Commercial kitchen deep cleaning
Fat cools and sets in the drains, trapping food and odour and feeding pests. A deep clean flushes and degreases the gullies - and the grease trap is a related, separate duty.
Short answer
Floor gullies and drains belong in every deep clean because they collect fat, food and odour - and left alone they feed pests and blockages. A deep clean flushes and degreases them. The grease trap that protects the sewer is a related but separate job, and what you let down the drain is a legal duty.
Grease leaves the cookline as a hot liquid and cools as it travels, solidifying inside pipes, sticking to the walls and trapping food waste until the bore narrows and the flow slows. The first signs are familiar: water pooling in floor gullies, gurgling, and a sour smell from decomposing food drifting back up the drains. Left longer it draws pests and becomes a hygiene and compliance problem in its own right - exactly the kind of thing that quietly drags a hygiene score down. Commercial floor channels are usually grade 304 stainless precisely so they can be lifted and sanitised.
A deep clean lifts the gully grids, clears and degreases the channels and traps, flushes the lines through with hot water, and clears the strainers that should be catching solids. Where a run is genuinely blocked, high-pressure jetting is the tool - and mechanical clearing is preferred over caustic drain chemicals, which damage pipes, seals and grease equipment over time. It is the same logic as the rest of the deep clean: reach the places a daily mop never gets to, set out in what a deep clean includes, surface by surface.
The grease trap, or interceptor, is a plumbing device that slows wastewater so fats float and food solids settle before the sewer - many conform to BS EN 1825. It is maintained on its own schedule, not as a deep-clean line item: the rule of thumb is to service it once grease and solids fill about a quarter of its depth, with a full pump-out, scrape and flush rather than just skimming the top. Large underground interceptors need a licensed waste contractor, and biological dosing can keep pipes and traps clear between services.
What goes down the drain is regulated. Under the Water Industry Act 1991 it is an offence to discharge anything that interferes with the free flow of a public sewer, which covers FOG. Under the Food Safety Act 1990, drain blockages from fat that cause a food hygiene failure can lead to prosecution or an emergency prohibition order. The Environmental Protection Act 1990 treats persistent food-waste odour as a statutory nuisance and places a duty of care on how you dispose of waste - so keeping records of licensed grease collections is worth doing. A deep clean clears the gullies and resets the surface drainage, which is necessary - but it is not a substitute for a grease-trap schedule or for daily strainer and clean-as-you-go habits, and a drain that blocks repeatedly is a jetting and plumbing job, not a cleaning one.
Questions
Because they are grease sinks. Fat cools and solidifies in the gullies and pipes, trapping food, breeding odour and attracting pests, and narrowing the bore until drainage slows. A deep clean lifts the grids, degreases the channels and flushes the lines.
A gully is the floor drain that carries waste water out of the kitchen; a grease trap, or interceptor, is a plumbing device that catches fats before the sewer. Gullies are flushed in a deep clean; the grease trap is maintained on its own schedule.
A common rule is to service it once grease and solids fill about a quarter of its depth, with a full pump-out, scrape and flush. Heavy-frying sites may need it every few weeks; larger underground interceptors need a licensed waste contractor.
Effectively, yes. The Water Industry Act 1991 makes it an offence to discharge anything that interferes with a public sewer, which covers fats, oils and grease. Blockages that cause a food hygiene failure can also lead to action under the Food Safety Act 1990.
It clears the gullies and surface drainage and resets them, but a drain that blocks repeatedly is a jetting and plumbing job, not a cleaning one. The deep clean is necessary maintenance; it does not replace a grease-trap schedule or daily strainer habits.
Phoenix Duct Clean · by the numbers
Phoenix lifts and degreases gullies, flushes the lines and clears the traps as part of a full kitchen deep clean. Quoted on survey, certificated on completion.