Wood Floor Hardness Rating

admin — Mon, 27 Jul 2009 05:28:40 +0000

Not all wood flooring is created equally. Wood hardness, as measured by the Janka scale, tells you whether a species of wood is appropriate for a house with 4 year-olds and elephants…or for slippered old folks!

In any case, you should protect your wood floor by laying down area rugs, keeping long-clawed animals out, and asking people to remove their shoes.

It’s interesting to note that some hardwoods are softer than so-called softwoods!

WOOD SPECIES	RATING UNIT*
Douglas Fir	660
S. Yellow Pine, Shortleaf	690
S. Yellow Pine, Longleaf	890
Black Cherry	950
Teak	1000
Black Walnut	1010
Heartpine	1225
Yellow Birch	1260
Oak, Red Northern	1290
Beech, American	1300
Ash, White	1320
Oak, White	1360
Cypress, Australian	1375
Hard Maple	1450
Wenge	1620
Bamboo, Timbergrass	1642
African Pedauk	1725
Hickory	1820
Pecan	1820
Purpleheart	1860
Jarrah	1910
Merbau	1925
Santos Mahogany	2200
Mesquite	2345
Brazilian Cherry	2350
Brazilian Walnut	3800

*The rating unit is determined by firing a .444 inch steel ball halfway into the wood being tested. A higher number means harder wood; lower number, softer wood.

Wood Floor Terms

admin — Mon, 27 Jul 2009 05:25:51 +0000

The wood flooring industry has some terms that are particular to their field:

Clear

The highest appearance and grade of wood. Clear means that the wood may have some minor characteristics, but only very minor. These characteristics might include tiny knots. Largely, the wood is considered to be as perfect as possible.

Close Grain (or Closed Grain)

Finely and closely arranged wood grain fibers.

Common

The lowest grade and appearance; lower than clear or select. This type of wood has the most amount of knots, wormholes, flags, and other characteristics.

Grade

The quality of the wood: i.e., clear, select, or common.

Janka Hardness Test

A unit that indicates the force needed to embed a .444 inch steel ball halfway into the piece of wood being tested. The harder the wood, teh higher the number. For example, Brazilian Cherry is very strong, at a 2350 Janka; Douglas Fir is very soft at 660 Janka.

Grain

The arrangement of the fibers of the wood.

Open Grain

Large pores and widely spaced fibers in the wood’s grain.

Plank

Wood flooring in widths of 4 inches or greater.

Pre-Finished

Fast becoming the norm, pre-finished wood floors are already sealed (usually with polyurethane) and in some cases, stained.

Select

A lower grade and appearance than clear. Select may have some characteristics such as knots or wormholes. Note that, with the right type of wood, select characteristics can be considered a desirable mark of distinction rather than a defect.

Specie

A fancy word for the type of wood: i.e., ash, beech, oak.

Strip

Wood flooring in the more common widths of 3 3/4″ or less.

Sub-Floor

An underlayment, such as 3/4″ plywood, that is installed under an existing finish flooring to provide stability for that finish flooring.

Tongue and groove

Found in strip. plank, or parquet flooring. On the edge of one piece of floor is a protruding piece called a “tongue.” On the edge of a different piece of floor is a cavity into which the tongue will lock. This cavity is called the “groove.” It is similar to the way a Zip-Loc bag works.

Unfinished

Essentially, raw wood with no type of stain or sealant. You will need to seal before using.

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