If you take the bark off with a draw knife it seals the wood by closing the pores. Chainsaws rough up the wood and open it up. The most important part is the bottom, you need to keep the bottom row away from mud and wet ground.
Ah, so that's why he stripped the bark off. That was my first question. My second question is: What's with the moss between layers? I assume it's to fill in the gaps and provide insulation, but won't it rot?
