cast-ironplumbingtoilet
I'm replacing a toilet's wax ring in my 1960 US home. With the toilet removed, I noticed ugly-looking bumps on the inside of the cast iron drain pipe:
Here's a closer, more tasty look:
Aside from any coprophobia, are these bumps a sign of a serious problem (e.g. corrosion)?
No, there should not ever be two traps on a single drain line.
The point of the trap is to create a water barrier which prevents sewer gasses from coming up the empty pipe and into the house.
When you have two traps on the same line, you end up creating a kind of vapor block in the line which prevents it from draining properly.
What do you do?
Get yourself some 1 1/2" PVC (not CPVC, which is yellow, PVC which is white) with a 90 deg elbow, and also get two Fernco couplings (black plastic couplings with straps on each end that can be tightened) that will fit the pvc and iron drain pipe.
Use a metal blade on a sawz-all and cut out the p-trap in your basement. (Have a bucket handy!) Leave room to connect the Fernco coupling on both sides. I'd cut the right hand side out just past the coupling.
Measure and cut the PVC so that with the 90 elbow the ends line up with the newly cut drain lines. Glue the PVC together and confirm the fit, then connect to the old drains with the Fernco.
Viola - a proper drain line that will drain smoothly w/ no vapor lock.
I had a similar problem once but the leak was visible and the outside of the toilet bowl was wet. Flushing from the tank produced leakage but flushing with a bucket did not.
It sounds like clean flush water is somehow escaping on its way from the flush valve to the toilet bowl. This could be from a misaligned tank fitting or a crack in the ceramic material. I assume that you have found no water running down the outside of the fixture.
Depending on the design of the toilet, the connection between the tank and bowl parts may include a metal fitting set into the bowl. This can become loose or cracked and thus leak water outside the flush pipe but still inside the toilet.
Or an imperfection or crack in the ceramic could allow clean water to escape from the rim passage or wash passage, well, whatever it's called and the design of these passages varies a lot. The point is, flush water can escape its proper path and still not get outside the toilet where you would see it.
EDIT: couple of pictures to show what I mean:
The red callouts show where an invisible leak might occur only when tank flushing and not when bucket flushing.
Best Answer
Yes, that is signs of corrosion and in another 100-150 years, that will result in leaks in that pipe...