Stair Terminology

We believe in education and transparency.  Here you will find the definition of most specific terms associated with staircases.


8070 – Standard 1″ Round Bullnose Tread


8071 – Retro-Fit Treads – replacement treads for stair renovations. Usually 1″ treads with a 5/8″to 3/4″ thickness with a round bullnose


8072 – Eased Edge Bullnose 1″ with a 1/8″ radius stair tread


8073 – Retro-Fit Treads, 1″ Eased Edge bullnose with a 3/4″ thickness for stair renovations.




Burl– A system of rails, newels, balusters, panels, screen or other ornamental components used to separate two areas. Balustrades used to minimize falls from elevated walking surfaces and the sides of stairs are also guards. A swirl or twist of the grain of the wood that usually occurs near a knot, but doesn’t contain a knot.


Character Marks– Naturally occuring marks in the wood, such as burls, flags and flecks, that give a unique appearance.

Check– A lengthwise separation of the wood that usually extends across the rings of annual growth and commonly results from stress

Crook– The distortion of a board in which there is a deviation, in a direction perpendicular to the edge, from a straight line from end to end of the piece.


Degrades – Wood flooring that is not of the grade being inspected. Also called “outs.”


Engineered Wood Flooring – An assembly made by bonding layers of veneer or lumber with an adhesive.


Figure – Inherent markings, designs or configurations on the surface of the wood produced by the annual
growth rings, rays, knots and deviations from regular grain.


Figure Skip – An interruption in the finish on the wood flooring


Flag – A heavy dark mineral streak shaped like a banner.


Flag Worm Hole – One or more worm holes surrounded by mineral streak


Flecks – The wide irregular, conspicuous figure in quartersawn oak flooring



Heavy Streaks – Spots and streaks of sufficient size and density to severely mar the appearance of wood.


Honeycombing  – Checks often not visible at the surface that occur in the interior of a piece of wood,  usually along the wood rays.



Knots – The portion of a branch or limb that has been surrounded by subsequent growth of the stem. The shape of the knot as it appears on a cut surface depends on the angle of the cut relative to the long
axis of the knot. In hardwood strip flooring, small and pin knots aren’t more than one-half inch in
diameter. A sound knot is a knot cut approximately parallel to its long axis so that the exposed section is
definitely elongated.



Medullary Rays – Strips of cells extending radially within a tree and varying in height from a few cells in
some species to four or more inches in oak. The rays serve primarily to store food and transport it horizontally in the tree. On quartersawn oak, the rays form a conspicuous figure, sometimes referred to as

Mill Run (Run of the Mill)  – Flooring that is milled from one grade of lumber, without being further separated by flooring grades.

Milling Defects  – Blemishes produced in milling flooring, such as chipped grain, torn grain, variation in machining, machine burn and mismatching.

Mineral Streak  – Wood containing an accumulation of mineral matter introduced by sap flow, causing an
unnatural color ranging from greenish brown to black.


Pin Worm Hole  – In hardwood flooring, a small round hole not more than 1⁄16-inch in diameter, made by a
small wood-boring insect.


Run / Lot Number  – Finish or packaging numbers used to identify wood flooring.


Shake – Separation along the grain, the greater part of which occurs between the annual growth rings.

Split – A separation of wood fiber running parallel to the grain.

Sound Wood – Wood that will crate a usable floor, and therefore not including soft wood due to rot, loose pieces that will fall out, or splits throughout the piece.