Trenchless or traditional sewer repair, and when each one is honest

The useful way to think about this is not method first but finding first. Each of these is something an inspection reports, and each one points somewhere.

Cracked, leaking or root damaged, with the bore still open

This is the case lining was designed for. The pipe has lost its integrity but its shape and path are intact, and a liner restores a continuous sealed interior without opening the ground. Root intrusion in particular is worth lining rather than repeatedly cutting, because roots come back through the same joints and here nothing goes dormant in winter to slow them down.

Collapsed, or badly offset at a joint

This rules lining out, and it is the point where a straight answer matters most. A liner needs something continuous to line. Where a section has caved in, or where two lengths have shifted so far that the bore steps sideways, there is no passage for the liner to be pulled through and no amount of preparation creates one. That is either pipe bursting, if the path is still workable, or excavation.

So blocked it cannot be cleaned or cabled through

Also a bar to lining, at least until it is resolved. The pipe has to be cleaned first, and if it cannot be cleared and cannot be cabled through, the liner has nowhere to go. Sometimes jetting resolves this and lining becomes available again, which is a sequence rather than a dead end.

Bad in one section, sound elsewhere

Worth separating out because it changes the size of the job rather than the method. A single failed length under a driveway is a very different proposition from a line that is uniformly thin over its whole length, and only an inspection distinguishes them. This is where a second opinion is most often worth having, in both directions.

What is specific to this ground

Sandy soil, a shallow water table and heavy seasonal rain move buried pipe here in ways that drier regions do not have to design around. Movement is what produces the offset joints that rule lining out, so a line that would have been a straightforward lining candidate a few years earlier may not be one now. Humid soil also corrodes cast iron faster than a drier climate does, which is why so many of these decisions arrive attached to a house built in the middle of the last century.

The questions worth asking before agreeing to either

• Can I see the footage? Not a summary of it. The recording is the evidence for whatever is being recommended, and it belongs to the job.
• Is the whole run being done, or a section? And if the whole run, what did the camera show in the parts that are not currently failing.
• What happens at the connections? Lining has to reinstate the points where branches join the main, and how that is done is a fair thing to ask about.
• What is the permit and inspection position? Sewer work is permitted work in these counties, and the answer should be immediate rather than improvised.
• What is restored afterwards? For excavation this is the part that dominates the disruption: slab, flooring, landscaping, driveway. It is a legitimate part of comparing the two.

The honest summary

Trenchless is genuinely less disruptive and it is the right answer for a large share of failures here. It is also promoted as universally better by people who only offer it, and it has a real boundary. If somebody recommends lining without having looked inside the pipe, or dismisses lining without having looked either, the problem in both cases is the same: a method chosen before the finding.