Commercial Grease Management for London Sites

A busy kitchen can send litres of hot fat, oil and grease into its drainage system in a single shift. Once that material cools, it coats pipework, catches food debris and gradually restricts the flow. Effective commercial grease management stops this routine operational issue becoming a blocked drain, a foul odour problem or an unplanned closure.

For restaurants, cafés, hotels, pubs, catering facilities and food-production sites across Greater London, grease control is not simply a back-of-house housekeeping task. It protects the premises, supports hygiene standards and reduces the risk of disruption during peak trading hours. The right approach combines suitable equipment, disciplined kitchen practices and planned professional maintenance.

Why grease causes commercial drainage failures

Fats, oils and grease, often called FOG, may look harmless when they leave a hot pan or dishwasher. They are warm and fluid at that point, but the temperature drops quickly inside the drainage line. The grease then begins to solidify on pipe walls, particularly around bends, joints and older sections of pipework.

Food particles, detergents and scale build up on this sticky layer. What starts as a reduced flow can develop into a complete blockage, causing sinks to drain slowly, floor gullies to back up or wastewater to surface in food-preparation areas. On larger sites, the problem may extend beyond internal pipework and affect external drains, manholes or the connection to the public sewer.

The operational consequences can be significant. Staff lose access to essential sinks and appliances, cleaning becomes more difficult, odours affect customers and employees, and a serious backup can create hygiene concerns. Emergency drainage work often restores service quickly, but repeated blockages usually point to a grease-control issue that needs addressing at source.

Commercial grease management starts in the kitchen

A grease trap or grease separator is designed to slow wastewater flow and separate grease from water before it enters the wider drainage system. The appropriate unit depends on the site, the volume of wastewater, the available space, the kitchen layout and the nature of the food being prepared.

Smaller under-sink grease traps can suit lower-volume applications where they are correctly installed and easy to access for cleaning. Larger commercial kitchens may require a grease separator, interceptor or an external unit designed for greater capacity. Choosing the largest possible unit is not automatically the answer. A poorly sized or inaccessible installation can be just as difficult to manage as no equipment at all.

Equipment only works when the kitchen team understands its purpose. Fat from roasting trays, fryer oil and pan residue should be collected separately rather than washed into a sink. Plates should be scraped into food-waste containers before washing, and drain strainers should be emptied regularly. Hot water and detergent can move grease further along the pipe, but they do not remove it from the drainage system.

Kitchen managers should make grease control part of normal closing procedures, not something addressed only after a blockage. Clear responsibility matters. If no one is assigned to check strainers, monitor the unit and report slow drainage, problems can develop unnoticed between scheduled services.

The difference between cleaning and maintenance

Grease traps need emptying and cleaning at intervals suited to their actual use. That frequency varies. A small café with limited hot-food preparation will have different requirements from a high-volume restaurant, hotel kitchen or central production facility. Menu changes, seasonal demand and increased covers can all alter the amount of grease entering the system.

During a proper service, the collected grease and solids are removed, the unit is cleaned, key components are checked and the surrounding pipework can be assessed for signs of restriction. Waste must be handled and removed through appropriate channels. Simply skimming the top of a trap or leaving settled solids in place does not provide an effective clean.

Planned maintenance also looks beyond the trap itself. Where grease has already travelled downstream, professional drain cleaning may be needed to remove deposits from internal and external lines. High-pressure water jetting can clear accumulated material, while CCTV drainage surveys provide a clear view of pipe condition, blockages, displaced joints or defects that may be worsening the issue.

This distinction is useful for facilities managers. Emptying a grease-management unit is a preventative task. Clearing a blocked drain is reactive work. Both may be necessary, but relying solely on emergency call-outs generally costs more, creates disruption and leaves the underlying cause unresolved.

Signs your site needs attention

Do not wait for wastewater to overflow before arranging an inspection. Early action is usually faster, cleaner and less disruptive to staff and customers. Common warning signs include:

• Slow-draining sinks, dishwashers or floor gullies

• Persistent smells near drainage points or outside manholes

• Gurgling sounds when sinks or appliances discharge

• Recurring blockages in the same kitchen area

• Grease visible in chambers, drain covers or external gullies

A single slow sink can occasionally be caused by a local obstruction. When several fixtures are affected, or the issue returns after basic clearing, there may be a wider restriction in the branch line or main drain. A CCTV survey can confirm what is happening without unnecessary excavation or guesswork.

Building a practical maintenance schedule

The best schedule reflects how the premises operates. Start by identifying every point where grease is likely to enter the drainage system, including pot-wash areas, combi ovens, fryers, food-preparation sinks and dishwasher discharge. Check whether existing grease-control equipment is correctly sized, accessible and being serviced properly.

From there, set a documented programme for grease-trap cleaning, drain cleaning and periodic inspection. High-use kitchens may need more frequent attention, particularly where fried food, sauces, meat preparation or high dishwasher volumes are part of daily service. Lower-use premises can often work to a longer interval, provided the unit is inspected and records show it remains within a safe operating condition.

Keep service records, waste documentation and notes on recurring faults. These are useful when responsibilities change hands, when a landlord or managing agent needs evidence of maintenance, or when a drainage contractor is asked to investigate a persistent issue. Good records turn a vague report of "the drains are playing up again" into information that can be acted on.

For multi-tenant buildings, responsibility should be agreed clearly. A restaurant may maintain its own kitchen equipment, while the property manager is responsible for shared drainage runs and external chambers. Problems at the connection between those systems can otherwise be delayed by uncertainty over who should arrange the work.

When emergency drainage support is needed

A blocked kitchen drain is not always a maintenance failure. A sudden high-volume discharge, a foreign object, damaged pipework or an issue in the public sewer can cause an immediate problem even at a well-run site. The priority is to protect staff, prevent contamination and restore safe drainage as quickly as possible.

Stop using affected fixtures where there is a risk of backing up, keep customers away from any contaminated area and avoid pouring chemical drain cleaners into commercial systems. Strong chemicals may not shift heavy grease deposits and can create safety issues for staff and engineers. A professional assessment can determine whether the drain needs jetting, mechanical clearance, CCTV inspection, repair or waste removal.

For sites with ongoing kitchen operations, response time matters, but so does follow-up. Once flow has been restored, ask what was found, where the blockage occurred and whether grease deposits were present. This helps determine whether the incident was isolated or whether the maintenance plan needs to change.

A reliable approach for London businesses

Commercial premises often have little room for downtime. That is why grease control should be treated as part of planned building maintenance alongside ventilation, refrigeration and fire safety checks. It reduces avoidable call-outs, protects drainage assets and gives managers better control over operational risk.

Burch Drainage Ltd provides planned drain cleaning, CCTV drainage surveys, emergency unblocking and liquid waste support for commercial sites across Greater London. With the right servicing interval and a clear response plan, grease need not be the reason a kitchen stops trading.

If your kitchen is experiencing recurring slow drainage or odours, arrange an assessment before the next busy service exposes the problem. A planned visit is usually the most practical time to find and remove the cause.