Fieldstone foundation--how to plug big gaps?
Our home was built c. 1800. It has a dirt floor cellar & rough fieldstone foundation, mostly huge stones, very stable.
When we bought the place 40+ years ago, the gaps between stones had long-ago been chinked with bricks and rocks (4" to 12" across). Some flat, some roundish, etc., held in by mortar, old and new.
Most have gradually fallen out. For years I plugged the gaps with wads of newspaper and fistfuls of fiberglass insulation jammed in as hard as I could with screwdrivers.
Too busy with other projects to do more. Small animals burrowed through, so I packed in more fiberglass. But we could still see daylight through the cellar wall here and there...
I've now pulled out most loose rocks (etc) and gone over the walls with whisk brooms & shop vac, getting out much loose grit/dirt/fiberglass. I'd like to stick rocks and broken bricks back into those holes and secure them--but HOW?
Upper holes show daylight (not shown in photo--that area was replaced with cement when cellar door was moved in 1970s). Several below-ground holes go all the way back to the underside of flowerbeds, where rodents tunnel open "chimneys" for air to escape (largest spaces not shown in photo). Not worried about water leaks. Just want cellar to be more rodent-proof and waste less warm air in winter.
Considering shoving pebbles/small rocks into deepest holes & cementing in place; after cement dries, shoving in larger rocks & more cement, & pushing cement into the narrower places. Apparently need an old-fashioned cement intended to gradually rot away. Alternative: cram in fresh fiberglass insulation.
Has anybody done repairs of this sort, who can advise me?