Waste line on OUTSIDE of house

Found this on an addition to a really old house - foreclosure- the previous owner added a toilet in the new addition but couldn’t get the waste line to the original part of the house - so he ran it out the wall, along the house, and back in to the original building - had to write it up and share -

“There is a black water waste line routed along the outside of the house. This does not meet any current (or past) acceptable standards for plumbing waste discharge. Recommend a licensed plumber examine this condition”




Two questions.

What reference prohibits an exterior installation of a DWV system, or is this based on the type of material used?

If it’s wrong, why would you recommend that it be “examined,” rather than recommend that it be “corrected?”

Other than looking but ugly the only issues in addition to the ones also found on interior (ie, slope, support, venting, etc) are;

  1. Is it protected from mechanical damage? The height shown in the photo would suggest that it is.

  2. Is there a chance of freezing? Even with a proper slope a trickle can freeze if it cold enough. Colorado gets rather chilly - Yes? There appears to be some insulation on the pipe. Is it enough? Is there other means to protect from freezing such as heat cables?

Those two things are really the only differance between this pipe and a burried one.

Yes it was “wrapped” with a silver cloth and duct tape - certainly not enough insulation for -10 degree winters; it had zero slope (look closely); and where it went back into the house it was actually knee high (the ground sloped up towards the front of the house) - suggested it be “examined” since a licensed plumber (they have to be licensed in CO) could say “sure, I like it”, but then he is on the hook, not me - even the buyer was agast at the installation - Was I too alarmist?

Forgot to add, no heat tape or any other method of keeping it from freezing - I guess I was looking at the concept presented in IRC 2003 P2603.3 even tho that may not have applied when it was installed in '92. - I know we don’t quote code, but this was just all wrong -

You may have a case with 2603.6, but I don’t see how 2603.3 would apply.

It is quite common to see a vertical exterior run in many older homes as the home predates having a Bathroom. I do not recall ever seeing a horizontal run of the drain line.

If connected to a Bathroom (Toilet), how is this line vented?