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Re: WOOD - Engineered Lumber vs. Sawn Lumber

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I believe that the "extra" 0.5 in 1.5*DL camber for G-Lam beams is to 
account for long term creep.  This would apply to roof or floor beams.  See 
Breyer's textbook third edition p.33 or NDS 3.5.2.  Note that if you want 
to calculate the total deflection of seasoned lumber you should use 1.5*DL 
also.  The recommended factor for green lumber 2.0*DL!

Kevin McCune



>I'm not sure how to explain this. If you camber the beam for 1.0*DL
>deflection then, theoretically, when the dead loads are applied the beam
>will be level. If you camber the beam for 1.5*DL deflection, after the 
dead
>loads are applied the beam will still have a negative deflection (camber)
>or "crown" equal to 0.5*DL deflection. Right?
>
>Regards,
>Bill Allen