Henley wrote:
Recently my kitchen sink started backing up into an old pipe. It was
cut and sealed outside at the main drainage pipe. Now the next joint
up is leaking. Do I need to replace the whole pipe or seal it? Could
a blockage in the drainage line be causing it to back up? I am
worried because this pipe is located against the wall of my house and
runs thru my utility room with the hot water heater and circuit
breakers.

I suggest you find what was and is causing the blockage and back up.
You don't fix a leak caused by a backup by sealing the leak, at least you
don't do it if you want it properly fixed. I may have it wrong, but it
sounds like you are trying to fix the symptom not the cause. Sort of like
sitting on a tack, and taking a pain pill rather than standing up.


--
Joseph Meehan

Dia 's Muire duit