Castle Hill Hospital — Cancer Screening Extension
A 600 m² Sika Sarnafil fully-adhered roof on a cancer screening extension at Castle Hill Hospital — with 2.2 m perimeter upstands welded the whole way around. Installed live, alongside an operating NHS oncology facility.
- Client
- Hull University Teaching Hospitals NHS Trust
- Location
- Cottingham, East Yorkshire
- System
- Sika Sarnafil PVC single ply, fully adhered, with 2.2 m perimeter upstands
- Area
- 600 m²
The Challenge
Castle Hill Hospital in Cottingham is one of the Hull University Teaching Hospitals Trust's major cancer centres. The brief was a 600 m² flat roof on a cancer screening extension — modest size, but the constraints made the job a serious one. The 2.2-metre perimeter upstands. The lower section of the roof was bounded by walls rising 2.2 m up to the next roof level — every metre of that perimeter needed the single ply membrane carried up the wall and terminated cleanly at the top. That is a lot of vertical PVC, a lot of welded seams worked from a harness or scaffold rather than flat on the deck, and a lot of detail at every change of plane. Live NHS oncology environment. The building was operating the whole time. Patients and clinical staff below, screening appointments running to their schedule, ambulance and patient transport access lanes next door. The roof was our problem to keep watertight; the hospital carrying on as normal was the priority that decided everything else.
Our Solution
We specified Sika Sarnafil PVC single ply, fully adhered. Sika Sarnafil is the same roofing membrane system used on Wembley Stadium, the Emirates and the Google data centre — top-tier, fully warranted, and the right choice for a building that needed to stay watertight for decades without trouble. Going fully adhered (bonded across the whole surface) rather than mechanically fixed was the right call for an NHS building. No mechanical fixings penetrating the deck, no through-bolts vibrating loose over time, no fixings to fail under wind uplift on a building with awkward exposure. More labour-intensive to install — but the right specification for the application. The 2.2 m upstands were welded by hand around the full perimeter, lap by lap, with proper Sika Sarnafil termination details at the head of each wall. Internal corners and external returns detailed individually, cap-flashed where the geometry required it. Site running was to NHS facilities-management standard throughout — full RAMS and COSHH documentation issued to the Trust before start, hot-work permits raised daily, no work outside agreed clinical windows, all access to and from the roof routed away from patient and ambulance routes.
The Outcome
600 m² delivered, hospital operating normally throughout. Sika Sarnafil manufacturer warranty registered, full documentation pack signed off to the Trust's facilities team. Six years on the roof is performing as specified, with no callbacks. NHS work is the kind of job where the documentation matters as much as the membrane. Doing it right opened the door to subsequent enquiries in the wider healthcare sector — exactly the reputation a single ply contractor wants to build.
The Castle Hill job sits in a category we approach a little differently from a typical commercial install: healthcare work. The technical specification is recognisable — Sika Sarnafil, fully adhered, proper upstand detail — but the surrounding discipline is what marks out the right kind of contractor for an NHS site.
Hot-work permits raised every shift. RAMS issued and acknowledged before any operative steps onto the roof. Access routes coordinated so patient transport and clinical traffic are never affected. Documentation packs handed over in the format the Trust’s FM team expects, signed off on completion. None of it shows up in a finished-roof photo, but all of it is the reason this kind of work keeps coming back.
The job, in photos
Spec, scope & references
- Lower-section flat roof bounded by 2.2 m perimeter upstands
Other work we’re proud of
Be Modern, Jarrow
Full strip-and-replace of a rotten 1,850 m² factory roof at Be Modern's Jarrow site. Live production beneath, new metal deck, 150 mm PIR thermal upgrade and Renolit PVC — finished without stopping the factory.
Defence & National Rehabilitation Centre (DNRC)
The £300m rehabilitation centre conceived by the Duke of Westminster for the UK Armed Forces — 11 roofs, 3,800 m² of Icopal Monoplan, finished to a standard worthy of a Royal opening.
Google Data Centre, Waltham Cross
28,000 m² of fully-adhered Sika Sarnafil at Google's £1bn Waltham Cross data centre — Skyguard's largest single project to date. Under strict security protocols, every weld checked, re-checked and double-checked. Water ingress was not an option.
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