I need to add a trap to my cast iron drain in my basement.
I'm going to remove my 4" cleanout and run the trap into that fitting.
Here's the difficulty:
My cleanout plug is threaded into a bushing held into the bell end of
a cast fitting. The threaded cleanout is a little shy of 4" (about 3
15/16) I bought a 4" threaded male PVC fitting but it is about 4 1/4.
Do they make a threaded PVC fitting that will go into a 4" female
Should I just remove the bushing and get the rubber boot that will let
me go from the bell end of the cast down to 4" PVC?
Very strange. AFAIK, all pipe fittings are based on inside diameter.
So the 4" PVC you have should go into the 4" cleanout threads.
Given that you say it misses by about 5/16 or so, I can't imagine
what you have. The Fernco type rubber coupling is probably
The clean-out plug was never intended to be used as a perm
connection, only to be removable for access to clean out
the line if it became blocked...
There is no such thing as a plumbing fitting which will screw
into the threads on clean out plug to extend the drain line...
Do this job properly with the correct type of fittings...
This might mean cutting the stack to install the correct
cast iron fitting using Fernco couplings on the stack and
then transitioning to the PVC piping on the stub of the
proper cast iron fitting you just installed on the stack using
an additional Fernco...
Actually that is not true.
There was an adapter sold at one time that did exactly that. I think I saw
it at an online plumbing specialty store just a year or so ago. The one I
removed from service went from a 4" CO to 2" female thread.
I do however agree that cleaning out the hub and using a rubber donut or
cutting the pipe and using a Fernco is the better approach.
Please come visit http://www.househomerepair.com
I actually know of one installed in a basement bathroom where the
homeowner added a sink to a bathroom that previously only had a shower
and a toilet...and a clean out in the slab.
IIRC it took 2 reducers: a cast iron 4" OD to 3 1/2" ID (female) reducer
that screwed into the clean out, then a cast iron 3 1/2" OD to 2" ID
(female) that accepted a threaded PVC adapter into which a 2" PVC drain
pipe was glued.
I'm not sure why a rubber donut wasn't used.
You will need to rework your system from the first available cast iron
bell end in good shape. I have had success in dealing with older bell
ends by using a 9" body grinder fitted with an abrasive cut off disc.
Cut a groove all the way around the pipe, then use the disc to cut
through about half way. Then tapping a cold chisel wedge into the cut
will neatly sever the pipe. If the cut is fairly close to the bell it
is easier to get a drill into the lead and oakum seal and get rid of
it. The bell can then be cleaned with the usual wire brush on a drill
or whatever. At this point measure the bell. Older 4" cast iron was
around 4 1/2" inner diameter IIRC, and the newer is 4 1/4". If you
just buy the appropriate Fernco fitting at your box store it may work
fine with your PVC. If it is a real sloppy fit you will have to call
Fernco customer service and they will likely find a dealer somewhere
who has the older large fitting. From there it will be standard PVC
work, fit up and glue. Good luck.
Found a tiny old supply house in Trenton that had a 4" XH TY-Seal.
for those of you who think I'm dumaas or a nut there is a difference
in sizes between 'service weight' and 'extra heavy' cast iron. The ID
of the hub on XH is about 1/4" bigger than standard service weight
see pages 14 & 15 of this pdf
I now know more about soil pipe sizes than I ever wanted to know.
Shout out to Perlstein plumbing - second time they bailed me out.
Well I wire brushed and sprayed the cleanout with PB blaster on my way
out the door this morning. When I got home I sprayed some more. No
luck. The fitting would not unscrew.
No matter, I already bought a 4" hub to 3" PVC Fernco donut. Melted
the all the lead out with a brazing torch then had to drill around the
steel bushing to get it to come out. Now I'm left with a 4" cast iron
Freakin donut is loose in the hub! I did some googling and it seems
that not all hubs are created equal size. Mine is marked 4xH PE but
the donut is no way gonna seal.
I wrapped a rag around the donut and got a seal for the night but now
I gotta figure some other way to get a seal...
How about some photos?
Pipe, having a "nominal size" that often bears little relationship to
its actual dimensions, is typically controlled by th OD.
That is, most 4" pipe has the same OD.
Threaded pipe elements (PVC, brass, steel, stainless) will all fit
together independent of wall thickness.
(pipe schedule) because the pipe gets thicker by reducing the ID.
As odd as it may sound your threaded plug might be 3-1/2"
Unfortunately cast iron pipe defines this standard because it was
never meant to be assembled by threaded joists.
Lead & okum(?) was used years ago and now no-hub coupling.
Without a photo its hard to tell what you've got but if no hub
coupling should let you do whatever you need to do.
One warning, if the rest of the drain system above this point it cast
iron, the section you cut our might be supporting the piping above.
Secure the pipes above the cut by blocking well at an old bell joint.
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