Hardwood floors can last for decades, even centuries, under the right circumstances. Or they can need refinishing – or worse yet, replacing – in a relatively short period of time. So how can you make sure that the wood flooring you choose will provide beauty and utility for years to come?

Although virtually all wood will scratch, some wood is much more resistant to scratching and other wear. One of the most important aspects determining wear is the hardness of the wood.

Wood hardness is evaluated using a measurement called the Janka Scale. It measures how much force it takes to press a .444” steel ball into the wood until it reaches half its diameter.

This calculation translates into a number that represents the pounds per square inch of force required to embed the ball. Most often, the ball is pushed into the side of the plank, resulting in a measurement of the “side hardness.” But sometimes, the end of the wood is also tested. The result of this measurement would be “end hardness,” which is obviously less important for wood flooring.

The results are expressed differently in different countries, so if you’re comparing results, make sure they’re all stated the same way.

The higher the number, the greater the wood’s ability to resist dents and other wear. It also indicated how hard the wood will be to saw and nail. Some wood that would be great in terms of wear would be very difficult to install. So if you’ve chosen extremely hard wood for your floors, you may want to leave the installation to a professional.

There are several other factors that affect wear, especially if you’re using engineered wood flooring. The thickness of the top layer, the material used in the core, and the direction of the grain will all make a difference.

The more traffic you expect in a room, the higher the Janka rating you should consider. With a Janka score of 690, Southern Yellow Pine is not a great choice for high-wear areas. A high-heeled shoe, dog paw, or pebble stuck in a sole could easily damage a pine floor.

Red Oak, the most popular American wood flooring, has a Janka score of 1290. And it’s durable enough to work well in most situations. If you need something more wear resistant, hard maple scores 1450. It’s used for basketball courts and bowling alleys. Santos Mahogany scores 2200; Brazilian Cherry scores 2345; and Brazilian Walnut scores 3680.

Although there are exceptions, the harder woods are often more expensive.

Understanding the Janka Scale and the importance of hardness in wood flooring will help you select a floor that performs beautifully in your home.

Read more about hardwoods here.