No-dig pipe repair restores underground pipes from the inside, using a resin-impregnated or UV-cured liner installed in place to form a new structural pipe within the existing one. Also known as trenchless pipe repair, it changes everything about a project’s programme, traffic management, contractor pool and cost certainty for the consulting engineer writing it into a specification. Insituform invented cured in-place pipe lining in 1971, and over 50 years of installations have made it the default trenchless method on UK and European infrastructure projects.
What follows is what every consulting engineer should be writing into a CIPP specification, from materials and curing methods through to the quality evidence and on-site supplies the project depends on.
What Is No-Dig Pipe Repair?
No-dig pipe repair rehabilitates an existing pipe from the inside without breaking ground. A resin-impregnated liner is fed in through manholes or chambers, then cured in place using water, steam, ambient temperature, LED or UV light depending on the system you choose. Once cured, the liner forms a structural, jointless pipe-within-a-pipe that bonds to the host.
It sits at the centre of UK infrastructure work because it restores hydraulic capacity, stops infiltration, blocks root intrusion and adds decades of design life without extensive groundwork. For engineers writing specifications, that means a method that protects against the three biggest cost drivers on traditional dig-and-replace work: utility strikes, traffic management and programme overrun.
What CIPP Can Be Specified For
CIPP works across a much broader range than most specifiers realise. It can be written into specifications for:
- Wastewater and stormwater pipelines in diameters from 100mm to 2,500mm
- Rising mains and pressure distribution pipework
- Pressure mains up to 1,200mm, including drinking water applications
- Lateral connections down to 50mm, including through 90-degree bends
Pipe shape is rarely a barrier. Round, egg-profile and other non-circular pipes are all in scope. Our CIPP felt liner was used recently to rehabilitate 127 metres of egg-profile sewer in Kassel, Germany, and a 1,700mm CIPP liner delivered a 320-metre rehabilitation in southern Spain. A well-written CIPP specification can confidently cover almost any host pipe.
How Long Does A CIPP-Lined Pipe Last?
The first CIPP liners installed back in 1971 are still in the ground and working today, more than 50 years later. Very few pipe rehabilitation methods have that kind of track record behind them. Decades of independent testing back up what those long-running installations already show: a long-lasting pipe repair that holds up under daily use.
For specifiers, that has two practical implications. It allows the engineer to write CIPP into the asset management plan knowing the rehabilitated pipe will outlast most surrounding infrastructure. It also removes the lifecycle cost argument behind dig-and-replace, because design life is comparable to new excavated pipework, without the surface disruption, traffic management or carbon footprint.
What To Specify On Materials And Curing Methods
Three variables shape CIPP performance, and the specification should name each one.
Liner Material
Polyester needle felt covers general-purpose sewer rehabilitation. Glass fibre reinforcement delivers higher mechanical strength and thinner wall sections. Composite carbon or glass reinforcement is the choice for medium and large-diameter rehabilitation up to 2,400mm.
Resin Selection
Resin must be matched to the chemical and thermal exposure of the host environment. Polyester is the standard. Vinyl ester suits higher chemical resistance. Epoxy is specified for drinking water and lateral applications. The spec should justify the choice on chemistry and operating temperature, not cost alone.
Curing Method
Warm water, steam, ambient, LED and UV are all valid. UV reduces energy consumption and on-site footprint. Steam is faster on larger diameters. Warm water remains the workhorse for traditional inversion installations. The right method depends on diameter, length, access and programme constraints.
Our CIPP solutions cover every combination, which means a specification doesn’t need to compromise to fit one supplier’s narrow product offering.
Quality Controls Your CIPP Spec Should Require
A strong specification names the proof the manufacturer must demonstrate, not just the finished outcome. Insituform applies 28 quality control checks for every single CIPP liner, manufactures under ISO 9001, and operates as a vertically integrated business across engineering, manufacturing and installation.
That depth matters because the gap between liner manufacture and on-site delivery is where programme risk usually shows up. Specify ISO 9001-certified manufacturing, vertically integrated supply, and named QC protocols on every liner. Ask for evidence of laminate testing, wall thickness verification and resin impregnation tracking. A serious CIPP manufacturer will provide it as standard.
What Your Contractor Will Need On Site
A complete specification also accounts for what arrives on the lorry alongside the liner. CIPP is an installed system, not a single product, and every component on site has to work as part of one system. The strongest specifications require the contractor to source the full set from a single manufacturer.
The on-site set typically includes:
- The liner, matched to the host pipe diameter, shape and condition
- Resin matched to the liner and to the chemical and thermal exposure of the host environment
- Glide foil to reduce friction during pull-in and protect the outer membrane
- Calibration hose to maintain consistent pressure during installation and confirm the cure is complete
- Canvas jacket to maintain the pipe’s shape while the resin cures
Most procurement mistakes here do not show up at the point of order. They surface mid-cure, when a mismatched resin fails to set cleanly or an off-spec liner refuses to calibrate against the host pipe.
Specifying both the liner and matched CIPP supplies from one source closes off on-site compatibility risks before they reach the project. It also gives the engineer a single point of accountability if anything underperforms.
How To Evaluate CIPP Lining Companies
Three criteria separate serious manufacturers from installation-only suppliers.
Manufacturing depth. Look for companies that manufacture their own liner, not those that factor and resell. We produce 1 million metres of CIPP lining a year on average, vertically integrated from R&D through to installation.
Sustainability credentials. Specifiers increasingly need real carbon and circular-economy credentials behind a CIPP choice. Our flagship products incorporate 75% recycled material, and our installations significantly reduce excavation, surface reinstatement and transport emissions compared with dig-and-replace.
Technical continuity. A long infrastructure programme cannot afford a manufacturer that loses its engineers mid-project. We operate with 0% staff turnover, except for retirement, so the technical team supporting the design stage is the same team supporting the contractor on site. We routinely work with consulting engineers, utilities, municipalities and contractors across UK and European infrastructure projects.
According to Water UK, England and Wales sit on over 500,000 kilometres of sewers, much of the combined network dating to the Victorian era. The rehabilitation challenge ahead is significant, and dig-and-replace is rarely the answer.
Specify CIPP With The Company That Invented It
Specification quality decides project quality. The strongest CIPP installations across UK and European infrastructure start with a spec that names the manufacturing depth, the matched supplies and the technical support behind the liner, not just the finished product on paper.
Bringing our engineering team in at design stage removes the late compromises that creep in when liner, resin and supplies arrive from different sources, and gives the contractor a clean, single-source delivery package to price against.
Explore our CIPP solutions and get our technical team on a call before the specification is finalised.
