Visited an interesting eco-build recently; walls done very neatly with a combination of cordwood / lime mortar fill plus straw-bale. Thats by-the-way; the builder passed on a little tip ...

Always erect posts in a building in the same sense with which the wood grew; otherwise, they will be more liable to insect attack. I think there was a complimentary rule for beams using compass orientation.

Can anyone confirm this?

Hmmm
Following that train of thought, it would seem that one should put them the other way. Sap flowed up the tree, so should the water. If you put them top down then water would never go up the timber because it would be down.....
Maybe.....
Bob

Sounds kind of Fung swayish . Orientation could be important from the point of view of exposing edge grain , as in a split log timber. The heart of the log should face out. This will deter insect attack ( in good wood). Dip ends in oil sealer and maintain the finish. That upside down theory is worth considering too. I,m goin out to the barn now to flip a beam , will let you know how experiment turns out. timbo out

Japanese carpenters consider it important to keep a post oriented the same way it grew. English tradition with jowl posts is just the opposite, as the butt flair is the part the jowl is traditionally shaped from. I've seen some very old jowl posts in the UK.

gh

GH you didn't tell us the condition of the bottoms of the jowled post. Was there signs of more deterioration or less? Seriously though what is meant by orientation in the first post? I like to keep an open mind when it comes to ancesteral knowledge. Some Japenese framers ( I believe ) would sharpen their chisel after each cut. I think they were probably paid by the hour.

We've kicked it around in the wondering about the way the grain is around branches, does standing a post upright drive the stress into the post better and upside down does it tend to shank out more...dunno.
I open the chip bag upside down all the time, they do seem to taste the same either way .

Don P , I think you hit the nail ( or peg) on the head. I bet compression loads would test much better in a natural orientation.

I see the theme has strayed from insect vulnerability to mechanical strength, but I'm sure these things are all related, and thanks for the ideas.

Of all these, reversing growth sense (as in a gunstock post) appeals to me; insects disoriented in not finding the wood structure layout as it would be in nature.

It lead me on to think about twist of fibres and vascular tissue. Has anyone noted whether torsion changes due to drying always exist in the same sense (cw or ccw), and if so, could this relate to the coriolis effect? Do trees (for a given species) growing nearer the equator twist more than those near the poles?