Cast Iron Waste Pipes - removal?

[BltByKrmn]

Has anyone removed cast iron waste pipes? My house is ~90 years old and I will be tackling the bathroom as my next renovation project so I need to decide if I should switch to PVC and remove the old cast iron.

How bad is it going to smell if I have to cut these pipes out? My fear is they are going to be coated with 90 years of fecal matter and I really don't want to deal with that sludge getting all over. The good news is all the pipes are in the same 20' area at the back of the house and all are exposed in my wide open basement.

[robr2]

If you can leave the cast iron, do so. They are much quieter than PVC and really don't "wear out".

If you need to remove them, be careful as they are heavy. The smell won't be any worse than other types of pipe.

[BltByKrmn]

It would make my life a lot easier to leave them, but how do I know they will hold for another 20 years? They look like **** but then again that's not indicative of their functionality.

[Bladecatcher]

Curious about this as well. The main drain pipe (6"?) from my ~40 year old house to the septic tank is showing some serious corrosion on the top side of it (runs fairly horizontal). Almost like something had been dripping on it for years, but there is nothing directly above it. Feels solid, but don't really know what's left of the pipe.

1. I don't know why the outside of it is corroding.
2. I don't know if this is bad or not...

I think it would be a fairly simple replacement, but 40 years of (mostly someone else's) crap is 40 years of crap. Pulling someone else's hair out of the drain traps was enough to make me dry heave.

[barry2952]

Good advice above. Nothing wrong with iron pipe.

However, it's a bit of a bitch to modify iron pipe and finding a plumber with the skills to do the joints is not an easy thing to do. The old pipe is coupled by inserting a standard pipe into a bell-shaped sleeve in a fitting or next piece of pipe. Once all the pipe is in place and supported the joints are tamped hard with a lot of cotton rope. Enough room is left to pour in molten lead to seal the joint, which is damn tricky in vertical joints. They can be a bitch to take apart. The best bet is simply breaking the pipe with a sledgehammer.

There is another huge drawback to PVC pipes in that they are not as thermally stable as iron pipe. It literally moves with temperature changes. When we use the bathtub in our house the pvc pipe makes contact with a floor joist, somewhere. As the tub is just about drained there's a thunderous sound of the rub spot breaking free and shaking the house.

[TwoLitreVW]

so.... just so i'm getting this right: cast iron pipes are GOOD?

the reason i'm asking is because i bought a house made in 1954 with cast iron waste pipes. all the plumbing in the house works great.... but when i had a plumber come out and inspect a slow draining toilet after we moved in, he ran a camera through the waste pipes.

he then proceeded to try and convince me that cast iron pipes are terrible, and that within a few months i'd have to tear em all out and replace the whole thing. he was willing to cut me a deal and run new PVC pipes for me for about $17,000.

at that point, i asked the neighbors (3 of which have lived in the 'hoood since the houses were constructed) if anybody has had catastrophic plumbing failures resulting in financial ruin. the oldest of them (a boomer who was raised in the home) said "tell your pipe monkey to go frack himself.... you have nothing to worry about."

i replaced the toilet myself, and so far, everything seems just fine.

[barry2952]

so.... just so i'm getting this right: cast iron pipes are GOOD?

the reason i'm asking is because i bought a house made in 1954 with cast iron waste pipes. all the plumbing in the house works great.... but when i had a plumber come out and inspect a slow draining toilet after we moved in, he ran a camera through the waste pipes.

he then proceeded to try and convince me that cast iron pipes are terrible, and that within a few months i'd have to tear em all out and replace the whole thing. he was willing to cut me a deal and run new PVC pipes for me for about $17,000.

at that point, i asked the neighbors (3 of which have lived in the 'hoood since the houses were constructed) if anybody has had catastrophic plumbing failures resulting in financial ruin. the oldest of them (a boomer who was raised in the home) said "tell your pipe monkey to go frack himself.... you have nothing to worry about."

i replaced the toilet myself, and so far, everything seems just fine.

