A CIPP specification lives or dies on the technical decisions written into it before the first liner is impregnated. It must translate CCTV coding, structural condition data, host pipe geometry and site constraints into clauses a contractor can price and install against, without leaving the ambiguity that always surfaces mid-cure. Insituform invented CIPP lining in 1971 when Eric Wood installed the first cured-in-place tube and today manufactures the CIPP Solutions range specified by consulting engineers, municipal asset owners and utility contractors worldwide.
Start With the Asset Condition, Not the Product
Every credible CIPP specification starts with what the host pipe is actually doing. That means CCTV footage with structural condition coding sitting on the specifier’s desk before any product decision is drafted, alongside a clear read on hydraulic loading, groundwater and geometry.
Insituform sees specs slip when the following inputs are missing or under-cooked:
- Structural class, partially or fully deteriorated. A fully deteriorated design must carry all soil and traffic loading on its own, and the impact of CIPP on pipe strength becomes a wall-thickness calculation from that point onward
- Host pipe substrate, whether vitrified clay, brick barrel, concrete, cast iron, ductile iron or plastic. Each behaves differently under inversion pressure and cure exotherm
- Diameter, ovality, and profile. DN sizing alone is rarely enough; a 15% ovality on an ovoid brick sewer is a very different specification to a circular concrete pipe at nominal diameter
- Groundwater regime. External hydrostatic head drives the buckling calculation for a partially deteriorated design
- Flow and access conditions. Whether the line can be taken offline, bypass pumping arrangements, and the traffic management window available at insertion and cure
Get those inputs on the page and the CIPP specification reads like an engineering deliverable rather than a product order. Bidder clarifications drop, pricing tightens, and the asset owner keeps control of the performance outcome across the whole trenchless pipe repair programme.
Match the CIPP Liner System to the Project Conditions
Once the asset condition is on paper, the liner system must match it. Our CIPP Solutions range is engineered so a specifier can name the right product line against the driver on the drawing, rather than forcing one liner across every scenario:
- Insituform CIPP Felt, the workhorse for gravity sewers and stormwater. Proven across DN70 to DN2500, hot-water or steam cured, and the reference product for standard municipal rehabilitation
- InsituMain Pressure, engineered as a fully structural liner for pressurised water mains and force mains, carrying internal working pressure independently of the host
- iPlus Composite, for fully deteriorated sections, non-circular geometries, and higher stiffness classes where a standard felt liner cannot deliver the structural rating
- iFlex Lateral, for lateral connections and junctions, so the specification addresses the weakest point in the network rather than leaving it as a follow-on package
- iPlus Glass UV, for programmes where hydraulic capacity, fast cure schedules and low VOC emissions are non-negotiable, particularly on live urban networks
Insituform manufactures and supplies the liner system. Installation sits with the specialist contractor named in the specification, and that split matters at spec-writing stage: the engineer can require a specific liner system on quality grounds without narrowing the installer pool below competent bidders in the project region. Our guide to pipe rehabilitation selection extends this decision tree where a programme mixes gravity, pressure, and lateral assets on the same network.
Building Manufacturer Credentials Into the Spec
A watertight CIPP specification is built on evidence. Marketing claims will not survive first bidder clarification, and they will not hold up when a lower-priced alternative liner is proposed against the spec at pipeline rehabilitation stage.
The clauses that hold up:
- Documented QC per liner. Require batch-traceable manufacturer records for every liner delivered to the project. Insituform runs 28 quality control checks for every single CIPP liner, and those records are available for any project we supply
- Certified manufacturing. Call up ISO 9001:2015 for the manufacturing facility by name. Our facilities are certified to the ISO 9001:2015 standard by SAI Global
- Continuity of supply. A multi-phase rehabilitation programme cannot afford a manufacturer that stalls mid-project. We produce 1 million metres of CIPP lining per year on average across our worldwide operation
- Documented recycled content. Where the client’s carbon strategy requires it, specify a manufactured percentage. Our flagship products carry 75% recycled material as a manufactured baseline across every liner
- Manufacturer track record. Specify a minimum number of years the manufacturer has produced CIPP as evidence of installed performance data. Insituform has over 50 years as the number-one manufacturer of premium, affordable and technologically advanced CIPP liner systems, with the first 1971 tube still in service
Written as clauses, these are the sections of the spec that survive value engineering. When a substitute is proposed, the answer sits inside the specification rather than in a follow-up email chain.
Build the Spec so It Holds Up
The specification is where a CIPP project earns its design life or gives it away. When the document reflects the real asset condition, matches the right liner system to the network, and requires evidence-backed manufacturer credentials as clauses, the rehabilitated pipe performs for the horizon the client is paying for.
Our technical team works alongside specifying engineers on the CIPP clauses that need to be right at first pass. Explore our full CIPP solutions range of the products your spec can call up, or speak to our technical team for specification advice on your next infrastructure project.
