How CIPP Pipe Lining Works: The Process Explained

How does CIPP lining work? CIPP lining works by pulling a resin-soaked felt tube into your damaged pipe and hardening it in place. The result is a new, jointless pipe formed inside the old one, with no digging.

Cured-in-place pipe (CIPP) lining is a trenchless repair method. Instead of tearing out a failed sewer or drain line, we build a new pipe inside the one you already have. Our crew inspects the host pipe with a camera, cleans out the debris, and inserts a felt tube saturated with resin. We then use an inflatable bladder or compressed air to press that resin-saturated liner against the walls of the old pipe. Once curing is complete, the resin hardens into a structural pipe that lasts for decades.

Here is a situation our crew runs into often in San Pedro and the older South Bay neighborhoods. A homeowner gets a quote for a full sewer replacement, complete with a trench across the front lawn. Before we price anything, Sebastian runs a camera down the line. The cast iron is cracked and heavily scaled, but the pipe is still round and still holding its grade. That line is a candidate for lining. No trench, no lawn repair, and a fraction of the disruption. This is what our "Repair over Replace" approach looks like in practice.

The CIPP Process Steps: A Phase-by-Phase Guide

Understanding the CIPP process steps helps property owners prepare for our crew and equipment. We follow a specific sequence so the new liner bonds correctly and restores full flow to your line.

Step 1: Camera Inspection and Mapping

Estimated Time: 1 to 2 hours

Before any repair begins, we find the exact location of the cracks, roots, or breaks. Our crew feeds a high-definition robotic camera into the host pipe through an existing cleanout. This lets us measure the pipe's diameter and length accurately. We also locate every lateral connection. Those are the smaller pipes branching in from your sinks and toilets. We reopen each one after the lining is finished. Our sewer camera inspection process is the same first step we use on any suspected line failure.

Most of the failing laterals we scope in older San Pedro and Torrance homes are cast iron or clay. Cast iron corrodes from the bottom up and builds heavy scale. Clay cracks at the joints and lets tree roots in. Both are strong candidates for lining, and both change how much cleaning the pipe needs in the next step.

Step 2: Cleaning and Descaling

Estimated Time: 2 to 4 hours

A resin-saturated liner will not stick to a dirty pipe. We use hydro jetting or mechanical scouring tools to strip the inside of the host pipe back to its original material. Descaling means scraping off the hardened mineral crust that builds up on old cast iron.

This step matters more than it sounds. Any debris left behind can create slugs, which are lumps of hardened resin that narrow the finished pipe and cause clogs later.

Step 3: Measuring and Wetting Out the Liner

Estimated Time: 1 to 2 hours

We measure a felt tube to the exact length of your line. The "wet-out" process means saturating that tube with resin. We run it through a calibration roller so the resin spreads evenly through the felt at a consistent thickness. That gives the finished pipe the same strength from one end to the other.

Step 4: Liner Insertion

Estimated Time: 1 to 3 hours

The resin-saturated liner goes into the pipe. We typically use an inversion tank. Air pressure turns the liner inside out as it feeds in, a little like pushing a sock through itself. That motion puts the resin-heavy side in direct contact with the host pipe wall. On shorter runs, we may pull the liner into place with a winch instead.

Step 5: Inflation and Calibration

Estimated Time: 30 to 60 minutes

Once the liner is in position, we insert an inflatable bladder, also called a calibration tube, or run continuous air pressure to expand it. A calibration tube is a temporary inner sleeve that pushes the liner outward. That pressure holds the resin tight against the old pipe wall, forces it into cracks and voids, and leaves a smooth interior.

Step 6: The Curing Phase

Estimated Time: 10 minutes to 12 hours, depending on cure method

Curing is the chemical reaction that turns liquid resin into a hard solid. Some resins set on their own. Others are sped up with heat or light. Cure times vary widely by method, and we break down each one below.

Once the liner reaches the hardness our resin manufacturer specifies, measured with a Barcol hardness gauge (ASTM D2583), the new pipe is formed.

Step 7: Reinstating Lateral Lines

Estimated Time: 1 to 3 hours

The liner is one continuous tube, so it initially covers the openings where your branch lines meet the main line. We send a robotic cutter through the new pipe to reinstate those openings, meaning cut them back open, precisely. That restores flow to every toilet and sink in the building without digging up floors or the yard.

