Hi, I have a 1901 Queen Ann in climate zone 5 in Northern Indiana and in every other frame cavity is filled with brown/grey loose fill/blown-in insulation that I can only assume has been there for awhile per the attic. They laid it over the floor in the attic and some open floor joists areas, and noticed that it has broken down into a black dust underneath. But it is still well packed in the cavities where filled, it has not collapsed, so thats good.
But I've been reading and finding different information on the ability of the house to breathe vs moisture barrier vs thickness of the exterior insulation/siding vs new insulation etc.
Well, my house has accumulated a lot within it's 118 years, from four to five layers of roof shingles (replaced) to five layers of siding material (Per images) that measures 3.5" thick, then you have in the interior, lathe strips and 1" of plaster wall.
So with what I read from another site, that with the exterior of thickness from the multiple siding materials, that I don't have to worry about moisture if I was to add more blown in or batting insulation.
Is that correct? Could I add more blown in insulation to the empty cavities or should I remove all plaster and lathe, attach vapor barrier by weaving it within the frame and cavities before adding insulation batting and dry wall (not sure if Id be good enough to replaster)
Thanks in advance!
(Added links to the images from google drive)