Question: Can you insulate around the soil stack?
I would like to know if it is an acceptable practice to insulate around
the soil pipe going up from the basement to the attic space. Our pipe
runs right behind our kitchen cupboards and bathtub area. In the winter
time these walls get extremely cold. When the furnace runs, cold air
flows down pass the soil stack into the semi-finished basement bathroom
and laundry. I was wondering if I could insulate this space with spray
foam or something similar. Please let me know if this would be
acceptable under normal codes and conditions.
Answer: I am not a plumber, and plumbing is not my forte. Our Plumbing site (see link below) may provide better answers. However, I find nothing in the Uniform Plumbing Code that would prevent you from
insulating around this pipe. The UPC specifications for soil or waste
stacks is mainly concerned with pipe diameter, height above roof, various
angles and sizes, and other things related to the flow of air. Of course,
if push came to shove, a permitting board would always say that because
this is omitted from the code does not mean it is expressly permitted.
But I think that's understood. I think you shouldn't have any problems
insulating your pipe.
