Replacing 'lost' insulation within wall cavity?
Decided this is best as two posts, so I'm going to deal with just one issue here, all suggestions appreciated.
Had to fish a wire through an outside basement wall- there is a 2x4 wall inside of the concrete wall of the basement. 80's vintage so the moisture barrier etc is not up to today's standards, and I noticed behind at least one outlet, they did not bother to insulate, which I've done before replacing the outlet box (had to remove so I could drill and fish wire through stud)
In order to fish the wire, I had to cut a couple of small holes in the wall to get the drill bit and fish tape through etc. After some prolonged probing etc the insulation is now pretty munched so there's quite a gap in these areas. I had figured on poking small tufts of insulation into the hole to replace it. As I understand it, you don't want to pack it in too tight or it will lose its effectiveness by not having enough puff in the insulation, so would this method be adequate? I had also considered spraying some spray foam, the spray can type, into the gap, I figured when it expands against the drywall and the remaining moisture/air barrier against the drywall, it'll seal it up, becoming its own barrier in that spot.
Does this sound ok? I will be encapsulating the new wire I ran through there which I assume will be ok. Is the combination of fibreglass (it's r-12 stuff if that matters) and spray foam adequate, or would I be better off just using the spray foam for the gap? It'd probably be the lower expansion stuff that's supposed to be safe for doors and windows.