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Extraction cleaning - frequency
The three-month, six-month, twelve-month bands are only the starting point. Here is how a competent cleaner actually arrives at the interval for your kitchen - and why it is measured, not just looked up.
The short answer
A TR19 Grease cleaning interval is calculated in two steps. First, daily cooking hours give a starting band - roughly 12 months for light use, 6 for moderate, 3 for heavy. Then that starting point is confirmed or adjusted by measuring how quickly grease actually builds in your system, because the standard ultimately judges by grease deposit, not by the clock. The result is an interval matched to your kitchen, not a category average.
Step one
The calculation starts with how many hours a day the extract system runs over hot cooking, because that is the biggest driver of grease build-up. TR19 Grease groups kitchens into broad bands on that basis: light use of roughly 2 to 6 hours a day points to a starting interval of around 12 months, moderate use of 6 to 12 hours to around 6 months, and heavy use of 12 to 16 hours to around 3 months.
This gives a defensible starting point rather than a final answer. Two kitchens open the same hours can still differ in how much grease they generate, so the hours band is where the calculation begins, not where it ends.
Step two
Hours alone do not capture how greasy the work is. Heavy frying, chargrilling and wok cooking throw off far more grease than gentle or intermittent cooking, so a kitchen doing greasy work at the top of its hours sits firmly at the shorter interval, while a kitchen with the same hours but lighter cooking may hold condition a little longer.
A competent assessment therefore weighs the menu and the equipment alongside the hours. A fish-and-chip kitchen and a sandwich kitchen open identical hours are not on the same interval, and the calculation reflects that difference rather than treating hours as the only input.
Step three
The decisive step is measurement. Because TR19 Grease judges a system by grease deposit thickness, the right interval is the one that keeps the system below the cleaning threshold between visits - and the only way to know that is to measure how quickly grease returns. Readings taken over time show whether the estimated band is right, or whether the system is caking up faster or slower than the hours suggested.
This is what turns an estimate into a calculated interval. If a kitchen placed on a nominal six-month band shows heavy build-up at four months, the interval is shortened to match what the system actually does. The measurement has the final say, because it reflects reality rather than a category.
What can change it
A calculated interval is not permanent. Anything that changes how much grease the kitchen produces can move it: a new fryer or chargrill, a busier trading pattern, a menu shift towards greasier food, or an extension to the cooking hours. Each of those is a reason to reassess, because the interval was calculated for the kitchen as it was.
That is why a good cleaner records the readings each visit and watches the trend, rather than setting an interval once and forgetting it. The frequency is a living figure, recalculated as the kitchen evolves, so it stays matched to the real grease load rather than drifting out of date.
Why calculate it properly
Getting the interval right cuts both ways. Set it too long and grease accumulates to a level that is a fire risk and a compliance failure, with a lapsed certificate that can undermine an insurance claim. Set it needlessly short and you pay for cleans the system did not yet need. A properly calculated interval sits between the two - frequent enough to control the risk, no more often than the grease load requires.
That is the value of measuring rather than guessing. A calculated, evidence-based interval keeps the system safe and compliant while not wasting money on unnecessary visits - which is exactly what the two-step method, hours then measurement, is designed to achieve.
Questions
In two steps: daily cooking hours give a starting band - roughly 12 months light, 6 moderate, 3 heavy - and then grease measurement confirms or adjusts it, because the standard ultimately judges by grease deposit, not the clock.
No. They give the starting band, but the type of cooking adjusts it - heavy frying and grilling throw off more grease - and measured build-up has the final say.
Because TR19 Grease judges a system by grease deposit thickness. Measuring how quickly grease returns is the only way to know the interval keeps the system below the cleaning threshold between visits.
Yes. A new fryer or grill, busier trading, a greasier menu or longer hours can all move it. A good cleaner records the readings and reviews the interval as the kitchen evolves.
Too long and grease builds to a fire and compliance risk with a lapsed certificate; too short and you pay for cleans you did not need. A calculated interval sits between the two.
A competent cleaner, by assessing your cooking hours and menu and taking grease-depth readings - then recording and reviewing them over time rather than setting a figure once.
We assess and measure your system, then set and review a cleaning frequency matched to how you actually cook.
