I am in the process of refinishing our basement, we already have a bathroom where the sink and toilet are on the outside wall of the house. The pipes right now come in from left and right of the room from other finished spaces but are exposed inside the room and look horrible... now I know why they did that, they only built the all with furring strips then drywall on the outside walls... I am about the demo this room and redo it as a 2x4 back wall with XPS foam behind it then R-13 insulation in the wall... my question is, can I run copper pipes in that new 2x4 wall? Will it be a freeze risk since its between XPS foam and wrapped in fiberglass insulation before the drywall?
This wall is below grade and where the pipes would run is 7 feet below grade, well below the frost line.