When does a “stem wall” that is part of your foundation become a “concrete foundation wall”?

[ICE]

Correct.

Design professional can specify 4000psi due to weathering potential or even mere preference, but so long as the f'c (design strength) is 2500psi or less, then an exemption from SI is permissible.

As long as you are not taking credit for 4000 psi, SI can be excused as no credit is due or given without SI and a crush test. If the design calls for in excess of 2500 psi there will be no credit given without the SI and lab crush test. But there again, apparently this doesn't hold true in other jurisdictions. To each their own.

 

[Joe.B]

It's an interesting dilemma for me and I was reaching out here for a range of opinions, not a definite answer. No one is going to have a definite answer, as each jurisdiction is tasked to interpreting and applying the code for their specific conditions. Yes, I'm in California, but it's a big state both in terms of population and geography. Where I'm at is on the opposite end of the state from where ICE is. He's probably a 12-14 hour drive. How many other states can you drive a relatively straight line for 14 hours and not cross a border? Texas, Alaska, Florida?

Anyways, it's very different up here and a LOT of stuff is ignored in neighboring jurisdictions... I can say with conviction that no "ordinary" single family home built here has ever been required to have more than 2500 psi. If this hadn't come to my attention I would have never even thought of it. On the flip side, in the six or so years I've been inspecting, I've only seen one purely prescriptive design, and they called out 2500 psi, and no one questioned it.

The question was brought to me and I'm trying to provide the best answer I can, and like so much of code it's not exactly clear. Thanks for weighing in with your opinions, it's much appreciated.