Integrate pipework for smarter riser systems

James Griffiths, Head of Projects at GF Building Flow Solutions (formerly Uponor), explains why specifiers should be rethinking their approach to riser systems and whole building pipework design. 

 With the UK’s urban areas continuing to experience significant growth, the demand for larger, more sophisticated buildings – from high-rise housing to mixed-use commercial developments – has never been greater. But as buildings grow larger, designing and installing water supply and heating pipework becomes more complex.  

Whether it involves mains cold water travelling from the supply point to individual flats, or heating systems operated by centralised boilers or district energy networks, consistent and efficient pressure distribution throughout the building is essential. The pipework risers that run vertically through these structures play a pivotal role in achieving this. Copper pipe has historically been the default material for risers and distribution systems. It’s a known quantity, but one that brings challenges, such as volatile material prices, heavy installation requirements, and the need for hot works. 

Multilayer composite (MLC) pipe is increasingly being specified as a modern alternative. MLC combines an aluminium core with polyethylene, inner and outer layers, delivering strength, pressure resistance, and hygienic performance similar to copper, but with added flexibility and ease of handling. Its ability to form natural curves reduces the need for fittings and connections, which helps to maintain water pressure and reduce the risk of leaks. Typically available in diameters of up to 110mm, MLC has coil lengths of up to 200 metres, depending on the size. This significantly reduces the number of connections needed, streamlining installation and improving long-term reliability. With no hot works required, the entire process is safer and more efficient on-site. 

Support all building areas  

Large-scale developments don’t just need robust risers; they need continuity and compatibility across the entire pipework system. A single-manufacturer solution simplifies everything from procurement and installer training to on-site quality control. It also allows for smarter integration between the trunk pipework, vertical risers, and final connections near the point of use. 

That’s where integrated systems like the Uponor RS Modular Riser System come into their own. Developed for use with MLC pipe, the RS Modular system allows installers to connect pipework of varying sizes (from 16mm to 110mm) using just 39 components, capable of creating over 300 different combinations. The fittings are pressed on a workbench and clicked together on-site. This enables quicker and more accurate installation, reducing the potential for errors. Short spacers and 45° elbows allow the system to be installed at virtually any angle. And, because the modular system allows for significant pipe size reductions in small spaces, it’s suitable for projects where plant room or riser cupboard footprints are tight. 

When large dimensions are needed 

For buildings with high water demands or complex heating systems, larger diameter pipework is often required. Systems like Uponor Instaflex are made from polybutene to offer pressure resistance of up to 16 bar for dimensions between 16mm and 225mm, and up to 10 bar for dimensions of 315mm. The system’s flexibility also enables small changes in direction without the need for fittings. Supplied in lightweight, flexible coils, Instaflex is much easier to handle and transport on-site, especially in high-rise buildings. While Instaflex may be slower to connect on site, much of the assembly can be completed off site through prefabrication. Sections arrive ready to install, saving time, reducing disruption, and enhancing project predictability. 

Design the right system  

While plastic systems can sometimes appear more expensive than traditional materials, that perception often arises when they are designed in the same way as copper. Working with manufacturers like GF Building Flow Solutions during the design phase allows you to fully optimise layouts and take advantage of system efficiencies, leading to significant cost and time savings overall. 

Ultimately, integrated riser systems deliver better results across the board. They offer fewer compatibility issues, simplified logistics, faster installation, improved water quality from MLC pipes and a cost-effective solution when designed correctly. They’re a win-win solution for developers and specifiers. 

www.uponor.com/en-en