Kitchen extract duct cleaning to TR19 Grease

A commercial kitchen's extract system quietly collects grease along the whole run of ductwork, from the canopy to the fan and out to the discharge. That grease is fuel: a flare-up at the hob can travel into the duct and turn a small fire into a building one. Cleaning it to a verifiable standard is how kitchens manage that risk and satisfy their insurers.

Why grease-laden ductwork is a fire risk

Every service, a fine mist of grease-laden air passes through the extract system and condenses on the inside of the ductwork. Over weeks it builds into a continuous layer that coats surfaces the kitchen team never sees. If a fire starts at cooking level, that internal grease can ignite and carry flame through the concealed duct run, spreading fire between floors and voids where it is hardest to fight. This is why extract cleaning is a fire-safety task, not just hygiene.

How often should extract ductwork be cleaned?

TR19 Grease links frequency to how hard the kitchen works. The intervals below are the widely used guidance figures:

Cooking type matters too - high-grease frying and char-grilling load a system faster than a light-use servery, so adjust to what your kitchen actually produces.

What TR19 Grease requires

• TR19 Grease is the Building Engineering Services Association (BESA) specification for the internal cleanliness of grease extract ductwork. In practice it means:
• Measuring grease build-up so the condition is assessed objectively, not by eye.
• Cleaning the full accessible run - canopy, filters, ductwork and fan - not just the visible parts.
• Fitting access panels where the duct cannot otherwise be reached, so the whole system can be cleaned and inspected.
• Producing a post-clean verification report with before-and-after photographs and a certificate recording what was cleaned and what could not be accessed.
• That documentation is the point: it turns 'we cleaned it' into evidence you can hand to an insurer or fire risk assessor.

Insurance and compliance

Frequently asked questions

• Is TR19 Grease a legal requirement?

  TR19 Grease is a specification, not a statute, but it is the recognised benchmark for compliance. The legal duties around fire safety and safe premises are met in practice by cleaning to TR19 Grease and keeping the certificates, which is also what insurers expect.
• How often does a busy restaurant need duct cleaning?

  A heavy-use kitchen running 12 to 16 hours a day is typically cleaned every three months. High-grease cooking such as frying and char-grilling may warrant more frequent cleaning; the measured grease build-up is the real guide.
• What do I get after the clean?

  A TR19 Grease verification report with before-and-after photographs and a certificate, recording what was cleaned and noting any areas that could not be accessed. This is the evidence you keep for insurers and fire risk assessments.