Keep the water flowing
Steve Bamforth, UK Strategic Project Director at Polypipe Building Services, explores how prefabrication and off-site work can support hospital retrofits while avoiding costly downtime.
Hospitals are among the toughest environments to retrofit. Drainage and water supply systems are often decades old, yet buildings must stay fully operational throughout any upgrade. There’s rarely room for downtime, and even less space for plant access, deliveries and materials.
It’s a major challenge for estates teams, especially when legacy systems start to fail. But with the right materials, planning and approach, complex pipework upgrades can be delivered with minimal disruption, keeping buildings running safely and efficiently into the future.
Plumbing systems are rarely front of mind for building occupants until something goes wrong. But in many hospitals, ageing systems are under increasing pressure, not just from age, but from the kind of waste they’re handling. Hospital drainage doesn’t just deal with water. Sterilisation processes, chemicals, disinfectants and medical waste all pass through these systems at higher temperatures and concentrations than domestic equivalents.
But because full replacements are expensive and disruptive, most systems have been patched over the years. The result is a mix of old and new materials that don’t always work well together. Different sections expand, corrode and degrade at different rates, and the cycle of failure, blockage and repair continues.
Working around people
Hospitals aren’t just hard to access; they’re also in constant use. Wards, theatres, labs and treatment rooms can’t be closed for days while services are replaced. That means upgrades often have to be done in tight overnight windows, or in small, isolated areas of the building.
This is where lightweight, prefabricated plastic systems offer a real benefit. Sections can be fabricated off-site based on accurate 3D scans and then delivered in sequence to site. Installation is faster, quieter and safer, especially in confined spaces where traditional materials are hard to manoeuvre.
At Cardiff Heath Hospital, a particularly challenging retrofit involved a severely degraded cast iron system that was leaking chemical and medical waste near critical care units. The hospital is due to be replaced within five years, but urgent repairs were still needed to keep it fully operational and ensure the safety of patients and staff. Repairs needed to be completed at a cost that reflect that the building is nearly ‘end of life’. With space tight and shutdowns of wards like intensive care not an option, a smart, staged solution was implemented using HDPE drainage components. Deliveries were carefully scheduled to match installation progress, and the system was fully replaced without disrupting the hospital’s day-to-day operations.
And it’s not just drainage. At Middlesex University Hospital, an upgrade to the water supply system used 3D scanning to map the existing pipework and prefabricate new sections. These were installed over several nights, with the system recharged and handed back every morning, keeping the hospital running throughout.
Safe, sealed and built to last
Safety is a central concern in any hospital environment, and modern plastic systems offer advantages here too. Drainage systems made from HDPE, when installed as a fully sealed system (with no expansion joints or ring seals), reduce the risk of leaks over time, which is particularly important in high risk areas like theatres and wards.
For water supply systems, anti-microbial pipework such as Polypipe’s MecFlow Fusion adds another layer of protection. Tests indicate that built-in anti-microbial additives can significantly reduce bacterial growth, including Legionella, offering an additional level of protection in settings where water hygiene is critical.
From an installation perspective, avoiding hot works is a major win, especially in older buildings where fire safety is a concern. MecFlow Fusion uses an electrofusion process which requires a specialist tool but eliminates the need for blowtorches or open flames. This reduces the risk of heat damage to surrounding structures, and faster, cleaner installation overall.
While sustainability isn’t always the first priority in a retrofit job with a tight budget, modern plastic systems, such as HDPE, generally have lower embodied carbon than traditional metal pipework, making them a lower impact choice in many retrofit scenarios. They’re also more efficient to transport, store and install, all of which helps reduce the overall impact of the project.
Flexibility matters
Perhaps the biggest lesson in hospital retrofit work is that no two jobs are the same. Every hospital has its quirks, whether it’s a tight riser, a lack of access or the need to tie in with systems that were never designed with upgrades in mind.
That’s why flexibility matters. Being able to combine loose components with part – or fully prefabricated sections, allows systems to be designed around the building, not the other way around. And the ability to cut, adapt and connect to existing legacy materials on site makes plastic systems especially well suited to retrofit work.
Retrofitting plumbing systems in hospitals will never be easy. But it doesn’t have to be disruptive, and it certainly doesn’t have to involve a like-for-like replacement of the system that failed. With the right approach, modern systems can be installed quickly, safely and with minimal impact, giving estates teams confidence in the drainage and water supply systems for the next 50 years.
