TR19 & standards
The three TR19 Grease use bands - and why the hours only set your starting interval, not your whole cleaning schedule.
The short answer
TR19 Grease sorts kitchens into three use bands by daily operating hours - light 2 to 6 hours means clean at least every 12 months, moderate 6 to 12 hours every 6 months, and heavy 12 to 16 hours every 3 months. Those intervals are minimums to start from, not a schedule to settle on: cooking type, system condition and your insurer can all pull the real interval shorter.
The three bands
The band is set by how long the kitchen actually operates each day, because hours on the cookline drive how fast grease builds inside the extract system. TR19 Grease gives three starting points:
Hours are the anchor, but the level of build-up matters too: a heavy-frying kitchen open eight hours can generate more grease than a light-cooking one open twelve. Where build-up is high, treat the kitchen as a band hotter than its hours alone would suggest.
Why the band is a floor
The interval that comes out of the band is the longest you should safely go - a minimum, not a target. Several things push a real kitchen to clean more often than its band implies. The type of cooking is the big one: heavy grilling, wok work and deep frying throw off far more airborne fat than steaming or baking. System condition counts too - older ductwork, long horizontal runs and tight bends trap grease and reach the limit faster.
Your insurer and your fire risk assessment can also set the pace. Many policies expect the canopy and plenum - the highest-risk zone - watched more closely than the rest of the run, on top of the daily and weekly cleaning your own team does. Two kitchens under one roof can legitimately sit in different bands, because usage and not the address decides.
When to move up a band
The band you picked on day one can go stale. Longer trading hours, a menu that shifts toward frying or charring, a jump in covers, or new high-output equipment should all trigger a review - not a wait until the next scheduled visit. Stretching the interval to save money is usually a false economy: thick, baked-on deposits take more labour and access to remove and raise the odds of an emergency call-out.
The honest way to confirm a band is measurement. A competent contractor takes grease-thickness readings, sees how fast the system loads between visits, and adjusts the interval to the evidence. That inspection record is also what an insurer will look for after a fire - a justified interval beats a number picked from habit.
Questions
Count the hours the extract system runs each day. Roughly, 2 to 6 hours is light (clean at least yearly), 6 to 12 hours is moderate (every 6 months) and 12 to 16 hours is heavy (every 3 months). Heavy frying or grilling can bump you up a band.
TR19 Grease is a specification, not a law in itself, but it is the benchmark insurers and fire risk assessors use. The intervals are minimum recommendations - your fire risk assessment or policy can require more frequent cleaning.
Not safely. The band interval is a floor. You can only justify a longer gap with inspection evidence showing grease is building slowly - and even then it should be documented, not assumed.
No. Usage decides the band, not the address. A busy all-day kitchen and a light daytime one in the same building can sit in different bands and need different cleaning frequencies.
Grease keeps building. Thicker deposits cost more to remove, need more access time and raise fire risk - and long gaps with no inspection record can lead an insurer to question whether reasonable precautions were taken after a fire.
Phoenix Duct Clean · by the numbers
We match the cleaning frequency to how you actually cook - and prove it with readings and a certificate.