Kitchen extract cleaning: first of all a fire question

Where grease collects

Filters catch only part of the grease aerosol. The rest settles further along the run, and the further it is from the canopy, the less often anyone looks.

• Canopy body and grease trays
• The vertical duct above the kitchen
• Horizontal runs and bends
• Roof or wall-mounted fan
• Fan housing and blades

Why filters alone are not enough

Washing filters weekly is essential, but it only addresses the first few centimetres of the problem. The run beyond them stays untouched, and it is that layer which burns longest and carries fire through the building.

How often to clean

Heavy-use kitchens every 3–6 months, moderate use every 6–12. The real decision is not made by calendar but by the measured thickness of the grease layer.

Cooking style matters too: fryers and grills contaminate several times faster than a steam-based kitchen.

The paperwork insurers ask for

After a fire the insurer almost always asks when the system was last cleaned. Every clean should therefore leave a record with before-and-after photographs — both evidence of maintenance and protection in a dispute over a payout.