Though traditionally, three Japanese cedar boards are bound to form a long triangle and a fire is started within the resulting tunnel, Weijnen built a brick oven to accommodate two six-foot-long larch wood boards at a time when he charred his wood in Amsterdam. After removing the planks from the brick oven, Weijnen doused them with water if the fires didn't go out on their own. He used his less successful pieces in the kitchen ceiling.  30+ All-Black Exterior Modern Homes by Zachary Edelson from Facade Focus: Charred Cedar