Choosing a repair method
Neither method wins in every case. Trenchless methods work inside the old pipe and need only small access points, while traditional repair opens a trench and replaces the pipe outright. Which one fits a given line depends on what the camera shows: the shape of the pipe, the depth of any belly, and whether the old pipe still holds its shape.
By Straight Line Sewer Pros
This post compares the two approaches side by side, names their limits plainly, and explains when digging is the honest answer even though it costs more disruption. It does not repeat either service page in full. For the full detail on each method, read our trenchless pipe lining page and our traditional sewer line replacement page.
Trenchless repair covers two main methods. Lining forms a new pipe inside the old one: a felt or fiberglass liner soaked in epoxy resin is inverted into the line and cured in place, a method governed by the ASTM F1216 standard for cured in place pipe. Bursting breaks the old pipe apart underground while a new HDPE pipe is pulled into its place behind a bursting head.
Both methods share one advantage. They need only entry and exit points instead of a full trench, so a lawn, a driveway, or a walkway can stay largely intact. That advantage is real, but it comes with a condition: the old pipe must still be able to guide the new one. A liner needs a host pipe to shape it, and a bursting head needs a path to follow.
Traditional repair means open excavation. We dig a trench along the failed section, remove the old pipe, lay a new PVC or HDPE replacement pipe on bedding gravel, reset the grade so waste flows downhill, and backfill. Trench work follows OSHA trench safety standards, with shoring and safe access, because a deep trench in Maine soil is serious work.
Digging disrupts more ground, and that disruption is the main drawback. Its advantage is completeness. A trench lets us see the whole section, fix the grade exactly, replace a collapsed pipe, and correct a deep belly that no liner can straighten. When a line has lost its shape, excavation is not the old fashioned option. It is the only option that fits.
The table below compares the two approaches on the points homeowners ask about most. Use it as a starting frame, not as a verdict, because the camera footage for a specific line can move the answer in either direction.
| Point | Trenchless | Traditional |
|---|---|---|
| Ground disturbed | Small access points only | Full trench along the section |
| Pipe result | Liner inside old pipe, or new HDPE pulled through | Brand new replacement pipe on fresh bedding |
| Grade problems | Cannot fix a deep belly or a badly offset joint | Grade reset exactly during the dig |
| Collapsed pipe | Usually cannot line or burst a fully collapsed section | Collapsed pipe removed and replaced |
| Best fit | Cracked or leaking pipe that still holds its shape | Collapsed, deeply bellied, or badly offset lines |
Notice what the table leaves out. It leaves out any promise about how long a repair lasts in a given soil, because that depends on the line, the ground, and the work itself. A good method badly applied fails, and a plain method well applied holds. The method choice is only half the job.
Trenchless fits best when the old pipe is cracked, leaking at joints, or corroded, but still holds a round shape and a steady grade. A liner seals those cracks from inside and gives the line a smooth new inner surface. Bursting fits when the old pipe is too weak to line but still gives a path for the new HDPE pipe to follow, such as a brittle clay run with many joints.
Access also favors trenchless. A line that runs under a driveway, a patio, or a mature tree is expensive to reach by trench, and a small access point avoids tearing that surface up. In those cases the saving is not only in the lawn. It is in the surface that would otherwise need rebuilding after the dig.
Digging is the honest answer when the pipe has collapsed, when a belly is deep enough to hold waste, or when a joint has offset so far that a liner cannot bridge it. In each case the shape of the line is the problem, and no method that works inside the old shape can correct it. An honest contractor says so even when the homeowner hoped for a no dig fix.
Digging also fits when the camera cannot pass at all. A camera that stops at a collapse has found the limit of trenchless methods in that spot. Clearing the blockage may let the camera through, but if the pipe behind the blockage is flattened or broken, excavation is how that section gets replaced and its grade reset.
If you are weighing these methods for your own line, start with a sewer camera inspection and bring the footage to the conversation. Call us at (207) 819-0831 or use our contact page. We work across Maine from 400 Congress St, Portland, ME 04101, and we will tell you plainly which method your footage supports.
Access is where trenchless methods earn much of their appeal. A lining or bursting job needs entry and exit points, usually at a cleanout or a small pit, rather than a trench along the whole line. A driveway, a walkway, a patio, or a mature tree over the line can stay in place, which matters when that surface would be costly or slow to rebuild.
Traditional excavation, by contrast, opens the ground along the failed section, and surfaces over that trench need restoration after backfill. That restoration is part of the job, not an afterthought, and it should be discussed before work starts so expectations are clear. A homeowner who understands the restoration scope can weigh it fairly against the trenchless saving.
Access can also decide a method on its own. A line under a new addition, a line under a deep patio, or a line in a narrow side yard with no room for a trench may leave only one practical method. The camera shows the line condition, and the site shows the access, and the two together point to the method that fits.
Trenchless repair is better when the old pipe still holds its shape, since it seals cracks with far less digging, but it is not better for a collapsed pipe or a deep belly. The camera footage decides, because the shape and grade of the line decide which method can actually work.
A sewer line usually cannot be lined when it has collapsed, when a belly is deep enough to hold waste, or when a joint has offset so far that a liner cannot bridge the gap. In those cases excavation replaces the section and resets the grade, which lining cannot do.
Trenchless lining and bursting both work on old clay pipe when the run still holds its shape and grade, since clay fails mostly at joints and through cracks. A clay run that has collapsed or sagged deeply needs excavation instead, because its shape is gone.
Lining forms a new pipe inside the old one from a resin soaked liner that cures in place. Bursting breaks the old pipe apart underground while a new HDPE pipe is pulled into its place. Lining keeps the old pipe as a host, while bursting replaces it outright.
A camera inspection shows whether the pipe holds its shape, whether its grade is steady, and whether any belly or offset is shallow enough for a liner to bridge. A line that is collapsed or deeply bellied will show that clearly on video.
Traditional repair disturbs the ground along the trench, not the whole yard, since the dig follows the line of the failed section. Lawns and surfaces over the trench need restoration after backfill, which is part of why trenchless is preferred when it fits.
Yes, a line can mix methods, such as lining a sound run and excavating one collapsed or deeply bellied section. The camera survey maps which sections suit which method, so the plan can match the method to each section instead of forcing one method on the whole line.
A cured liner forms a new structural pipe inside the old one when the host pipe still gives it shape, and it is rated under the ASTM F1216 standard. It is not the same as a new replacement pipe, and it cannot correct grade, so its fit depends on the condition the camera shows.
When both methods are possible, weigh ground disruption against the condition of the line. Trenchless saves surfaces and digging, while excavation gives a brand new pipe and an exact grade reset. A camera review with your technician will lay out both options for your specific line.
Bring us your camera footage, or book a camera run, and we will compare both methods against what your line actually shows.
01
A new lining formed inside the old pipe, with far less digging than a full replacement.
02
Open excavation and a new pipe, chosen when the old line cannot be saved another way.
03
The old pipe is broken apart underground while a new pipe is pulled into its place.
Last updated: October 28, 2026