Trenchless Sewer Line Replacement? (Post: house, landscaping, utilities)

[stephorama]

Know anything about it? Ever had it done? Recommendations for a good company? We've had several plumbers out. Some say we need to clean the sewer line by blasting with water, some say we need to replace 50+ feet of line under the slab - some say do it by jack-hammering the slab, others say to tunnel under the slab. Some say, "OH NO! Don't tunnel!" Foundation company which we have a warranty with says tunneling is no problem.

Estimates range from $8000 to $15000. Have yet to see a plumbers camer show us a break. Beginning to seriously distrust plumbers!

Any and all suggestions helpful - aside from selling the house. (Pretty sure the folks we bought from failed to disclose this problem - but that's another story for another day.)

heavy sigh

[loves2read]

frankly there is not enogh info in your post
WHAT is your problem
clogged plumbing lines?
backed up sewer?
foundation problem due to plumbing lines?

[escanlan]

Originally Posted by stephorama

Know anything about it? Ever had it done? Recommendations for a good company? We've had several plumbers out. Some say we need to clean the sewer line by blasting with water, some say we need to replace 50+ feet of line under the slab - some say do it by jack-hammering the slab, others say to tunnel under the slab. Some say, "OH NO! Don't tunnel!" Foundation company which we have a warranty with says tunneling is no problem.

Estimates range from $8000 to $15000. Have yet to see a plumbers camer show us a break. Beginning to seriously distrust plumbers!

Any and all suggestions helpful - aside from selling the house. (Pretty sure the folks we bought from failed to disclose this problem - but that's another story for another day.)

heavy sigh

If you search for "trenchless sewer line" you will come up with a great deal of information to include videos showing the process. There are pros and cons to the method and I'll list some here. I've installed underground utilities, mostly electric, but we used some of the same techniques, sans the ram head, for our installations. We have also run into many issues that these trenchless sewer line replacement people can also run into.

Pros:

1. It can be less destructive to your landscaping, foundation, flatwork (sidewalks and driveways), etc. As long as the conditions are there to properly pull the new piping it can go much faster.
2. The amount of labor to perform this procedure is obviously significantly less than a full trenching and replacement.

Cons:

1. It is less destructive to the elements described above. But depending on the run you might not encounter some of these issues such as having to dig across a driveway or sidewalk. If what you are mostly destroying is your landscaping then that can be replaced easily anyhow.
2. Along with number 1, if your driveway, sidewalk, etc., is in bad shape then this is an opportune time to repair it anyhow by removing and replacing part of it.
3. If part of your problem is being caused by invasion of roots then you just might have to remove that vegetation (trees, bushes, etc.) to prevent future damage. It might also be blocking the way for a proper installation of the new flexible pipe and need to be removed.
4. This procedure follows the current pipe however it might run. If the current pipe is not properly sloped, has locations where it turns up, locations where it drops and then returns up, these are potential problem areas. These problem areas can easily be reproduced by this trenchless process. Digging with a backhoe, manually, etc. can ensure that the drainage pipe is laid with proper slope, no variations, etc.
5. If there is one thing that can really cause you problems is that not all utility lines and obstacles are always where they are suppose to be, in the condition they are hoped to be, and locatable completely down to the inch. When laying utilities we NEVER, EVER, took a chance that the utility locates and markers were 100% correct. That results in a lot of hand digging to make sure we don't cut that gas, electric, water, etc., line. Since the trenchless system can not see what is around it then you always run that risk of snagging or damaging other lines. That comes into play very strongly when running this system under a homes slab. It is extremely difficult to locate utilities under a 4"+ thick slab, not to mention rebar or Post Tension cables.
6. The amount of labor that is required is considerably less. But the prices I have been seeing do not really reflect the reduced labor. Part of that is due to the high cost of the equipment used for this procedure. They have to pay for it and if they are not performing a lot of these then that means the cost is going to be higher.

For all of the cons if the process flows smoothly, and there are no underground obstacles, then this process has promise to it. This would be especially true under the slab if it is needed there. It sounds though that you need a good plumber that is going to scope your drain system, map all the problem areas and provide you a recording with explanation that you can see to make a good decision with.

This action of scoping, mapping, recording, is going to cost a little more money but honestly I would highly recommend it. By doing this you might well find that there is nothing wrong with the under slab section and you can just replace the section exterior to the home. It might also find relatively minor problems that can be handled with other methods than replacement. Worst case scenario is that the scoping will identify how badly deteriorated the system is, including under the slab, indicating a major replacement. The scoping can also help determine if there are rises and drops in the system that can cause future issues with a trenchless replacement method.

Here is a possible alternative I found on a home I inspected awhile back. It too was an older home on a slab that had experienced major under slab sewer line damage. This home had all of the major fixtures (toilets, tubs, showers, etc.) on outer walls or close to outer walls. Instead of hammering through the slab the owner re-routed all of the sewer drains straight to the outer wall near it. This required a lot less slab hammering than replacing the original runs. They then ran the drains around the perimeter to the main drain and out. The old main line was filled with grout and allowed to harden to prevent it from collapsing and causing other slab issues. Here in Texas we don't have much of a frostline since our temperatures do not normally get cold enough, long enough to cause issues. Since most slab footers are 2' deep, and the drains have to be under them (with proper protective support so slab does not bear on it) then this is generally an acceptable alternative. It would only depend on if your plumbing arrangement is configured to allow it, the local building department would allow it, and you can find a plumber that would do it.

[stephorama]

loves2read - I just asked if anyone knew anything about trenchless pipe replacement, not a diagnosis. We've had repeated backups - several plumbers and none have clearly indicated the problem. Have leak detections folks coming out Tues.

escanlan - WOW! Thank you for so much information and your suggestions. ALL of our plumbing is around the outside walls of the house (aside from the kitchen). Not sure if rerouting will be an option.

Trying to stay positive and hope for the best when the leak detection people come out.

Thanks!

[MarkSt.A]

Originally Posted by stephorama

Know anything about it? Ever had it done? Recommendations for a good company? We've had several plumbers out. Some say we need to clean the sewer line by blasting with water, some say we need to replace 50+ feet of line under the slab - some say do it by jack-hammering the slab, others say to tunnel under the slab. Some say, "OH NO! Don't tunnel!" Foundation company which we have a warranty with says tunneling is no problem.

Estimates range from $8000 to $15000. Have yet to see a plumbers camer show us a break. Beginning to seriously distrust plumbers!

Any and all suggestions helpful - aside from selling the house. (Pretty sure the folks we bought from failed to disclose this problem - but that's another story for another day.)

heavy sigh