Some bitter nut hickory has made it's way into a "local woodlot" frame I am helping out on. While all of the timbers (green) that have thus far made it into the frame seem sound, and quite beautiful if I might add, several pieces have recently given me pause to think. While cutting timbers to length, dramatic checks have opened up, quite literally with a bang, several feet up through the timber, through the heart and from side to side of the timber. This is in timbers with no discernible reaction content (straight and twist free and from dense growth).
Does anyone out there have any experience with this phenomena in bitter nut timbers, and can you provide any insight into what the heck is going on.
Two questions:
Should we expect the timbers already incorporated in the frame to explode as dramatically during the post raising drying process?
Are there any methods that might be employed to mitigate the possible checking (splitting actually).
Thanks

Are you sealing the end grain to slow moisture loss at the cut ends? I don't have experience with this wood, but sealing the endgrain is best practice to reduce checking.

I've seen hickory logs do that within hours of being felled. Quite dramatic as you say. And quite worrying, I imagine, if it's your brand new tie beam that just popped.

I would be concerned about that happening to any of the hickory timbers.

The best thing you can do now is try to slow or stop the moisture leaving the ends as Brad pointed out by sealing with something like anchor seal. You could also run some structural screws in the ends you are worried about to try to keep them from checking, but I am not sure how effective it would be. Once they've split like that in the frame, I'd have to see it to know what to do.

best of luck

Growth stress rather than drying stress is causing this, I've posted the link previously to a paper on this, I'll try to dig it back up. Hickory can have a large amount of growth stress.

Here it is;
http://www.fs.fed.us/ne/newtown_square/publications/technical_reports/pdfs/2004/316papers/Cassens1GTR316.pdf#search='tension%20growth%20stress%20tree%20checking'

We had a discussion recently on "Wood Behavior", or maybe misbehavior the thread is here;
http://www.tfguild.org/forums/ubbthreads.php?ubb=showflat&Number=20921&page=1

Thanks, that helps a great deal. My reading of the growth stress report indicates that restricting the ability of log ends to expand immediately after felling can limit if not eliminate the phenomena. My primary concern with the bitter nut timbers already included in the unraised portion of the frame are that the stress of raising the bents might induce one of the "instant checks" during the raise (and I do mean instant check!! the 7x9 timber I was kerfing out went off like a mouse trap going off). The timbers that have provided the violent displays have all been from trees cut within 24 hours of notching.
The idea of kerfing the non view faces of the timbers has been previously discussed with the owner/builder, and I am encouraged to see it's mention the "Wood Behavior" thread.

That makes sense Don, since the ones i've seen were freshly felled -- certainly not enough time for moisture levels to drop below the fiber saturation point, even just on the very ends.

Interesting...

It is pretty wild, I've had a few of those bombs go off in the sawmill, ours are mostly mockernut but I imagine about the same. Gabel, I've been curious and you might be in the right place, is pecan more stable?

We've not sawn a lot of pecan, but it does seem to be more stable than hickory. I've never seen this behavior (growth stresses causing explosive end splits soon after felling) in pecan, so it's got that going for it.

I've milled a fairly good amount of Shagbark Hickory.
I haven't seen one pop from tension (yet) but they'll bend into bananas if you don't keep turning them.

I've only got two hickory timbers in my frame (neither experienced raising stresses), both appear to be doing well.
They check pretty good.