Insulating an old, dirty, inaccessible space.
I own an 1880’s 3 story townhouse in the Northeast (west of Philly). In the rear of the first floor is a one story addition, which I believe was built later over what was a porch. (Just a guess) Most of the house has a full basement, however half of this addition has less than 12 inches between the bottom of the joists and the dirt floor. The space in inaccessible – the photo below was taken by sticking my hand in a 6×12 hole in the stone foundation. The inaccessible space has rough dimensions of 4 feet by 17 feet.
As you can guess, that wood floor above gets very cold in the winter – but there is also the problem of mold and moisture. I am planning some renovations for the room above (bedroom) including insulating the exterior walls. But that will not, of course, get to the issues described above.
I do not want to use spray insulation in the rest of the basement, and this seems like a small area to call in for spray insulation – assuming the contractor can contort the wand to get everything. Any ideas for insulating this space would be appreciated. I’ve even thought of sticking cans of Great Stuff in there to puncture. Crazy, I know.