What is the Janka wood hardness scale?
The Janka hardness test is an industry wide standard applied to all wood. The test itself measures the force required to sink a .444 inch steel ball halfway into the wood. This force is generally far more than a wood floor would endure during the course of daily use.
The Janka wood hardness test is a good indicator of how prone a particular wood species is to denting, wear and other damage. The Janka rating is also useful in determining whether a wood will be difficult to work with. The harder the wood, the harder it is to saw and nail, which is important for the installation process.
The Janka wood hardness scale goes from 0 to 4000 and the number assigned is the result of the previously described test. Red oak, with its rating of 1290, is used as the benchmark for comparison of the other species. The higher a number is on the Janka hardness scale, the harder the wood is. A lower number indicates a softer wood.
The rating assigned to a particular species is an average. As with any other product from nature, the wood used for flooring is all unique. There is some slight variance in hardness within a species that can depend on factors like where the wood is harvested and how it is cut.
Hardwood, softwood and exotic hardwood
Hardwood species are deciduous trees native to North America that have broad leaves, produce some kind of fruit or nut and go dormant in the winter. These trees are plentiful and make up almost half of the trees in the U.S. The most common hardwood is oak and it is by far the most popular for flooring. Other popular hardwood species include maple, birch, ash, hickory, walnut and American cherry.
Softwoods, or conifers, have needles instead of leaves and produce cones that contain seeds. These trees are also native to North America and very common. Softwoods are not as popular as hardwoods for flooring use, but are used extensively for other purposes. Pine flooring is the most popular and is readily available. This softwood species is also considerably cheaper than many others used for flooring. Other softwood species include spruce, fir, redwood and hemlock.
Exotic hardwoods, also called tropical hardwoods, are not native to North America. This hardwood is imported for use in the U.S. from South America, Africa and Asia. Many of these species are native to the rainforests and some are now raised commercially. Exotic hardwood is usually extremely hard. Popular exotic hardwoods used for flooring include Brazilian cherry, mahogany, teak and tigerwood.
Generally, domestic hardwood species have a higher Janka hardness rating than softwoods. Also, exotic hardwood species have a higher Janka rating than domestic hardwoods, but there is some overlapping in these categories.
Why is the Janka wood hardness rating important?
While the Janka hardness rating is likely not the most important factor in your decision, it should be considered. For example, American cherry is a softer hardwood with a Janka rating of 950. This softness means American cherry is more prone to damage than some other hardwoods like oak.
Alternately, Brazilian walnut is one of the hardest woods, with a Janka rating of 3680. Extremely hard woods don’t have as much flexibility to accommodate temperature and humidity changes. Without as much flexibility, these hard woods can be prone to splitting in dry climates. Situations like these can affect how happy you are overall with your flooring choice.
The professionals at Gowdy Flooring can answer all your hardwood flooring questions. Give us a call at (806) 353-6226 or browse our website to see our flooring choices and services. You can also connect with us via e-mail. Visit our showroom and office located at 5205 S. Coulter St. in Amarillo, Texas.