Trenchless Sewer Repair: How It Works and When It Beats Digging
Tearing up your yard, driveway, or landscaping to find a pipe that can’t be seen does not make for an ideal situation. Traditionally, the only way to fix a sewer line was to dig up the damaged section and replace the broken pipe.
With trenchless sewer repair, damaged lines are fixed with little to no digging, using methods like pipe lining or pipe bursting to restore or replace the underground pipes.
Learn more about trenchless repair, the two main repair methods, when it’s a better choice, when digging still wins, and why it all still starts with a camera inspection.
What Is Trenchless Sewer Repair?
Trenchless sewer repair involves accessing the end of a damaged pipeline to assess and fix it without extensive digging, whereas traditional repair requires digging up a large area, or the full length of the line, to expose the damaged pipe.
Important note: Neither option is excavation-free. Both require some digging, but the trenchless approach requires far less digging.
It Starts with a Sewer Camera Inspection
The first step in trenchless sewer repair is a camera inspection of the line. This provides insight into the pipe’s material, condition, and exact location of the damage. This information helps determine the best approach for the repair.
A thorough cleaning follows the camera inspection to remove debris and ensure the walls are smooth for the repair to work properly.
At Cannonball Mechanical, we use tools like sewer rodding and cameras to provide the best results.
The Two Main Trenchless Methods
Pipe Lining (Cured-in-Place Pipe, or CIPP)
Also known as pipe-in-pipe repair, this method installs a new, durable pipe inside the original sewer line. A resin-saturated liner is drawn into the existing pipe and cured, creating a new, seamless pipe inside the original one.
This repairs the sewer by sealing cracks and separated joints, and blocks entry points where roots can get in. For a pipe lining repair to work, the existing pipe must be intact enough to support the liner.
Pipe Bursting
Pipe bursting repairs work by fracturing the old pipe while pulling a new HDPE pipe into its place. This works in collapsed lines and other situations where lining is not suitable. Pipe bursting causes some ground movement, so evaluation of the site is important to ensure it’s suitable.
Pipe bursting is sometimes described as ‘semi-trenchless,’ but it’s still far less destructive to driveways and landscaping than traditional repairs.
Lining vs. Bursting: Which One Fits?
The repair approach depends on the damage and location. Bursting is a better option when a pipe is beyond repair or needs upsizing, while lining is a good choice when the pipe is still mostly sound.
How It Works:
- Pipe Lining: A resin-saturated liner is drawn into the existing pipe and cured, forming a new seamless pipe inside the old one.
- Pipe Bursting: A bursting head fractures the old pipe while pulling a new HDPE pipe into its place.
Best For:
- Pipe lining: Pipes that are still mostly sound. It can only repair moderate damage, like small holes or cracks.
- Pipe Bursting: Pipes that are beyond repair or need upsizing. Works where lining can’t, like collapsed lines.
What it Fixes or Improves:
- Pipe lining: Seals cracks and separated joints and blocks the entry points where roots get in.
- Pipe Bursting: Replaces the old pipe with a new pipe, generally making it a more comprehensive, long-term solution.
Limitations:
- Pipe lining: Slight reduction to the pipe’s inner diameter and depends on the old pipe being sound enough to hold the new liner.
- Pipe Bursting: Causes some ground movement, so the site must be suitable for it. It’s usually not an option if the existing pipe has a belly.
When Trenchless Beats Digging
Consider the benefits of trenchless sewer repair:
Less Disruption
Property disruption is one of the biggest practical differences. Trenchless avoids opening a trench across the yard.
Overall Cost
Trenchless repairs typically cost more upfront. But they can lower the total expense by avoiding excavation and property damage. Often, costs are comparable, or cheaper, once you include costs for concrete replacement and landscape restoration.
Root Resistance
New pipes are jointless, eliminating any root entry points.
Good Candidates
A line with minor cracking may be a good fit for pipe lining, while a line that’s beyond repair or collapsed may be a candidate for bursting.
When Traditional Excavation Is the Better Choice
Trenchless repairs may have less impact on site, but they are not always the best choice. Certain situations demand a traditional approach to address the damage.
Sagging Lines (Bellies)
A belly in a sewer pipe is where sagging disrupts the normal gravity flow, which can lead to backups or pooling. Trenchless methods follow the existing path and cannot correct slope. Fixing a sag requires digging and re-grading.
Collapsed or Badly Misaligned Pipe
A collapsed or misaligned line may need excavation. When a pipe is crushed, there’s no host pipe left to line, and depending on the severity, bursting may not be an option.
Short, Easy-to-Reach Damage
If a short, damaged section has easy access, digging is the cheaper, faster option compared to using trenchless equipment.
Other Situations
Excavation may also be needed when utilities conflict with the pipe’s route, when the layout can’t fit access pits, or when repairs are needed at the connection to the city main or a cleanout.
Signs Your Sewer Line May Need Repair
- Multiple slow drains: A single slow drain usually means a localized clog, but several slowing simultaneously often means an issue with the main sewer line.
- Gurgling: Gurgling sounds when you flush, use an appliance, or run water can mean there is partial blockage.
- Odors: Smells of sewage inside or near the yard can mean a crack, blockage, or break letting gases escape.
- Yard Changes: Leaks can lead to soggy spots, indentations, or patches of grass that are noticeably greener.
- Pests: A damaged sewer line can attract pests like rodents and insects.
Damaged sewer lines typically get worse over time rather than improving on their own. If you notice any of these signs, learn more about our sewer cleaning and inspection services.
Trenchless Sewer Repair FAQ
Does trenchless sewer repair require any digging?
Yes, trenchless sewer repair requires digging, but it’s far less than traditional excavation methods.
Can trenchless repair fix a sagging sewer line?
No. Trenchless methods follow the existing pipe’s path and can’t restore its slope, so a belly requires excavation.
Can pipe lining fix a collapsed pipe?
No, lining requires an intact host pipe, though pipe bursting may work on collapsed lines.
Can trenchless repair stop tree roots?
Lining seals cracks and joints where roots can enter, and the finished pipe is jointless.
Is trenchless repair more expensive than digging?
While it can be more expensive upfront, overall costs can be comparable or cheaper when you factor in yard and driveway restoration.
Get the Right Answer for Your Sewer Line
No sewer repair decision should be made without seeing the inside of the pipe first. At Cannonball Mechanical, we rod, televise, and locate sewers. We offer complete water, gas, and sewer line installations for residential and commercial properties. Every team member is union-trained, licensed, bonded, and insured, with at least 20 years of experience.
Our company has been family-owned since 1974 and stands behind our work with a full guarantee.
To get started, call 630-896-4888 or contact us online, and we will reach out as soon as possible.
