Kitchen Extract Cleaning to TR19 Grease

How often should kitchen extract ducts be cleaned?

BESA sets the baseline by daily cooking hours:

These are minimums, subject to a competent person conducting a cleanliness risk assessment. A kitchen doing heavy frying at eight hours a day can foul faster than a lighter kitchen at twelve, so it should be the reading that sets the next visit.

Full detail on what the readings mean is on the TR19 certificate page.

What is measured, and what counts as clean?

Grease deposit thickness, at named points along the run. BESA publishes two figures worth knowing. A mean deposit of 200 microns is the maximum that should be allowed to build up between scheduled cleans. A reading of 500 microns or more is the point at which that section needs cleaning immediately rather than at the next visit.

You will see a post-clean target of under 50 microns quoted widely. We could not trace it to BESA or to any primary document, only to other contractors’ pages, so we do not quote it and we do not certify against it. Ask anyone who does where the figure comes from.

What if a section cannot be reached?

Then it does not get cleaned, and the record says so. This is the single most common gap between a clean that was carried out and a clean that can be evidenced. A duct run built without access panels can be cleaned at the canopy end and nowhere else, and the grease that matters most for fire spread is usually in the horizontal run nobody can open.

Access panels are meant to be designed in at installation, positioned so that every internal surface can be cleaned and visually inspected. Retrofitting them is ordinary work and it is the thing that turns a partial clean into a full one. Where access panels go and why the spacing figures disagree.

Why insurers and environmental health officers ask for it

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.

That is the careful version, and it is careful on purpose. You will find pages claiming an insurer will refuse a fire claim outright without a current certificate. No policy wording, ombudsman decision or judgment could be found saying that, so it is not written here. What can be supported is the sentence above: the documentation is treated as part of the risk, and its absence is something an insurer can argue about.

An environmental health officer is asking a different question. Their interest is the kitchen as a food premises and whether it is being kept in a condition that supports safe food production, so what they usually want to see is a schedule that is being followed and a record of the last visit.

Is it the landlord’s job or the tenant’s?

The lease decides, and the two common patterns split differently. Where the extract system is demised to the unit, cleaning almost always sits with the tenant who operates the kitchen. Where the ductwork runs through common parts to a shared discharge, the landlord often retains the riser and the fan while the tenant keeps the canopy and the section inside the unit.

That split is where systems get missed: each party assumes the other has the riser. If you are not sure which you are, look for who is billed for the extract fan maintenance and where the demise drawing puts the duct. We are happy to quote the whole run and let you recharge the part that is not yours.

What does the work actually involve?

1. Survey the run and measure grease depth at each access point, recording where the readings were taken.
2. Open existing access panels. Where a run has no access, we say so rather than cleaning what we can reach and calling it done.
3. Clean canopy, filters, plenum, ductwork and fan, working back from the canopy so soil is not pushed into cleaned sections.
4. Re-measure, photograph, and record the result against the start reading.
5. Issue the documentation, including any section left uncleaned and what access would be needed to reach it.

What does kitchen extract cleaning cost?

Extract cleaning in the South East starts from around £350, and TR19 ductwork cleaning from around £495. Duct length is the main variable, along with how many access points already exist and how long it has been since the last clean. Work outside service hours costs more again.

Retrofitting access panels adds cost on the first visit and removes it on every visit after, because the next clean can be measured properly instead of estimated.

Who needs it

• Restaurants
• Pubs and bars
• Hotels and banqueting kitchens

Sources

• Kitchen extract system cleaning, thickness figures and baseline intervals: BESA. Checked 15 August 2026.
• Regulatory Reform (Fire Safety) Order 2005: legislation.gov.uk. Checked 15 August 2026.
• Prices are the ranges observed in live UK search results on 13 August 2026, and are starting points rather than quotes.