Pharmaboy - thanks for the links.
I have had a look at the DPR tables and have a few questions. I am looking a buiding a small shed (3x4m) on a slab with a gable roof. Looking at the tables for 2400mm studs there a several columns I'm not to sure about.
Frame Size (75 or 100mm) - I assume that this is the depth of the wall frame?
Roof Span in mm - is this the span along the wall frame (ie the length of the frame) or is it the roof span perpendicular to the wall frame (ie the distance between the two frames spanned by the rafters/truss)?
I also have a question re timber grading - I have access to recycled hardwood 50mm x 75mm - what stress grade should I use? It is well seasoned! I was thinking F11 or F14?
"If something is really worth doing, it is worth doing badly." - GK Chesterton