Takeaways and delivery-only dark kitchens often cook for longer hours than a typical restaurant, with fryers, grills and woks working flat out through lunch, evening and late-night orders. That kind of cooking produces a lot of grease, and it builds up in the extract fast. This guide covers the particular risks, how often cleaning is likely to be needed and the daily habits that make the biggest difference.
Why these kitchens build up grease fast
Deep frying, chargrilling, griddles and high-heat wok cooking all send large amounts of grease-laden vapour into the canopy. Long opening hours mean there’s little time for the system to rest, and busy staff may not get round to filter cleaning every day. In dark kitchens, several brands can share one cooking line or one extract, so the system works harder still.
The result is the same in every case: thicker grease in the canopy, plenum, duct and fan, and a bigger fuel load if a fryer or grill flares up. Grease also slows extraction, which makes a hot kitchen hotter and pushes smells out into the street.
How often to clean
BESA’s minimum cleaning intervals are based on hours of use: every 3 months for heavy use (12 to 16 hours a day), every 6 months for moderate use (6 to 12 hours) and every 12 months for light use (2 to 6 hours) (BESA). Many takeaways and dark kitchens open long enough to fall into the heavy band.
These are minimums. Grease thickness readings show the real picture. BESA says grease shouldn’t exceed a mean of 200 microns between cleans, and that 500 microns or more anywhere needs immediate spot cleaning. High-output frying and grilling kitchens may need cleaning more often than the minimum. See how often to clean a kitchen extract.
Daily habits that make a difference
- Clean or swap grease filters daily if you fry or grill heavily. See our grease filter guide.
- Never cook with filters missing or out of place.
- Wipe the canopy and empty grease channels at the end of every shift.
- Keep fryer oil topped up and changed, and don’t let fryers overheat.
- Collect used oil separately, and keep the grease trap emptied. See grease traps explained.
A grease filter exchange service can take the filter job off busy staff altogether.
Need it done? Duct Doctor cleans and tests kitchen extract and ventilation systems across London and the South East, with a certificate and photo report after every clean. Get a fixed quote.
Smells and neighbours
Takeaways are often below flats or close to homes, and frying smells travel. Many have odour control equipment, such as carbon filters or electrostatic units, and planning conditions may require it to be maintained. Those units load up quickly with heavy frying, so they need regular attention. See odour control maintenance.
Shared extracts in dark kitchens
Where several kitchen units share ductwork, a riser or a roof fan, agree who is responsible for cleaning each part. One brand cleaning its canopy does little if the shared duct is full of grease from everyone else. The site operator, landlord and each tenant should know who books the cleans and who keeps the certificates. See landlord and tenant responsibility.
Cleaning without losing orders
Takeaways and dark kitchens can’t afford to switch off during trading. Cleans are best booked after the last orders, overnight or before opening. Duct Doctor works evenings, overnight and weekends across London and the South East, and every clean comes with a TR19® certificate and a photo report. Ask about a maintenance contract so cleans are booked in automatically at the right interval.
Quick answers
How often should a takeaway extract be cleaned?
Many fall into BESA’s heavy band, every 3 months as a minimum. Grease readings may show it needs to be more often.
Do dark kitchens need TR19 cleaning?
The same fire risk applies, so the same standard is the accepted benchmark.
Can you clean after we close at midnight?
Yes. Overnight cleans are planned so the kitchen is ready for the next service.
Related services
More advice
- How Often Should a Kitchen Extract Be Cleaned?
- Grease Filter Cleaning: How Often and How
- Kitchen Odour Control Maintenance Explained
- Kitchen Extract Fires: How They Start and Spread
- All advice
This guide is general information. It isn’t legal or insurance advice: check your own policy wording and lease, and speak to a qualified adviser about your fire risk assessment.