Design

Supports (Truss Carriers)

1. Size -
   Examples: 2x6, 2x8, 2x10, 2x12, LVL
2. Species & Grade -
   Examples: Select Structural Hem Fir, #1 Southern Yellow Pine
3. Quantity -
   Examples: 2, 3, 4, 5, 6 Members
4. Connection Requirements of Members (connection to column, connection to each other)
1. Nails
1. Size -
   Example: Shank Diameter and Length
2. Type -
   Examples: Ring Shank, Spiral Shank
3. Quantity & Location
4. Coating - Approved Hot-Dipped Galvanized or Stainless Steel (if in treated wood)
2. Bolts
1. Size
2. Hardness
3. Quantity & Location
4. Coating - Approved Hot-Dipped Galvanized or Stainless Steel (if in treated wood)
5. Note: Not all the Same Size Dimensional Lumber is Equal
   (1) Base Design Value for 2x12 #2 Doug Fir Larch - Fb=900
   (2) Base Design Value for 2x12 Select Structural Hem Fir - Fb=1400
   Fb = Allowable Extreme Fiber Stress in Bending
   Source: Western Lumber Product Use Manual 5-01 The fiber stress values, along with other design values, are used to determine what the 2x12 will support.