My home, located in Southern Westchester County NY, has a sun room off the main house with only a crawl space beneath it. The remaining part of the house has a basement beneath it.  We do not have water/humidity problems in our basement.

During the winter, the sunroom (180 sq ft) is much colder than the rest of the house.  The sunroom floor is also significantly colder than the rest of the house. We upgraded the windows a few years ago and now have decided to weatherize this room as much as possible for year round comfort.

I had a contractor come in and he open cell foamed (Thermoseal 360) the exterior walls and also the floor (from above, no access from below).  For the floor, there was no backing that the foam was sprayed to.  It was sprayed side of joist to side of joist (2x10s).

I am not sure the floor was a good idea and am now looking at an option to remove the foam and encapsulating the crawl space as a better option.  The crawl space is unvented (unless air is leaking through the foundation walls) and likely does have some air transfer with the adjacent unfinished basement where there is a small gap for pipes and wires.

Is removing the spray foam from the joists and encapsulating the proper option?  I am worried about the potential moisture issues that have been created with the open cell foam.  The crawl space is mostly above grade and is about 18 inches below the 2x10s (so roughly 30 inches from top of joist to dirt floor).

Some pictures of the spray foam in the sunroom, the exterior foundation  around the sunroom and a beer label (100 years old – it closed due to prohibition) I pulled from the debris when i cleaned out the crawl space.  I think this kind of shows that moisture issues are not really present (currently).