Flooring Glossary
As you are exploring Twenty & Oak, you will come across plenty of terms which may be unique to the flooring industry. We have cross-referenced these terms from our Education and Inspiration articles to our Glossary for added assistance during your selection process.
Common Flooring Terminology Explained
Acclimation
This is the process of bringing the temperature of a product up or down to closely match that of the environment where it is being installed, before installation, and is typically 24-48 hours. This is especially important for hardwood flooring since it is a natural product and movement is expected as seasonal temperatures fluctuate. Other types of material may be brittle when exposed to long-term cold temperatures, and you may have an installation disaster if the material is not brought to room temperature. These products have various acclimation time requirements, depending on the construction. Regardless of the product, your installer should carefully follow manufacturers’ recommendations regarding acclimation time.
Backing
The layer beneath a flooring surface that offers structure and support. Common in carpet and vinyl.
Bevel Edge
Edges of planks that are slightly angled to highlight individual board appearance after installation.
Ceramic Bead Overlay
Microscopic ceramic particles suspended in a clear liquid overlay for superior wear resistance. *
*Reference: Metroflorusa.com
Character
The natural visual interest in a hardwood floor. This can include any or all of the following: natural color variations, random grain patterns, and knots.
Click and Lock
A DIY-friendly installation method where planks snap together, similiar to a tongue and groove hardwood floor, without glue or nails. Often found in laminate and luxury vinyl flooring.
Core
The center layer of a floor plank. Types include SPC (Stone Plastic Composite), WPC (Wood Plastic Composite), and HDF (High-Density Fiberboard).
Cup or Crown
The natural result of expansion or contraction of hardwood material when exposed to uncontrolled climates, especially water. Solid Hardwood that has become wet and has cupped or crowned will eventually move mack to its original form once moisture has been removed and the wood has dried over a period of time.
Distressing
Various methods, using hand tools or machinery, create chatter marks and other markings on hardwood to create a time-worn visual. Distressing is created on laminate and vinyl floors using embossing technology.
Durability Rating (AC Rating)
A 1–5 scale used to measure laminate flooring’s resistance to abrasion. AC4 or AC5-rated floors are ideal for active homes with heavier traffic including pets or children.
Edge Treatments
Also described as a beveled edge where the edge of floor planks are eased and/or beveled on side edges and/or ends that help hide minor irregularities, such as slightly irregular subfloors. Usually preferred over “square edges,” this treatment is present either as a 2-sided or 4-sided bevel on various plank and tile collections. However, square edges make seams less visible, and with hardwood can make a refinishing process a little easier.
Embossed in Register (or In-Register Embossing)
An embossing (stamping) process that produces texture which actually follows the pattern in the design image on a non-natural product, such as vinyl. This technology adds ultimate realism to achieve the look and texture of a natural wood or stone material. For example, Beauflor's waterproof flooring collection.
Engineered Hardwood
Dimensional stability is achieved with multiple layers of cross constructed wood veneers with the stained specie of choice on the top. The cross-layer construction of the veneers is designed to reduce expansion and contraction.

Floating Floor
Floating floors are designed so that when the floor is installed the flooring pieces are not nailed or glued down, but instead rest on top of an underlayment.
Gauge/Mil
Referred to in “mils,” the gauge is the overall thickness of a product, such as sheet vinyl, vinyl planks and tiles, and rigid core products. Not to be confused with a millimeter, a mil is equivalent to one thousandth of an inch, and is a manufacturing measurement term. For engineered hardwood the wear layer is measured not in mil's but millimeters. See Wear Layer and Wear Layer for engineered hardwood terms below.
Gloss Level
The level of polyurethane coating as it relates to the amount of light that it will reflect. Matte, low gloss, semi-gloss and high gloss are all relative terms to the gloss level of any type of hardwood or vinyl flooring.
Grain
The pattern in wood or wood-look floors. It can be straight, spiral, or interlocked.
Janka Hardness Scale
The Janka hardness test measures a wood species' resistance to denting and wear by determining the force needed to embed a steel ball half-way into the wood's surface. This force, measured in pounds-force (lbf), is the Janka score. Higher Janka scores indicate harder and more durable wood.
Examples:
- Ipe (Brazilian Walnut): 3680 lbf
- Hickory: 1820 lbf
- White Oak: 1360 lbf
- Red Oak: 1290 lbf
- Pine: 400 lb
Laminate Flooring
Laminate flooring is a multi-layered, synthetic floor covering that simulates the look of natural materials like wood or stone. It's made by bonding several layers together, including a high-density fiberboard core, a design layer with an image, and a protective wear layer. Not to be confused with Luxury Vinyl Plank (LVP) or SCP (Stone Composite Plank) where all three may have similiar visual appearances from above but have varying constructions underneath.
Luxury Vinyl Plank (LVP)
A durable flooring material that mimics hardwood but is waterproof and easy to install. Luxury vinyl plank (LVP) flooring is a multi-layered, composite flooring material designed to mimic the look and feel of hardwood, while being more affordable and easier to maintain. It's composed of individual planks that are installed similarly to real wood, often with a click-lock or glue-down system. LVP is known for its water resistance, durability, and ability to withstand wear and tear.
