Quote from nutmeg:
Speaking of wood. Nice article on wood.
If someone invented wood today it would never be approved as a building material. It burns, it rots, it has different strength properties depending on its orientation, no two pieces are alike, and most cruelly of all, it expands and contracts based on relative humidity. Can it get worse? But, of course. Wood expands differently based on orientation. However, despite all of these problems, wood is the material of choice when it comes to building houses
http://www.buildingscience.com/documents/insights/bsi-023-wood-is-good-but-strange/