In addition to the shower ptrap, l have an unused toilet pipe in basement floor. 4 inch wide.
I have a temporary cap (wing nut with rubber ring that expands) in place at moment.
Want more permanent solution.
Under the slab is 45+yr old cast iron piping.
I plan to cram a bunch of paper down the toilet pipe leaving at least 4 inches of pipe empty
And then use hydraulic cement to seal it.
Or do I have to excavate around pipe and beneath slab (4 inch thick concrete), cut the pipe,
and then do the hydraulic cement. Obviously there’s no ptrap below slab, just cast iron encrusted.
I guess there is some advantage to disengaging the pipe from the slab (maybe).
Is this procedure something I need to get inspected by city or ask a licensed plumber to review before’doing’?
Thanks for the ideas and advice.
Carl

Quote

..... Is this procedure something I need to get inspected by city or ask a licensed plumber to review before’doing’? .....

Probably YES


there may NOT be 'permanent' dead ends in either potable or sanitary piping

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

good grief !!! what is he supposed to do? hire an excavation crew with a 20 ton excavator to remove his basement floor because someone pulled a toilet that was installed 50 years ago?
cram the pipe with some pages out of old union magazines, fill the space left with hydraulic cement and go about living the rest of your life.

no,

he is supposed to ascertain the tie in point of the 'toilet branch' (probably by using a 'beacon locator' or 'cameraing' the line), open the slab THERE, cut the line and apply the cap or plug

the old piping may THEN be abandonned as it is no longer a plumbing dead end


OP,

if the 'branch' is 24" or less it is NOT a dead end (for plumbing purposes)


THIS IS THE CODE REQUIRED MINIMUM STANDARD

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

It safe to assume the soil pipe is within 2 ft of the main sewer pipe,
Just saying we’re not talking about 10 feet of unused pipe.
I would think large unused runs would be what we’re trying to avoid.
Alternatively I could make this a vent pipe, I would have to transition
to 1.5 inch vent pipe, but technically it would not be terminated.

Correct

24" max for a 'termination w/o dead end'

if it is actually 28" ? who really cares !

knowledge is power

IMO:

'pull' the small 'riser' from the trap - stuff newspaper as far in as you can reach - leave the 'down piping' open for the mortar - fill 'er up


ps. grout, mortar, and concrete CONTRACT as they set/cure - they do NOT expand

pps. cement+water=grout ~ cement+sand+water=mortar ~ cement+sand+graded stone/gravel=concrete

cement is a dry powder

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



Edited 1 times.

Last time I did it I did three layers.

Newspaper loosely near the bottom. Then I applied liberally some expansion foam over the newspaper. Once the foam kind of hardens in 1 hour, I poured regular concrete not hydraulic cement.