Cast iron can rust through. The joints can come apart. Soil that supports the pipe can wash out. That being said, the stuff is tough as nails. The reason we don't use it in standard construction is simply cost. It's costly to buy and you typically need two workers to install it. Cast iron is still used in construction where party walls between apartments and hotel rooms to keep the sound level low. It's surprising how much noisier PVC is.

[robr2]

Good advice above. Nothing wrong with iron pipe.

However, it's a bit of a bitch to modify iron pipe and finding a plumber with the skills to do the joints is not an easy thing to do. The old pipe is coupled by inserting a standard pipe into a bell-shaped sleeve in a fitting or next piece of pipe. Once all the pipe is in place and supported the joints are tamped hard with a lot of cotton rope. Enough room is left to pour in molten lead to seal the joint, which is damn tricky in vertical joints. They can be a bitch to take apart. The best bet is simply breaking the pipe with a sledgehammer.

Very rarely will a plumber make modifications to an existing system with jute and lead. Most times if you are adding to a system that has cast iron waste pipes, the plumber uses a chain cutter to remove a section and attach a fitting. The fitting is then connected to the stack with rubber sleeves and clamps.

he then proceeded to try and convince me that cast iron pipes are terrible, and that within a few months i'd have to tear em all out and replace the whole thing. he was willing to cut me a deal and run new PVC pipes for me for about $17,000.

I'm guessing said plumber had his eye on a new boat and was in need of a down payment.

[GeoffD]

I had 1950 cast iron waste pipe in my summer place. From 60 years of moisture down in my crawl space, I had some major corrosion issues and had to replace it with PVC. At this point, I think I have maybe 2 feet of remaining cast iron where it passes through the foundation wall. From there, it goes to a new-ish holding tank where it is pumped up to the sewer in the street.

I also had corrosion issues with my copper domestic water pipes and replaced those with PEX.

I wouldn't replace plumbing that didn't have those kinds of issues.

[BltByKrmn]

So if I do want to keep them, how do I know if they are bad? Some of them look like they have rust icicles forming which I can't imagine is a good thing?

[barry2952]

So if I do want to keep them, how do I know if they are bad? Some of them look like they have rust icicles forming which I can't imagine is a good thing?

They are no big deal. They are easily knocked off with a rooter. They really don't come in contact with waste as that flow is typically in just the very bottom of the pipe.

[fasttt600]

I am in the process of transferring mine over to pvc. My house is 110 years old, and didn't look ideal. about two months ago the lateral collapsed outside, so now I will have pvc all way to the main!!!
If you have everything open and your planning on moving any of the positions, now is the time. I also like the switch over because I was able to put a clean out in multiple locations(hopefully alleviating headaches down the road) The cost of materials is fairly cheap, it just comes down to time....

[White Jetta]

I just had a 3 hour battle with some 4 inch iron vent piping and my 5 pound mallet a little over a week ago. It was tough to do but had to be done to move the piping into a better position to clear the new bathroom ceiling height. I then mated the new pvc 4 inch vent stack to the bell shaped female end going into the crawl space and sealed it up with a pound of plumbers putty.

My house was built in 1925.

[winstonsmith84]

I had to cut a soil pipe that lead into my main drain last year. I just cut the iron pipe about 6" from the lead/rope packing seal and used a compression PVC fitting over the pipe. I really did not have that much build up in the pipes. 1/4" or so.

[formula14]

if you are moving fixtures around than it would be easier to get rid of the cast iron. I have a house from 1900 that I moved the bathroom fixtures around and ended up renting a cast iron cutter and removed a few thousand pounds worth of it which also helped the second floor framing. I left about 4 ft of it in the basement and used a rubber and metal sleeve to connect the pvc. If you aren't moving fixtures than i would leave it. As someone else pointed out is much quieter than PVC. I think some high end new construction still use it.

