Most commercial roof failures are not sudden. A split in a flat roof membrane, a blocked outlet or a failed flashing typically gives months of warning — but only if someone is looking. For property managers and commercial landlords, a written inspection schedule is the single cheapest risk control available.
The schedule most UK insurers expect
- Twice a year: a full inspection in spring and autumn. Spring catches winter damage; autumn prepares the roof for the worst weather.
- After severe weather: any storm with high winds or heavy rain warrants a check, especially on older flat roofs.
- After any work on the roof: other trades (air-con engineers, solar installers, aerial fitters) regularly damage membranes and flashings without reporting it.
- Before lease events: a documented condition survey protects both landlord and tenant at the start and end of a lease.
What each inspection should cover
- Membrane or covering: splits, blisters, ponding and UV degradation.
- Drainage: outlets, gutters and downpipes clear and flowing.
- Flashings and upstands: the most common failure point on any commercial roof.
- Penetrations: vents, plant and cable entries sealed and intact.
- Edge details and parapets: wind uplift starts at the edges.
Why drone surveys suit commercial roofs
Traditional commercial roof inspections mean access equipment, permits and someone walking the roof — which itself damages older membranes. A drone survey photographs the entire roof in high resolution without anyone setting foot on it, and every defect is circled, graded and mapped so a roofing contractor can price repairs without a separate access visit.
Keep the records
Insurers increasingly ask for evidence of planned maintenance when a claim arrives. A dated photographic report from each inspection is exactly that evidence — and comparing reports year on year shows whether a defect is stable or getting worse.