An Overview Of The CIPP Pipe Lining Process
What Is CIPP Lining? Cured-In-Place Pipe Explained for Delaware County Homeowners
CIPP lining — cured-in-place pipe — is a trenchless method of rehabilitating a damaged sewer lateral without excavating the pipe. A resin-saturated liner is inserted into the cracked or root-invaded pipe and then cured with heat, steam, or UV light to form a rigid new pipe inside the old one. The host pipe — clay tile in most Delaware County homes built before 1960 — stays in the ground; the liner carries the structural function going forward. No trench, no lawn damage, no lost landscaping.
CIPP installation is the most common residential sewer repair we perform in Delaware County. The county built out rapidly between 1920 and 1965, and that era of construction used clay tile sewer laterals with mortar joints. Those joints have been deteriorating for decades, and they are exactly where CIPP lining restores the pipe without replacing it.
The CIPP Installation Process, Step by Step
Step 1: Camera Inspection
Every CIPP job begins with a push-camera run through the lateral. The camera establishes pipe diameter, identifies root intrusion, cracked joints, offset sections, and any portion too severely damaged to accept a liner. Not every pipe qualifies — a crushed or missing section requires excavation or pipe bursting instead of lining. The camera determines which path is appropriate before any equipment is ordered.
Step 2: Hydro-Jetting
The pipe must be clean before the liner goes in. We use high-pressure hydro-jetting to clear roots, grease, sediment, and debris from the pipe walls. A second camera pass confirms the pipe is clean enough for full liner contact. This step is not optional — a liner installed into a dirty pipe will not seat correctly and will not achieve rated service life.
Step 3: Liner Sizing and Preparation
The liner is a fiberglass or felt tube saturated with a thermosetting or UV-curable resin. Wall thickness is specified based on pipe diameter, host pipe condition, and the structural load requirements of the installation. For the 4-to-6-inch laterals typical in Delaware County residential properties, thickness selection follows the design standards in ASTM F2561.
Step 4: Liner Installation
The saturated liner is inverted into position using water pressure or air, pushing the liner outward against the pipe walls. Full contact between the liner and the host pipe must be maintained throughout the entire run. Any section that fails to seat is flagged during the post-cure camera inspection.
Step 5: Curing
The resin cures by heat — steam or hot-water circulation — ambient temperature, or UV light, depending on liner type and site conditions. Heat curing is standard for residential laterals. A properly cured liner is rigid and structural, not flexible, and adheres to the host pipe interior for the life of the installation.
Step 6: Final Inspection and Lateral Reconnection
After curing, we run a final camera to confirm the liner is continuous, seated correctly, and free of voids or wrinkles. Any branch-line connections that were sealed over during installation are reopened with a robotic cutter from inside the pipe.
CIPP Liner Testing: Standards and What the Lab Verifies
CIPP liner testing refers to the quality verification process that confirms a cured liner meets the structural specifications required for a long-term sewer rehabilitation. Testing happens at two points: the manufacturer tests liner material samples before products ship, and field quality control verifies the installed liner meets design requirements.
Two ASTM standards govern residential lateral CIPP work. ASTM F1216 covers pressure-pipe applications. ASTM F2561 covers cured-in-place rehabilitation of non-pressure drainage conduits — the standard directly applicable to residential sewer laterals. A CIPP liner testing lab evaluates samples for wall thickness, flexural modulus, and flexural strength after curing. These properties determine whether the liner will carry the design load without deflection or cracking over its rated service life.
Resin testing — sometimes called CIPP resin testing — verifies that the resin used in the liner has cured fully and reached the specified mechanical properties. An incompletely cured liner will not achieve rated strength and may leach unreacted resin compounds into groundwater. Reputable installers specify the liner product in use by manufacturer and model and can confirm which ASTM standard it has been tested against. These are not optional details — they are how you verify the installation will perform over its rated 50-year service life.
CIPP vs. Pipe Bursting: Which One Applies?
