Hi Graham,
We’ve tried it all here at Northwest Shou Sugi Ban.
Green wood can be charred, as you suspect, but I would avoid it for the durability and longevity that you might want.
We did a small cabin using the inexpensive green cedar fencing boards (like you used to be able to get at Home Depot for $2). While the finish looked pretty good, I don’t feel like we were able to get a true deep char, heating the timbers through with enough intensity, due to the steam that the moisture creates.
I don’t think you can count on the flash heating of the charring process to also be able kiln dry your timbers. We only use properly kiln dried after that experiment.
That’s my 2 cents,
Steve Keyser
www.northwestshousugiban.com
