My house has old (large diameter) steel central heating pipes. These travel through the basement before passing up through the house. My concern is that when they pass through internal walls they are cemented directly into the wall (i.e. they are in tight contact with the brickwork).
My question is - is this normal, or should they be insulated as they pass through the internal brickwork? (I've no idea whether the heat loss in this case is significant or not).