make a wood floor. Thinner width pieces are referred to as “strips.” The wider width pieces are referred to as “planks.” The planks are available at random lengths ranging anywhere from one to seven feet in length.


A clear protectant applied to the top of a finished wood floor to help prevent wear, tear, and damage.

Pre-Finished Wood Floor

These floors have already been sanded and finished at the manufacturer’s plant and are ready for installation out of the box. Pre-finished floors typically have a stronger protective finish as several coats of polyurethane are sprayed on during manufacturing.

Pull bar

A tool used to secure planks together tightly at the tongue and groove joints. The tool is helpful at the edges of a room when using a tapping block is not available.



Registered embossing

This technique produces a 3D laminate plank to mimic the appearance of a real wood floor. The core is raised or reduced at key points in the patterns so you get the look and feel of a natural wood floor.

Rotary Cut

Rotary cut displays a wider array of the natural graining of the wood, with a more bold appearance.




Used to level uneven floors, screed is a liquid latex solution spread over a floor and hardened to create a level flooring surface for the installation of a wood floor.


A grade of oak: featuring few knots and little dark graining.

Sliced Cut

Sliced cut displays a more uniform graining and color pattern than rotary cut.


Solid refers to one of the three types of wood flooring.

Solvent-Based Urethane

This is an oil based urethane finish used to protect floors from damage, wear, and tear.

Square Edge

This refers to the edge of the board, all finished squarely to fit together uniformly and create a smooth finish.

Stapled Down

Similar to the nail down method, the staple down method staples the wood planks to the subfloor.


This refers to the size of the boards used to make a wood floor. Thinner width pieces are referred to as “strips.” The wider width pieces are referred to as “planks.” The planks are available at random lengths ranging anywhere from one to seven feet in length. There are several species used to create strips.



Tapping block

This is a plastic block used to protect the planks and strips from damage as they are tapped into place with a hammer. This block prevents the hammer from coming into direct contact with the piece of flooring.

Tongue and Groove

Tongue and groove refers to a specific joint method for wood floors to come together. One edge has a tongue, while another edge has a groove. The tongue and groove fit together to install the floor in a room. The tongue on one plank fits snuggly into the groove of the next plank.




An underlay serves as a sheet of protection between the subfloor and the floor. There are several different types and grades of underlays available. They often serve as a moisture barrier, and an insulator to lessen noise from walking on the floors.

Un-Finished Wood Floor

An unfinished wood floor gives more user control over the finished look of the floor. The wood is installed in a home, then sanded and finished to match decor preference, then sealed with a protective urethane coat. A variety of species of wood and finishes are available.


Cured factory wood finishes that are cured with ultraviolet light instead of heat.



Water-Based Urethane

This is a water based urethane finish used to protect floors from damage, wear, and tear.

Wedges and spacers

These tools are used to maintain the expansion gap around the edges of the flooring during installation. Wedges and spacers are also valuable to make a straight edge against a wobbly wall to start the floor installation off right.

(2) Comments

  1. I don’t understand what the rating system is for vinyl flooring. for example: 5mm. What is the 5mm pertaining to? Is that the thickness?

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