Hardwood Rating System and Why It Is Important

Janka Wood Rating for Common Species
Courtesy of Build Direct

When building a new home or renovating the floor of an existing property, you want the best floor in the market. However, the wide range of choices available can decide to narrow down your choices overwhelming. There are many flooring options, and if you decide to install a hardwood floor, there are still many types of hardwood species available. Luckily you are not alone. In this article, we will discuss the Janka hardwood rating system  (wood hardness scale). The rating can help you to select the perfect flooring type for your residential or commercial property.  

Janka wood Hardness Scale

The Janka Hardness Scale is an essential tool that determines the hardness of wood and its ability to withstand wear and tear. Developed in 1906 by Austrian wood research Gabriel Janka, later, in 1972, the American Society for Testing and Materials (ASTM) standardized it. Noteworthy, wood floors are natural. Therefore, the Janka rating measures the qualities inherent to the particular tree species. It is used as a hardness standard for durability in different species of wood.

The rating is calculated based on the amount of force required to lodge a 0.444-inch steel ball up midway through wood planks. The higher the Janka rating, the harder is the species of wood. The system measures a wood’s capacity to withstand damage and to dent.

The Janka Rating Industry Standard

Red oak is the most popular flooring option in the flooring industry. It is used as a standard of comparison with other woods because it has a median Janka rating of 1290. Red oak is used as an industry standard because it is neither too soft nor too hard, but just right. It is also abundant in the USA. 

Why the Janka Rating System is Essential

There are hundreds of wood species in the world. The Janka rating system has classified all or most of these woods from the hardest to the softest. Therefore, it is easier to know what functions suit a certain wood tree species. Out of the many tree species, only a few are suitable for use in the flooring industry.

For wood floors, any Janka rating higher than 950 is suitable for flooring. But again, you have to consider other factors when choosing a flooring wood species. You can compare red oka hardness with other tree species. Here is the Janka Hardness rating for some popular hardwood used in the flooring industry:

Janka Ratings of Common Flooring Hardwood

  • Brazilian Cherry 2350
  • Hickory 1820
  • Hard Maple 1450
  • White Oak 1360
  • Red Oak 1290
  • Yellow Birch 1260
  • Black Walnut 1010
  • Black Cherry 950

Besides that, the hardness rating of hardwood also reveals certain features about the wood, namely, the workability, durability, and cost.

Workability of a Hardwood

Builders use the Janka rating system to determine how easy or difficult it is to cut and nail a wood species. Floor installation for hardwoods with a high Janka rating like hickory is harder than softer wood like red oak. For example, Brazilian walnut has a Janka rating of 3684. It has high shock resistance and durability. However, to work with it best, woodworkers predrill it for screwing.

Durability and Sturdiness of Hardwood

Contractors and homeowners can use the Janka hardwood rating system to know which wood suits their flooring or furnishing needs. The scale classifies wood depending on its density, revealing how much the wood will hold up against wear and tear like denting and scratches. The higher the Janka rating, the more resistant the wood is to wear, dents and scratches. For example, high traffic areas or homes with pets and children should opt for flooring options with higher Janka ratings.

Cost of Hardwood

Most hardwoods with a high Janka rating take decades, if not hundreds of years, to grow and mature. As such, they are more expensive than softwoods. The charges for installing them are higher because they require more effort to nail and cut, which takes a longer period, pushing their installation costs up.

Wood Stability Test

Apart from the Janka rating system for measuring the hardness of hardwood, stability is another method of wood grading. Stability indicates the level of wood expansion when exposed to varying humidity. After harvesting, some woods have to be dried longer while others have to be acclimatized before installation, depending on their stability. While red oak is stable, hickory and maple are not stable because they take in moisture quickly.

Conclusion

When selecting a wood type, you can use various variables. You can use the natural color of the wood, the stability of the wood, its hardness, and costs to determine your preference. To know the hardness of wood for your flooring project or any other wood-related project, you should use the Janka Rating System. It shows the relative hardness or softness of woods.