Guide from the team
Documented ductwork cleaning is a condition of cover in most UK commercial policies. Here is what that means in practice and what to check in yours.
Published 8 September 2026
If you run a commercial kitchen, or a building that contains one, the honest answer is: very probably, yes, and the place to confirm it is your own policy. Documented cleaning of kitchen extract systems is a condition of cover in most UK commercial policies. Policies differ, and the only wording that matters is the one in your schedule. But the pattern across the market is consistent enough to act on.
Commercial policies covering premises with catering typically include a condition, sometimes called a frying condition, requiring the extract system to be cleaned at defined intervals by a competent specialist contractor, with records kept. Some wordings name TR19 Grease explicitly; others just say something like “cleaned regularly by a specialist contractor.” Either way, the insurer expects the kitchen extract system to be professionally cleaned on a schedule, and expects proof.
The TR19 Grease intervals are the market’s reference point, based on how heavily the kitchen is used: 12 to 16 hours a day (heavy use) calls for cleaning every 3 months, 6 to 12 hours (moderate) every 6 months, and 2 to 6 hours (light) every 12 months. If your policy sets its own intervals, follow the policy; where it refers to industry guidance without figures, these are the benchmark. Our article on how often kitchen extract ductwork should be cleaned has the detail.
TR19 Grease itself is industry guidance published by BESA, not legislation. The legal duties sit in the Regulatory Reform (Fire Safety) Order 2005, which requires fire safety measures to be maintained in efficient working order, and in your fire risk assessment, which has to address grease loading in the extract system. Insurers lean on TR19 Grease because it is the established standard for discharging that duty.
An insurer assessing a claim after a kitchen fire will not crawl through fire-damaged ductwork to establish how clean it was; they will ask for your records. The TR19 Grease certificate, backed by a report with photographic evidence and measured grease levels, is the document the market recognises as proof that the system was professionally cleaned to standard, by whom, and when.
A certificate is only as credible as the process behind it, though. Clean Ducts is a BESCA Vent Hygiene Associate member: BESCA is BESA’s certification body and runs the Vent Hygiene Register, and membership means our operatives are TR19 trained and our completed work is independently audited, so the certificate in your file is verified rather than self-declared. What is in a TR19 report breaks the document down section by section.
Precision matters here, because the internet is full of overstatement on both sides. A missing certificate does not automatically void your claim regardless of cause. Nor is documentation a formality.
If a fire involves a grease-laden extract system and you cannot evidence the cleaning your policy requires, you risk the claim being reduced or rejected for breach of a policy condition. How that plays out depends on the wording, whether the breach is connected to the loss, and the circumstances of the fire. A folder of dated certificates removes the argument before it starts.
Extract fires do not always stay in the kitchen either: a duct fire can breach compartment lines. Testing records for your fire dampers and records of general ventilation and ductwork cleaning sit alongside the extract certificates in the same evidence trail.
First, check your policy schedule and wording for any condition relating to kitchen extract, frying equipment or ductwork cleaning. Note the required interval and any named standard. If the wording is unclear, ask your broker to confirm in writing what the insurer expects.
Second, keep the evidence filed and current. After every clean, file the certificate and report together and diarise the next one. If an insurer, a broker at renewal, or a fire risk assessor asks for evidence, you want to produce it in minutes, not go searching after a loss.
If you are not certain when your extract system was last cleaned, or cannot lay your hands on the certificate, that is the gap to close first. Request a free survey and we will assess the system and tell you where you stand, or ask for a TR19 quote. Surveys carry no obligation. And if you have an existing TR19 report from another contractor, send it over and we will read it.
Neither TR19 nor TR19 Grease is law: both are industry guidance published by BESA. The legal duties come from the Regulatory Reform (Fire Safety) Order 2005, which requires fire safety measures to be maintained in efficient working order, and from fire risk assessment duties. Separately, documented extract cleaning is a condition of cover in most UK commercial policies, so legal duty and insurance point at the same work.
Not automatically, and anyone who tells you a claim fails regardless of cause is overstating it. But if a fire involves a grease-laden extract system and you cannot evidence the cleaning your policy requires, you are exposed to the risk of the claim being reduced or rejected for breach of a policy condition. The outcome depends on your wording and the circumstances, which is why dated certificates matter so much.
Keep the certificate and the full report together: the scope of the clean, the measured grease levels before and after, the photographic evidence, and any areas that could not be accessed. File them with your fire safety records and note the next clean date, so you can show a continuous cleaning history rather than a one-off.
Send us your existing report or book a free survey. A named engineer replies within 24 hours.