What do I need to replace corroded cast iron drainage pipes underneath slab foundation?

[Jeremy Andrews]

I recently found out that it's legal in Texas to get a permit for attempting your own plumbing repairs under the slab, and I'm rather desperate because my Mom and I absolutely cannot afford the prices plumbers are charging even if she takes out a loan or refinances the house. They all want $15,000-$20,000 on average, and one place even quoted us $30,000. Our insurance will not cover anything underneath the slab. Bear in mind that the house itself was $87,500, so that's almost a quarter of a house to us. We're still paying on a previous plumber that charged us $7,000 and didn't fix the problem well enough. We don't have the money for another monthly payment unless we get rid of Internet and cell phone service entirely for 10 years. Basically, we don't have the money to get these kind of things repaired by professionals.

I have plenty of time to learn what I need to know because I'm currently out of work and only go to school intermittently when we can find the money. I'm also not claustrophobic or afraid of dirt. What I'm wondering is, can I do this myself without breaking the bank? We have cast iron pipes that are supposedly fraught with serious rust and holes all the way back to the main line, and everyone we've consulted thinks they need to be replaced. I'm not sure how honest these contractors are or whether they're trying to soak us for everything we've got, which is another reason I'd prefer to be able to see the pipes for myself.

I'm positive that I'll need a shovel to dig under the slab, the pipes themselves, and a wrench to unscrew the existing pipes. Possibly also some protective clothing and a helmet with a built-in light. I probably can't afford any kind of large pieces of motorized equipment like a jackhammer. Things like a laser level, calipers, or a metal detector might be within our price range if we need those. I also plan to read the city codes thoroughly and try to ensure that the job would pass inspection scrutiny. I have no intention of rushing the job, breaking any laws/codes, or cutting corners.

I'm banking on the idea that the majority of the cost is probably for excavation and labor rather than the materials themselves. If that's actually the case, I could save a lot of money if I'm willing to put all my time and energy into this project.

I know trying to DIY something as complex as plumbing without experience seems like a pipe dream, and I truly do respect the amount of training that professional plumbers undergo in order to get their jobs, but it's worth bearing in mind that a professional is not an option for us, and the only other option is trying to sell the house for less than we paid for it (due to having to disclose the plumbing issue that was never disclosed to us and didn't surface for several months), or else just living with the bathroom drains broken like we've been doing for the past month.

 

[Standardairconditioner]

Your situation is common, and a good local contractor should be able to show you good pics they have done before, as well as explain throughly what will happen. All this will also give you a clear idea of what you are up against. It won't cost you anything for more of them to come over to give more quotes. You can certainly find one that will give you satisfying answers.

It appears time is one thing you have a lot of, so dig through as many Youtube videos as you can, there are many there specific to main sewer pipes.

Trenchless sewer pipe lining (no digging) may be on interest to you, Formadrain, Nuflow.

 

[Sponsor]

 

[Gary Swart]

I can't add too much to the previous post, but here are a couple of thoughts. You will have to break out concrete. Small rotor hammers are fairly inexpensive. Try Harbor Freight. Another way is to hire a concrete cutting company. Yeah I know limited funds, but these guys are fast and clean. Might not be an arm and leg. As far as the old pipe is concerned cut it out. Again, you would need some tools. Unless you know where the pipes are, cutting new channels would be simpler and you just leave the old. You will have a modest investment in tools and equipment, but very little labor cost. Chipping concrete with a hammer and chisel would be very difficult and time consuming and a jackhammer, even the small one I mentioned, are super dirty. The dust is almost impossible to contain. Another idea to consider is plumbing the new drain on top of the slab if you can avoid crossing room. Not the first choice for sure, but maybe.

 

[Standardairconditioner]

Not the first choice for sure

I definitely would not do any of the things you mentioned. It's all gambling and guessing and what-if's that can open up more cans of worms and unnecessary debt, especially for a DIY.

