Seal of quality for trenchless renovation contractors
CIPP quality: No reason to panic
With latest reports of declining CIPP liner quality, German testing institute Siebert + Knipschild warns of excessive pessimism. Based on 6,000 samples out of three European countries in one year, the inspection engineers rather conclude: More installation companies than ever fulfilled the requirements for successful CIPP sewer renovation, rewarded by the Seal of quality. Instead of complaining about a perceived decrease in quality, Siebert’s managing director is asking everyone to instead consider the question: What makes a good CIPP product?
“Much more than just the source CIPP product, it’s the combination of multiple factors – a sensible call for bids, a made-to-measure liner and a successful installation and curing procedure – that adds up to a final judgment of any given contractor’s work”, says Andreas Haacker, managing director at Siebert + Knipschild, Germany’s leading institute of testing CIPP materials. Quality of the process in particular correlates with a contractor’s experience with a system, the equipment as well as personal qualification.
Further influencing the final judgement is the sense of “next-gen” sustainability, both regarding climate protection as well as the longevity and durability of the CIPP liner. “In short, it’s all about having a PLAN: Planning, Liner quality, its’ Application and Next-gen sustainability all need to be up to par”, says Haacker. “Whether you are a client, a contractor, or a manufacturer: Each of them is equally key to success.”
Liner-only rankings „like Formula One without a driver“
What liner yielded the best results? This question is flawed in the eyes of Andreas Haacker: “We purposefully don’t rank the liner manufacturers in our scorings without looking at the contractors’ work – this would warp the results. Imagine ranking only the racecars in Formula One, completely ignoring the skill in piloting the vehicles. We look at the full picture instead.”
Another point on the chemical engineer’s mind: „There is a risky tendency among communal decision makers to minimize prices and maximize pipe diameters at any costs. It is generally more successful to carefully consider the curing process and adjust the timeframe with regards to the general conditions. Process technology plays a decisive role here.” It should be noted that contractors work with different systems regarding their UV curing equipment. This is not always taken into account within the DIBt’s qualifying admissions. If no references or previous experiences are available, Haacker recommends ordering residual styrene analyses to assess the successful curing of the entire wall thickness.
An appeal to standardise wall thickness specifications
One aspect that may lead to confusion is a perceived wall thickness discrepancy between a sample and the product information sheet. Nothing to worry about, says Andreas Haacker: “Usually the reason for this is quite banal. Wall thickness specifications in the manufacturer information are not unified. For the test and the static consideration, the wall thickness of the supporting laminate structure is decisive as a reference value, because this already includes the reaction shrinkage”, he says. “If we receive a sample like that, we usually just ask to clear up this misunderstanding.” As chairman of the board of the pipeline rehabilitation association (RSV), Haacker advocates for a standardised way to note wall thickness to prevent confusion on the construction sites.
Siebert + Knipschild bases their seal statistics on around 6,000 datasets from Germany, the Netherlands and Austria.
“Sustainable product for the next generations”
Never before have so many contractors been awarded with the seal as this year. “Exceptional standards of quality in every area are becoming more essential for companies. We are seeing an increased effort from contractors to not only fulfil requirements, but also to give clients the safety of a durable and sustainable product for the next generations.” A CIPP liner’s depreciation period is usually around fifty years, however, the expected life cycle is much longer than that, according to Haacker.
In the same vein, house connection systems have high requirements for CIPP liners, appearing multiple times in this year’s seal statistic. “The companies in this field are increasingly using the seal to build up trust for the systems”, explains Haacker.
Among the 26 contractors honored with the seal, some hail from countries outside of Germany such as Austria and the Netherlands. “We are seeing growing interest in the seal from companies both domestic and foreign.” As such, English-language application documents and information are available for download on the Siebert + Knipschild website.
Siebert + Knipschild delivers quality data on demand
According to Haacker, the seal is a good reference for successful projects – for both clients and contractors. To be eligible, a minimum of twenty samples per system must be provided in the previous calendar year. The testing institute inspects the wall thickness, e-module, bending strength and watertightness. 95 % of samples must pass the requirements to be eligible for a seal. The testing will examine components sent from the contractors as well as the clients of the individual projects. They must be from four or more different construction measures.
All in all, the seal is a good opportunity for clients to get an overview over which companies deliver good quality. Contractors benefit from a recognition of their consistently high-quality work as well. Another perk seeing increased recognition from the companies: Those ordering the seal will receive a certified statistic over a year. “Companies will use the yearly data for their internal quality assurance. We can provide this data on demand”, notes Haacker.
Companies can apply on the website
Preparations for the seal award 2022 are already underway. German- and English-language application materials and a detailed checklist of the criteria can be found on the Siebert + Knipschild website. For projects where the public sewer network operator has initiated the inspection, a declaration of consent is required and available for download as a template as well.