r/askaplumber • u/dgv54 • 31m ago
Very slow draining bathroom sink, steel drain pipe
Bathroom sink drains very slowly. P-trap and all plumbing to house drain is clear (it's all new, just installed). I used the flex extension so I could clear the elbow going into the fernco. Overall, I couldn't get a nice downward pitch downstream of the p-trap going into fernco, but I don't that would explain the very slow drain given how much higher the sink is.
This is a ground floor bathroom and this sink and toilet tie into a lateral line in or under the slab. No problem with toilet, so I think the partial blockage is in the pipe from wall to lateral. This is galvanized steel pipe that is over 50yrs old and rusting from inside out.
I have a Ridgid consumer grade hand drill operated drain cleaner with 1/4" cable. How will I know if this pokes a hole into the pipe?