1. LUMBER SIZES AND BOARD FOOT MEASURE
Presentation 6:
LUMBER SIZES AND BOARD FOOT MEASURE

2. Lumber Lumber sizes are indicated by a series of numbers.
Thickness″ × Width″ × Length′
For example, 1″ × 10″–12′
(One inch thick × 10 inches wide and 12 feet long)

3. Lumber Names Three general types: Boards – 1 inch or less in thickness
e.g. 1x6
Dimension Lumber – 2 inches in thickness
e.g. 2x6
Timbers – larger than 2 inches in thickness
e.g. 4x6
1x6
2x6
4x6

4. Actual vs. Nominal
Actual dimensions of lumber are smaller than the name implies.
For example:
A nominal 2x6
Is actually
1 ½″ × 5 ½″
5 ½″
1 ½″
2x6 6″ 2″
2x6

5. Actual vs. Nominal Nominal Actual 1x4 ¾″ x 3 ½″ 2x4 1 ½″ x 3 ½″ 1x6

6. Lumber Volume Lumber may be purchased by the piece.
e.g., 36 – 2x8–16′
Large quantities of lumber are often purchased by the board foot (bdft).
e.g., 750 bdft of 2x4’s
This is typically done at the wholesale level.
Also allows for varying board lengths.

7. Board Foot Measure Board foot measure refers to a volume of wood.
It is defined as the volume of wood measuring 1″ × 12″ × 1′
1 foot 1″
12″

8. Board Foot Measure 1″
12″ 1′
A board foot may have different shapes and still be a board foot (bdft).
Cutting and stacking the pieces yields a 2x61′
Cutting and placing the pieces end to end yields a 1x62′
Each has the same volume of wood. 2″ 6″ 1′ 1″ 6″ 2′

9. Board Foot Measure All of the following equal ONE board foot. 2″ 6″ 1′3″ 2′ 1″
12″ 1′ 1″ 3″ 4′ 1″ 4″ 3′ 1″ 6″ 2′

10. Note: Thickness (inches), Width (inches), & Length (feet)
Board Foot Measure
Formula for figuring board feet is:
Example – How many board feet are in 180 pieces of 2x816′ long?
Answer: 3840 bdft.
180 × 2 × 8 × 16 ÷ 12 = 3840 bdft
Bdft = # pieces × Thickness″ × Width″ × Length′ ÷ 12
Note: Thickness (inches), Width (inches), & Length (feet)

11. Conclusions
Actual sizes of lumber are smaller than nominal sizes. A 2x10 is actually...
1 ½″ × 9 ¼″
Board foot is a measure of lumber volume.
How many board feet in 10  2x68′?
10 × 2 × 6 × 8 ÷ 12 = 80 bdft.