Thanks for the replies, this is an incredibly useful forum. My questions relate to assessment of existing roof framing (for solar panel install). I live in an area with many century-old homes that have rough sawn lumber roof framing. Analyzing using dimensional lumber could be 50%...
Noted. because span tables are for service level deflections (L/180 to L/360), I figured the tables indicate spans than are well clear of max bending stress or shear. assumption is that deflection for service governs. Make sense?
I'd like to learn how to identify species and grade, in lieu of...
Thanks to all for input. I created the attached table showing factor to apply to span table max span values to determine max span for true size lumber. Factors are calculated based on the fact that bending stiffness, dictated by moment if inertia, depends on cube of rafter/joist height...
Has anyone ever seen a span table for old ACTUAL dimension floor joists? Ie for 2X4 which are actually 2x4, not nominal 1.5 x 3.5. I realize that without a structural stamp, its hard to tell the exact attributes of such wood. Still, an actual dimension lumber span table would be a useful...
