I’m in the process of encapsulating my crawl space, and although I’ve done countless hours of research, purchased materials, and have begun the project, I still find myself trying to figure out just how to do this the ‘best’ way. The difference between DIY and paying someone, I suppose

So the question, I have a crosswall between the space and the basement. I didn’t plan to use my foam board on this wall, and only run the vapor barrier 6 inches up the wall from the floor. All other 3 walls are getting full treatment, with 3 inches left at top for termite code. Is this appropriate for concrete block wall that is technically sharing 2 conditioned spaces once encapsulation is complete? I’ll probably use the stego sticky tape vertically, 6 inches into the crosswall from the corners of the exterior walls to seal off the vapor barrier. Or should I terminate at the corner, as to not allow moisture within the barrier to reach that wall?

And lastly, more structural than encapsulation, I’m constructing a retaining wall halfway onto the crawlspace. Its on a slope from the garage footer so I want to backfill against that wall, but don’t want to backfill the whole space. It will be 15 blocks long, 6 blocks high using 8x8x16″ CMUs. Should I fill the cores of the entire wall? Or space some rebar every few feet and only fill the corners and rebar voids? And since the wall will only be 4 feet high, and will already be 7ish feet below exterior grade, is compacted stone footer sufficient or do I really need to pour a concrete footer in there?