Ron J. asked how the band and floor joists are anchored to the foundation.
So far, I have found no evidence of any type of fastener, bolt, or other device that would accomplish this.
The exception is the sunroom addition, which is 10 years old, and which has only a crawlspace and cinder block foundation. It appears that 4x4 lumber (or slightly smaller) was threaded vertically into the openings in the cinder block foundation. The band is then bolted to the 4x4 lumber.
Aside from the apparent lack of connectivity to the foundation, is there anything folks think I should do regarding the untreated joists in contact with the concrete?