The Janka hardness test, which applies to solid hardwood versus engineered hardwood, measures how resistant wood is to scratches, dents, and normal wear. The results of this test help fabricators determine if a piece of wood is suitable enough to use as flooring in either a residential or commercial setting.
The Janka test has become the standard method of testing for the entire hardwood flooring industry worldwide. Testing yields pinpoint accurate results that professionals and consumers throughout the flooring industry can rely on.
The purpose of the test is to develop a measurable scale that ranks the hardness of wood (more on that below).
Researchers take a 0.444” (11.28 millimeters) steel ball and use air pressure to force it into a piece of wood. The objective is to force the steel ball halfway into the wood plank. How many pounds per square inch (PSI) of force required for the ball to go halfway into the wood determines the Janka Hardness Score.
Since the hardness of the wood varies with the direction of the wood grain, researchers use two types of tests to generate a score:
The Janka Hardness Scale ranks the hardest to the softest wood based on the wood’s hardness score. The score or measurement is stated in pounds-force (lbf). Thus, the higher the score, the harder the wood substance.
Below are some examples of common hardwood flooring and the Janka Hardness score of each. All of these values are from The Spruce’s article on the subject.
3684 - Brazilian Walnut
2350 - Brazilian Cherry
2345 - Mesquite
2200 - Santos Mahogany
1820 - Hickory
1360 - White Oak
1320 - Ash
1290 - Northern Red Oak
1260 - Yellow Birch
Experts recommend investing in flooring that has a score of at least 1,000 lbf or higher, but wood runs the gamut as far as strength goes. You can go way overkill or end up with a solid hardwood flooring that’s far too flimsy to suit your needs—which is why it’s important to know your woods!
For instance, Australian Buloke has an incredibly high Janka Hardness Score of 5,060 lbf, as per The Wood Database. Wood this strong far exceeds industry suggestions for flooring. On the opposite end of the scale, Balsa wood has a score of 67 lbf, also per The Wood Database. Thus, it falls well below flooring industry standards.
As important as this measurement is for determining the suitability of wood for a project, it’s not the only piece of information that needs to be taken into account. The Janka Hardness Scale gives insight into only a wood’s physical strength; it doesn’t by any means show all the characteristics of a given species. This means that other factors, like water resistance or lack thereof, very well can come into play.
When you’re purchasing hardwood, it’s critical to take the wood’s entire profile into account, not just how it measures up on the Janka Hardness Scale. Though it does indeed give a look into a species’ physical strength, it’s by no means comprehensive.
Paradoxically enough, solid wood flooring comes in two overarching categories: hardwoods and softwoods. These names can be misleading in terms of a wood’s placement on the Janka Hardness Scale! It’s not always the hardwoods that come out on top, and it’s not always the softwoods that get beat out.
According to Mainly Woodwork, categorizing these woods has nothing to do with how hard or soft they may be, but the type of tree that they come from. “Hardwoods are deciduous,” claims the site, “which means that they seasonally shed their leaves and regrow them. Softwoods are evergreen and stay green all year round. The names… do not correlate directly to the hardness or density of the wood.”
Generally speaking, hardwoods do tend to be a little tougher from a Janka standpoint, though there are more than enough exceptions to warrant caution. When choosing a wood flooring species, don’t take its category as an indicator of how strong or weak it is. Instead, look up the exact Janka score. Not only will this give more accurate information than any generalization ever could, but it will also show you where your potential wood species stands in relation to others you’re considering.
To learn more about choosing a species of hardwood for your floor, check out our blog on the subject!
Are you looking for the perfect flooring to complete your home design? E Hardwoods & Flooring offers natural hardwoods, engineered wood flooring, solid prefinished wood flooring, vinyl plank flooring, and vinyl tile flooring through our eCommerce store—all of which are nothing less than top-notch!
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