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Re: WOOD - Engineered Lumber vs. Sawn Lumber

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This makes it tough to frame a wall over a beam with a crown in it.

Regards,
Bill Allen

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> From: Kevin McCune <kmccune(--nospam--at)willdan.com>
> To: seaoc(--nospam--at)seaoc.org
> Subject: Re: WOOD - Engineered Lumber vs. Sawn Lumber
> Date: Thursday, September 11, 1997 8:33 AM
> 
> 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
> 
>