In 1906 a wood scientist from Austria by the name of Gabriel Janka created a scale that can determine the hardness of various woods. In the USA this scale was officially recognized in 1927 by the American Society for Testing and Materials. A breakthrough in woodworking and flooring, this scale has helped tons of manufacturers and buyers in making the right decisions. However, the Janka scores shouldn’t be considered as absolute truth. The scale only shows how hard a wood is, it doesn’t stand for its strength or durability.
The Janka hardness scale can seem confusing to some, but this feeling will immediately go away after you read this short Q&A. Here are the most common questions about the Janka Scale and the best given answers:
HOW ARE THE RATINGS DETERMINED?
The scale and the ratings it shows are determined by a very easy and simple test. Since the time of Janka, the testing involves a piece of wood and a steel ball. Experts only need to place a 0.444″ steel ball on a 2″x2″x6″ wooden plank. Afterwards, they measure how much force is needed (pound per square inch, PSI) for the ball to go halfway into the plank. The more force needed, the softer the wooden piece is.
WHAT DOES THE SCALE LOOK LIKE?
Just like the testing, the scale is really simple to understand. It starts from 0 (representing the softest) and ends at 4000 (representing the hardest material). There isn’t a wooden piece out there that scores 0 on the Janka Hardness Scale since this means that that piece of wood has literally no hardness or ability to avoid dents and scratches. A score of 4000 on the other hand is completely possible, but these planks are extremely hard to cut and adjust.
CAN IT MEASURE EVERY TYPE OF WOOD?
The short answer is: no! Firstly, for a wooden piece to be tested it must have a flat grain. Planks with vertical grains can be tested, but the results won’t be accurate and usually aren’t shown on the Janka Scale. Secondly, some types of wooden materials such as engineered wood has softer layers in its design and are therefore excluded from the Janka scale.
WHAT ARE GOOD RATINGS AND WHAT ARE BAD?
The Janka hardness scale only represents the ability of a wooden piece to withstand wear & tear. It doesn’t stand for the wood’s durability or any type of other resistances such as those to moisture, mold, or insects. A good Janka rating can be from 900 to 5000, but it will only rate the wood’s ability to resist scratching and denting.
The worst scores on the Janka scale are currently held by Balsa wood which rates at 100. This is why this type of wood is only used for small craft projects. For a wooden plank to be used as a flooring material, it should score at least at 900.
DOES ENGINEERED WOOD HAVE A LOW RATING?
As we mentioned before, engineered wood cannot be measured and rated according to the Janka scale. Engineered wood is completely man-made which makes it impossible to get one rating that will be applicable to all products out there. Even though this applies to all types of wood (the manufacturing process determines the quality), it is most evident in engineered or man-made wood.
The layers of soft wood which can be found in engineered wood are put there with a reason and are a part of its initial and groundbreaking design. Logic tells us that the more layers of softwood means a softer wood, but with engineered wood this isn’t that simple. Point being: do not focus on the Janka scale when shopping for man-made hardwood flooring.
IS OAK A GOOD OPTION ACCORDING TO THE JANKA SCALE?
Red oak scores at 1260 on the Janka scale while white scores at 1360. This fact draws away many buyers from purchasing oak for their new hardwood flooring. But, oak’s quality doesn’t depend only on its Janka ratings. As mentioned before, these ratings are worth nothing if you treat your floors poorly. Oak has a lower score than other materials, but it will provide you with tons of benefits if you show it proper care.
ARE THERE ANY WOODS THAT HAVE SCORES AROUND 4000?
Yes, there are! Bamboo and Eucalyptus can have scores from 3800 to 5000. These exotic materials are the strongest when it comes to avoiding wear and tear, but this doesn’t necessarily mean that you should instantly buy them. Strand woven bamboo is one of the best materials out there, but it will give a high performance only if you treat it with the needed care and respect.
ARE HIGH RATED WOODS MORE EXPENSIVE?
The Janka hardness scale, however valuable it may be, doesn’t determine pricing. You will find how some woods with high scores on the Janka scale are much less expensive than those with low scores. This is because price is influenced by trends and availability.
So woods that are easier to find (being more available for manufacturers) tend to be cheaper. That is the main reason why oak is cheaper, not having anything to do with its ratings on the lower spectrum.
SHOULD I AVOID BUYING WOODS WITH LOW RATINGS?
Lower Janka rating only means that the wood will be more prone to wear and tear. So yes, if you have a house with lots of heavy furniture and kids frequently running around the house, it is recommended that you purchase a material with higher Janka ratings.
HOW IMPORTANT IS THE JANKA HARDNESS SCALE?
Truth is, the quality of your new hardwood flooring will mostly depend on how it is treated. Buying bamboo won’t provide you with an eternal, all-resistant new floor. For the material to achieve maximum results, it must be properly manufactured and maintained.
The best thing you can do to assure your new floor is of highest quality is to choose the right manufacturers and installers. Apart from ratings, the installation process also determines end results. The Janka scale is a great indicator and guide, but don’t discourage yourself from buying oak or cedar if you are truly in love with these hardwood flooring materials.