How to seal old drain pipe in foundation?

[Dante M. Catoni]

I have a sink in my basement that is hooked up to a 2.5" drain pipe that
goes to the septic tank that is no longer used. I want to cut the pipe
flush with the wall and seal it up. The pipe is probably from when the
house was built in 1935. Can it be welded? If not I can cut a steel plug
and epoxy it in the pipe, unless someone has a better idea.

Thanks
Dante

[DanG]

It matters a great deal as to what the pipe is made of and what
it is doing.

It sounds like sanitary sewer, but has it been open all these
years or is it plugged now? If so, how is it plugged?

It could very well be a piece of galvanized pipe threaded into a
cast iron fitting. Remove galvanized nipple, replace with
threaded plug.

It could be cast iron - no you wouldn't weld it. The very best
would be to pop out the sanitary t and replace with straight pipe
(pretty good size job)

DIY is great, but this one may be time for a plumber.

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______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)
dgri...@7cox.net

"Dante M. Catoni" <dcat...@cox.ne> wrote in message
news:fipij.20232$hO4...@newsfe19.lga...

[Harry K]

Probably cast iron so no welding except by an expert.

Cut flush, plug with mortar or cement pre-mix. May have to add a
bead of caulk around the perimeter of the plug as mortar and premix
shrink slightly as it dries.

Harry K

[Robert Allison]

That is going to be cast iron and difficult to weld. It could be
brazed, but it would be simpler to plug it this way;

Stuff some fiberglass insulation down into the pipe about 6" or so.
Fill the cavity above the insulation with non shrink grout. Do whatever
you want to finish off the repair, but while the grout is drying, you
can slip a screw anchor into it to receive the screw for a cover plate,
if you want.

Robert Allison
Rimshot, Inc.
Georgetown, TX

[lett...@invalid.com]

SInce you do not mention the material it was made of, I can only
assume it's threaded galv. steel pipe, or cast iron, since that was
common in 1935. First, are you sure you will never want it again?
I'd avoid cutting it off flush if there is ever a chance to need it
again. Also, it can be useful as a cleanout for snaking out the pipes
in the future. So, I'd suggest you do your best to plug it with a
removable plug and not cut it flush to the wall. It might unscrew
from another piece where you can put a standard screw in galv or pvc
pipe plug. If not, use a sawsall and cut it off, leaving about 3 or 4
inches sticking out of the wall. Then get a small piece of PVC to
match the diameter, and glue a cap on the PVC. Let the cap dry for a
few minutes and attach the capped PVC to the original pipe stub with a
rubber Fernco coupler. This is an easy an cheap fix, and will allow
you to use this pipe in the future for snaking the system and/or
connecting something.

[dpb]

Robert Allison wrote:
> Dante M. Catoni wrote:
>> I have a sink in my basement that is hooked up to a 2.5" drain pipe
>> that goes to the septic tank that is no longer used. I want to cut the

>> pipe flush with the wall and seal it up. ...
>
...

> Stuff some fiberglass insulation down into the pipe about 6" or so. Fill

> the cavity above the insulation with non shrink grout. ...[etc...]...

What he said... :)

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