What is a Janka Rating?

Wood has been used to build structures for centuries. While it’s used in a variety of products today and can be found in the walls of your home or deck, certain species make an excellent floor covering. Hardwood flooring is still one of the best options for homeowners today, but not all wooden flooring is equal from a durability standpoint.

Whether you are considering installing solid hardwood or engineered hardwood flooring in your home, you should consider durability. Homes with heavy foot traffic or large pets can experience issues rather quickly with the wrong type of wood. That’s why understanding the Janka rating is critical when shopping for hardwood flooring, and we’re going to explain what a Janka rating is and tell you how some popular species stack up on the scale.

The Janka Hardness Test

Named after its inventor, Gabriel Janka, the Janka Hardness Test is a way to determine how durable a species of wood is. This, in turn, allows manufacturers to decide which types of wood are suitable for hardwood flooring. While the test is not something you can perform on your own, it’s simple to comprehend.

This scale measures how much force is needed to drive a 11.28-millimeter steel ball into a sample of wood halfway. In most cases, the sample used in testing is a 2” x 6” and will be at least 6 to 8mm thick. While wood can be tested in many different forms and results can read in different ways, the scale makes things simple for consumers to understand.

Janka Scale Ratings

The first thing to remember about the Janka Rating scale is the fact that not every wood is suitable for flooring. While it may be tempted to look for the species with the highest rating, it could be more trouble than it’s worth – if it’s even available.

Exotic species are harder than domestic species and cost more. Many species are harvested from rainforests as well, which isn’t the best option if you want an eco-friendly flooring alternative. Bamboo flooring is an exception to that rule, but it’s also technically a grass… not a tree.

Availability can be an issue with exotic species, but so can installation. There is a significant difference between the hardness of Oak and Curupay, which will make the installation process more difficult for yourself or any contractors involved as well.

With that in mind, here’s a small sample of the Janka scale featuring some popular domestic species along with exotic options. Different countries use different standards, but our table uses lbf, which is pounds of force and represents the U.S. standard.