Commercial drainage
Grease traps in Southport
Grease traps and grease separators for restaurants, takeaways, hotels and canteens. We fit new ones, repair or replace old ones, and survey the ones you have. Use our calculator below for an idea of the size your kitchen needs.
What we do
New grease traps fitted
Sized for your kitchen, then fitted and connected into your drains. Under-sink units for small kitchens, or a separator in the ground outside for busy ones, dug in with our own machines.
Repairs and replacements
Cracked or rotten units, broken lids and baffles, leaking joints, and traps that are simply too small for the kitchen they serve. Repaired where it is worth it, replaced where it is not.
Condition surveys
We check the trap, its lid, baffles, seals and pipework, and look down the drain beyond it with a CCTV camera to see if grease is getting through. You get a plain written report.
What a grease trap does
Water from sinks and dishwashers carries fat, oil and grease. Hot, it runs. Once it cools in the drain it sets hard, sticks to the pipe and catches everything else that comes along.
A grease trap slows the water down in a tank so the fat floats to the top and the food solids sink to the bottom. Cleaner water carries on to the drain, and the fat stays in the trap until it is emptied.
The rules
The Building Regulations say commercial hot food kitchens should have a grease separator built and sized to BS EN 1825, the British Standard for grease separators.
Putting anything into a public sewer that stops it flowing is an offence under the Water Industry Act 1991, and water companies can charge for clearing blockages caused by fat.
Grease trap size calculator
A quick estimate of the grease separator size your kitchen needs, using the method in the British Standard for grease separators (BS EN 1825-2).
It works from how many hot meals you serve a day and how long the kitchen runs. It is a guide only: we confirm the size on site before anything is ordered.
Fill in the form and press Work it out to see an estimated size.
How the sum works
Peak flow = meals a day × litres of water per meal × peak factor ÷ (kitchen hours × 3,600).
Litres per meal and peak factor: restaurant 50 and 8.5, hotel 100 and 5, hospital 20 and 13, canteen 5 and 20, 24 hour kitchen 10 and 22.
Nominal size (NS) = peak flow × density factor (1, or 1.5 for heavy fats) × temperature factor (1, or 1.3 over 60°C) × detergent factor (1, or 1.3 with detergent, 1.5 for hospitals).
The answer is rounded up to the next standard size: NS 1, 2, 4, 7, 10, 15, 20 or 25. The sludge trap, the part that catches food solids, should hold at least 100 litres for every NS.
A kitchen can also be sized from its sinks, dishwashers and cooking equipment. We do that on site.
Types of grease trap
Under-sink grease traps
A small box fitted under or beside a sink. Fine for a cafe or small takeaway with one or two sinks. They fill quickly, so they need emptying often.
Below-ground grease separators
A large tank buried outside, taking the waste from the whole kitchen. For restaurants, hotels, canteens and anywhere with a commercial dishwasher. Bigger capacity, emptied less often.
Automatic grease removal units
Units that skim the fat off by themselves into a container you empty. They need power and servicing, but stop the trap filling with fat.
Makes we fit
We can supply and fit all the main makes, or fit one you have already bought. We choose the unit to suit your kitchen's size, space and budget, not the other way round.
Kingspan Klargester
The NSG range of below-ground grease separators, from 500 litres for a small restaurant up to 11,000 litres and beyond for big kitchens.
ACO
The Lipator range of grease separators, below ground and free standing, plus ACO drainage channels for kitchen floors.
Kessel
German made grease separators, including the EasyClean range, for indoor and below-ground use.
GreaseMaxx
Plastic grease traps from small units up to large below-ground tanks. A good value option.
Grease Guardian
Automatic grease removal units that skim the fat off into a container, for busy kitchens that want less emptying.
Goodflo
Grease traps and automatic units for commercial kitchens, from under-sink to below ground.
Stainless steel under-sink traps
Simple 20 to 100 litre stainless steel boxes for cafes, takeaways and small kitchens.
Signs your grease trap needs looking at
- Kitchen sinks or floor gullies draining slowly
- A smell of old fat around the kitchen, the yard or the manhole covers
- Grease building up in the manholes downstream of the trap
- The trap overflowing, or needing emptying far more often than it used to
- A cracked lid, a rusted steel unit, or baffles that have broken off inside
Taking over a kitchen?
Get the grease trap and drains surveyed before you sign. A trap that is too small, broken or missing is expensive to put right once you are open, and a survey gives you something in writing to take to the landlord.
How we fit a grease trap
- 1
Survey
We look at the kitchen, the sinks and equipment, the drains and where a trap can go.
- 2
Size it
Worked out to BS EN 1825-2 from your meals, kitchen hours and equipment.
- 3
Written quote
The unit, the digging and the connection to the drain, in writing.
- 4
Fit it
Dug in and connected, at a time that keeps your kitchen running as far as possible.
- 5
Test and hand over
Tested, with the lids accessible for emptying, and advice on how often it will need emptying.
Questions people ask
Does my kitchen need a grease trap?
If you cook hot food commercially, almost certainly. The Building Regulations (Approved Document H) say the drains from a commercial hot food kitchen should have a grease separator built to BS EN 1825, or another effective way of removing grease. Your water company can also act if fat from your premises blocks the public sewer.
What happens if fat gets into the sewer?
It sets hard and builds up into blockages, which can cause sewage to flood back into your premises or your neighbours'. It is an offence under the Water Industry Act 1991 to put anything into a public sewer that stops it flowing freely, and water companies can recover the cost of clearing it.
What size grease trap do I need?
It depends on how many meals you serve, how long the kitchen runs, and what goes down the drains. Try the calculator above for an estimate. We confirm the size on site, because an undersized trap fills too fast and lets grease through.
What does NS mean?
Nominal size. It is the standard way grease separators are sized, roughly the flow they can handle in litres a second. The standard sizes are NS 1, 2, 4, 7, 10, 15, 20 and 25.
Which make of grease trap is best?
There is no single best. Kingspan Klargester, ACO and Kessel are the big names for below-ground separators, GreaseMaxx is good value, and Grease Guardian and Goodflo make automatic units. The right one depends on the size your kitchen needs, where it can go, and how often you want it emptied. We fit them all.
Can a grease trap go inside the kitchen?
Small under-sink units, yes. Larger separators usually go outside in the ground, so they can be emptied without carrying waste through the kitchen.
How often does a grease trap need emptying?
It depends on its size and how busy the kitchen is. A small under-sink unit can need it weekly, a large separator every few weeks or months. If yours needs it far more often than it used to, it may be too small for the kitchen now.
Can you check an existing grease trap?
Yes. Our condition survey checks the trap, its lid, baffles and seals, and puts a camera down the drain beyond it to see whether grease is getting past. Useful when you take over premises, before a lease ends, or if the drains keep blocking.
Also worth a look
Book a grease trap survey
Phone lines open Monday to Friday 8am to 5pm, Saturday 8am to 1pm. WhatsApp a photo of the job any time.