How Is Hardwood Flooring Hardness Tested?

The hardness of your wood floor is determined primarily by the hardness of the species of wood you chose. That hardness is rated on the janka hardness scale. It measures somewhere between 100 and 4000, with 4000 being the hardest. There are several imported woods that come close to being around 4000 but they’re almost impossibly difficult to work with. They’re very dense and hard or very brittle. They don’t make the best floors. Domestic woods such as red and white oak typically rank about 2,000 on the hardness scale.

How Is it Tested?

In 1906, an Austrian researcher named Janka invented a test for the hardness of wood. He devised a test in which a steel ball 0.444 inches in diameter is placed on a piece of wood about two inches thick. Force is then applied directly onto the steel ball until it sinks 50% of its diameter into the wood. The amount of pounds of force required to sink the steel ball halfway into the wood is the janka hardness rating of the wood. For example, balsa wood, a very soft wood used for crafts, only requires about 100 pounds of force to sink the steel ball. It’s the softest wood on the scale. Ipe, or Brazilian walnut, require about 3,684 pounds. The median is generally considered to be red oak at 1,290.

It is a commonly available wood and generally about in the middle of the distribution of hardnesses.

Does it Matter?

The hardness of your wooden floor does matter. If you have a red oak wooden floor, it will be sufficiently hard to withstand most pressures of life. However, the wood can get scratched. The wood can get scratched by sharp things such as your pet’s claws or sliding a piece of furniture. Also, it can be dented or scratched by weight. Red oak withstands 1,290 pounds of force over 0.444 inches. However, it starts denting much sooner than that. The weight you place on a pair of stiletto high heels could be enough to dent a wood softer than red oak. If you drag your feet, it’s enough to scratch even red oak if it’s not properly finished.

A good finish will be absolutely crucial to keeping your hardwood floor in good shape. Also, choosing a wood that is at least in the thousands on the hardness scale is important. Anything around 1,300 is easy to work with and very resilient to scratching.

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