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Extraction cleaning - frequency
Grease extract has its own cleaning clock, set by how many hours a day you cook. Here is how TR19 Grease turns your cooking volume into an interval - and how to work out which category your kitchen falls into.
The short answer
TR19 Grease sets kitchen grease extract cleaning frequency by how many hours a day the system runs over hot cooking. Light use - roughly 2 to 6 hours a day - points to every 12 months; moderate use of around 6 to 12 hours to every 6 months; and heavy use of about 12 to 16 hours to every 3 months. The category is confirmed by measuring how quickly grease actually builds in your system.
The three categories
TR19 Grease groups kitchens by cooking intensity because that is what drives grease build-up. A village hall used a couple of hours at a time is a very different proposition from a takeaway frying from mid-morning to midnight, and the standard reflects that with three broad bands tied to daily cooking hours.
Light use - in the region of 2 to 6 hours of cooking a day - points to cleaning roughly every 12 months. Moderate use of around 6 to 12 hours points to every 6 months. Heavy use, around 12 to 16 hours a day, points to every 3 months. These are the starting intervals; the exact figure for your kitchen is confirmed by what the system actually looks like inside.
Finding your category
Working out your band starts with cooking hours, but the type of cooking matters too. Heavy frying, grilling and chargrilling throw off far more grease than gentle or intermittent cooking, so a kitchen at the top of its hours and doing greasy work sits firmly at the shorter interval. A kitchen with the same hours but lighter cooking may hold condition a little longer.
That is why the honest way to set the interval is to combine the hours with a look inside the system. Measuring how quickly grease returns after a clean confirms whether your nominal category is right, or whether a change of menu, a new fryer or longer trading has pushed you into a shorter one.
Why the interval is measured
The cooking-hours bands are a guide, not the final word. TR19 Grease ultimately judges a system by grease deposit, so the right interval is the one that keeps the system below the cleaning threshold between visits. If readings show a kitchen on a nominal six-month cycle is caking up faster than expected, the interval is shortened to match reality rather than the category.
This matters because the risk is real and physical. Let a heavy-use system run to a light-use interval and grease accumulates in the concealed runs to a level that is both a fire risk and a compliance failure. Measuring build-up is what keeps the schedule honest and the system safe.
Why keep to it
Sticking to the right interval is not housekeeping - it is fire safety and cover. Grease in extract ductwork is combustible and sits in concealed runs where a fire can travel, so the frequency is set to keep that fuel from accumulating. Under the Fire Safety Order the responsible person must manage that risk, and cleaning at a sensible interval is how it is managed.
Insurance reinforces it. Most policies covering a kitchen require cleaning to a stated frequency, certificated. Let the interval slip and a fire claim can be reduced or refused for want of a current certificate. Keeping to the interval, with a dated certificate each time, is what keeps both the fire risk and the cover under control.
Not just the grease line
This grease-extract clock applies specifically to kitchen extract, where combustible grease sets the timing. Other ductwork in the same building runs on a different logic: dry supply and general ventilation ductwork is cleaned on dust build-up and air-quality need, and laundry ducting on lint accumulation and its own fire risk. A whole-building plan usually covers all three on their own intervals.
So the answer to how often depends on which duct you mean. For kitchen grease extract, it is the cooking-hours bands confirmed by measurement; for the rest, it is assessed on build-up. A survey sets sensible intervals across the lot, so nothing is either neglected or cleaned needlessly often.
Questions
By daily cooking hours under TR19 Grease: light use of 2 to 6 hours a day points to every 12 months, moderate use of 6 to 12 hours to every 6 months, and heavy use of 12 to 16 hours to every 3 months - confirmed by measuring grease build-up.
Start with daily cooking hours, then factor in how greasy the cooking is - heavy frying and grilling throw off more grease. A look inside the system and measured build-up confirm the right band.
No. The bands are a guide; TR19 Grease judges by grease deposit. If readings show a system building up faster than its nominal category, the interval is shortened to match reality.
Grease is combustible and accumulates in concealed runs where a fire can travel. The interval keeps that fuel from building - a fire-safety duty under the Fire Safety Order and usually an insurance condition.
No - this is the grease-extract clock. Dry ventilation ductwork is cleaned on dust and air-quality need, and laundry ducting on lint build-up. A survey sets sensible intervals for each.
Grease accumulates to a level that is both a fire risk and a compliance failure, and a lapsed certificate can mean an insurer reduces or refuses a fire claim.
We measure how your grease extract builds up and set an honest cleaning frequency for how you actually cook.
