Was going to write more about the breakdown of knowledge into hierarchies, but got involved investigating the structural properties of wood, in particular Canadian Redwood which isn’t otherwise mentioned in the Australian Timber Structures code AS1720. Seems to have a reputation for strength but seems to be contrary to what I can find in qualitative descriptions, though quoted modulus of rupture (MOR) seems high. A New Zealand timber website suggests has similar properties to Western Red Cedar. References to Western Red Cedar indicate strength grades of F4, F5, F7 and F8 available, and strength group S7 and S8. Other references indicate Redwood is a softwood. Now starting to question the difference between the MOR quoted around the web and the bending stress given in AS1720 for the strength grades: seems they are based on different concepts.