Glossary
There are specialized terms referring to all sorts of aspects of prefinished wood flooring, Here are the most frequent.
Annual growth ring
The layer of wood growth, including spring and summerwood, formed on a tree during a single growing season.
Check
A short, narrow, shallow separation of the wood, perpendicular to the annual growth rings. May be located in the centre or at the ends of boards.
Character marks
Natural “imperfections” in the wood such as mineral streaks, knots and coloration that give the product its unique appearance.
Engineered wood flooring
A floor made up of a hardwood surface bonded to a substrate.
Grade
The classification of flooring strips based on the natural color and character marks in the wood (mineral streaks, knots, etc.). The grade refers to the appearance of the product.
Gloss
The gloss level or luster of a surface is determined by the amount of light it reflects. A glossy surface reflects more light than a matte surface.
Heartwood
The part of the tree between the pith and the sapwood. It is usually darker than the sapwood.
Hardwood
Generally, one of the botanical groups of deciduous trees that have broad leaves in contrast to the conifers of softwoods. The terms have no reference to the actual hardness of the wood.
Janka hardness
A hardness test measuring the force required to drive a 0.444" (11.3 mm) steel bearing half its depth into the wood. The more force required, the harder the wood. Red Oak is the industry benchmark for comparing the relative hardness of different wood species.
Knot
The portion of a branch embedded in the wood. There are several types of knots, including sound and open knots.
Micro V-joint
The 45° angle at the junction between the surface and the side of the flooring strips when they are laid side by side. The result is a small “V” shape, whence the name “V-joint.”
Mineral streak
A general term describing a pigmentation in the wood. This coloration appears in the form of a streak or stain ranging from greenish brown to jet black.
Open knot
A knot that is open in the centre; it is often filled with wood putty.
Pith
The soft-surfaced core of a tree trunk or branch.
Pin knot
A tiny sound knot, less than 1/8" (3.2 mm) in diameter.
Relative humidity
The ratio of the amount of water vapour present in the air to the amount of water that can be held by that air at a given temperature.
Rays
The cellular structure of the tree extending from the outer part of the tree toward the centre (perpendicular to the annual growth rings).
Sapwood
The part of the tree located near the outside of the trunk, between the heartwood (duramen) and the bark. It is usually of a lighter color than the heartwood.
Split
A lengthwise separation of fibres resulting from natural, environmental and/or mechanical pressures. May be at the end of a board or on the surface.
Wood oxidation
A natural phenomenon by which the color of wood changes
after exposure to air and ambient light. This change varies depending on the
species.