Slide 40 of 67
USE THE PROPER LUMBER GRADE & SIZE OF HOLD-DOWN STUDS
- Different lumber grades and sizes determine the effect of uplift on a house structure
- You must know the grade of lumber that you are working with
- When an engineer designs the connection of a hold-down device to a framing member, the grade and size of the lumber helps determine how much uplift the framing member can take.
- For example, “Construction” grade 2 x 4 studs can take a maximum 4,540 pounds of seismic uplift.
- “Stud” grade 2 x 4 studs can take only 3,140 pounds.
- The maximum seismic uplift for “Stud” grade 4 x 4 studs is 7,330 pounds.
- Discussion of Figure
- Learn to recognize different lumber grade stamps
- Shown here is “1 and better” (top) and “Select Structural” (bottom)