Cured-in-place pipe lining installs a new structural pipe inside the old one without a trench. This page explains how the liner actually works and how to tell if your line qualifies.
What a cured-in-place liner is
CIPP stands for cured-in-place pipe. The product is a flexible felt or fiberglass tube, saturated on site with a two-part epoxy resin, that is pulled or inverted into the existing sewer pipe and then pressed against the old pipe wall with air or water while the resin hardens. When it cures, you have a continuous, jointless pipe bonded inside the original. The old pipe becomes a form; the liner becomes the sewer.
The strength comes from the cured resin and the fabric together, not from the host pipe. A properly designed liner is rated by its manufacturer to carry soil and traffic loads on its own, which is why cured-in-place pipe lining for sewer laterals is treated as a structural repair rather than a coating. That distinction matters when you compare it to spray or brush coatings, which seal a surface but do not add meaningful strength.
How the installation actually goes
- Clean. The line is hydro jetted to bare wall. Roots are cut, scale is knocked off cast iron, grease is flushed. Anything left behind becomes a bump in the new pipe.
- Measure. The camera run gives the length, diameter, and the exact footage of every branch connection (kitchen, laundry, bathrooms) that ties into the run being lined.
- Wet out. The liner tube is cut to length and impregnated with resin, usually on a table in the driveway, then rolled to remove air pockets. Once the resin is mixed the clock is running.
- Install. The tube is inverted with air pressure from a cleanout or a small access pit, or pulled in with a winch and then inflated with a bladder. Either way, the goal is a liner pressed tightly against the host pipe with no wrinkles.
- Cure. Ambient-cure resins harden over a few hours. Hot water or steam speeds that up. UV-cured liners use a light train pulled through the tube. The crew keeps pressure on until the liner is hard.
- Reinstate and verify. A robotic cutter opens each branch connection, and a final camera pass records the result.
For a typical residential lateral of 40 to 100 feet, this is a one-day job. Water use in the house is off for most of that day. Longer runs, multiple branches, or a line that needs a lot of prep can push it to two.
Which pipes are good candidates
The liner needs a host pipe that still holds its round (or nearly round) shape and has a mostly consistent diameter. Beyond that, the material barely matters.
- Vitrified clay with root intrusion, cracked segments, and offset joints up to roughly a quarter of the diameter. This is the classic case in the 1950s and 60s tracts around Anaheim, Fullerton, Garden Grove, and Westminster.
- Cast iron under slab with scale, pitting, and channeling along the bottom. Once cleaned, the liner bridges the thinned floor and stops further corrosion. Coastal homes see this earlier than inland ones.
- ABS and PVC with separated glue joints, a crushed spot, or a bad transition fitting.
- Orangeburg, the bituminous fiber pipe found in some postwar homes, can usually be lined if it has not collapsed or gone badly oval. The common claim that Orangeburg always has to be dug up is not correct; it is a shape question, not a material question.
Which pipes are not candidates
A liner follows the pipe it is installed in. It cannot lift a low spot, close a gap, or make a flat pipe round.
- Bellies. A liner installed through a sag creates a smooth sag. Water still stands there. If the belly is short and shallow it may be tolerable; if it is holding several inches of water over a long stretch, the section needs to be re-laid or the line burst.
- Collapsed or missing sections. The liner has nothing to press against. It may inflate into the void and leave a weak bulge, or it may not pass at all.
- Severe offsets. A joint stepped more than about a third of the pipe diameter will fold the liner. These are usually handled with a small excavation at that one joint, then lining the rest.
- Pipes that need to be larger. Lining reduces the inside diameter by roughly the liner thickness. That is rarely a flow problem on a residential lateral, but a line that was already undersized should be burst and upsized instead.
Ask for the post-lining video. It should show a smooth, wrinkle-free wall from end to end, each branch connection opened fully and cleanly, and the camera passing all the way to the city main or the property-line cleanout.
Reinstating branch connections
This is the step that separates a good lining job from a bad one. When the liner cures it seals over every pipe that joined the run: the kitchen line, the laundry, the bathroom groups. Each one has to be reopened from inside using a remote cutter guided by camera. A cutter that misses the center leaves a lip that catches debris; one that overcuts damages the liner. The count of connections should be agreed before the job starts, and the final video should show each one. If your house has a branch the contractor did not know about, you will find out the first time that fixture is used. That is why the pre-lining camera run matters as much as the liner itself.
Design life and what it depends on
Liner manufacturers generally rate their products for around fifty years of service. That figure assumes proper resin mixing and full cure, correct liner thickness for the pipe depth and soil load, and a clean host pipe at installation. It does not assume the host pipe survives; the liner is designed to stand alone once the clay or cast iron around it degrades further. Roots cannot enter a jointless pipe, so the recurring root problem goes away. What the liner does not change is the slope of the line or the habits of the people using it, so a belly still holds water and grease still builds up if it is poured down the drain.
Because installation quality is the whole story, it is worth talking to more than one of the trenchless lining crews working across Orange County and comparing how each describes their cleaning, their cure method, and their reinstatement process. If you are still unsure whether your line is a lining case or a replacement case, there is a practical walkthrough of how to tell lining from replacement that covers the decision from the camera footage forward.
Common questions in Orange County
Does lining reduce the size of my sewer pipe?
Slightly. A typical residential liner is a few millimeters thick, so a 4-inch clay pipe ends up a little under 4 inches inside. Because the new wall is smooth and jointless, flow is usually better than before, not worse.
How long is the water off during a lining job?
Plan on most of one working day. The crew needs the line dry and unused from cleaning through cure and reinstatement. They will tell you when fixtures can be used again.
Can a liner be installed through a bend?
Yes, through gradual sweeps and standard 45-degree fittings. Tight 90-degree elbows and back-to-back fittings are harder and sometimes need a small dig at that point.
What happens to the old pipe?
It stays in the ground as the form the liner cured against. Over time it can keep deteriorating; the liner is designed to carry the load by itself when that happens.
Is CIPP lining permitted in Orange County cities?
Generally yes. Most cities treat lateral lining as sewer repair work that needs a permit, and your contractor pulls it. Ask to see the permit and whether an inspection is required before the access point is closed.