C - E wood flooring terms

C
Chatter marks - slight, closely spaced indentations causing a ripple effect on the surface of a wood floor - usually caused by sanding machines that have out-of-balance drums or bad drive belts.

Check - a lengthwise separation of the wood that usually extends across the rings of annual growth and commonly results from stress set up in wood during air-drying or kiln drying.

Chipping - occurs when a dried film of finishing material separates from the underneath surface in the form of flakes or chips. It is usually caused by insufficient elasticity or improper adhesion to the base material.

Color change - visual changes in the color of the wood species caused by exposure to light, deprivation of light and air, or some chemical reaction.

Coniferous - see softwoods.

Crazing - minute, interlacing cracks or checks on the surface of a dried film of finishing material.

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.

Cross-directed - laying material perpendicular to the material below it.

Cross pull - a condition occurring at an end-joint with the ends of flooring strips pulled in opposite directions.

Crow footing - a species of crystallization (see 'Checking') wherein the lines come together at a central point.

Crowning - individual strips with the center of the strip higher than the edges - the opposite of 'cupping'.

Cupping - a concave or dished appearance of individual strips with the edges raised above the centre - the opposite of crowning.

Cure - to change the properties of an adhesive by chemical reaction (condensation, polymerisation, vulcanization etc) and thereby develop maximum strength. Generally accomplished by heat or a catalyst.

D
Damp proof membrane (DPM) - a sheet polythene used under floors to keep moisture at bay.

Deciduous - see 'Hardwoods'.

Delamination - the separation of layers in a laminate floor, through failure of the adhesive or between plies, or between layers of stain and/or coating.

Diffuse-porous woods - hardwoods in which the pores tend to be uniform in size and distribution throughout each annual ring, or to decrease in size slightly and gradually towards the outer border of the annual growth ring. Hard maple is an example.

Dimensional stability - the ability to maintain the original intended dimensions when influenced by a foreign substance. Wood is hygroscopic (readily takes up moisture) and isn't dimensionally stable with changes in moisture content below the fiber saturation point. Engineered wood flooring, however, is more dimensionally stable than solid wood.

Distressed - a process used to give a lived in look. Various techniques are used to create surface damage, dents, scratches and imperfections to edges and face. Boards are then finished with oil to soften defects and give the appearance of a well worn, though not necessarily period, floor.

Drier - a catalytic material added in small amounts that improves the drying or hardening properties of oils or varnishes. Usually organic salts of lead, cobalt, manganese, zinc and iron, such as naphthenates, resinates and linoleates.

Durability - the ability of a wood species or finish to withstand conditions with which it comes in contact, without an appreciable change in appearance.

E

Eased edge - the chamfered, or beveled edge, of strip flooring, plank, block, and parquet at approximately 45-degree angle. Eased edge is considered to be less of an indentation than beveled edge flooring - see 'Beveled Edge'.

End joint - where two pieces of flooring are joined together end to end.

End lifting - swelling of the top layer of engineered wood flooring, occurring at an end joint.

End matched - a male projection milled on one edge of a strip, plank, slat or unit to be engaged with a female counterpart on an adjoining unit. See 'Side-Matched' and 'Tongue & Grooved'.

Engineered - a multi-layered wood flooring board comprising a surface veneer of real timber (approximately 3.6 - 4mm) bonded to a central softwood core and a counterbalancing backing of softwood. All layers together produce a 14mm thick board. Various width options available.

Equilibrium Moisture Content (EMC) - the moisture content at which wood neither gains nor loses moisture when surrounded by air at a given relative humidity and temperature.