The drain pipe of the sink is leaking. I opened the cover board from ceiling of the basement, and saw some leakage. When I pressed it with one finger, it broke into a big hole. The pipe feel brittle. I am not sure what's kind of pipe it is. Here are the pictures. The internal diameter is 2 inch. The thickness of the pipe is about 1/8 inch.
It is not PVC, not cast iron. The outside color looks like copper, but 1/8" may be too thick for copper pipe. I kocked the pipe, it doesn't sound or feel like the copper. It is easy to break more pieces by fingers around the hole. I guess it may be vitrfied clay pipe, but not sure. I checked the electric conductivity of the surface of the pipe, it is conductible.
The house is about 30 years old.
I ever thought to repair it with something like PVC-to-Cast Iron adapter, but not sure whether the pipe is strong enough.
If it is vitrfied clay pipe, how to fix it?
Thanks for your helps,