If the duct catches fire, the paperwork gets read.
Most kitchens only think about the extract report twice a year: when the cleaner sends it, and when it is filed. The third time it gets read is the one that matters - after a fire, by the insurer.
One insurer has published what it expects. Aviva's Loss Prevention Standard for commercial kitchen extract systems (version 1.4, 10 October 2024) is public, and it reads like a checklist for the record itself. It is one insurer's guidance, not the law, and your own policy wording comes first - but it is a fair picture of what an insurer will look for.
Seven things the record should show
- How often the system is cleaned, and why. Aviva gives a guide by daily cooking hours - roughly every three months for 12 to 16 hours a day, six months for 6 to 12 hours, and yearly for up to 6 hours - and says the real interval should come from a risk assessment and any cleaning condition in your policy.
- Readings before and after. A mean grease thickness kept below 200 microns, with pre-clean and post-clean readings across the system, not one number for the whole job.
- Whether the whole system was cleaned. A plain yes or no. If no, which parts were left and why - agreed in advance where possible.
- Before-and-after photos. Of the parts they belong to, not a gallery at the end.
- A recommended next clean. Set from the readings, so the interval can tighten or relax.
- Access problems and hazards. Missing access panels, damaged filters, anything that stopped a clean.
- Who did the work. Aviva points to accredited, third-party certificated contractors working to BESA's TR19 Grease guidance.
The London Fire Brigade's guidance note GN86 (revision 3) makes the same point about areas not cleaned: they belong in the report, with the reason, because an unexplained gap is what gets questioned later.
Keep them, and compare them
Aviva also asks for formal records of every inspection and clean, and for each new report to be compared with the last. A kitchen whose readings climb visit on visit is telling you the interval is too long. That only shows if the reports sit side by side.
What to ask your cleaner for
Ask for the seven items above in every report, sent the same day, locked once sent. Corrections should come as a new revision with the original kept - so the record the insurer reads is the one you were sent.
Where SMART Reports fits
SMART Reports is reporting software for the firms that do the cleaning. The engineer records readings and photos on the phone; the mean and the pass are worked out from the readings, never picked; areas not cleaned and remedials are recorded; the next clean date is set from how often the kitchen is used. The office checks it and sends a locked report and certificate the same day, and a correction re-issues as Rev B with the original kept.
Read next: The kitchen extract post-clean report, explained
Sources
- Aviva, Loss Prevention Standard - Commercial Kitchens Extract Systems and Cooking Ranges, v1.4, 10 Oct 2024 (read 29 Oct 2026)
- London Fire Brigade, GN86 rev 3 (1 May 2022) (read 15 Oct 2026)
TR19® is a registered trade mark of the Building Engineering Services Association (BESA). Smart Solutions Bristol Ltd is not affiliated with or endorsed by BESA.