Google Data Centre, Waltham Cross
28,000 m² of fully-adhered Sika Sarnafil at Google's £1bn Waltham Cross data centre — Sky Guard's largest single project to date. Under strict security protocols, every weld checked, re-checked and double-checked. Water ingress was not an option.
- Client
- Sub-contractor to a major UK roofing contractor (end client: Google)
- Location
- Waltham Cross, Hertfordshire
- System
- Sika Sarnafil 1.8 mm (Fully Adhered)
- Area
- 28,000 m²
The Challenge
Google’s Waltham Cross data centre is a hyperscale tech facility — the kind of building where a single drop of water past the membrane is a multi-million-pound business-continuity event. Servers live below the roof. There is no margin for error.
The project ran under strict client confidentiality: no progress photos during construction, no social media, no signage. Materials and operatives were managed under tight access protocols. Every detail had to be defensible at three levels — manufacturer specification, insurer requirements, and Google’s own engineering standards.
The build also had to drive standing water reliably to every outlet across 28,000 m² of large-span data-hall roof — meaning bespoke tapered crickets and cut-and-shut detailing across the field.
Our Solution
Sky Guard was sub-contracted to a major UK roofing main contractor to deliver the single ply package. The full build-up:
1. Existing metal structural deck.
2. Vapour control layer to manage moisture from the building below.
3. Insulated Kingspan composite roofing panel — specified to meet thermal and fire performance for hyperscale data centre use.
4. Sika Sarnafil 1.8 mm membrane, fully adhered across the entire 28,000 m². The gold-standard PVC single ply system — the same membrane technology used on Wembley and the Emirates.
5. Custom-fabricated tapered crickets installed across the roof to ensure positive water flow to every outlet, with zero ponding tolerance.
Every weld was inspected, re-inspected and double-checked. 5 months on site. Zero compromises on detail.
The Outcome
Delivered on programme, waterproof on handover, fully signed off to Sika’s manufacturer specification with the full membrane warranty registered. The completed roof is now part of Google’s UK data centre estate — a £1bn facility that brings serious cloud infrastructure to Hertfordshire (and which the BBC reported on at handover).
This project remains one of the most technically demanding and confidential single ply installs in Sky Guard’s history — and the kind of reference that puts the firm firmly on the radar for future hyperscale and high-spec commercial work across the UK.
Google’s Waltham Cross site is a £1 billion hyperscale data centre — one of the largest cloud infrastructure investments in the UK, reported by the BBC at announcement. Behind the security perimeter and the press silence, dozens of specialist contractors quietly built a facility that now handles serious volumes of UK cloud workloads.
Sky Guard delivered the single ply waterproofing package across the main data hall roof — 28,000 m² of fully-adhered Sika Sarnafil. At 28,000 m² this is Sky Guard’s largest single install to date — roughly the footprint of four full football pitches of Sika Sarnafil. The spec, the security and the standard of finish were as demanding as the scale.
“Google said it will invest more than £790m in Hertfordshire on a new state-of-the-art data centre.” — BBC News
Reference jobs like this open doors. We can’t put a Google logo on our van — we wouldn’t want to even if we could — but quietly, this is one of the credentials we’re proudest of.
The job, in photos
Spec, scope & references
- Main hyperscale data hall roof — 28,000 m²
Other work we’re proud of
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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.
Gradel Quadrangles, New College Oxford
A 2,400 m² curved timber roof at New College Oxford. 16,000 individually surveyed plates. Every one welded by hand. The most ambitious single ply detail Sky Guard has ever delivered.
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