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Re: Lumber grading from small mills

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Jordan,

To my understanding, anyone can "grade" a piece of lumber.  You just need
to get your hands on a grading rules book/publication from the appropriate
organiztion that deals with the wood species that you want to grade (you
can see a list of those organizations with their "species" in the NDS
Supplement).  Thus, you can grab a grading rules book and take a look a
piece of lumber yourself and determine a grade.

Typically, however, it is desired to have "certified" grader do the
grading of lumber.  A certified grader would be someone who has had some
"formal" training and presumably testing of how to apply the grading
rules.  This also means that this person must pay money to "remain
current" with their certification much like you and I must pay money to
remain "current" with our license.  The idea of this route, obviously, it
to in theory ensure that you don't get some dude off the corner just
coming and saying "Oh, that is Select Structural" and not know if that
dude really knows what he is saying.

Most dimensional (i.e. 2x, 3x, etc) is graded at the mills by certified
graders.  The issue becomes a little more "sticky" when dealing with
timbers.  The grade of timbers can be changed by cutting the length of the
timber (some of the grading criteria on timbers, I believe, is governed by
the the slope of grain, number of knots, etc in the middle third of the
member...thus, if you "buy" a 20 ft White Oak timber that then gets cut in
half to become 2 10ft long roof rafters or such, the grade could
potentially change as your middle 1/3 of the member in question just
"changed").  I don't believe that one can grade logs per the typical
grading criteria per these various organizations' grading rules...you need
to see things like grain slope and number of knots and other "defects" in
order to use the typical grading rules...I believe.

The point is that you can specify that lumber/timbers must be graded by a
certified grader.  There are certified graders that can be hired to come
grade lumber/timbers.  The timber (for traditional timber framing) that we
use is generally NOT graded by a certified grader.  We don't have a
certified grader on staff as it is rather expensive to keep the
certificates up-to-date (keep in mind that you must have certificates from
different organiztaions for different species so cost can add up quick),
but we do have people on staff who are familiar with the grading rules for
the species that we typically use.  As such, we can "unofficially" grade
the material we use.  If the project requires certified grading (i.e. the
project specifications done by the AOR or EOR), then we will try to talk
the AOR/EOR out of it, but will do it if required.  If it is required,
then we hire a "consultant" who is a certified grader to come in and grade
the timbers for that project.  In our case, this usually then "certified"
by a piece of paper rather than a stamp on the timber as most clients
would not really like to have a lovely black ink stamp in the middle of an
exposed timber.

So, you can certainly require that a contractor/manufacturer hire a
"consultant" grader to come in and grade any non-graded lumber or timber
on a project.  Just keep in mind that it is an added expense and you will
likely be "forced" to justify yourself to someone who does not want to pay
that expense.  It all becomes a choice on your part of how much of an
issue do you want to make of it.  It becomes more "difficult" to be
justified in forcing the issue if you are dealing with a long established
lumber/timber supplier who may have staff on hand who realistically can
grade just fine but are not certified (and this is not to say that you
would still not be justified...just that the arguement becomes tougher).

HTH,

Scott
Adrian, MI


On Thu, 2 Feb 2006, Jordan Truesdell, PE wrote:

> I've avoided this question in the past, but it seems to be knocking on
> my door a bit more recently...
>
> How does a local builder get local lumber and timber (and logs, for that
> matter) graded? I've read about grading and certifying, and that they
> are different, but haven't a clue about the details. Is there a good
> reference for how (especially) rough sawn lumber can be used for modern
> structures built under the IBC/IRC. Some of this stuff is coming from
> actual small mills, and other stuff might be coming from a
> bandsaw-on-a-trailer operator who does taxidermy in the fall and taxes
> in the spring.
>
> Now, I mentioned lumber because there's a little voice in the back of my
> head telling me that you can't get lumber sizes graded outside of a
> certified(?) mill, but I'd like to find out about timber sizes as well.
> If it can't be done, I want a thick document with which I can smite all
> the log/rustic style home builders (and owners) who waltz into my
> office. If it can be done, I want to know how so that I can draw up some
> guidelines to get aforementioned log home builders on the right track.
>
>
> Jordan
>
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