I want to vent dryer through the rim joist of this home but it looks like this home has some sort of stone sheathing underneath the cedar shake. I can only see it from the basement. I can't really tell from outside without some destructive testing.
I am trying to figure out what this is, poking it with a screwdriver it appears to be hard as stone and would quickly dull my hole saw. The sill plate is atypical too. It looks to be more like a 4x6 with the floor joist notched and resting on it.
There is room above this beam for the dryer vent but I don't want to open a can of worms.
The foundation is 24" thick feild stone.
Any idea what I have? Could it just be plaster?
EDIT: Picture attached. I was wrong, there is no room above the beam. Above it you can see the hard material. Either way, I'm not sure I want to drill through the thick sill plate beam now.