A blocked drain in a restaurant at 6pm on a Friday is a crisis. In an office building, it is a health and safety incident. Commercial drains fail in a different way from home drains. Volumes are higher and the waste is harsher. The cost is lost trading hours and regulatory risk, not mere inconvenience. High-pressure jetting is the standard fix for commercial drains in London. However, the frequency, spec and cost differ a lot from a home job.
Why Commercial Drainage Fails Faster
Commercial kitchens send out grease, food scraps and detergent at rates no home kitchen can match, because they cook all day. One busy service may send more grease down the drain than a home kitchen does in a week. The grease cools as it travels. It sets on pipe walls and builds up at every bend.
London's sewers have a known fatberg problem. The Whitechapel fatberg of 2017 weighed 130 tonnes. Restaurant grease is a main ingredient, since it sets hard in cold pipes. Thames Water expects food businesses to keep fat, oil and grease out of the public sewer. The law supports this through the Water Industry Act 1991. In practice, that means grease traps and regular drain maintenance.
Offices face a different challenge. Their pipes are wider and the layouts are more complex, because they serve many floors. Maintenance cycles are also long. As a result, build-up can grow unseen until something fails.
What Commercial Drain Jetting Involves
The core method matches home jetting, although the scale is bigger. A self-propelling hose and nozzle fire high-pressure water along the pipe. The differences lie in scale and access.
Flow rates. Commercial units pump more water than home machines, because the pipes are wider. The extra flow is needed to flush loose debris through wider pipes.
Access. Commercial sites have larger chambers and more access points. For example, in a restaurant, we need the kitchen floor drains, the grease trap, the inside chamber and the outside chamber. We agree clear routes through the kitchen in advance.
Grease trap servicing. A grease trap needs its own cleaning. It may be a passive trap under the floor or a larger tank outside. If you jet the drain before emptying the trap, you simply push grease into the sewer. Many commercial jobs therefore include trap emptying.
CCTV reporting. Commercial clients often want a CCTV report too. It proves compliance for insurers and regulators, while it also shows structural faults that could cause later failures. Our CCTV drain survey service often goes with commercial jetting.
How Often Does Commercial Drainage Need Jetting?
The right interval depends on your business type, volume and layout. Use these as a guide.
Busy restaurants and food service. Jet kitchen drains monthly or quarterly, since volumes are high. Empty the grease trap at least quarterly, and monthly for high volumes. The Environmental Health Officer (EHO) for your borough may set a minimum in your licence or an improvement notice.
Cafes and small food outlets. Quarterly jetting is usually enough, although grease still builds up. Check the grease trap monthly, and empty it when grease fills a good part of it.
Office buildings. Jet the main drain runs once a year. However, if the building has a large canteen, treat that area like food-service drainage.
Hotels and serviced apartments. Jet kitchen drains quarterly and guest room runs yearly. Since a hotel with a restaurant should treat its kitchen as high-volume food service.
These are industry guides, not legal rules. The legal standard is plain. Your drains must not block. You also must not send enough grease into the public sewer to cause a blockage.
Choosing a Commercial Drainage Contractor in London
Commercial drainage is a specialist field, and quality varies. When you compare contractors, look for four things.
High-flow equipment. A van with a home jetting unit cannot handle a commercial kitchen. Ask about flow rate and pressure range.
Grease trap capacity. If you have a trap, the contractor needs a licensed waste carrier certificate, because grease trap waste is controlled waste, so nobody may pour it down a drain.
CCTV skills. A contractor who can jet and survey in one visit gives you maintenance proof and a condition report together.
Maintenance contracts. A planned programme beats ad hoc call-outs, because you get a history of the work. You get set visits, steady reports and a service history. It also gives you compliance evidence and often lowers the cost per visit.
Our commercial drain jetting service covers London. It suits restaurants, hotels, offices and shared commercial buildings.
What Does Commercial Drain Jetting Cost in London?
Commercial jetting is priced differently from home work. The price of one kitchen visit depends on run length and the number of access points. It also depends on whether trap emptying is included. We quote annual contracts for a single-kitchen restaurant individually, since each site differs.
For a full breakdown by business type, visit our drain jetting cost page.
Compliance Evidence and Insurance Documentation
Regular jetting does more than keep drains flowing. It also creates the paper trail that insurers and regulators expect when something goes wrong. EHOs who inspect food premises increasingly ask for drainage records. They want to see them beside cleaning schedules and pest control logs. A full history of jetting visits, trap tickets and CCTV reports shows you meet your duties under the Water Industry Act 1991.
Commercial building insurance often asks for proof of reasonable drain maintenance. Cover for escape of water and sewage backup may depend on it. Since the 2017 Whitechapel fatberg, insurers have asked for more paperwork after a claim. Businesses with no maintenance trail may find a claim declined or cut. A planned jetting programme with regular reports is cheap protection.
For multi-tenancy buildings, the freeholder should treat drainage like fire alarm tests or lift checks. The facilities contract should name it. The records should sit in one place, and leaseholders should be able to see them on request.
FAQ
Am I legally required to maintain my commercial drains?
Yes. The Water Industry Act 1991 stops businesses from putting material into public sewers in amounts that cause a blockage. Fat, oil and grease are the main concern for food businesses. If you fail to maintain your drains, Thames Water can take enforcement action. Environmental Health can also issue improvement notices.
Do I need a grease trap?
London planning authorities and Environmental Health often ask for grease traps on new food premises. Older premises may have no trap. Even so, you must still stop grease reaching the sewer. A grease trap is the most practical way to comply.
Can jetting be carried out during opening hours?
It depends on the layout. We can usually jet outside drains without disturbing service. However, inside kitchen work, especially floor drains, normally needs a shutdown. That means early morning before service or a closed day. We work around your trading hours wherever possible.
What is the difference between a passive grease trap and a grease interceptor?
A passive trap is a small unit under the kitchen sink. It slows the flow so grease floats to the top. An interceptor is a much larger tank in an outside chamber. High-volume kitchens need interceptors, while smaller outlets can use passive traps.
Can I request help with a commercial drain emergency in London?
For an emergency, such as a blocked drain during service, request a quote online via our contact form.
Because every property is different, start with our guides to high-pressure drain jetting and commercial drain jetting advice. We also cover high-pressure drain jetting in Haringey and high-pressure drain jetting in Kensington, so you can see how the work runs near you.
