Sugi trees grow straight and fast, up to about 60 metres tall when mature. The wood is fragrant, naturally rot and insect resistant, and does not easily mildew or stain blue (i.e. blue mildew stain which is why many species such as pine are generally painted and not oiled if used for cladding at all), due to a very high tannin content. The bark is soft and fibrous, and the tiny, needle-shaped leaves grow radially from each twig.

The harder, summer growth rings (“late wood”) are thicker than with cedar or larch or many other species, which is critical for our heat treatment process. With many other trees, the soot will erode off almost immediately since it’s so soft, whereas cypress produces a more substantial soot layer that lasts decades without maintenance. Sugi has a Janka hardness ranging from 320–350 and is used for all types of construction applications, ranging from framing, to flooring, to wall cladding, to roof decking, to shingles.