Phoenix Journal · Ductwork
A fryer fire is over in minutes, but the ductwork above it can decide whether your insurer pays out or walks away. Here is what a loss adjuster really looks for - and the paperwork that settles it.
The fire itself lasted minutes. The argument about who would pay for it lasted the best part of a year.
It started the way these things usually start - a fryer left on a touch too long, a pan of oil that crept past its flashpoint, a flame that found the film of grease coating the inside of the canopy. By the time the brigade left, the kitchen was a write-off and the flat above it was uninhabitable. The owner did what you would do. He rang his broker, filed the claim, and assumed the policy he had paid into for eleven years would do its job.
Then the loss adjuster arrived. He did not spend long looking at the charred fryer. He walked past it, reached up to the run of ductwork above the cooking line, and unclipped an access panel. What he found inside that duct - not the pan, not the fryer - is what decided the claim. This is a column about that panel, and about the quiet paperwork that determines whether a chip-pan fire is a bad day or a business-ending one.
People assume a fire investigation is about the flames. It is not, or not only. Once the cause is established, the more expensive question is whether the fire was allowed to spread by something the policyholder should have controlled. Grease-laden ductwork is the classic example. Oil vapour rises off every fryer and griddle, condenses on the cool metal of the extract system, and hardens into a fuel lining that runs the whole length of the duct - often straight through the ceiling void and into the parts of the building nobody ever sees. When an adjuster opens that access panel, he is not being nosy. He is looking for the difference between a contained fire and a fire that travelled.
The relevant law is the Regulatory Reform (Fire Safety) Order 2005, which makes the "responsible person" - usually the business owner or occupier - legally accountable for managing fire risk on the premises. That duty sits alongside the Health & Safety at Work Act 1974 and, crucially, the express terms of the insurance policy itself. Most commercial policies now carry a condition requiring the extract system to be cleaned to a recognised standard at a sensible frequency. If a fire is shown to have been fed or spread by neglected ductwork, and there is no evidence the duty was met, the insurer has grounds to reduce the settlement or decline it outright. The pan started it. The duct is what turned a claim into a dispute.
What the adjuster wants, in practice, is a short chain of evidence you either have or you do not:
Notice what is missing from that list: anyone's opinion that the kitchen "looked clean". The canopy and the filters are the bits staff wipe down nightly, and they are almost always spotless. The fire does not travel through the bits you can see.
Almost every operator who has a claim challenged will say, honestly, that the kitchen was cleaned. And it was - the surfaces were. The problem is that a nightly wipe-down and a certified extract clean are different jobs, and only one of them leaves a record an insurer will accept. The owner in our chip-pan case had a rota for the canopy and the filters. What he did not have was a single dated certificate for the ductwork behind them, going back years. The adjuster measured the grease inside that duct, held the figure against the standard, and the conversation was effectively over. Not because the man was careless in spirit, but because he could not produce the one thing the policy quietly required.
The reason a certificate carries weight is that the underlying standard is measurable. TR19® Grease does not ask a cleaner to make the duct "nice". It puts a number on it, and that number is what turns a subjective judgement into evidence. Understanding the figures is worth a few minutes of any operator's time, because they are the same figures the adjuster will be working from - and knowing them changes how you buy the service.
Grease thickness is measured, not eyeballed, using a Deposit Thickness Test for hard, carbonised deposits or a Wet Film Thickness Test for softer grease. The thresholds are specific. A mean deposit above 200 microns across the system means the whole run needs cleaning. A single localised reading above 500 microns means that spot needs attention straight away, whatever the average says. After a clean, the system should verify at below 50 microns - a demanding target that is hard to hit without doing the job properly and easy to demonstrate once you have.
That last figure is the one that protects you. A post-clean reading under 50 microns, photographed and certificated on a dated report, is difficult for anyone to argue with twelve months later. It says, in a language the insurer already speaks, that on this date the fuel had been removed. Keep the reports and you have built the paper trail our chip-pan owner wished he had:
The uncomfortable truth behind many failed cleans is that the ductwork was never fully reachable in the first place. You cannot certify what you cannot open, and a system built without proper access forces a cleaner either to guess or to leave sections untouched. The standard is clear about this: access panels should be positioned so that every part of the run can be inspected and cleaned, broadly at intervals of no more than two metres and at every change of direction, made of the same material as the duct and secured with quick-release catches per the ductwork specification DW144. If your system has long sealed stretches with no way in, that is not a detail - it is a section of the building nobody has looked inside for years.
This is also where good extract design and fire protection meet. Ventilation that crosses fire compartments should be handled deliberately at the design stage, which is worth reading up on if you are fitting out or refurbishing - the principles behind specifying fire dampers in ventilation design and the duties set out when the Regulatory Reform (Fire Safety) Order is defined both bear directly on how far a kitchen fire can travel and who answers for it afterwards.
Our chip-pan owner rebuilt, eventually, mostly out of his own pocket. The lesson he took from it was not that fires are unpredictable - they largely are not, in a kitchen - but that the defence against the worst of them is written down long before anything ignites. A dated certificate, a measured reading, an access panel someone can actually open. Unglamorous paperwork, right up until the morning it is the only thing standing between you and the loss.
Questions
Yes, and it happens. Most commercial policies now carry a condition requiring the kitchen extract system to be cleaned to a recognised standard at a sensible frequency, and the Regulatory Reform (Fire Safety) Order 2005 makes the responsible person accountable for managing that risk. If a fire is shown to have spread through neglected, grease-laden ductwork and you cannot produce evidence the system was cleaned and certified, the insurer has grounds to reduce or decline the settlement. It is rarely the cause of the fire that sinks a claim - it is the absence of a paper trail.
TR19 Grease sets the frequency by how hard the kitchen works. Heavy use of twelve to sixteen hours a day should be cleaned every three months, moderate use of six to twelve hours every six months, and light use of two to six hours every twelve months. Each clean should come with a certificate, before-and-after photographs and measured grease readings verifying the system below 50 microns, because that record is what an insurer will ask to see rather than an assurance that the kitchen looked clean.
Phoenix Duct Clean · by the numbers
Phoenix surveys and cleans kitchen and building ductwork to the TR19 standard - measured, cleaned and certificated, UK-wide.