Solar Panels on Profiled Metal Sheet Roof Roofs — UK Installation Guide
Everything you need to know about installing solar PV on a profiled metal sheet roof factory roof: fixing method, dead load, structural requirements, warranty implications, and pricing.
Quick reference
- Fixing method: rail-mounted with sheet penetrations to purlin
- Added dead load: 12–15 kg/sqm
- Structural survey required: recommended for all roofs over 20 years old
- Compatibility: 70% of UK industrial roofs
- Pros: most common UK industrial roof type, well-understood install procedure
- Cons: penetrating fixings require careful sealing to maintain weathertightness and manufacturer warranty
How profiled metal sheet roof solar PV installs work
Installation procedure for a profiled metal sheet roof factory roof:
- Structural survey — chartered engineer assesses purlin spacing, fixing condition, and snow/wind loading per BS 6399 / EN 1991. Recommended for all roofs over 20 years old.
- Mounting installation — using rail-mounted with sheet penetrations to purlin. Adds 12–15 kg/sqm of dead load (well within most modern industrial roof capacity).
- Panel mounting — portrait orientation with optimised row spacing for shading, MCS commercial certification.
- DC cabling and isolators — surface-mounted with manufacturer-approved cable trays where penetrations are required.
- Inverter placement — typically inside the building or on weather-protected exterior wall. Connect via AC cabling to MDB.
- G99 grid connection — final commissioning with DNO witness, MCS certification issued.
Total physical install time for a 250 kW system on this roof type: 5–10 days. Final grid connection requires a 4–8 hour outage, scheduled around your shutdown window.
Cost implications for profiled metal sheet roof installs
Most UK commercial solar quotes price by kWp installed, but the underlying roof type meaningfully changes the labour and mounting costs. For the same system size:
- Standing seam metal: baseline cost (cheapest install) — clamp-fix is fastest and uses fewest components
- Profiled metal sheet: +3–7% over standing seam — rail-mounted with penetrating fixings adds time and sealant cost
- Flat ballasted membrane: +5–10% over standing seam — ballast (~5 kg/sqm of additional concrete) costs and crane time
- Mechanically fixed flat: +5–8% over standing seam — flashed penetrations to deck
Roof refurbishment, if needed, typically adds £40–£80/sqm depending on system — but as covered in our roof weight load guide, it can sometimes unlock long-deferred capex.
Profiled Metal Sheet Roof solar — FAQs
Will solar PV void my profiled metal sheet roof roof warranty?
No, when installed by an MCS-certified contractor using systems that carry roofing-manufacturer acceptance (Kingspan, Tata Steel, Euroclad, SIG). We secure manufacturer sign-off in writing before work starts.
How much extra weight does solar PV add to my profiled metal sheet roof roof?
For this roof type: 12–15 kg/sqm. Most post-2000 UK industrial roofs can take 20–30 kg/sqm of additional dead load with no structural intervention. Older roofs may need engineer sign-off — covered in our roof weight load guide.
Can I install solar PV myself on a profiled metal sheet roof roof?
Above 17 kW per phase, no — G99 grid connection requires an MCS-certified commercial installer. Below that, technically yes but you lose warranty acceptance from major panel and roofing manufacturers, plus face DNO acceptance issues.
How long do solar panels on a profiled metal sheet roof roof last?
25–30 year manufacturer performance warranty (typically 84–87% output guarantee at year 25). Real-world life 30–40 years with one inverter replacement at year 12–15. Roof and PV warranty timelines align well on most modern UK industrial buildings.
Quote my profiled metal sheet roof factory solar install
Free desk-based feasibility from your roof drawings and meter data within 7 working days. We’ll confirm structural compatibility before any quote.
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