Maximum Span Calculator for Joists & Rafters

Species (country abb.)  
Size  
Grade  
Member Type  
Deflection Limit  
Spacing (in)  
Exterior Exposure  
Wet service conditions?

Incised lumber?
Live Load (psf)  
Dead Load (psf)  



       

The Maximum Horizontal Span is:
12 ft. 9 in.
with a minimum bearing length of 0.45 in. required at each end of the member.

PropertyValue
Species (country abb.)  Douglas Fir
Grade  No. 2
Size  2x8
Modulus of Elasticity (E)  1600000 psi
Bending Strength (Fb)  1240 psi
Bearing Strength (Fcp)  625 psi
Shear Strength (Fv)  180 psi


Country Abbreviations
  Austria as   Czech Republic cz
  Estonia es   Finland fi
  France fr   Germany de
  Latvia lv   Lithuania lt
  Romania ro   South Africa za
  Sweden se   Switzerland ch
  Ukraine ua    

While every effort has been made to insure the accuracy of the information presented, and special effort has been made to assure that the information reflects the state-of-the-art, neither the West Coast Lumber Inspection Bureau, The American Forest & Paper Association nor their members assume any responsibility for any particular design prepared from this on-line Span Calculator. Those using this on-line Span Calculator assume all liability from its use.


The Span Calculator was designed and created by Cameron Knudson and David Pollock at Washington State University. Support for development of this version of the Span Calculator was provided by West Coast Lumber Inspection Bureau © 2005