Structures Subject to Vertical Loads

 

Load path

1. sheathing

2. small beams

• most-closely-spaced members
• rafters, joists, subpurlins
• e.g. 2 foot OC

3. medium beams

• beams, joists, purlins
• e.g. 8 foot OC

4. large beams

• girders
• e.g. 18 to 40 foot OC

5. columns or bearing walls

 

For live loads, use tributary area of member being designed instead of loads from smaller members.