CIPP Process Timeline at a Glance

The cured-in-place pipe process runs in seven stages: camera inspection, cleaning, liner measurement and wet-out, insertion, inflation, curing, and lateral reinstatement. Most residential lateral jobs finish in a single working day. Longer runs and slower cure methods can extend into a second day.

How Long Does the Resin Take to Cure?

Curing is the most variable part of the CIPP process. Pipe diameter, ground temperature, the resin system, and the method our crew uses on site all change the timeline.

Here are the general ranges by method:

• Ambient Curing: The resin hardens on its own at the temperature of the surrounding air and ground. This typically takes 6 to 12 hours. It suits smaller residential lines where speed is not critical.
• Steam Curing: Circulating steam brings the resin up to temperature quickly. Most residential runs cure in roughly 2 to 4 hours.
• Hot Water Curing: The original CIPP method. Heated water circulates through the liner and is held at temperature until the resin sets, which typically takes 6 to 8 hours.
• UV Light Curing: The fastest modern method. We pull a "light train" through the pipe and the resin hardens almost immediately. Depending on pipe length, this runs from about 10 minutes to an hour.

We monitor temperature at both ends of the pipe to confirm the resin has fully hardened.

Curing times range from about 10 minutes to 12 hours. The method decides it: ambient air, steam, hot water, or ultraviolet light.

Do I Need to Leave My Home During CIPP Lining?

You generally do not need to leave your home or close your business during CIPP lining. That is one of the main advantages over traditional dig-and-replace work. There are three things to plan for.

1. No water use. You cannot run water while the liner is being installed and cured. That means no flushing, no dishwasher, no showers. The lateral connections are temporarily covered, so anything you send down a drain has nowhere to go. It can back up into the house or ruin the uncured resin.
2. Noise and equipment. Our trucks, compressors, and boilers make a moderate amount of noise, and our vehicles will be parked near the access point for the working day. Our crew works in boot covers, keeps the work area clean, and leaves your property the way we found it.
3. Odor. You may notice a faint plastic-like smell while the resin hardens. How strong it is depends on the resin system. Polyester and vinyl ester resins contain styrene, which has a sharp odor people detect at very low levels. Epoxy systems, common for lining pipes inside an occupied building, give off far less. Either way, we run exhaust fans to pull fumes away from your living space.

There is one thing you can do the day before. NASSCO, the trade association that sets CIPP standards, advises homeowners to make sure their sewer traps are full of water before lining starts. A dry or damaged trap is the usual path for odor to reach living space. If you have a floor drain that rarely sees water, run some down it and let us know.

Plan on no water use for the full working day. On a UV-cured or steam-cured residential line, that is often 6 to 10 hours. On an ambient-cured line, it can run into the following morning. We give you the specific window in writing before we start.

Quality Control and Final Inspection

After the resin liner installation is finished, we run a final camera inspection. We navigate the camera through the full length of the new pipe to confirm there are no wrinkles, fins, or missed reinstatements. This footage becomes a permanent record of the repair.

We walk you through that footage and provide a detailed inspection report. You see the smooth, jointless interior of your new line for yourself. This final check confirms the repair meets our standards and local building codes.

Every CIPP project ends with a final camera inspection to verify that the resin-saturated liner has formed a smooth, defect-free interior surface.

Request a Trenchless Pipe Inspection

Dealing with repeat backups or slow drains? CIPP lining is often the most cost-effective fix. It restores your line and leaves your landscaping, driveway, and hardscape intact. Not sure whether your problem has reached that point? Here are the early warning signs your sewer line is failing, and here is what sewer line repair typically costs.

Lining is not the right answer for every pipe. If the camera shows a collapse or a back-pitched line, we will tell you so and price the correct repair. What we will not do is quote you a full replacement for a pipe that can be relined.

Stephens Plumbing, Heating & Air Conditioning has served the South Bay and Orange County since 1986. We are licensed and insured under California contractor License #508377. Your camera inspection comes with a free estimate. You get a full-price quote in writing before any work begins. Our team is available 24/7 for emergencies.

Managing a commercial or multi-family property? See how pipe lining works in occupied commercial buildings, or browse our full range of sewer line and trenchless repair services.

Contact Us Today to schedule a camera inspection of your host pipe and receive a detailed repair plan.