Our house was built in early 1930's. When we remodeled 20 years ago we did not put insulation between the interior wall (between bedrooms and bathrooms). On the outside walls we put up pink foam board between the outside wall and drywall. I would like to do sometype of blown in insulation between all walls. Is this possible and/or smart. We live in Michigan and the house is considered "tile" brick (kinda like the size of a cinder block, but browns). Thanks for reading.