Hardwood Flooring Glossary

There are a number of terms that you may hear or read when shopping for or learning about hardwood floors. Here's a list of some of the most common words, and their definitions, that should make the entire process easier for you.

Above Grade - Any floor that is above the level of the surrounding ground on which the structure is built.

Acrylic Impregnated - Wood that has had acrylic monomers injected into the cell structure to give increased hardness and then finished with a wear layer over the wood.

Acrylic Urethane - A slightly different chemical make up than Polyurethane with the same benefits.

Aluminum Oxide - A chemical added to the urethane finish for increased abrasion resistance of the wear layer, which is becoming extremely popular on the better grade wood floors.

Below Grade - A cement slab poured below the level of the surrounding terrain.

Better - A quality of oak. Better Oak has some small knots and very little dark graining.

Beveled Edge - These products have a very distinctive groove in them. Beveled edge planks lend themselves to an informal and country decor. With the urethane finishes applied at the factory today, the beveled edges are sealed completely, making dirt and grit easy to be swept or vacuumed out of the grooves.

Buckle - The raising of hardwood floors, often at the joints, that can occur due to expansion caused by high humidity.

Ceramic - Advanced technology that allows the use of space-age ceramics to increase the abrasion resistance of the wear layer.

Clear - A quality of oak. Clear Oak has no visual blemishes or knots and is extremely expensive.

Cross-Ply Construction - Engineered wood plies that are stacked on top of each other but in the perpendicular direction is called cross-ply construction. This construction creates a wood floor that is dimensionally stable and less affected by moisture than a solid wood floor. Cross-ply construction allows the plies to counteract each other, stopping stop the plank from growing or shrinking with the changes in humidity. The other advantage for you is versatility. You can install these floors over concrete slabs in your basement as well as anywhere else in your home.

Cupping - A type of warping with a concave condition; the sides are higher than the center.

Eased Edge (also known as Micro-Beveled Edge) - Each board is just slightly beveled. Some manufacturers add an eased edge to both the length of the planks as well as the end joints. Eased edges are used to help hide minor irregularities, such as uneven plank heights.

Engineered - Engineered wood floors are generally manufactured with 2, 3, 5 or more thin sheets or plies of wood that are laminated together to form one plank. Most engineered floors can be nailed down, stapled down, glued down, or floated over a wide variety of subfloors, including some types of existing flooring.

Finish-On-Site (also known as Finish-In-Place) - Unfinished hardwood is installed in the home and then sanded, stained and coated with 2-3 coats of urethane finish.

Floating Floor Installation - An installation method where the floor is not mechanically fastened to any part of the subfloor. A thin pad is placed between the wood flooring and the subfloor. Then a recommended wood glue is applied in the tongue and groove of each plank to hold the planks together.

Glue Down - An installation technique where the recommended mastic or adhesive is spread on with a trowel to adhere the wood flooring to the subfloor. (Engineered wood floors and parquets can be glued down. Solid strip floors and plank floors cannot.)

Graining - Each wood species has its own unique graining and texture. The graining on the boards is determined by the way it has been cut. Natural variations in the color and grain are normal and to be expected.

Janka Hardness Test - This wood hardness rating test measures the force needed to embed a .444 inch steel ball to half its diameter in a piece of wood. The higher the number the harder the wood.

Knot - On a piece of wood, the round, harder, usually darker in color, cross section of where the branch joined the trunk of the tree.

Laminate - Laminate is a manufactured product that simulates the look of hardwood, ceramic tile, natural stone and many other types of flooring.

Long Strip Plank -Long Strip Plank floors are similar to Engineered floors and have several wood plies that are glued together. The center core is generally a softer wood material and is used to make the tongue and groove. A hardwood finish layer is glued on top of the core. The top layer can be almost any hardwood species and is made up of many smaller individual pieces that are laid in three rows. This gives the effect of installing a board that is 3 rows wide and several planks long. Long Strip floors come in a wide variety of domestic and exotic hardwood species and when damaged they are easy to replace.

Moisture Cured Urethane - A similar chemical make up as solvent-based urethanes, but this finish needs the humidity (moisture) in the air to cure.

Moldings - Moldings 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 method for installing hardwood floors is typically used with the 3/4" solid products. However, there are adapters available for thinner flooring sizes as well. 2" nailing cleats are used with a wood flooring nailer and mallet to attach the flooring to the subfloor.

Number 1 Common - A quality of oak. Number 1 Common Oak has more knots and more dark graining than "Better."

Number 2 Common - A quality of oak. Number 2 Common Oak has more knots and more dark graining than "Number 1 Common."

On-Grade - A cement slab that exists on the same plane as the surrounding terrain.

Plank - Wider boards for hardwood flooring.

Polyurethane - A clear, tough and durable finish that is applied as a wear layer.

Pre-Finished Wood Floor - Hardwood boards that have already been sanded, stained and finished at the manufacturing plant. In many cases this can provide a harder, better- protected surface.

Rotary Cut - A cutting process that displays a larger and bolder graining pattern.

Select - A quality of oak. Select Oak has some small knots and very little dark graining.

Sliced Cut - A cutting process that shows a more uniform pattern.

Solid - Solid wood floors are one solid piece of wood that have tongue and groove sides.

Solvent-Based Urethane - A polyurethane finish with oil used as part of the chemical make up.

Square Edge - The edges of all boards meet squarely creating a uniform, smooth surface that blends the floor together from board to board.

Stapled Down - An installation technique where 1-1/2 to 2 inch staples are used versus nailing cleats to attach the wood flooring to the subfloor. A pneumatic gun is used to drive the staple into the wood flooring and subfloor.

Strip - Narrower boards for hardwood flooring. The most common wood species used for solid strip floors are red oak, white oak, maple, cherry, white ash, hickory or pecan.

Tongue and Groove - The joining of two boards, one board having a tongue on its edge that fits into a groove in the edge of the other.

Trim - See Moldings.

Un-Finished Wood Floor - See Finish-On-Site.

UV Cured - Factory wood finishes that are cured with Ultra Violet lights versus heat.

Water-Based Urethane - A polyurethane finish with water used as part of the chemical make up.