I have one use case that actually makes sense. In one of the facilities I work in my desk is in the founders old house from the 1970s and for some reason the waste plumbing is too shallow and at too little of an angle into the main that it freezes and gets backed up every year. Because of the cost to fix it, and because there’s probably a reason that it’s wrong to begin with (everyone that would know is dead now), we use single ply in that building during the cold months because it breaks down easier.
I have one use case that actually makes sense. In one of the facilities I work in my desk is in the founders old house from the 1970s and for some reason the waste plumbing is too shallow and at too little of an angle into the main that it freezes and gets backed up every year. Because of the cost to fix it, and because there’s probably a reason that it’s wrong to begin with (everyone that would know is dead now), we use single ply in that building during the cold months because it breaks down easier.