Hi Brian. I didn't check how old this thread is, but if it is current... I am using some recycled cedar (of British origin I presume) and I find it difficult enough to work with, especially when it comes to cleaning out the doves and tails after initial cutting. Cedar (British) is very brittle apparently, and I have confirmed this as I lost a tail on my first joint for the project; just snapped off with no sign of a knot or a crack. I wouldn't say don't use it unless it's Canadian cedar, but just be careful. Even when it is wood "just lying around" we still paid for it or won it from a skip or somewhere else, so just as precious if not more so!