Wood Flooring Glossary of Terms

A | B | C | D | E | F | G | H | J | L | M | P | Q | R | S | U

Like most other industries, wood flooring has some very specialized terminology and technical terms used to describe the methods and tools of the trade. Here are some of the most important terms you are likely to encounter on this Web site.


- A - undefined

Acclimation - letting flooring adjust to the environment in which it will be installed. This is crucial to prevent excessive expansion or contraction due to humidity in the air or other job conditions.

Accent Strip - a strip of wood flooring used in contrasting color to the rest of flooring. Can be used around the edges of a room, around a fireplace, or other features in order to highlight a specific area.


- B - undefined

Belt Sander - almost the same machine as a drum sander. Differences are that instead of being directly driven by a belt and pulley with a slotted drum, it is driven by an overhead spindle and has no slotted drum. However, some machines have both. The main advantage of a belt sander is that it uses belts — continuous loops of sand paper — thus in theory leaving fewer chatter marks.

Bird's Eye - a character found in maples. Very appealing, but relatively rare and expensive.

Border - a decorative inlay of different colored woods assembled in a pattern around the perimeter of a room or rooms. Flooring is used to fill in and around the border, commonly called the "field."

Buffer - a walk-beside sanding machine used for fine sanding, commonly called "screening."

Bull Nosing - a plank of wood with a curved edge. Normally used at the tops of stairs or edges of an upstairs catwalk. Makes a nice finished edge for flooring.

Butt Joint - where the ends of boards meet together in a wood floor.


- C - undefined

Cupping - the uplifting of the edges of flooring due to excessive moisture.

Curling - the end result of what happens to flooring when it was sanded when the moisture was still too high in the wood. When the flooring dries out, the edges curl downward, causing crowning in the center of the boards.


- D - undefined

Digs - a term used by floor refinishers for edger gouges.

Door Jamb Saw - a specialty tool for undercutting door jambs, cabinets, etc. Makes for a professional look. Drum Sander - a walk-behind sander used for sanding large areas. Many run on 220V power. Uses cut sheets of sandpaper on a cylindrical, slotted drum.


- E - undefined

Edger - small but powerful disk sander used for sanding areas that a drum sander can't reach. Difficult to master. Engineered Flooring - layered flooring designed for stability with a thin hardwood layer on the surface.

Expansion - wood floors expand and contract with different humidity levels, so it is paramount that at least 3/4 inch be left by the edges of walls to allow for this movement.


- F - undefined

Flooring Nails - sometimes referred to as "cleats," these are special nails used in a flooring nailer. They are either "L" or "T" shaped.


- G - undefined

Grade - wood flooring is sold in specific grades. Select is the best, with no knots and a very uniform color. Number One Grade has some small knots, dark streaks, and imperfections. Rustic — or Tavern Grade as it is sometimes called — has lots of knots, worm holes, and many color variations. There are also smaller classifications among these grades.

Grain Raise - the lifting of wood surface fibers due to moisture in the application of finish.


- H - undefined

Heartwood - wood from the interior portion of a tree. Generally darker in appearance and harder than sapwood.


- J - undefined

Joint Staggering - this term is self-explanatory. It is an important part of professional floor laying, and results in a tight and appealing-looking floor.


- L - undefined

Lambs Wool Applicator - floor finish applicator used on a pole for coating large areas.

Lap Marks - refers to marks left from a brush or lambs wool applicator when finish is not applied evenly, or sometimes when climate conditions are not ideal.


- M - undefined

Medallion - a decorative design of parquet flooring assembled in the center of a room or in a high-visibility area. Many come factory-made, but they can be custom-made as well.

Medullary Rays - striations that appear in some wood species when quartersawn. These are usually visible in oak with a golden color.

Mill Marks - marks left on the flooring surface from the factory. Some manufacturers are better than others, which require little or sometimes moderate sanding.

Moisture Content - how much water or humidity is absorbed into the flooring.

Moisture Meter - a meter that is used to check the amount of moisture in wood. This is done to make sure flooring is not too wet or dry, thus preventing excessive expansion or contraction.


- P - undefined

Peeled Veneer - engineered wood flooring with peeled veneer is generally cheaper than sawn veneer flooring. It is made basically by peeling a log on a large lathe to produce a thin layer of wood for the flooring surface. Underneath that are layers of other woods sandwiched together at different angles to promote stability.

Plain Sawn - the normal sawing process by which most flooring is produced.

Prefinished - flooring that is factory-finished. No sanding or finishing is necessary after installation.


- Q - undefined

Quartersawn - a log that is cut into four pie-like sections. Sections are then sawn perpendicular to the growth rings. This results in vertical grain which is more stable and beautiful than plain sawn wood flooring. In some species like oak, medullary rays are clearly visible.


- R - undefined

Radiant Heat - a heat source that is installed under finished flooring. Flexible tubing is installed in concrete or under the subfloor. Heated water is fed through the tubing, thus warming the flooring surface. This type of heating is relatively new to many contractors and builders. Great attention should be paid to wood flooring choice and installation procedures if radiant heat is desired.

Random Width - wood flooring that is laid in a pattern of different widths.

Rift - a sawing technique similar to quartersawing, except the saw angle varies slightly. This process produces vertical grain which is more uniform in appearance and also more stable.

Rosin Paper - pink paper that is laid down on top of the subflooring before installation of the wood floor itself to prevent squeaks.


- S - undefined

Sandscreens - carbon-tipped mesh used on a buffer as a finish sanding to even out the smoothness of a floor. Also used between coats to smooth grain raise and to promote adhesion of coats.

Sapwood - wood that is new growth on a tree. Normally it is softer than heartwood.

Sawn Veneer - refers to engineered wood flooring. It means that the top layer of wood is actually sawn. This is better than peeled veneer. It looks better, is more stable, and generally can be sanded, depending on the manufacturer.

Solid - wood flooring that is not engineered. Comes in varying widths and thicknesses.

Species - refers to the type of tree from which wood flooring is made.

Square End - refers to how flooring is made and sold. Some flooring comes with the ends of the boards already squared. Others (mainly unfinished flooring) have to be cut by the installer. Prefinished flooring normally comes either square end or square-microbeveled end.

Squaring Up - term for starting the first row of flooring parallel and perpendicular to walls in order to have the floor run in a straight line to the opposite wall.

Staining - to apply a wood stain to alter a wood floor's appearance and color.

Stop Mark - a gouge that is left when the operator stops moving as a drum or belt sander is running. Normally caused by amateurs, rarely seen when professionals do the work.

Subfloor - underneath floor upon which finished flooring is laid. We recommend 3/4-inch CDX plywood for nail-down applications.


- U - undefined

Unfinished - flooring that must be sanded and finished after installation.