Trenchless sewer repair vs digging: lining, bursting or an open trench
Updated
The short answer
Choose between trenchless sewer repair and digging by the defect, not the price. Pipe lining suits a line that still holds its shape — cracks, root entry, leaking joints — and usually needs no digging. Pipe bursting replaces a badly deteriorated or collapsed line through two small pits. Digging is what corrects a belly, and is often cheapest in open, shallow ground.
How urgent · Plan for it
Choosing a method is rarely urgent once the line is flowing again. Take the time to see the camera footage and get at least one trenchless and one open-trench price for the same run.
How each method works
Pipe lining, also called cured-in-place pipe or CIPP, builds a new pipe inside the old one. The line is cleaned and inspected, a felt or fibreglass tube saturated with resin is pulled or inverted into it — usually from the cleanout — and cured with hot water, steam or UV light until it hardens. Branch connections are reopened from inside with a robotic cutter. There is normally no digging, and most residential jobs finish in a day.
Pipe bursting replaces the pipe along the same path. A pit is dug at each end; a cone-shaped bursting head is pulled through the old pipe, fracturing it outward into the soil while dragging a new pipe — usually HDPE with fused, seamless joints — in behind it. It can install the same size or larger. Most jobs take one to two days.
Dig and replace opens a trench along the full run, removes the old pipe, and lays new PVC on properly compacted bedding at the correct slope, before backfilling and restoring the surface. It is the only method that can change the line's route or grade.
Which method can fix which defect
This is the table that matters and the one sales conversations tend to skip. A method that can't fix the defect the camera found is the most expensive option at any price.
| What the camera found | Pipe lining | Pipe bursting | Dig and replace |
|---|---|---|---|
| Roots at joints | Yes — seals the joints | Yes | Yes |
| Cracks, leaking joints | Yes | Yes | Yes |
| Minor offset joints | Usually, if the liner can pass | Yes | Yes |
| A belly (sag holding water) | No — the liner follows the sag | Limited — follows the old path | Yes — the only way to re-grade it |
| Collapsed section | No — can't pass the collapse | Often, if the head can pass; else a pit at the collapse | Yes |
| Orangeburg that is ovalising | Only while still round | Usually preferred | Yes |
| Channelled or scaled cast iron | Often, after descaling | Yes | Yes |
| Pipe too small for the house | No — slightly reduces diameter | Yes — can upsize | Yes |
| Under the house slab | Usually the best option | Needs an interior pit | Costly — trenching through the floor |
General suitability. A contractor who has seen your footage may reasonably reach a different answer for a particular section — ask them to explain it against the defect.
Cost, disruption and lifespan compared
Per foot, the three methods are priced in overlapping ranges; what separates the totals is restoration. For a 50-foot line under a concrete driveway, the planning ranges come to $7,250 – $19,500 dug, $5,050 – $14,500 burst and $4,750 – $14,000 lined, including permit and camera inspection.
| Pipe lining | Pipe bursting | Dig and replace | |
|---|---|---|---|
| Price per foot | $90 – $250 | $80 – $220 | $100 – $250 |
| Digging | Usually none | Two pits | The whole run |
| Restoration | Minimal | Two pits' worth | Full trench — lawn to driveway |
| Typical duration | About a day | One to two days | One to three days |
| Changes slope or route | No | No | Yes |
| Joints left for roots | None | None (fused HDPE) | Gasketed or glued joints |
| Expected life | Commonly designed for 50 years | 50+ years | 50–100 years for PVC |
Per-foot ranges from HomeAdvisor and NuFlow (2025–26). Trenchless manufacturers claim 30–50% overall savings against digging once restoration is counted; that holds under hardscape and much less in open lawn.
When digging is the better choice
Trenchless methods are marketed as the modern default, and under a driveway or a house they usually are. But there are common situations where an open trench is the better engineering and sometimes the lower price.
- The line has a belly that needs correcting. Only excavation can re-grade it.
- The line is shallow and runs under open lawn, where restoration is cheap.
- Much of the run is collapsed or badly deformed, so a liner can't pass and a bursting head would need several pits anyway.
- The cleanout, the connection at the house or the tap at the main needs replacing too, and those will be dug up regardless.
- The line's route is the problem — too close to a foundation, under a planned addition, or with too many bends.
- Your utility specifies materials or methods for sections it will inspect or later take ownership of.
The downsides of lining
Lining is a genuinely good repair for the right pipe, which is exactly why its limits deserve stating plainly.
- It depends on the host pipe. The old pipe has to be clean, passable and still round enough to support the liner during installation.
- It reduces the inside diameter slightly. In a 4-inch line that rarely matters, because the smooth surface flows better than rough old pipe, but it rules lining out for a line that's already undersized.
- It can't change slope. A belly lined is a belly with a smooth surface.
- Quality varies with the installer. Wrinkles at bends, poorly reopened branch connections and incomplete curing are the usual defects — insist on a post-installation camera recording.
- Warranties differ widely. Ask how long, what they cover, and whether they transfer to a buyer.
The downsides of bursting
- It needs pits, which means some digging and restoration at each end and at any sharp bend.
- The old pipe is pushed into the surrounding soil. That's a risk near other buried utilities, shallow foundations or in crowded ground, so an accurate utility locate is essential.
- It follows the old alignment, so it can't correct a significant belly or reroute the line.
- Some pipe materials, such as asbestos-cement, come with local rules about being burst in place.
Questions to ask before you choose
- Show me the footage — where is each defect, and how far from the cleanout?
- Which defect does this method fix, and is there any it won't?
- What exactly goes in: liner type and thickness, or pipe material and diameter?
- How will branch connections be reopened or reconnected?
- Will I get a camera recording of the finished line?
- What does the warranty cover, for how long, and does it transfer?
- Who pulls the permit, and is the city inspection included?
- What restoration is in the price?
- If you find a collapse partway through, what happens and what does it cost?
Frequently asked questions
- Is trenchless sewer repair worth it?
- Usually, when the line runs under a driveway, patio, landscaping or the house and the pipe still holds its shape — it avoids tearing out and replacing those surfaces. It's less compelling in open, shallow lawn, and it can't fix a belly.
- What are the disadvantages of pipe lining?
- It relies on the old pipe being passable and round, it slightly reduces the inside diameter, it can't correct slope, and results depend heavily on installer quality. Always ask for a post-installation camera recording.
- Is pipe bursting better than lining?
- For a badly deteriorated, deformed or undersized pipe, usually yes, because it replaces the pipe rather than relying on it. For cracks and root entry in pipe that still holds its shape, lining is usually less disruptive and similar in price.
- How long does a sewer pipe liner last?
- Cured-in-place liners are commonly designed and warranted for a 50-year service life. Real-world life depends on installation quality and what goes down the drain.
- Can a belly in a sewer line be fixed without digging?
- Not really. Lining follows the existing sag, and bursting follows the old path. A significant belly is corrected by excavating that section and relaying it at the right slope; a shallow one is often monitored or kept clear with periodic jetting.
- Can pipe lining be done under a house?
- Yes, and it's often the best option there, because the alternatives are trenching through the floor slab or digging a pit inside the house. The line needs to be clean, passable and structurally sound enough to host the liner.
- Can you line Orangeburg pipe?
- Only where it still holds its round shape. Orangeburg that has started to ovalise, blister or collapse usually can't take a liner, so bursting or digging is normally recommended.