"Australopithecus scobis" wrote in message
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Ground contact, though, I gotta chime in. Ground contact often means dirt
out in the rain. I made raised garden beds out of plain old 2x. They
rotted out at the bottom. They got alternately wet and dry, wet and dry,
and away they went. OTOH, your typical viking craft sunk in a lake
somewhere, or some prehistoric Australian pine tree sunk in a
bog, will become saturated with water, but won't rot. So, yes, wood
immersed in liquid water will come into equilibrium, become saturated. No,
that's not why we keep wood off the ground. One situation,
equilibrium moisture content, is sorta kinda static. The other, ground
contact, has to do with change. Rotting could happen in either case;
greater than 25% moisture or alternating wet/dry.


Oxygen is the determinant. The bacteria and fungi that do the deed are
aerobic. Bottoms of bogs (sorry, blokes, I know what a bog is to you) and
lakes are poorly oxygenated. Also often very acid and thus highly
mineralized, another thing the decay bacteria don't like.

There are a bunch of logs that sank in the big lake north of here waiting to
come to market after a hundred years. Trouble is, they make big holes when
they're lifted.