blogTL;DR: CIPP (Cured In Place Pipe) lining is a no-dig drain repair method that forms a new pipe inside a damaged one. A resin-soaked liner is pulled or inflated into the drain, then cured until it hardens into a jointless pipe. It repairs cracks, root ingress and leaking joints without digging up your garden, driveway or floor. This guide covers how it works, when it suits your drain, and how long the repair lasts.
Most homeowners meet CIPP (Cured In Place Pipe) lining at the worst possible moment: after a CCTV camera has found a cracked or root-damaged pipe running under a driveway, a patio, or the kitchen extension. The traditional answer was excavation. Dig it up, replace the broken section, then rebuild whatever was on top of it.
Lining changed that. A structural liner cures inside the existing pipe and seals the damage without breaking ground, which matters enormously in Cornwall where a drain often runs beneath granite paving, a shared lane, or a listed property with no vehicle access.
The catch is that lining is not right for every pipe, and not every contractor installs it to the standard it should be installed to. This guide explains what CIPP lining is, how the process runs from survey to sign-off, when excavation is still the better call, and what a properly specified liner should deliver.
What Is CIPP (Cured In Place Pipe) Lining?
CIPP (Cured In Place Pipe) lining is a trenchless drain repair method that installs a new pipe inside an existing damaged one. A flexible liner saturated with resin is inserted into the drain, pressed tight against the pipe wall, and cured until it hardens into a permanent, jointless pipe that carries the load of the original.
The vocabulary is worth pinning down before we go further.
- Host pipe: the existing damaged drain, made of clay, pitch fibre, cast iron or plastic.
- Liner: a felt or fibreglass sleeve soaked in thermosetting resin, meaning a resin that hardens permanently once cured and does not soften again with heat.
- Curing: the chemical hardening process, triggered by ambient temperature, hot water, steam or ultraviolet light.
- Trenchless (or no-dig): any repair carried out through existing access points such as manholes or inspection chambers, with no excavation.
CIPP is the most widely used form of Drain Pipe Relining, and the two terms are often used interchangeably. The finished liner has no joints along its length, which removes the exact weak points that roots and groundwater exploit.
The performance requirements for these liners are set out in BS EN ISO 11296-4, the British and international standard covering cured-in-place pipes for renovating underground non-pressure drainage and sewerage networks. The standard specifies the resin systems, carrier materials and test methods that a compliant liner must meet, including service temperatures up to 50°C.
How Does CIPP Lining Work?
CIPP lining follows a fixed sequence: survey the drain, clean it, measure it, install the resin-soaked liner, cure it in position, then survey again to prove the repair. A domestic liner is typically installed and cured within a single working day, and the drain returns to normal use once the resin has hardened.
Here is how a Clear Stream engineer runs the job.
- CCTV survey and diagnosis. A camera runs the full length of the pipe to find the damage, measure it, and confirm the pipe diameter and material. No liner should ever be quoted without one. Our CCTV Drain Survey produces the footage and report that the design is based on.
- Cleaning and preparation. High-Pressure Jetting strips the pipe wall back to bare material. Where scale, hardened fat or intruding roots are present, descaling or root cutting is carried out first. Resin will not bond to a dirty pipe.
- Measurement and liner cutting. The liner is cut to the exact length of the damaged run and matched to the pipe diameter.
- Resin saturation. The liner is impregnated with resin, either off site or on site depending on the system, then loaded ready for installation.
- Installation. The liner is inverted (turned inside out under air or water pressure) or winched into the drain through an existing access point, then inflated so it presses hard against the host pipe wall.
- Curing. The resin hardens in position. Ambient curing takes the longest, hot water and steam are faster, and UV curing is faster still.
- Reinstatement and final CCTV. Any branch connections covered by the liner are reopened with a cutting robot, and a final camera survey records the finished pipe.
That final survey is the part homeowners should insist on. It is the documented evidence that the liner is seated correctly, the connections are open, and the pipe runs clear from end to end.
When CIPP Lining Is the Right Repair
CIPP lining works when the host pipe is damaged but still holding its shape. If the camera shows a pipe that is cracked, fractured, root-infested or leaking at the joints, and the line and level are still sound, a liner will restore it to full structural strength without excavation.
