OK to Split the Pith?

[Cornerstone]

I recently started cutting the beams to build a saw shed, and I have this 21' 12x12 I'd like to make two 6x12's out of. If I do it the pith will be cut right down the center. It's my understanding that the beam might develop a curve to it if I do. Is it a big no no to do this? The wood is post oak. I've seen contradicting YouTube videos on the subject.




 

This shows a nearly 3 ft long check on one end. I don't have to use this log but I'm curious what is considered acceptable when it comes to checking. You can see the pith is basically in the center and will be exposed if I cut it in half.


 

Thanks for any response.

[Jeff]

It is not. The pith should be in the center of the beam, or none of it.

[Southside]

Never cross the streams, and never split the pith.  Pretty much the same bad results of ending the known universe are the consequences of either.  

[Jeff]

@123maxbars did a video recently about this, reactions of the pith in a post said three times fast, don't remember the title of the vid. Nathan should.

[Old Greenhorn]

If you are using them for dunnage to lay on the ground and lay a lot of weight on top you can do that because who cares where or how they bend. But if you are building, the simple answer is 'NO'. The detailed technical answer is "Hell no".

[customsawyer]

The "check" in the end of that timber is already showing it has stress in it. If you split the pith in that timber you will have two timbers that won't work. If you center the pith you will have one that will work.

[Cornerstone]

Well that answers that! Thank you gentlemen. I'll take a few more 2x's off it and bring it down to a clean 6x12. 

[Joe Hillmann]

A couple weeks ago I was working on a project I was down to my last scrappy log and needed 2 4x4's.

I figured it cant be that bad to split it down the middle. I ended up with two bananna shaped 4x4's that I couldn't use.

[YellowHammer]

That cant has so much shake in it, I'm not sure it would make one good beam after it has dried, splitting the pith or not. 

Splitting the pith is good if you want to make McDonald's arches, but otherwise, it's a "low yield" approach.

[Chilterns]

I think that this practice is very much dependant on the tree species involved, for example, I quartered a big Douglas Fir butt log thru the pith to make 4 corner posts for a single bay timber-frame and did not experience any distortion difficulties with same.

I also recall Richard Harris (author of Discovering Timber-Framed Buildings) drawing to our attention that the four threshing floor corner posts of Court Barn at The Weald & Downland Museum were quartered from the same oak tree. This barn now features on a popular UK TV program - "The Repair Shop".

There is no doubt that especially some hardwood species are very prone to stress release deformation upon thru and thru conversion but if this practice was an absolute "No No" then how would we ever make planks ?

[YellowHammer]

If pith sawn wood is attached to something stronger than it is, then it can be forced straight.  If pith sawn wood is attached to something weaker than it is, then it will pull what it's attached to and ruin it.

For high quality hardwood that we sell, we never make 4/4 boards through the pith.  Pith sawn wood is known as "firewood" or "pallet wood" because with our Appalacian Harwood, it will never dry straight, and also has pith checks which make the wood structurally unsound.  Whatever kinds of checks seen in a log or green cant will multiply several times as it dries.  Pitch checks, pith stress or any other pith defects never get better as wood dries, they get worse.  If "worse" results is a usable piece of wood, then it's not a complete waste. With the cant in the picture, I would never take any boards from the circular area of the pith showing shake, any of the those boards will be DOA off the mill because as they dry, they will be garbage.  So at least for lumber, I would avoid and saw completely around that area and the shaky center would go into the fire.  Pith and heart checks are one issue, but that cant has shake, or growth ring delimitation, and is a death sentence.    

The only time I can use pith sawn 4/4 boards is for pallets because I can use a nailgun and force them straight to the pallet frame with lots of nails.  Shake wood is completely unsound and unusable.

Many years ago, I once used partially contaminated pith sawn hickory for roof trusses, hoping the truss frame would keep them straight, and a few weeks later, the pith sawn boards had moved and warped so much that they had ripped out of the metal roofing and left ovals or holes.  No bueno.  I never forget that one, it cost me a lot of time and money.  

[Brad_bb]

I would not split the pith, especially on oak.  I had some long oak rafters that I ordered and were split pith.  A bunch of them turned into banannas.

[Ianab]

Those first few growth rings of most trees are "juvenile" wood, and behave accordingly. High in tension, likely  to split or otherwise freak out. Some really stable woods you might be able to get away with it as the checking and warping might not be enough to be a reject.  But even with the pretty stable Monterrey Cypress I usually saw, anything within ~2" of the pith is suspect. If you can saw a board / beam 2" from the pith, probably OK. If you can keep the pith IN a large beam or post, generally OK. If I can get a decent 6x4 around the pith it's a garden landscape sleeper, saleable but low grade.