Janka Ball Hardness & Hardwood Floor Durability

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Dear Rob: I have three very large dogs and two kids. I was told not to put in hardwood floors because it will get scratched, but if I did, I should go with a really hard wood. How do I know how hard a wood is?

-Darlene D. from Oklahoma City, Oklahoma

Dear Darlene: With three dogs and two kids, your floors will certainly take some abuse, but you can minimize the damage and extend the life of your floor with a harder wood. The harder a wood is, the less susceptible to denting and scratches it will be. Although more expensive than oak, many of the South American Hardwood like Brazilian Cheery (Jatoba), Brazilian Teak (Cumaru) and Brazilian Walnut (Ipe) are incredibly hard woods and would certainly hold up better to your lifestyle.

Wood hardness is calculated by using the Janka Ball Hardness Test. So, to determine how hard a wood is, all you have to do is look for the Janka Hardness of that species of wood.

The Janka Ball Hardness Test measures the force required to embed a 11.28 millimeter (0.444 inch) steel ball into wood to half its diameter. This method was chosen so that the result would leave an indentation 100 square millimeters in size. It is one of the best measures of the ability of a wood species to withstand denting and wear. It is also a good indicator of how hard a species is to saw or nail.

The Janka Ball Hardness Test ranks hardness in a range from about 350-3800. The most common hardwood used for flooring in the United States is Red Oak which has a relatively low hardness of 1250. The Janka ranking for Red Oak is 1290, whereas Brazilian Cherry has a Janka of 2350, which is nearly double that of Red Oak. That means that you can reasonably expect much more durability from Brazilian Cherry than that Red Oak. It’s important to not however, that no matter how hard the wood you choose is, the finish can still be scratched or worn under heavy use. There are certain finishes that are more durable, and will also help extend the life of your floor, but that is a topic for another post.

Now the downside to this is that the harder a wood species is, the more expensive it usually is. Red Oak is very common, readily available, and inexpensive. People staying in their homes for a long time will benefit from the upgrade to a harder wood as it will add value to the home, help their home sell faster in the future, and most importantly, the harder floors reduces will reduce the cost of maintenance, as the floor will need to be sanded less often. A softer (cheaper) floor may be less expensive up front, but it will need to be sanded more often, which shortens the life of the floor and costs much more long term.

Below you find a short list of common wood species and their hardness:

Wood Flooring Species

Hardness

Ipe / Brazilian Walnut / Lapacho

3684

Cumaru / Brazilian Teak

3540

Strandwoven Bamboo

3200

Brazilian Cherry / Jatoba

2350

Hickory / Pecan, Satinwood

1820

Rosewood

1780

Merbau

1712

Highland Beech

1686

Wenge, Red Pine

1630

Zebrawood

1575

Natural Bamboo (represents one species)

1380

Australian Cypress

1375

White Oak

1360

Ash (White)

1320

American Beech

1300

Red Oak (Northern)

1290

Heart Pine

1225

Carbonized Bamboo (represents one species)

1180

Brazilian Eucalyptus / Rose Gum

1125

Black Walnut

1010

Teak

1000

Black Cherry, Imbuia

950

Southern Yellow Pine (Longleaf)

870

Southern Yellow Pine (Loblolly and Shortleaf)

690

Douglas Fir

660

-Rob

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