Trenchless Pipe Relining vs. Digging Up the Pipe

When a sewer or drain line under your yard, driveway or floor fails, the traditional fix is to dig down to it and replace it. Trenchless pipe relining offers another route: building a new pipe inside the old one, working through an access point instead of a trench.

Relining can save a lot of disruption, but it isn't the right fix for every pipe. Here's how it works, when it's a good fit, when digging is still the better answer, and what to expect if you go ahead.

What pipe relining is

Pipe relining is often called cured-in-place pipe, or CIPP. A typical job follows these steps:

1. Camera inspection. The plumber runs a camera through the line to see the damage and confirm the pipe is a candidate.
2. Cleaning. The pipe is cleaned thoroughly, often with high-pressure jetting. Cast iron usually needs descaling to remove the rough buildup on its walls.
3. Liner installation. A flexible liner soaked in resin is pulled or inverted into the old pipe through a cleanout or another access point.
4. Curing. The liner is pressed against the walls of the old pipe and left to harden. Depending on the system, curing may use hot water, steam, UV light or simply time.
5. Reopening branch lines. Where other drains tie into the lined pipe, those openings are cut back open from inside.
6. Final camera inspection. A second look confirms the liner is smooth, tight and fully open.

The result is a new, seamless pipe formed inside the old one.

When relining works well

Relining tends to be a good fit when the existing pipe still holds its shape but has problems such as:

• Cracks, small holes or corroded walls
• Roots coming in through joints, since a lining covers those joints
• Cast iron with heavy scale and corrosion that's still structurally intact
• Leaks in a line that would be costly or disruptive to reach

It's especially worth considering when the pipe runs under something you'd rather not tear up: a slab floor, a driveway, a pool deck, mature landscaping, or a finished kitchen or bathroom. Many older South Florida homes have cast iron drains under the slab, and lining them from inside can avoid opening up long stretches of floor.

When relining isn't the right fix

Relining needs a sound path to follow. It's usually not a good choice when:

• The pipe has collapsed. The liner needs the old pipe as a form, and the camera and liner have to be able to pass through.
• There's a belly or sag. A liner follows the shape of the old pipe. It seals the pipe, but it doesn't change the slope, so water and waste will still collect in a low spot.
• Joints are badly offset or separated. Large misalignments can keep the liner from seating properly.
• The pipe is too damaged to clean. If it can't be cleaned properly, the liner can't bond and seat the way it should.
• The pipe needs to be bigger or rerouted. Lining slightly reduces the inside diameter, and it keeps the pipe in its existing location.
• The damaged section is short and easy to reach. Sometimes a small excavation and a straightforward replacement is the simpler fix.

There are other trenchless methods too, such as pipe bursting, which pulls a new pipe through the path of the old one. Your plumber can tell you whether any of them suit your line.

When digging is the better answer

Excavation lets the plumber replace the pipe outright. That means it can fix problems relining can't: a collapse, a belly that needs the slope corrected, a line that needs to be rerouted or upsized. The tradeoff is disruption. Digging means restoring whatever was on top, whether that's landscaping, pavers, concrete or, for lines under the slab, the floor inside your home.

Relining and digging at a glance

Relining:

• Little or no digging, working through access points
• Less restoration of floors, driveways and landscaping
• Keeps the pipe's existing path and slope
• Depends on the old pipe being intact enough to line

Digging and replacing:

• Fixes collapses, bellies and slope problems
• Allows rerouting or changing the pipe size
• Means opening the ground or floor and restoring it afterward
• Can be the simpler choice for a short, easy-to-reach section

What to expect on a relining job

If relining is a good fit for your line, here's what the process usually looks like from the homeowner's side:

• A camera inspection first. Ask to see the video. It's the basis for the whole recommendation, and you can learn more about our camera inspection service.
• A written plan and price. It should say which sections will be lined and how branch connections will be handled.
• Permits where required. Your contractor should handle any permit your city requires.
• Access points. The work is done through existing cleanouts where possible. If there isn't a usable one, an access point may need to be added.
• Limited water use during the work. The drains connected to that line can't be used while the pipe is cleaned, lined and curing. Your plumber will tell you when you can use them again.
• A final video. Ask for a copy of the after-video for your records.

Good questions to ask: What curing method do you use? How will the branch lines be reopened? What happens if the camera finds a section that can't be lined? A clear answer to each is a good sign.

You can read more about trenchless pipe relining on our service page.

Get an honest recommendation

Whether your line is a good candidate for relining or needs to be dug up, the decision should start with what the camera shows. Call Father & Son Plumbing at (786) 922-5974. We're a family-owned, licensed and insured plumbing company (Florida license CFC1433358) with bases in Hallandale Beach and Aventura, serving South Florida since 2008. We're open Monday through Friday and Sunday, 8 AM to 5 PM (closed Saturday). The $49 service call is waived when you go ahead with the repair, and you'll get a written price before any work starts.