Under-slab sewer leak

[DeSotoSteve]

I started a thread a couple of weeks ago about a possible leak in my sewer pipes under my slab. Thanks to the help I got here, I was able to perform my own static pressure test for less than $50 (inflatable ball and air hose). I confirmed that I have a leak. Not only did I observe a water level drop, but I also saw water seeping through the brick veneer below the slab level.

A plumbing company is coming out tomorrow morning to discuss options and cost estimates. My research thus far suggests they'll probably want to run a camera and, depending on success, possibly start isolating sections of the system. Then, they'll probably talk about digging holes in my floors.

Some questions for you experts:
1. Can you give me some idea of "reasonable costs?" for locating the leak--the camera, isolation process, time?
2. How do you typically determine the price for the repair? I'm sure it's based on a time estimate, but what can I expect?
3. How do you guys feel about pipe re-lining? The house is only 9 years old so the sewer pipes are all PVC. Is re-lining even an option for PVC?

Any advice/insight is appreciated.

Thanks,
Steve

 

[Caduceus]

I think we should answer the questions in bite-size chunks as we go. Let's start with the camera inspection. Some companies will do it for free in the hopes of getting the sewer repair/replacement job. Otherwise, expect anywhere from $225 to $500 for an inspection and location service.
If your sewer is PVC and it has broken and is leaking you may have a more serious issue than first thought. Primarily, the sewer may not have been backfilled properly. In this situation, more of the sewer will continue to shift over time and shear the pipe/fittings. It would be best to wait until the camera inspection is complete to see if evidence of 'bellies' or 'humps' inside the pipe are visible.
Secondary is that the fittings may not have been glued. This could also be the case throughout the sewer and leaks will continue to get worse as supporting soil is washed out from around the pipe. Again, let's wait for the camera inspection before drawing too many conclusions.

 

[phishfood]

The most common reason for under slab drainage leaks that I run into is damage, usually from the concrete contractor driving form stakes into the pipe.

That said, it would be real hard to give an estimate for time or pricing on something like this. There is no way to know how many leaks you might have or where the leaks are located. It might take considerable time with the camera to even locate the leak, or it might be located on the first trip down the line. And then there is no telling how long it might take to get to the leak and fix it.

 

[Another-Plumber]

I would call around and get 3 estimates, no use paying a plumber to camera and locate a line if they dont get a job, even though the floor is marked, the new plumber doing the job will tell you, ill dig it up, HOWEVER if the problem is not here, i cant be responsible for xtra cost... try to get each plumber to camera the line for free in hopes to get the job, just be clear on this to them, tell them money is on your mine (be polite) and in most cases the plumber will help you out. good luck with your job, and remember the small ads = lower prices and the BIG ads = BIG $$$
Good Luck

 

[Another-Plumber]

as far as price, expect to pay at least $1000-$2000 a day for repairs...

 

[PipeLining]

I would call around and get 3 estimates, no use paying a plumber to camera and locate a line if they dont get a job, even though the floor is marked, the new plumber doing the job will tell you, ill dig it up, HOWEVER if the problem is not here, i cant be responsible for xtra cost... try to get each plumber to camera the line for free in hopes to get the job, just be clear on this to them, tell them money is on your mine (be polite) and in most cases the plumber will help you out. good luck with your job, and remember the small ads = lower prices and the BIG ads = BIG $$$
Good Luck

I agree with everything this guy says except the part about the cost of Ads. As a small company (10 employees) we pay BIG $$$ads so we can create awareness and beat the shonks out there. BIG $$ads also mean that the company have the resources to fix any problems that they may incur. "YOU GET WHAT YOU PAY FOR".

 

[PipeLining]

Oh and yes - it is possible to LINE a pipe that is PVC - any type of pipe depending on the diameter. Also, if you have 2 access points then your floor will not have to be dug up if you choose PipeLining, however we are in Sydney, Australia so not sure on the quality of your 'Lining' Companies where you are.

 

[Another-Plumber]

pipelining may also be an option, check into it

 

[DeSotoSteve]

Thanks for all the great advice. One company came out yesterday and told me they'd camera the line for $400. However, if they couldn't see the problem with the camera and had to start isolating sections, the cost would be $1292. His estimate for the actual repair seemed to be in the area of about $1500 per day.

I spoke with another compoany that said their camera charge is $300 but they'd apply half of it to the repair if I let them fix it. Of couse, I suppose they could just jack the cost of the repair by $150 if they wanted to. So far, I haven't been able to find anyone who is willing to find the leak for free in hopes of getting the repair job. I guess I'm leaning toward the $300 guy and will hope that he's honest about applying half to the repair cost.

Thanks again for all the great comments.

Steve

 

[Another-Plumber]

yea, steve, let them drop the price on you and tell them of the other offers... im sure the price stands even if you let the plumber walk out the door...

 

[PipeLining]

Thanks for all the great advice. One company came out yesterday and told me they'd camera the line for $400. However, if they couldn't see the problem with the camera and had to start isolating sections, the cost would be $1292. His estimate for the actual repair seemed to be in the area of about $1500 per day.

I spoke with another compoany that said their camera charge is $300 but they'd apply half of it to the repair if I let them fix it. Of couse, I suppose they could just jack the cost of the repair by $150 if they wanted to. So far, I haven't been able to find anyone who is willing to find the leak for free in hopes of getting the repair job. I guess I'm leaning toward the $300 guy and will hope that he's honest about applying half to the repair cost.

