This week’s truss: Flat Roof Optimization
Question:
What would you do to make this truss design more efficient?
Top Chords: 2×4 Southern Pine #2
Bottom Chords: 2×4 Southern Pine #1 or Select Structural (B4, B5)
Webs are 2×4 Southern Pine #3 or #2 (W2, W20)
Building Code: CBC 2022
Loads (psf unless otherwise noted):
TC Live Load 20
TC Dead Load 20
BC Live Load 0
BC Dead Load 10
Wind: 160 mph
Carried trusses with net reactions of 100 lbs downward at 13’10 and 26’
The answer will be posted on Thursday!
This is not a production truss! This is simply an example for Truss Tuesday conversation. Join the conversation on LinkedIn.
Updated: Thursday, March 14th, 2024
Answer:
Here are the first things we would change:
- Offset the splices. Lining them up like this creates weak points in the chords
- Position a vertical underneath each point load
The results:
- No more Select Structural in the bottom chords
- Total plate area reduced by 25%