From past experience, I found out that the Southern Pine codes were enacted by a private company and shoved through the system, making THEM the authority.
Being in the South USA at the time, I tried to get a graders certificate. Was told the grading certificate went to the SAWMILL, not the person that was the "official" grader of SP. There was no way a portable sawmill would get certified.
Anyone with a brain that works, can look up the strengths of most construction lumber and compare what they have to what is acceptable for construction.
For example, the old Long leaf/ Fat lightered/ Heart Pine, that once dominated the lower east/south USA was proven stronger than steel. Now, if it's not certified by some shill organization, it can't be used as support construction lumber, even though it was removed from 100+ year old factory buildings and was to be recycled as construction grade lumber.
There is no way a 1.5" X 3.5" piece of SPF is as strong as a 2" X 4" piece of that same material.
I have checked supplier tags in a Home Depot in Florida recently, and it was from Ervine Sawmills in Canada. Meanwhile, California has a serious death rate of timber from the drought, going to waste because the tree huggers won't allow removal of this from the eco system. It's MUCH better to watch it burn, taking out housing and wildlife, instead.
Down here, do as you please with whatever lumber you can get your hands on.