Damage That Lines Well
- Longitudinal and circumferential cracks
- Root ingress through joints and cracks
- Open or displaced joints in clay pipework
- Corroded or worn cast iron
- Deforming pitch fibre pipes (common in properties built between the 1950s and 1970s)
- Small holes and localised fractures
Patch Liners vs Full-Length Liners
A patch liner repairs a single defect, typically half a metre to two metres of pipe. It suits one cracked joint or a single point of root entry, and it is the faster, lower-cost option.
A full-length liner runs from one access point to the next and renews the entire length. It is the right specification where a pipe has multiple defects along its run, or where the material itself has failed and a patch repair would simply move the problem three metres downstream.
When Excavation Is the Better Call
Lining is not a fix for everything. Excavation, or a point repair followed by lining, is needed where:
- The pipe has fully collapsed and there is no bore left to line through
- Deformation exceeds what the liner can accommodate
- Joints are so badly displaced that the liner cannot pass or seat correctly
- The pipe run has severe backfall and needs relaying to the correct gradient
A liner reinstates the pipe you have. It does not correct a pipe that was laid to the wrong gradient in the first place. If a survey shows standing water because the fall is wrong, lining will hold that fault in place permanently, which is why the diagnosis matters more than the technique.
How Long Does a CIPP Lining Repair Last?
A correctly installed CIPP liner is a permanent repair, not a temporary patch. The cured liner is a structural pipe in its own right, designed to carry ground load independently of the host pipe around it, and it has no joints for roots or groundwater to penetrate.
Liner design life is calculated from long-term flexural modulus testing, a measurement of how the material resists bending stress over decades under both wet and dry conditions. That test method is defined in BS EN ISO 11296-4, and any contractor quoting a liner should be able to produce the data sheet for the system they are installing. If they cannot name the standard their liner is tested to, that tells you what you need to know.
Three things determine whether you get that design life:
- How thoroughly the pipe was cleaned before the liner went in
- Whether the liner thickness was designed for the pipe diameter, depth and ground conditions
- Whether the resin was fully cured before the drain was put back into service
Every lining repair Clear Stream carries out is covered by our 5-year guarantee, and the final CCTV footage is yours to keep.
CIPP Lining vs Excavation: What Actually Costs More
The liner is rarely the expensive part of a drain repair. Excavation is. Once you factor in reinstatement, the no-dig option is very often the lower total cost, even before you account for the days a property spends out of use.
Consider what sits above a typical Cornish drain run. Granite setts. A resin-bound driveway. A slate patio. A conservatory floor. A shared access lane that three neighbours need to use. Digging the pipe out means lifting all of it, then paying a groundworker to put it back, and reinstatement rarely matches the original surface exactly.
Lining works through the manhole or inspection chamber that is already there. The surface stays where it is.
For landlords and holiday-let owners the arithmetic is sharper still. A dig-and-replace repair in July can cost a week of bookings on top of the repair invoice. A liner installed in a day does not. Our Drain Pipe Relining service is quoted as a fixed price before any work starts, so the number on the quote is the number you pay.
There is no call-out fee, and our engineers reach any address in Cornwall within 1 to 2 hours.
Why Cornwall Properties Are Strong Candidates for Lining
Cornwall’s building stock and ground conditions make no-dig repair the sensible default across a large share of the county. Older clay pipework, pitch fibre installed during the post-war building boom, granite foundations, high coastal water tables and narrow access lanes all push in the same direction.
Clay pipes were laid in short sections with mortar or collar joints. Every joint is a potential entry point, and after decades of ground movement, tree root pressure and salt-laden groundwater, those joints open up. Clay is the single most common material we line in Cornwall.
Pitch fibre is the other one. Laid widely between the 1950s and 1970s, it deforms into an oval under load and delaminates from the inside out. Where the deformation is within tolerance, a liner reforms and reinforces the pipe. Where it has failed completely, it comes out.
Then there is access. Plenty of Cornish properties sit at the end of a lane a mini digger cannot reach, or behind granite walls that cannot be taken down and rebuilt at any sensible cost. Lining needs a van, an inspection chamber, and a working length of hose.
