Crack in cast iron soil stack - replace just cracked section or all cast iron parts?

[LilaciousNYC]

The house is a little over 80 years old. I have a spliced image of the riser below (sorry, I couldn't get the camera back far enough to take it all in, and the flash created a haze over the image). The pic shows the first floor where the cast iron soil stack has a long vertical crack running about 24" long - noted in red. Running my fingers along the crack, it feels like a seam split along the length with the crack being about 1/16" wide.
Behind this wall in the image is a powder room. On this stack, the cast iron connections run down to the basement and branches out above the second floor to service two bathrooms.

A property manager suggested replacing ALL cast iron pipes and fittings (tees, bows, flanges, etc..) on this soil stack. Meaning, replace everything to the 2F bathtub, shower, toilets & lavatories. His reasoning is that all these pieces are old and will fail on this 80 year clock just as this piece did. This would involve opening up ceilings on the 1F to get to those fittings.

I am leaning towards just replacing the damaged piece in the picture.
What is reasonable here?
Is the property manager (also handyman) right and replace all?
Or should only the cracked segment be replaced?
Or should the full vertical lengths be replaced (and leave the tees, wyes, elbows...)?
Thank you everyone.

 

[PapaDisco]

Cast iron is great stuff, but it will channel over the years and the water will wear its way through. You see that the earliest on horizontal runs, but the verticals certainly do it to. You could camera the pipes to evaluate. A split seam is highly unusual, but is possible depending on the quality of the pipe.

I'd cut out the damaged section with the intent to just replace it, and while it was out take a good look at both of the ends it's attaching to for any channeling and erosion on the rest of the pipes. If it's negligible, then just replace the bad section. If it's bad, then go all the way and replace the rest of the pipe of similar age.

 

[Sponsor]

 

[Sylvan]

I have existing cast iron in my home from 1921 and it is still in good condition.

If I had signs of the CI being compromised, I would not hesitate to replace it with CI as I like quiet, safe and long lasting plumbing systems.

I did replace the CI for this account as it was over 123 years old in the Bronx (Riverdale)

 

[John Gayewski]

I would just replace the section for now, who knows if you'll have more failures it could've been slightly cracked for a long time and finally opened up. It could not happen again for 20 years or six months.

Tap on it and see how it sounds.

 

[LilaciousNYC]

Thank you everyone. That segment of the soil stack was replaced with PVC. The plumber also did a colonoscopy of the soil line out to the municipal connection and all looked pretty good.
The plumber did warn me beforehand that cutting out the old cast iron might jiggle the entire system around and have ricochet effects on other portions of cast iron so we proceeded with caution. He said afterwards that the cut felt solid, i.e. the joints above and below seemed well fastened and didn't jiggle around so he was confident that his work would cause other issues with the remaining system. He surmised that the opening up of this seam may have been initiated by soil stack replacement work on the floor below. That is, the work below 15 years ago (also replaced with a PVC segment) jiggled the system above and resulted in slow deterioration along this seam.
In any case, got some mass loaded vinyl and started wrapping the PVC for sound attenuation then started to worry about plastics reacting to each other and melting each other over time. So I got some kraft paper and wrapped the PVC. Then I wrapped the mass loaded vinyl sheet around that.

There have been no leaks but now the 2F shower whistles while water is running....

 

[Sylvan]

You better buy lots of smoke detectors as PVC in a fire is what is killing people from the World trade center attacks long after the attack.

NYC only allows PVC to be used in residential 5 stories or less and banned from any commercial installation regardless of height

For a cheaper system then the plumber should have offered a compromise

Cast iron for the drainage systems for a quiet safe system and PVC for venting

Also, when one of my companies repipe a system we give them a capital improvement form to sign, and they can usually get a tax write off.

Labor is the expensive part of the trades and materials are about 1/2 the cost of labor (rule of thumb)

"Captain Alexander Hagan, President of the Uniformed Fire Officers Association (UFOA), said, “Fire Officers take an oath to ‘protect the lives and property of the citizens of New York City’ and there is an ongoing interest to the public if laws regarding the purchasing and use of PVC products by the City are not being complied with. PVC is among the most serious dangers to humans and the environment when it is burned. … From a fire perspective, we urge compliance of the City to ensure an environmentally friendly purchasing process.”

 

[LilaciousNYC]

You better buy lots of smoke detectors as PVC in a fire is what is killing people from the World trade center attacks long after the attack.

NYC only allows PVC to be used in residential 5 stories or less and banned from any commercial installation regardless of height

For a cheaper system then the plumber should have offered a compromise

Cast iron for the drainage systems for a quiet safe system and PVC for venting

Also, when one of my companies repipe a system we give them a capital improvement form to sign, and they can usually get a tax write off.

Labor is the expensive part of the trades and materials are about 1/2 the cost of labor (rule of thumb)

"Captain Alexander Hagan, President of the Uniformed Fire Officers Association (UFOA), said, “Fire Officers take an oath to ‘protect the lives and property of the citizens of New York City’ and there is an ongoing interest to the public if laws regarding the purchasing and use of PVC products by the City are not being complied with. PVC is among the most serious dangers to humans and the environment when it is burned. … From a fire perspective, we urge compliance of the City to ensure an environmentally friendly purchasing process.”

Thank you. The property is not in NY.

 

[Sylvan]

PVC really does not care where it is installed. The dangers are still there.

BTW Labor is much cheaper outside NYC so the plumber should have told you the plus or minus of each material