Full sewer line replacement is the most expensive plumbing decision a homeowner makes, and it is sold considerably more often than it is warranted. Not always dishonestly — a badly scaled cast iron line genuinely looks alarming on camera. But looking bad and being past saving are different things.
Here is the framework we use, and the questions worth putting to anyone who has quoted you a replacement.
The question that actually matters
It is not how old the pipe is. It is: does the pipe still have structural integrity along its full length?
A pipe that has lost diameter has a cleaning problem. A pipe that has lost its wall has a replacement problem. Those look superficially similar on a screen and cost very different amounts to resolve.
| What the camera shows | What it needs |
|---|---|
| Scale and tuberculation, wall intact | Descaling — not replacement |
| Roots at one or two joints, pipe sound | Cut roots, then line the joints |
| Cracks along a sound, round pipe | CIPP lining |
| One damaged section, rest of run healthy | Spot repair |
| Corroded through along the invert | Replacement — the pipe has lost its floor |
| Belly holding standing water | Replacement with regrading; lining preserves the sag |
| Collapse | Replacement, usually by pipe bursting |
When repair is the right answer
Repair — whether that is a spot fix, descaling or a full-length liner — is correct whenever there is still sound pipe to work with.
This covers a large share of what we see in older Montgomery and Prince George’s County housing. Clay laterals in Chevy Chase and Takoma Park typically fail at the joints while the barrel sections remain solid. Cast iron in Bowie and Silver Spring typically loses diameter to tuberculation long before it loses wall thickness. Both are repairable, and both get quoted as replacements more often than they should.
When replacement is genuinely necessary
- The pipe has collapsed, or the camera cannot pass a crushed section
- Cast iron has corroded through along the bottom — the invert is gone, and no amount of descaling restores a floor that no longer exists
- A significant belly is holding standing water, which lining would seal in place rather than correct
- Damage is distributed along the whole run rather than concentrated in one section
- The lateral is materially undersized for the home’s current fixture count
In those cases replacement is the honest recommendation, and modern replacement rarely means a trench — pipe bursting handles most of them through two access pits.
The maintenance trap
There is a middle case worth naming, because a lot of households sit in it for years without recognising it.
If you are having the same line cleared every twelve to twenty-four months, that is not maintenance. It is an annual payment against a problem that has a one-time fix, and over ten years it frequently exceeds the cost of resolving it properly.
Root intrusion is the classic version. Cutting restores flow and leaves the joint open, so the roots return on schedule. Lining removes the joint, and the cycle ends.
Getting a second opinion
If a replacement quote does not sit right, get another inspection. Ask for the footage from both, and ask each contractor to point at the specific frame that justifies their recommendation.
We provide the video and written findings either way, including — and this happens regularly — when the finding is that your line is fine and does not need the work somebody else proposed.