One important point on responsibility before you commit to any repair. Ofwat confirms that drains within your property boundary are the property owner’s responsibility to maintain, while private sewers outside the boundary largely transferred to sewerage companies on 1 October 2011. If a survey shows the defect sits beyond your boundary, the Consumer Council for Water advises contacting your wastewater company first. A good survey tells you which side of that line your damage falls on before you spend anything.
What Should You Expect From a CIPP Lining Quote?
A proper CIPP lining quote is built from CCTV evidence, not guesswork. It should state which section of pipe is being lined, the liner type and thickness, the curing method, whether connections need reinstating, and a fixed price. Anything vaguer than that is not a quote, it is an estimate waiting to grow.
Ask for the following before you sign anything:
- The CCTV survey footage and written report identifying the defect
- The liner system being used and the standard it is tested to
- Confirmation of a post-installation CCTV survey
- The guarantee period in writing
- A fixed price, not a day rate
Clear Stream engineers are uniformed, certified, and carry out the survey, the lining and the final inspection as one job. If a blocked drain turns out to be a structural fault rather than an obstruction, we tell you on the day, show you the footage, and quote the repair before we leave.
Get the Pipe on Camera Before You Commit
Cracked, leaking and root-damaged drains do not improve with time. They leak wastewater into the ground, undermine foundations, and eventually collapse, and a collapse is the one outcome that takes lining off the table entirely.
If you have a recurring blockage, a smell you cannot trace, or a survey report you do not fully understand, get the pipe on camera and get the options in writing.
- CIPP lining repairs a damaged pipe from the inside, with no excavation
- It suits cracked, jointed, root-damaged and deforming pipes, not collapsed ones
- The repair is permanent, and ours carries a 5-year guarantee
Call Clear Stream Drainage Solutions on 01872 222555 to book your CCTV Drain Survey and get a fixed-price quote for lining. No call-out fee, and an engineer with you within 1 to 2 hours anywhere in Cornwall.
Frequently Asked Questions
Is CIPP Lining the Same as Drain Relining?
Yes. Drain relining is the general term for repairing a pipe from the inside, and CIPP (Cured In Place Pipe) is the most common method used to do it. When a Cornwall drainage company quotes for relining a domestic drain, it is almost always a CIPP liner they are installing.
Can a Collapsed Drain Be Lined?
No. CIPP lining needs a host pipe that still holds an open bore for the liner to inflate against. Where a pipe has fully collapsed, the failed section is excavated and replaced, and the remaining run can then be lined if the survey supports it.
Does CIPP Lining Reduce the Diameter of the Drain?
The liner adds a few millimetres of wall thickness, so the internal diameter reduces slightly. Flow capacity is rarely affected, because the cured liner has a smooth, jointless bore that moves water more efficiently than the cracked or scaled pipe it replaced.
Will CIPP Lining Stop Tree Roots Returning?
Yes, within the lined section. Roots enter drains through open joints and cracks, and a cured liner seals both. Roots cannot penetrate the resin, so the lined length is protected. Any unlined section of the same run remains at risk, which is one reason full-length liners are specified where root ingress is widespread.
Do I Need Building Regulations Approval to Reline a Drain?
Repairs and alterations to existing drainage in England fall under Approved Document H of the Building Regulations, which covers foul water drainage and building over sewers. Requirements depend on the pipe, its location and its ownership, so confirm the position with your building control body or water company before work starts. Clear Stream will tell you where a survey suggests approval applies.
How Long Does the Drain Need to Be Out of Use During Lining?
Most domestic liners are installed and cured inside one working day, and the drain returns to normal use once curing is complete and the final CCTV survey has been carried out. UV and steam curing are the quickest options where speed matters, such as an occupied holiday let mid-season.
Can a Septic Tank Drainage Run Be Lined?
Yes, where the pipe is a suitable candidate. The inlet and outlet runs serving a tank are lined the same way as any other gravity drain, and the survey will show whether the damage is in the pipework or in the tank itself. If the tank is the problem, our Septic Tank Maintenance team handles that side.
