Depends on the type of wood plus the treatment the woods gets. Usually pieces are put in a furnace at a certain temp, i forget, to kill everything in the wood and dry it out,  this improves lifespan greatly. after that the piece is oiled to give it a protective layer. after this you'd be re-oiling once every 10 years if kept dry and clean i guess.

I think 'old oak' is more than sufficient for this task. Old oak is 'older than a 1000 years' which means 800 years is also acceptable apparently. Old oak is rare but 'quelle surprise': I can hook you up