[alleghenyman]

Has anyone removed cast iron waste pipes? My house is ~90 years old and I will be tackling the bathroom as my next renovation project so I need to decide if I should switch to PVC and remove the old cast iron.

How bad is it going to smell if I have to cut these pipes out? My fear is they are going to be coated with 90 years of fecal matter and I really don't want to deal with that sludge getting all over. The good news is all the pipes are in the same 20' area at the back of the house and all are exposed in my wide open basement.

They can corrode. They also can crack due to temperature cycles or settling in an old house. I didn't realize how bad mine were until I got into the wall. They might be best left alone if they are in good shape but beware the strains they can be put under in an old creaky house.

I replaced mine during a bathroom gut renovation. It ran down an outside wall and was cracked down the side, probably from the freeze-thaw cycle. Where it connected to the toilet, it was cracked, because the floor had sagged probably 2 inches over 80 years. The pipes under the floor that drained the tub to the stack weren't flowing properly either due to the floor sagging. The floor was covered in "mud" which was really 4" of cement and then subway tile that weighed about 4000 pounds, and walls with heavy subway tile, and a cast iron tub that weighed 500 pounds empty. I took 1500 pounds of scrap metal alone to the scrap yard.

It was really easy to replace. I started out carefully using a diamond blade in a reciprocating saw, because I preserved the cast iron pipe run from near the ceiling to the roof vent. This probably wasn't worth the hassle but at the time I was afraid of replacing the whole thing. On the way down it came out really easily with some bending and light hammer work - it was brittle and cracked easily. I had to open up a wall in the kitchen below but easily covered it with drywall, and in the basement connected the PVC to the copper drainline with a rubber "Fernco" coupler. It was probably the easiest part of the whole bathroom job and I am glad I won't have to worry about it again in my lifetime.

And no, it was a little crusty but it wasn't coated in an inch of nightsoil.

[alleghenyman]

Slow draining toilets can be caused by clogged vent pipes.

so.... just so i'm getting this right: cast iron pipes are GOOD?

the reason i'm asking is because i bought a house made in 1954 with cast iron waste pipes. all the plumbing in the house works great.... but when i had a plumber come out and inspect a slow draining toilet after we moved in, he ran a camera through the waste pipes.

he then proceeded to try and convince me that cast iron pipes are terrible, and that within a few months i'd have to tear em all out and replace the whole thing. he was willing to cut me a deal and run new PVC pipes for me for about $17,000.

at that point, i asked the neighbors (3 of which have lived in the 'hoood since the houses were constructed) if anybody has had catastrophic plumbing failures resulting in financial ruin. the oldest of them (a boomer who was raised in the home) said "tell your pipe monkey to go frack himself.... you have nothing to worry about."

i replaced the toilet myself, and so far, everything seems just fine.

[AJB]

I would replace it. My house is only 70 years old and we were going to leave the cast iron waste pipe, but it was in pretty bad shape. And it had pin holes in it once it had exited the house and was in the ground. Just yank it out. PVC is much easier to work with, plus if you goto sell, the next guy won't have to worry about it.

[Jettavr666]

I would replace it. My house is only 70 years old and we were going to leave the cast iron waste pipe, but it was in pretty bad shape. And it had pin holes in it once it had exited the house and was in the ground. Just yank it out. PVC is much easier to work with, plus if you goto sell, the next guy won't have to worry about it.

I mostly feel the same way. Cast iron is durable and quiet, but not as durable in the long run than PVC. PVC is easier to work with, cheaper, doesnt rust, and doesnt have nearly as many joints that can fail. Also cast iron lines can crack all along them which can lead to huge repairs and nasty smelling leaks.

[AJB]

One thought I thought that there was some black pvc-like pipe that was thicker gauge and was quieter than regular pvc.

[robr2]

The black pipe is ABS. The white pipe is PVC.

AFAIK, the wall thickness of schedule 40 ABS and PVC is the same.

[AJB]

After googleing around a bit, PVC vs ABS, seems each has there pro's on con's. And also various by building code.