I have uncovered a long covered up fire on my first level ceiling. After remediation with soda/sand blasting I have had the areas sprayed with Sentinel's 538 encapsulation product - claimed zero voc. The smoke smell still lingers a bit and before I drywall the area I am thinking about filling the gaps in the decking and between joist with a caulk or spray foam. After trying a tube of big stretch and a can of great stuff for comparisons I am have reservations about using a whole lot of this stuff throughout the ceilings. The painters and sandblasters were not able to reach into these nooks and crannies where I suspect the small amount of residual smell is coming from these areas. Any advice on product(s)that may be used in these spaces that range from 1/16"-1/2". Thanks in advance. I tried uploading photos but with no luck