Determine the number of board feet required for joists on a one-story house 30′ × 40′, in which 2 × 8 joists will be placed 16″ OC.
A. 2,052
B. 1,224
C. 1,632
D. 1,536
I honestly don't know what formula to use for this. Everything I see online leads me to no answer on here.
Here is a hint: if you sketch out the floor plan you will see the entire area. Your joists will have to be all the way across the floor (to hold it up). And they are every 16 inches. If you break your floor up into 16 inch sections you will know how many joists are needed.
16" OC means a 2x8 every 16 inches.
40' = 31 joists
I'll assume the joists are 30' long
that's 930 ft of 2x8 =
a board foot is 12"x12"x1"
I'm still not understanding.
Is the answer B?
To determine the number of board feet required for joists, we need to calculate the total length of joists needed, considering their dimensions and spacing.
First, let's calculate the total number of joists required. Since the house is 30 feet wide, which means it requires joists parallel to this dimension, and the joists are placed 16" on center, we can calculate the number of joists needed by dividing the width of the house by the spacing between joists:
Number of joists = (Width of the house / Joist spacing) + 1
Number of joists = (30 ft / 16 in) + 1
Before we continue, remember to convert the width and spacing to the same unit. Since we are calculating in feet, let's convert the spacing from inches to feet:
Joist spacing = 16 in / 12 in/ft
Number of joists = (30 ft / (16 in / 12 in/ft)) + 1
Next, let's calculate the total length of joists, considering each joist is placed along the 40-foot length of the house:
Total length of joists = Length of the house * Number of joists
Total length of joists = 40 ft * Number of joists
Finally, we need to convert the total length of joists into board feet. Since each joist is a 2x8, which means it has a cross-section of 2 inches by 8 inches, and there are 12 board feet in a cubic foot, we can calculate the number of board feet:
Number of board feet = (Total length of joists * Cross-sectional area) / 12
Number of board feet = (Total length of joists * (2 in * 8 in)) / 12
Now that we have the equation to calculate the number of board feet required, let's evaluate the options:
A. 2,052
B. 1,224
C. 1,632
D. 1,536
By substituting the values into the equation, we can determine the correct answer.