How Often Should Kitchen Extract Ducts Be Cleaned?

Five things get called the kitchen clean

The question arrives in seven different forms and they are not seven ways of asking the same thing. Filters, canopy, ductwork, grease trap and deep clean run on five separate clocks and involve three different trades. The most expensive misunderstanding in this trade is a manager who believes the extract system is covered because a deep cleaning contractor visits every quarter.

Only the third row produces the record an insurer or an environmental health officer asks for by name. The other four matter, and none of them is evidence that the ductwork was cleaned.

How often should the ductwork and extract fan be cleaned?

On the BESA banding, by daily cooking hours rather than by covers, floor area or turnover.

Every one of those figures is a baseline subject to a competent person conducting a cleanliness risk assessment. The band tells you where to start. What the kitchen does inside those hours decides where it ends up.

What actually sets your interval?

A measurement decides it, and the band is only where you start. BESA publishes two grease thickness figures. A mean average of 200 microns is the most that should be allowed to build up between scheduled cleans, and a reading of 500 microns or more calls for that section to be cleaned immediately rather than at the next visit.

That is why an honest cleaning contract is written to be reviewed. If the readings at 6 months are nowhere near 200 microns, the interval was too short and you are paying for it. If a section is over 500 microns at 6 months, the interval was too long and the risk assessment says so in writing. Four things move a kitchen off its banding faster than hours alone:

• What is cooked. Heavy frying, chargrilling and wok cooking load a duct far faster than baking or steaming at the same hours.
• Seasonal menus. A pub that changes to a fried winter menu has changed its cleaning interval, whether or not anybody recalculated it.
• The duct route. Long horizontal runs and low velocity sections collect faster than a short vertical riser.
• Filter discipline. Filters that are not cleaned pass grease straight into the ductwork, which moves the whole system up a band.

How often should commercial kitchen canopies and hoods be cleaned?

The canopy is cleaned at the same visit as the ductwork, on the same banding. In UK specifications it is a canopy; hood is the North American term for the same item, and both spellings turn up in the same building’s paperwork.

What matters more than the word is the scope. Wiping the stainless steel face is not canopy cleaning. The plenum behind the filters, the capture area and the fixings are where the grease is, and a canopy clean that does not open the canopy has cleaned the part nobody was worried about. What a canopy clean covers.

How often should grease filters be cleaned?

Daily on a heavy frying line, weekly on a light one, and it is kitchen staff work rather than contractor work. Baffle filters come out by hand and go through a sink or a dishwasher. Food hygiene law asks for ventilation systems to be built so that filters and other parts needing cleaning or replacement are readily accessible, which is the legal shape of a practical point: filters are meant to be a routine job, not an event.

Filters are also the cheapest control on this page. Every gram of grease caught at the canopy is a gram that never reaches the ductwork, and the ductwork is the expensive clean.

How often should a grease trap be cleaned?

A grease trap is a drainage item and a different contractor’s job. It appears on this page because the same manager tends to ask both questions in the same week, and the two answers get filed together.

Drainage serving a commercial hot food kitchen is required to have a grease separator complying with BS EN 1825, or another effective means of grease removal, under Approved Document H of the Building Regulations. Emptying frequency is set by fill rate, which is why a busy restaurant can be on a monthly cycle and a lighter kitchen on 8 to 12 weeks. The trade convention is to empty before accumulated fats and solids reach a quarter of the trap’s capacity; no primary source could be found for that quarter, so treat it as a working rule rather than a published threshold.

How often should a commercial kitchen be deep cleaned?

To whatever interval the site’s documented cleaning schedule sets, commonly quarterly on a managed contract. A deep clean covers surfaces, equipment, floors, wall and ceiling finishes and the parts of the kitchen that daily cleaning cannot reach.

It does not cover the inside of the ductwork, and this is the confusion worth clearing up before an inspection rather than during one. A deep cleaning certificate and an extract cleaning record are two documents, and only one of them answers the question an insurer asks.

What happens if the interval is missed?

Most commercial insurers treat TR19-compliant kitchen extract cleaning as a condition of cover or a key factor in assessing fire claims. Failing to keep your extract system TR19-compliant, or lacking documentation, can jeopardise your right to indemnity and give your insurer grounds to dispute or reduce a claim.

Separately from insurance, the Regulatory Reform (Fire Safety) Order 2005 puts a duty on the responsible person for the premises to carry out a fire risk assessment and take reasonable fire precautions. A grease laden extract system running above a cooking line is a fire risk assessment finding, and the cleaning record is the ordinary way of showing it was dealt with.

The practical version is simpler than either. Grease accumulates whether or not anybody schedules a visit, and the interval is only ever a prediction of when it will matter. How a TR19 grease clean is carried out, and what is in a TR19 certificate.