Both CIPP and pipe bursting are trenchless sewer repair methods, but they apply to different conditions. CIPP installs a liner inside the existing pipe and requires the host pipe to be structurally intact enough to hold the liner in position. Pipe bursting pulls a new pipe through the old lateral while fracturing it outward — used when the pipe is too collapsed or misaligned to serve as a CIPP host. The camera inspection determines which method is appropriate; a contractor who recommends one without a camera first is guessing.
UV CIPP Lining
UV CIPP is a variant of cured-in-place pipe lining that uses ultraviolet light rather than heat or steam to cure the resin. The liner is pre-saturated with a UV-sensitive resin and pulled into position rather than inverted under water pressure. A horizontal UV light train — a linked chain of UV lamps with a camera mounted at the front — is then drawn through the installed liner at a controlled speed, curing the resin as it passes. Cure times are faster than thermal methods: a typical residential lateral reaches full cure in 20 to 40 minutes after the light train completes its run.
UV CIPP liners meet the same structural requirements as thermally cured liners. Flexural modulus and wall thickness requirements under ASTM F2561 apply equally to UV-cured installations. The curing method does not change the quality requirements — it changes the speed of cure and the equipment required on-site. The camera at the front of the UV light train provides real-time inspection during the cure cycle, which is a meaningful quality-control advantage over thermal curing, where liner condition can only be confirmed by a separate post-cure camera run.
Whether a job uses UV or hot water curing, the result the homeowner should verify is the same: a post-cure camera showing the liner is continuous, fully seated, and free of voids or wrinkles from end to end.
CIPP Lining for Storm Sewers and Municipal Drain Lines
CIPP lining is used in storm sewer rehabilitation as well as sanitary sewer laterals. Storm sewer CIPP involves the same basic process — liner installation, curing, camera verification — but the design standards differ because storm drain lines are typically larger-diameter, are not under continuous hydraulic pressure, and carry stormwater rather than sewage. ASTM F1216 and F1743 cover larger-diameter pressure and non-pressure pipe lining applications.
In Delaware County, storm drains and municipal inlet lines have been rehabilitated using CIPP methods as an alternative to full pipe replacement. The same factors that make trenchless lining attractive for residential laterals apply to municipal work: avoiding excavation in developed areas, minimizing road and property disruption, and completing rehabilitation without taking the system out of service for extended periods.
Residential homeowners asking about storm sewer CIPP are usually dealing with a private yard drain or downspout drain connection that runs under the property. These are private structures, not municipal lines, and their rehabilitation follows the same process as a sanitary lateral. The camera establishes what you have, and the liner seals it if the pipe is structurally sound enough to hold it in place.
Frequently Asked Questions
Does CIPP lining work on clay tile pipe?
Yes — clay tile is the most common CIPP host pipe in Delaware County. The liner bonds to the clay interior and seals the mortar joints permanently. As long as the pipe walls are intact enough to hold the liner in place, clay tile is an excellent candidate.
What does a CIPP liner testing lab actually test?
A CIPP liner testing lab tests cured liner samples for wall thickness, flexural strength, and tensile modulus. These values are compared against the design minimums specified by ASTM F2561. Testing confirms the liner was fabricated to specification and that the resin cured completely in the field. Ask any CIPP installer which liner product they use and which ASTM standard it was tested against — a reputable contractor has that information on hand.
Can CIPP cover only a short section of the pipe?
Yes. Spot lining installs a short liner segment over a specific crack, root entry point, or offset joint when the rest of the lateral is in acceptable condition. Spot liners are sized to the specific defect and do not run the full length of the pipe. A full-length camera run identifies whether a spot liner is appropriate or whether the full lateral needs to be lined.
Schedule a CIPP Evaluation in Delaware County
If a camera inspection has shown root intrusion, cracked joints, or infiltration in your lateral, CIPP lining is likely the right repair. Call Advanced Drains & Underground Solutions at 1-855-DONT-DIG (1-855-366-8344) to schedule an inspection and lining assessment. We serve all of Delaware County, PA.