The current foundation is half 1790s fieldstone and half poured concrete capped with concrete block (from earlier foundation collapses). The joints between these two materials are definite problems insofar as air infiltration and structural integrity. The air infiltration stems from cracks between concrete blocks, the fit between rocks of the old wall and poor foundation/sill contact in many/most areas.
It would be highly desirable to tighten this up.
Potentially thinking closed cell spray foam directly to foundation walls and/or perhaps to underside of subfloor. Joist span is irregular to the point of being random. Will spray foam stick to the underside of subfloor and will it stick to concrete or rock? Is this the way to approach, or is there another way? I realize this will trap moisture (oh, yes there is a lot of that) and intend on installing a power vent system to run in the non-heating season. Ideas?
Cellar is unusable area that I have no desire to improve or access. Only facilities in there is some newly installed pex. Just need to improve this problem.