The framing member seams promising, but again, I am having trouble getting the length of the board. Height and width, no problem, but length? I can query the 'line length' or span but not actual length of a pitched board.
I also can't figure out how to query the area, so can't use length=volume/area.
I can get the 'nominal dimension' (i.e. 1" x 12" x 18') which is semi-useful, but that value can't totaled or manipulated. So again, the value I want is right there, (in this case the 18') but I can't bring it in to a worksheet in a useful way.
I will try extrudes again, but I think it would be faster and more accurate to 'trim' a house w/ framing member tool, as it has miter settings, and pitch and bevel cuts.