We recently bought a new home. The house used to be a two family home. Somewhere around 2000 the second floor was renovated and the house converted to a single family home.
After a recent roof leak I realized that the house has two soil stacks. After some investigation I found that one soil stack services two toilets, two bathtubs and one sink. The second soil stack only services one second floor sink.
Both soil stacks are 4 inch cast iron pipe and go from the roof all the way into the basement and disappear into the concrete floor. They are about 10 feet apart.
Can the soil stack that is only servicing the one sink be cut back into the house and capped with the hole in the roof repaired?