I am seeking advice/infomation re.Insulating the walls of a 1931 historically significant building located on one of our YMCA childrens camps. Specifically - Can walls with exterior siding but having no paper barrier between siding and studs be effectively insulated without removing siding. If so how and with what? Important note: camp located on West Coast, British Columbia, Canada. Coastal Rainforest can be quite wet certain times of tear. Hoping for reply - John.