If I was to build a 4-bent 25'x25' barn (top plate 14' high) as pictured on page 3 of Sobon's HISTORIC AMERICAN TIMBER JOINERY then what is a good brace length? The tie beam is below the plate. Barn timbers will be white pine and the shouldered braces will be oak.
In some timberframe design books, I see diagonal brace lengths of 45.25" (49.25" including length of tenon). But, in some old existing barns, I see longer brace lengths of maybe about 5,6,7 feet.
Is a brace length of 45.25" too short?