Let the camera decide. Do nothing if the pipe is round, tight and mostly clear. Spot-line one isolated crack or root-filled joint. Reline the whole run when defects repeat along it. A liner cannot fix a collapsed or badly shifted pipe, so that needs replacement.
What the three choices mean
Do nothing means leaving the pipe alone and watching it. It is a real option, not a brush-off.
Partial reline (also called a spot or point repair) puts a short liner over one damaged stretch. NASSCO, the trade group that sets standards for this work, describes spot repairs as localized repairs that use the same cured-in-place pipe (CIPP) technology as a full liner.
Full reline cures a new resin pipe inside the whole old one, end to end. A felt or fiberglass liner soaked in resin is pulled or turned inside out into the old pipe, inflated, and hardened with heat or ultraviolet light. Portland's Bureau of Environmental Services says the result is a smooth interior that restores the pipe to near-new condition, and that the work needs little or no digging.
Read the footage: what each finding points to
| What the camera shows | Best move | Why |
|---|---|---|
| Round pipe, tight joints, little or no roots | Do nothing for now | Nothing is broken, so a liner would fix a problem you do not have |
| Roots at one joint, rest of the pipe sound | Clear the roots, then spot-line that joint, or re-scope later | The damage sits in one place |
| One crack or hole in a short stretch | Spot repair | A short liner covers a localized defect |
| Roots or cracks at several joints along the run | Full reline | Each joint you leave open is another way in for roots |
| Collapsed section, joints pulled apart, or a dip that holds water | Replace the pipe (trenchless bursting or digging) | A liner follows the old pipe, so it cannot fix slope or a missing section |
Ask the crew to show you the footage at the actual defect, not just a still image. A good video carries a distance counter, so anyone can find the same spot again later, whether that is a second-opinion plumber or you in five years.
NASSCO says CIPP fits when the old pipe has cracks, fractures or holes but has "generally maintained its original shape." Once the shape is gone, lining stops being the answer.
When doing nothing is right, and when a spot repair falls short
A sound line with clear joints does not need a liner, and no plumber should sell you one. Doing nothing still means acting sensibly. Keep the cleanout reachable, keep big plantings away from the line, and get a camera look again if the line starts clogging. The City of Phoenix advises against planting a tree or large shrub near your sewer line or cleanout, because roots go looking for water.
A spot liner fixes the spot. If the camera shows the same weakness repeating, such as roots at joint after joint, patching one leaves the rest open. That is where a full reline earns its keep. NASSCO calls a properly installed lateral liner a permanent solution against root intrusion, the most common problem found in laterals, and gives it a minimum life expectancy of 50 years. Old clay lines are the classic case. Their joints are where roots get in, as the City of San Luis Obispo notes, so trouble tends to repeat along the run. Our page on roots in old clay sewer pipes covers that one.
When a liner will not work
Lining has limits, and honest contractors name them up front. Crafton Tull, an engineering firm that designs sewer rehabilitation, lists what CIPP cannot correct: pipe sags, severely offset joints, pipe intrusions, and large holes where the liner could balloon into empty space. Portland adds that it cannot enlarge a pipe. A liner also needs a passage to travel through, so a fully collapsed section has to be dealt with first.
The reason is simple. A liner takes the shape of what it goes into. If the old pipe has a low spot that holds water, the liner will hold water in that same spot. If two sections have shifted apart, the liner has nothing solid to bridge. For those lines, replacement is the fix. NASSCO describes pipe bursting as the trenchless way to install new pipe where the old is too far gone, and digging is the fallback when a line must be moved or its slope corrected. See trenchless sewer repair versus digging for how those compare.
Two practical points from Portland: relining needs temporary limits on water and sewer use while it cures, and the resin can give off an odor during curing. Plan around limited laundry and showers, and ask how long the restriction will last.
### Three examples of how the decision goes
These are made-up examples to show the logic, not real jobs.
A round clay line with roots at two joints. The pipe is otherwise sound and the roots are the only problem. Cleaning restores flow, and a full or partial liner would seal the joints. If the roots keep returning after cleaning, lining becomes the durable answer. If they don't, doing nothing but periodic checks is fine.
A cracked section under the sidewalk. In Phoenix the homeowner maintains the sewer line to the city main, but for single-family and duplex homes the city repairs broken piping in the public right-of-way. Before you pay for a liner in that stretch, read who is responsible for the sewer line in Phoenix and contact Water Services.
A dip in the line that holds water. The camera shows a low spot with standing water and debris collecting. Lining will not fix the slope. Expect replacement, and get the footage to show the low spot to any second opinion.
What to ask before you say yes
Crafton Tull says lining can usually be done "within hours instead of weeks" and is cost effective compared with trenching and site restoration, which is why it is worth asking about before you agree to dig.
- Can I see the footage, with each problem marked and where it sits along the line?
- Is the liner covering every defect on the video, or only the worst one?
- Will the connection at the house and the cleanout be included?
- Will you run a camera again after the liner cures and give me that video?
- What does the warranty cover, and who backs it, the installer or the material maker?
Crafton Tull notes that suppliers and contractors typically provide separate warranties, so ask about both. Ask for the answers in writing, and hold on to the before and after videos, because they are your record if a problem comes up later. Once you have a written scope, compare it with the factors that drive sewer line replacement cost and the steps in a full replacement.
HQ Plumbing gives free estimates and upfront pricing, so you can compare a spot repair, a full liner and replacement on the same footage before you decide.