I'm still trying to figure out what they spent $7000 on. If no repairs were done on the sewer line, all they could do was auger a clog-chopper and camera pre/post-inspect, and that certainly will not cost anywhere that much.

Some of the trenchless sewer pipe lining videos were really impressive. Without any digging, they work from the city sewer main side, and the whole job takes 4 hours. Seems to be a semi-franchised business, with manufacturers represented nationwide, but may not be available in all cities.

 

[hj]

renchless works outside, but not inside under a slab. The very FIRST thing I would do is have a professional video pipe inspection, but NOT from a plumber who has a vested interest in wanting to replace the pipes., with a DVD showing the REAL condition of the piping, since what you are describing seldom happens in a residence. I just replaced a the underfloor cast iron, ( it was only a seven foot section before it came out of the floor. He had been told the old pipe was deteriorated and cracked. I had my own inspection done and I could not see any problem, but since the other company was one of the larger ones in the area, he wanted to go ahead with the replacement. When I removed the old pipe, it was NOT deteriorated, nor was it cracked. In fact it was in such good condition that it was almost impossible to break it with a hammer.

 

[Jeremy Andrews]

Thanks for all the advice. I was worried that perhaps I was just being paranoid in not wanting to trust what the contractors were saying, and I didn't even know that there were independent companies that would do the video camera work.

There's actually a possibility that I won't have to dig very far to reach the pipes anyway... the first contractor who replaced 10 feet of pipe on one bathroom was upset and claimed he didn't charge enough money for the job, and he only spent 2 hours filling the hole he made back there (which took a week to dig out) when he finished up. He claimed that the bathroom pipe had lost its fall, but that it also needed replacement due to corrosion, etc.

My Mom thinks it's possible that he left the tunnels under there and only filled up the portions of dirt we could see. I'd like to think no one would do something like that, but you never know. On top of that, his workers went the wrong way underneath our house and dug up my Mom's plants on the opposite side of the house from where the bathroom was located. She was standing in the yard on the other side of the house from where they started the hole, and saw the dirt in her garden cave in... looked down and saw the worker's face. We then had to argue about the extra money/time it was costing him to dig the right way, and he got mad when we said (as politely as we could) that he'd already bid the job and it wasn't our fault his workers had no sense of direction.

All I know is that before he came out, we were only having problems with one bathroom that we'd been having issues with off and on for a year. After he left, everything worked for about six months, and then all the other drainage plumbing in the house started having issues. I'm wondering if it's possible the people digging the wrong way under the house could have caused some other pipes to lose their fall by mistake, and that might be the real issue rather than corrosion or holes in the pipes. Alternatively, if he left the tunnels in place, it's possible the house might have settled enough to push the pipes down into the soil, thus causing them to lose their fall that way. I do know that everyone we've had out here is saying that water is standing in the pipes, although I guess I won't know until I get someone reputable to do the video camera work.

 

[Jeremy Andrews]

Well, we had some more camera work done, and also got some more quotes. Apparently the reason it's so high is that that they're having to redo everything that Jimmy Cash did in the first place. The cast iron pipes were not properly joined to the new PVC pipes, and there are problems with the joint. They've confirmed that the pipes are shifting around under there, and that pretty much the only reason this could be happening is that it wasn't backfilled properly. As a result of the shifting, the old pipes dragged the new ones back down, and now all the plumbing in the house is on its belly.

Also, I've observed recently that my bedroom door always slams itself open when I open it, while my mother's bedroom door always slams itself towards the closed position. Both doors are facing each other, so that means both doors are leaning west now, towards the area under the house where they were digging in the wrong direction.

The good news is that my Grandma told my uncle about my Mom's problem, and now my uncle is paying the $15,000. She's humiliated, of course, and is angry that she told him, but now we can have it fixed. The bad news is that I'm now wondering whether the first plumber might have messed up our foundation to the point that we'll have to have it repaired. This house is starting to seem like a money pit.