Cross check or Cross grain?

[Scott G]

I have a timber that the grain is running straight down the piece, but it is getting checks that run diagonally across the piece.  Grading rules only allow 1" of slope in 6" for a #2 grade timber.  But is that rule only for grain or can it be used for checks.  The piece is straight now, but more than likely it will start twisting.  Is this piece still a structural #2? 

[beenthere]

The annual ring structure may be running straight, but the checks are following the grain. And that is the slope that needs to be considered when grading. Easy to confuse annual rings and the grain direction of the fibers. High slope of grain will reduce the strength and will likely cause the twisting that you suspect.

[Don P]

#2 is 1 in 8  ;). #1 is 1 in 10, #3 is 1 in 4. Beenthere is right, checking follows the grain, slope of grain can be real hard to spot.

[Scott G]

Not to get into a pissing match but according to NELMA:

"26.0 POSTS AND TIMBERS (80.00 WWPA)
5" X 5" and Larger

26.3 No. 2 (80.12 WWPA)
No. 2 Posts and Timbers are used in all general
construction. The grade is designed for the many uses
where heavy material is needed and where
serviceability is important.
Characteristics and limiting provisions are:

Slope of Grain — 1 in 6. :P


Thank you for the information, after rechecking the piece it was grain that was sloped.

[Jim_Rogers]

Scott:
You're quote of the grade rule book maybe be true, I haven't opened mine to verify but there is another category of timbers other than "posts and timbers" and that is "beams and stringers".
And the slope of grain may not be the same in that section.....
When anyone is sighting rules we have to make sure that everyone is using the same category to have a complete understanding...
A timbers that fails as a beam or stringer, may pass as a post.....
Jim Rogers

[Don P]

Jim, Scott,
Quite true, I was in dimension lumber grade rules  :

[SwampDonkey]

Most checks follow the rays of wood where tissues run longitudinal with them, also happens between early and late wood. End checks are mainly along the rays and surface checks are mainly between early and late wood, but also follow the rays at the same time.

[source: Text Book of Wood Technology 4th Ed., page 331-334]

[beenthere]

SD
What do you find in that Textbook under the Chapter Defects in Wood, section on
Defects Due to Direction of the Grain?
I think that is what is the issue here, but I could be wrong. I'm thinking you were quoting in the section on seasoning and machining defects.
The question on diagonal checking pertains to the fiber alignment deviating from the direction parallel to the long axis of a piece of wood. Termed 'cross grained', and the associated checking along these fibers on a tangential face.

[SwampDonkey]

We are talking about two different things yes. I was talking checks, you were talking grain.  Both mentioned in the first post. ;D