A method of measurement in hardwood lumber. It is useful to find the overall volume of wood in a slab or board. One board foot is the equivalent to a 12″ x 12″ square x 1″ thick piece of wood. All slabs and lumber here at Nature’s Board Room are listed in sizes of board feet, and are priced “per board foot”.
A simple formula for calculating board feet would be to multiply the length (in inches) x the width (in inches) and dividing by 144. Now take that figure and multiply by the thickness (in inches)
For example, a wood slab that measures 24″ wide x 96″ long x 2″ thick would be 32 board feet in size.
24 x 96 = 2,304.
2,304 ÷ 144 = 16.
Multiply 16 x 2 (our thickness in inches) = 32 board feet.
So this slab would be 32 board feet in size.
Similarly, a 12″ wide x 12′ long x 1″ thick board would be 12 board feet.
The Janka scale:
In the description for each species you’ll find a “Janka hardness” rating specified in lbs.
Janka hardness rating is the industry standard in comparing lumber “hardness” from one species to another.
Janka Hardness: The amount of force in pounds (lbs) required to imbed a .444″ diameter steel ball into the wood to 1/2 the ball’s diameter. This number is based on wood that has been dried to 12% moisture content.
The Janka rating determines how well a species will withstand dents/dings and wear – and helps determine the difficulty nailing, screwing, sanding, or sawing that species will be. Woods like Eastern White Pine (380 lbs on the Janka scale) are known for their soft structure and therefore are on the lower end of the Janka scale. The USS Constitution, fittingly named “Old Ironsides” for it’s ability to withstand direct hits from cannons, was made from Live Oak which is one of the hardest woods in North America with a Janka rating of 2,680 lbs.