Thanks again for all the great comments.

Steve

Definitely go with the $300 guy, you will not find many Plumbers who will not charge for fee to do this. Clarify with the plumber that the only charge for finding the problem is only $300 (so no labour, tax on top). Then make sure they put it in writing. Also before he commences ask him if you can get the DVD copy of the camera footage, then when he gives you a quote to repair, you can then shop around giving the DVD to other plumbers for a quote. Also, a plumber using and Electric Locator should be able to find the problem spot very easily - maybe enquiry about that too?

 

[para1]

We do tons of slab leaks ,and I would say 85% or better we do by tunneling from outside to get to the problem. This way there is no distruction or inconvienence to ypur living space. We did a 64' tunnel under a church awhile back (5 days) , they never knew we were there.

 

[havasu]

It seems to me that a shoring wall would be alot safer when entering that pit.

 

[Caduceus]

Yeah. Very unsafe. See: Man's death in trench collapse ruled accident | The Times Leader, Wilkes-Barre, Scranton PA

 

[DeSotoSteve]

Here's the latest... Plumber and two helpers came out Monday as scheduled. He ran the camera through the c/o on the side of the house and wasn't able to see any breaks in the line. He then tried running a smaller camera through the shower drain but it couldn't make the bend at the bottom of the pipe. Next, he ran the small camera down the tub drain--nothing obvious. Then he tried one of the lav drains--still nothing. So, for an extra $95, he pulled the toilet and tried the camera there--nothing. The only thing they found was that I had about a 10-ft run of pipe that had bellied, which isn't surprising since it is right under the part of the house where the slab has seemed to settle.

Next, we plugged the main c/o and filled the system for another static pressure test (as I had already done). The water began dropping and they could see it seeping through the brick veneer. They again ran the camera down the tub drain. They tried to tell me that there is some kind of nut there that is prone to breaking. They wanted to give me an estimate to bust up the floor to repair it. I was willing to accept that, but I noticed that the water level kept dropping below that point. When I asked about it, they said I could have another problem in the pipe going to the toilet (about 3ft away), but I definitely had an issue in the tub drain. He said we needed to tear into the tub drain, then we could maybe see what else might be going on. The estimate? $2,800 assuming the only problem is the tub drain.

I spent $395 for the work they did. There were 3 of them and they were there for 3 full hours so they probably ended up losing money on me. However, I don't feel like I know much more than I did before they started. I'm certainly not going to agree to another $2,800 for them to "explore" since they couldn't convince me they'd found the leak. Given how quickly the water drops and the fact that enough is leaking that you can see it seeping through the bricks within 10 minutes of starting the static pressure test, I'm thinking there's something more significant than a broken nut.



So, although I'm out $395, I'm breaking ties with this plumbing company (did I mention that one of the guys was hitting on my 21-year-old daughter while he was there? not too happy about that, either).

Unless you folks have any other advice, I guess I'm going to try another plumber who was just recommended to me as being one of the best when it comes to locating leaks.

In the picture below, you're looking a the west side of the house which required a lot of fill dirt. You can see the water seeping through the brick just above the ground. You can also see the c/o where they first inserted the camera. The tub in the master bath is directly above the c/o. Approximate slab elevation is around 5 ft. The drawing below the picture is an approximate floor plan. The vertical red line shows the 4" pipe that has the 10' belly (starts about 2 ft in from the c/o). The horizontal red line represents the main line through the other c/o to the sewer (the one I plugged for the static pressure test). I have no idea how the laterals to the various fixtures are laid out from these main lines.

 

[Caduceus]

I pictured things this way: Sewer plugged and filled with water. Water level drops because of leak. Once water level stops dropping, insert camera. Water level will stop dropping once immediately below the leak. See with camera and locate. That is where a/the leak is.

 

[Another-Plumber]

my guess would be that the leak it at the highest point that you can see water, since water goes down, and NOT up in most cases, the tub is a good place to start since the drain go bad every 25 years or so, however, you cut into the wall behind the drain to replace that, aprox cost $350-$650... And since they didnt offer to run the camera down the roof vents, is quite alarming, you can hit all the vent in an hour or less.... I like what you wrote
"I guess I'm going to try "another plumber" who was just recommended to me as being one of the best when it comes to locating leaks." thanks for the KIND WORDS lol

 

[Another-Plumber]

i bet you the tub waste and overflow is bad from you picture, the tub is the closes fixture.....

 

[Another-Plumber]

very nice work para

 

[DeSotoSteve]

Ha! I didn't catch the "Another Plumber" reference when I wrote that. So, dare I ask how much you'd charge for a service call from San Diego to Memphis?!?!

Seriously, there was another detail I failed to mention... When he ran the camera through the tub overflow, the pipe was very loose. You could move it from side-to-side and forward/backward. The plumbers said they probably never came back and filled "the box" with concrete after the slab was poured. Apparently that's pretty common.

The drain-end of the tub backs up to an interior wall (toilet area) so it would be pretty easy for me to open up the sheetrock and have a look from the back-side. I suppose I could do that and repeat my static pressure test while it's open to see if I can see any water escaping.

Do you think it's worthwhile for me to do that, or just wait and put my trust in "another plumber"?

Thanks again for all the comments. If nothing else, I'm learning a lot.

Steve