Construction Supervisor License Practice Exam

If fifty joists sized 2 " x 10 " x 12 ' are required to frame a floor, how can you calculate the total board feet needed?

1. By multiplying the quantity by width, thickness, and length in inches

2. By dividing the total lumber cost by price per board foot

3. By summing the volume of each joist

4. By measuring the total area covered by the joists

The correct answer is: By multiplying the quantity by width, thickness, and length in inches

To determine the total board feet needed for framing with joists, the process involves understanding how to calculate board feet, which is a unit of measure for lumber volume. The formula to calculate board feet for a piece of lumber is to multiply the thickness (in inches), width (in inches), and length (in feet) of the lumber, and then divide by 12. In this case, each joist is 2 inches wide, 10 inches thick, and 12 feet long. To find the board feet for a single joist, you can perform the calculation as follows: 1. Convert the dimensions: - Thickness = 10 inches - Width = 2 inches - Length = 12 feet (which needs to be converted to inches for the formula: 12 feet x 12 inches/foot = 144 inches). 2. Calculate board feet for one joist: \[ \text{Board Feet} = \frac{(Thickness \times Width \times Length)}{12} = \frac{(10 \times 2 \times 144)}{12} = \frac{2880}{12} = 240 \text{ board feet per jo