Moisture Barrier
A moisture barrier for flooring is a layer placed beneath the flooring material to prevent moisture from rising from the subfloor and damaging the flooring. It acts as a shield against water vapor, liquid, or condensation, protecting the flooring from issues like warping, mold, and mildew. Typical applications of moisture barriers are in rooms where the subfloor is on ground concrete like basements or first floors. Products are plastic films or setting materials that act as vapor barriers. Areas like crawl spaces that have high humidty can casue moisture problems, especially for hardwood floors.
Plank Width
The horizontal measurement of each plank. Wider planks can make rooms appear larger. On Twenty and Oak you can search hardwood products by the products width.
Resilient Flooring (AKA Vinyl Flooring)
Resilient flooring is a type of floor covering that offers comfort and bounces back from compression. It's defined as anything that isn't made from textile, wood, stone, ceramic, or concrete. Essentially, it's a hard surface that provides some give and flexibility underfoot. Resilient flooring is a general term for flexible floor materials like vinyl, linoleum, and rubber.
Rigid Core
Providing many of the durability attributes of a true waterproof product, this material is in the format of a dense, solid polymer core (SPC) or a light-weight foam expanded polymer core (WPC). Dent resistance, dimensional stability, warmth and softness are varied, according to the construction of this core and/or the presence of a pre-attached pad.* Examples are Palmetto Road's Impact and Inspire collections, and Beauflor's Pure collection.
*Floor Covering Weekly, Lauren Moore, March 19, 2018
Scraping
The top surface of each hardwood flooring plank is randomly scraped, by machine or by hand, to create a distressed design that adds visual interest. Laminate or vinyl products are also available with this visual, mimicked with embossing technology.
Scratch Resistance
The ability of flooring to resist surface damage from foot traffic, pets, or furniture. For scratch-resistant flooring, consider tile (ceramic or porcelain), laminate, and luxury vinyl plank (LVP). Tile, particularly porcelain, is known for its hardness and resistance to scratches. Laminate and LVP offer durable wear layers that help protect against scratches.
Screen and Re-Coat
The protective urethane is removed from a hardwood finish through a sanding process and a new coat of urethane can replace scratched, worn surfaces for a fresh, renewed look. This process can be achieved on any solid or engineered hardwood floor that has a thick enough wear layer.
Solid Hardwood
A solid plank of lumber that is milled to a uniform thickness and width. Solid floors are best installed over a flooring system with a well ventilated crawl space. Solid Hardwoods are not recommended to be installed over concrete sub floors.

SPC (Stone Plastic Composite)
Stone Plastic Composite (SPC) flooring is a type of vinyl flooring with a rigid core made of stone powder (typically lime) and PVC plastic, making it durable and waterproof. It's designed to mimic natural wood or stone, but offers benefits like water resistance and dimensional stability. SPC flooring is a popular choice for areas prone to moisture, like bathrooms and kitchens.
Subfloor
Usually a plywood or particle board product, this is the layer of floor that sits on top of floor joists when a structure is built on a crawl space. The quality of this product is often relative to the performance of the chosen floor covering.
Surface Treatment
Distressing, scraping, wire brushing, sawmarking, and antiquing are all examples of surface treatments. These are achieved on hardwood either by hand or by machine, and by embossing technology on other types of flooring. Any of these textural treatments add visual interest, can conceal wear or scratching, and add realism to the design. A combination of these treatments are offered in several collections, which enhances these attributes. Examples of combined treatment products are the Riviera collection and the River Ridge collection, both by Palmetto Road.
Tongue and Groove
The molded edges of hardwood or vinyl planks designed to create a locking system where one side of the flooring plank fits into another to form a tight seal. The tongue and groove conceals shrinkage and achieves a flush installation.
Underlayment
A product that is laid between the subfloor (or concrete) and the chosen floor covering to ensure certain performance attributes. Moisture issues, subfloor imperfections and sound can all be improved with various types of underlayment manufactured for these purposes.
UV Cured Urethane with Aluminum Oxide
A poly urethane coating is applied over the stain on a hardwood plank, and cured with ultra violet lighting. For increased durability and protection, Aluminum Oxide (a naturally derived mineral) is added. The combination results in a hardwood floor that can carry a 25 to 50-year finish warranty.
Wire-Brushed Finish
Each hardwood plank is run through machinery that applies a wire brush to the surface, removing the softest grain of the hardwood. This creates visual interest, increased durability and will also conceal scratches on hardwood. Laminate and vinyl flooring are also available with this added visual, which is achieved with embossing technology.
Wear Layer
Usually the second layer from the top, in a vinyl or rigid core construction, this layer performs against wear, rips, tears, gouges and indentations. The surface of this layer is covered with a finish that protects against scratches, scuffs and stains. 12 mil+ is ideal for residential use.
Wear Layer – Engineered Hardwood Floors
Also referred to as the “face,” this engineered hardwood layer is the stained specie of choice, with cross layers of veneers underneath. Ranging usually from 1 millimeter to a little over 4 millimeters, the thickness of the wear layer can determine price range and warranty longevity. For example,
Veranda's Charleston collection has a 4 mm wear layer, all of
Somerset's engineered collections have a 3 mm wear layer and
Hearthwood collections offer 1.5 and 2.5 mm options.
In Hardwood Floors the wear Layer is the top layer and it's thickness affects your ability to sand and refinish your floors. Recommended
engineered hardwood wear layer thickness for sand and refinish is 4mm and no less than 2.5mm per NWFA, the National Wood Flooring Association.
Photo Credits: iStock