I live in the North East. I insulated my unfinished/unheated basement ceiling with R-13. I wanted to block most of the warm air from leaving through the upstairs floors, but not block all of it. We do spent some time down there and I didn't want it to be very cold. I also feel the insulation cuts down some of the noise from the boiler and washing machine. Was this a waste of time? Should I have used R-19? Should I insulate the walls?