Wet Service Factor C_M

 

M subscript = moisture

 

Strength ↓ as MC ↑

 

For sawn lumber, use C_M if MC in service exceeds 19% for an extended period of time.  Otherwise, C_M = 1.0.

S-DRY, KD, or S-GRN does not matter.

For glulam members, use C_M if MC in service exceeds 16%.

For connection design, MC at time of fabrication and in service is considered.