Pros and Cons of Trenchless Sewer Repair: Is It Right for Your Line?

Trenchless sewer repair replaces or lines a damaged sewer line through small access pits instead of a trench along its whole length. For many South Bay homes, where laterals run under driveways, walkways and mature trees, that’s a big advantage, but trenchless isn’t right for every pipe.

Here are the honest pros and cons, so you can weigh them against what a camera inspection shows about your line.

The main benefits are less damage to your property, faster repairs and long-lasting results: the crew works from one or two small pits (or an existing cleanout), so lawns, driveways and patios mostly stay in place, and many jobs are finished in a day or two. The main limits are that trenchless can’t fix every pipe (a collapsed line or a deep sag usually needs some digging) and that the repair itself can cost more than a plain open-trench replacement.

This post weighs trenchless on its own. For how the methods work step by step, see what trenchless sewer repair is; to compare it with digging a trench, see trenchless vs. traditional sewer repair.

Pros: 8 Benefits of Trenchless Sewer Repair

Trenchless methods solve the problems that make sewer work disruptive: the trench, the time it stays open, and the restoration afterward. CPI uses three of them: pipe bursting (pulling new HDPE pipe through the old line while breaking it apart), CIPP lining (curing a resin-soaked liner inside the old pipe) and spot repairs of single sections.

1. Much Less Property Damage

A traditional replacement digs a trench the full length of the line, through whatever is on top of it. Trenchless work needs only one or two small access pits, usually a few feet across, at the ends of the line, and lining can often be done through an existing cleanout. Your lawn, landscaping, driveway and walkways mostly stay where they are, so there’s far less to rebuild afterward.

2. Faster Repairs

Much of the time in an open-trench job goes into digging, backfilling and restoring the yard. Without that, many trenchless lateral replacements or linings are done in a day or two, compared with several days plus restoration for a trench.

3. Lower Total Cost in Many Cases

The trenchless work itself can cost more (see the cons below), but the total is often lower once restoration is counted. Open-trench jobs get expensive when they go under concrete driveways, patios, retaining walls or mature landscaping, and all of that has to be broken out and rebuilt. Trenchless avoids most of it. A new or lined pipe also resists roots and leaks at the joints, which means fewer repeat repairs.

4. Longer Pipe Life with Durable Materials

Pipe bursting leaves a new seamless HDPE pipe in place of the old one. CIPP lining creates a new jointless pipe inside the old one that resists corrosion and cracking, and because there are no joints, roots have no way in. Both are designed to last for decades when they’re installed correctly.

5. Gentler on the Environment and Your Trees

Less digging means less disturbed soil, fewer truckloads of dirt hauled away and less heavy equipment running on site. It also means less root cutting near trees and shrubs, which matters on South Bay streets with mature street trees.

6. Better Flow Through the Line

New HDPE pipe and cured liners have smooth interior walls without the offsets, rough joints and scale of old pipe. Waste flows more freely, and there are fewer places for grease, debris and roots to catch, so clogs are less likely and the line needs less maintenance.

7. Lower Risk to Other Utility Lines

Gas, water, electric and communication lines often run near a sewer lateral. Because trenchless work digs only at the access pits, there’s much less risk of damaging another utility and causing a service interruption. (Horizontal directional drilling is another trenchless method, used mainly to install new lines along a planned path rather than to repair an existing lateral.)

8. Less Disruption to Daily Life

A trench can block a driveway or front yard for days. With trenchless work you can usually keep using most of your yard and driveway, the mess is limited to the pits, and the plumbing is back in service quickly.

Cons: Disadvantages of Trenchless Sewer Repair

Trenchless isn’t the answer for every line. Weigh these drawbacks against what a camera inspection shows.

1. Hidden Damage Can Change the Plan

A sewer camera shows the inside of the pipe: cracks, roots, offsets and buildup. What it can’t fully show is outside the pipe, such as a sag in the grade, a void in the soil or a section that’s about to collapse. A liner follows the existing pipe, so it doesn’t fix a sag or a badly offset joint. That’s why the line has to be camera-inspected and cleaned (often hydro jetted) before the work, and why a plan can change once the crew is in the line.

2. Needs Specialized Equipment and Skilled Technicians

Bursting heads, winches, lining and curing equipment take training to use well. A poorly sized liner, a missed side connection or a pipe pulled off grade leads to leaks, wrinkles or new blockages. Lining also narrows the pipe slightly, and connections from other drains have to be reopened from the inside with a cutter.

3. Not for Severely Damaged Pipe

Lining needs an existing pipe that still holds its shape, and bursting needs a path to pull through. A collapsed section, a severe sag that needs regrading, or a line that has to be rerouted usually needs an open trench, at least for part of the run. Many jobs combine methods: a spot dig at the bad section and trenchless for the rest.

4. Higher Upfront Cost for the Repair Itself

The equipment and materials cost more than plain PVC pipe in a trench, so the repair price can be higher. For a short, shallow line under bare soil, a trench may be the better value. In San Jose, CPI’s typical prices are: a spot repair of one bad section $2,000 to $5,000, a typical lateral replacement $6,000 to $15,000, and long, deep or street-connection work $15,000 to $20,000+, with the method chosen to suit the line. See sewer line replacement cost for what drives the price, and CPI’s trenchless sewer repair in San Jose for how a job is done.

Is Trenchless Right for Your Line?

It’s a good fit when the camera shows cracks, root intrusion or leaking joints in a pipe that still holds its shape, or an old clay or cast-iron lateral that can be burst and replaced, especially under a driveway or landscaping. It’s a poor fit for a collapsed pipe or a deep sag. See trenchless vs. traditional sewer repair, what trenchless repair is and sewer line repair methods.

Why Hire a Sewer Line Professional for Trenchless Repair?

Trenchless work leaves little room for error. The right method depends on an accurate camera inspection, the pipe has to be cleaned and measured before a liner is ordered or a bursting head is chosen, and every side connection has to be found and reopened. Mistakes show up as leaks, blockages or a failed City inspection. A licensed sewer contractor with trenchless experience inspects the line, explains which method fits, pulls the permit and verifies the finished pipe with a final camera run.

Trenchless Repair in San Jose

• Driveways and hardscape. Many South Bay laterals run under driveways; trenchless avoids breaking concrete.
• Street trees. Roots in clay laterals are the usual reason for repair, and trenchless means less digging near the trees.
• Permits. San Jose requires a plumbing permit and a City inspection to repair or replace a building sewer, trenchless or not. When the line is repaired or replaced at the property line, a property line cleanout must be added within 5 feet of the property line (City of San Jose, sewer projects).

CPI Service performs all three methods: pipe bursting, CIPP lining and spot repairs. CPI Service repairs and replaces sewer lines throughout San Jose and the South Bay. See sewer line replacement, request a free estimate or call (408) 978-3093.