Trenchless Sewer Line Limitations?

[Super_Chunk]

So, I bought a 1933 house (yay?). The sewer inspection came back showing some "bellies", slightly offset segments(?) and some roots. The recommendation was, of course, to replace the line.

One bid was to go trenchless, but the 2nd bidder said I would need a trench to smooth out those low spots. He went on to say that, if I went trenchless, the pipe that was pulled through would follow the first pipe and still have low spots. Is this true?

[Maybe I should add that the 2nd bidder had no idea about the 1st bidder's recommendation. And, the 2nd bidder recommended trenching, even though we have one of those ridiculously landscaped front yards.]

I did a quick search of the forum about 'trenchless', but the discussion always seems to be geared around whether a new line is even needed. Let's just assume that the decision has been made to replace the line.

I would prefer trenchless, but obviously don't want to set myself up for premature failure or other future problems.

Thanks in advance,
- Mike
Portland, OR

 

[hj]

IF there is enough resistance on the pull line, then it MAY pull straight, (normally it will follow the path of least resistance and replicate the low spots), but since there is no way to "fill" the low spots and the pipe, by definition, is flexible, it probably will eventually conform to the existing high/low conformation.

 

[Sponsor]

 

[Dj2]

I prefer a trenched line over a trenchless line.