Hardwood Flooring Hardness Rating

The Janka, or "side," hardness rating of wood floor is a relative measurement of resistance to impact and wear. It gives prospective flooring buyers a good idea of the wood's durability. This is obviously very important for matching flooring material to its intended application. Higher levels of foot traffic would require a more durable wood species and thus one with a higher Janka rating.

The Janka test basically involves measuring the amount of force, in pounds per square inch (psi), required to embed half the diameter of a 0.444-inch steel ball into the face of a wood sample. Of course, several tests are performed to find the proper amount of force, and then a series of tests are averaged to determine the rating. Technically, the average includes samples of tangential (plain-sawn) and radial (quarter-sawn) material.

If you are a do-it-yourselfer, there is another point you need to keep in mind about the hardness of wood. The harder the wood, the more difficult it will be to saw or nail. Unless you have top-of-the-line equipment and a lot of wood flooring experience, you may not want to select the species with the highest Janka rating. Picking a softer wood would be easier to work with, but it does have its drawbacks. Being softer, it will certainly dent much easier and possibly scratch easier, depending on the finish. All it takes is one step from a shoe with a pebble stuck in the sole, or a step with a spike high heel, and you have instant floor damage.

The higher the number the harder the wood, this should only be used as a general guide when comparing various species of wood flooring.