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Re: Lumber grading from small mills

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Jordan,

Yeh, I have a close relationship with the timber framer...I work for them
part-time! ;-)

We primarily use Oak (White and Red) and Doug-Fir for our timber frame
members.  That probably accounts for 95+% of our timber frame members.  We
do occasionally get other "odd" species (have done some Western Red Cedar
myself).  Our standard grade that we use is No 2, unless there is a need
for something stronger.

I am comfortable that our folks down at the yard (we have a large
supply on hand of Oak) or the folks from the suppliers that we get
wood from "grade" (not typically by certified graders) the timbers close
enough.  You first have to remember that visual grading is not as much a
science as an art.  In otherwords, it is not exactly what I would call an
extremely precise process.  Thus, I have no doubt that there is some "pad"
in the grading process and also some "pad" in the allowable values from
the NDS due to the realization that the grading may be slightly "plus or
minus".  Anyways, there are folks down at our yard that do know the
grading rules and realistically could likely easily be certified graders
if we wanted to incurr the expense of getting them and keeping them
certified.  So, the point is that we do "grade" the timbers...just not
typically in an "official"

Beyond that, it usually helps that timbers are typically larger than
needed from a stress point of view and deflection is rarely an issue.  In
addition, I usually don't make use of the 1.15 load duration factor (in
general, governing load combo is gravity loads with snow loads).

Scott
Adrian, MI


On Fri, 3 Feb 2006, Jordan Truesdell, PE wrote:

> Scott Maxwell wrote:
>
> >Jordan,
> >
> >You can certainly go shell out some $$$ to buy various grading rule books
> >since I know how much extra cash you got clogging up your pockets!!!
> ><grin>
> >
> >
> >
> You know me so well...sometimes I can't find the keys in my pocket for
> all those benjamins I saved by skipping code additions ;-)
>
> I forgot to ask - what do you use for design values if you don't get
> your timbers graded?  I know that you have a close relationship with
> your timber framer, so you can be comfortable with what they're using.
> Do you have a "standard" for your design?  For example, when you're
> building with Northern Crabapple, do you base your designs on the #4
> Dense values in the NDS?  Will you up your values to a higher grade if a
> high dollar client decides to have their frame built entirely from Clear
> Select Southern Dogwood?
>
> I base my pine timbers on Eastern White No. 2, and make sure I'm not
> very close to 1.0 on my ratios, and logs on either the EWP2 I use for
> timbers or, more frequently, the ILBA tables.
>
> Jordan
>
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