The long-term performance of sewer networks depends on several factors, including pipe material, installation method, operating conditions and maintenance requirements. As UK water companies upgrade ageing wastewater infrastructure, decisions made during the specification process can influence asset performance for decades.
Leon Woods, Country Manager – UK at Steinzeug-Keramo, a wienerberger company, highlights the importance of selecting materials that can withstand the operational demands of wastewater networks while supporting long service lives.
The challenge of maintaining ageing sewer infrastructure
Sewer networks are among the longest-lived assets managed by water utilities. Maintaining their structural integrity is essential to reducing the risk of leakage, service disruption and environmental pollution.
As populations grow and existing infrastructure ages, utilities face the combined challenge of maintaining established networks and extending capacity to serve new developments. Network extensions must also integrate with existing systems, making pipe compatibility and installation requirements important considerations.
Woods argues that material selection should take account of the entire operating life of an asset, rather than focusing solely on initial installation requirements.
Selecting pipes for open-cut and trenchless installation
The choice of installation method can influence the technical requirements of a sewer pipeline. Conventional open-cut construction and trenchless techniques place different demands on pipe strength, dimensional accuracy and joint performance.
For open-cut applications, Steinzeug-Keramo supplies its KERA.Base and KERA.Pro vitrified clay pipe systems in diameters from DN 100 to DN 1000. The company states that these systems are manufactured in accordance with the European standard EN 295 and are intended for new sewer construction, rehabilitation and network extensions.
For trenchless construction, the company’s KERA.Drive jacking pipes are available in the UK in diameters from DN 150 to DN 600. Applications include guided auger boring, microtunnelling and pipe jacking, where pipes must withstand installation forces while maintaining alignment and joint integrity.
Connectors, short pipes and other specialist components can also influence how new pipelines connect with existing infrastructure, particularly where site constraints require adjustments during installation.
Vitrified clay sewer pipes are used in wastewater infrastructure where corrosion resistance and long-term durability are important considerations.
Material durability and wastewater operating conditions
Vitrified clay pipes are manufactured using clay, chamotte and water, which are fired at high temperatures to produce a dense ceramic structure. The resulting material offers resistance to corrosion and abrasion, properties that are relevant to wastewater infrastructure.
Pipe durability is particularly important where wastewater chemistry, mechanical loads and long-term exposure can affect infrastructure performance. Material selection must therefore consider the conditions expected throughout the operational life of the network.
Steinzeug-Keramo identifies chemical resistance, structural stability and resistance to static and dynamic loads as key characteristics of its vitrified clay systems. The company also highlights the smooth internal surface of the material as a factor supporting hydraulic performance.
These characteristics form part of a broader specification process in which engineers must assess hydraulic requirements, structural loading, installation conditions and whole-life maintenance needs.
What does the evidence say about service life?
The potential service life of sewer pipes is an important consideration for asset owners, particularly where replacement involves excavation, disruption and significant capital expenditure.
Steinzeug-Keramo states that vitrified clay pipes can achieve service lives of 150 years or more under suitable conditions. The company references research conducted by the National Clay Pipe Institute in the United States in 1982, which examined more than 50 sewer systems installed before 1880 that remained operational at the time of the study.
Some of the systems reportedly dated back to 1815, illustrating the longevity achieved by particular historic installations. However, the performance of individual networks depends on installation quality, ground conditions, loading, maintenance and other site-specific factors.
The company also cites research by Project Hub 360 suggesting that vitrified clay pipes can offer economic advantages over extended operational periods. The underlying assumptions and comparison methodology would need to be considered when applying such findings to individual projects.
Whole-life costs and sewer asset management
For water utilities, the cost of a pipeline extends beyond the initial purchase and installation of the pipe itself. Inspection, maintenance, rehabilitation, disruption and eventual replacement can all contribute to whole-life expenditure.
Materials that retain their performance over long periods may help reduce the frequency of maintenance interventions and replacement works. However, the most appropriate solution will depend on project requirements, including installation method, operating environment and budget.
Woods identifies long-term stability as a significant consideration when specifying wastewater infrastructure, particularly where assets are expected to remain operational across multiple investment cycles.
Pipe specification during AMP8
The UK’s AMP8 investment period places renewed attention on wastewater infrastructure, asset health and network resilience. For water companies planning upgrades and extensions, pipe specification decisions must account for both immediate construction requirements and long-term operating performance.
Factors such as corrosion resistance, structural stability, joint performance and compatibility with existing networks can influence the suitability of different pipe materials and installation methods.
While vitrified clay is one established option for sewer construction, engineers must evaluate materials against the requirements of each project rather than relying on a single characteristic or claimed service life.
For Steinzeug-Keramo, the central argument is that material specification should be considered as a long-term asset management decision, with durability and whole-life performance assessed alongside installation costs. Further technical information is available from Steinzeug-Keramo.
Frequently Asked Questions
Pipe specification influences the structural integrity, hydraulic performance, maintenance requirements and potential service life of sewer infrastructure. Engineers must consider operating conditions, installation methods and whole-life costs.
Vitrified clay sewer pipes are ceramic pipes manufactured from materials including clay and chamotte, fired at high temperatures. They are used in wastewater networks because of properties including corrosion resistance and structural stability.
Steinzeug-Keramo states that vitrified clay pipes can achieve service lives of 150 years or more under suitable conditions. Actual performance depends on installation quality, loading, ground conditions and maintenance.
Yes. Specialist vitrified clay jacking pipes can be used for trenchless installation techniques, including microtunnelling, guided auger boring and pipe jacking, where appropriate to the project design.
EN 295 is a European standard covering requirements for vitrified clay pipe systems used in drains and sewers. EN 295-7 addresses vitrified clay pipes and joints for pipe jacking.
