With one notable exception, Board Feet of Lumber, like units must be used when multiplying numbers to find volume. So, you need to convert 4 inches into feet and then multiply the square area in feet by the depth in feet. 4 inches = 1/3 of 1 foot (12 inches) = .3333 feet 1,...
However, from the suggestions on this board it seems as though it will be easier to anchor some angles for the lateral support. If this is done I have more questions (since I haven't done this either): 1) What is a good bolt spacing for an angle loaded in thi manner?? I can run...