I have never quite seen anything like this method used for the floor joists that sit on top of the basement walls. Home was built 1972. I believe that behind the galvanized tin is concrete, but not sure exactly where the upstairs walls are resting (possibly on a concrete stem wall of sorts behind the tin, which I am guessing is the inside of a concrete form. And then also notice the floor joists are cut at an angle so not really much of the 2 x 8 joists are supporting the floor above.
(It is a half basement and a crawlspace. Area over the basement is all constructed this way. The third picture is in the crawlspace where it makes a transition. the forth is a zoomed pic. in the crawlspace.)
Is any one familiar with this or seen this type of construction or have any ideas?? Keep in mind that in my area code inspections back when the home was built were pretty much nonexistent and if it was it was probably done by somebody’s uncle.