Rat Blockers
Keeping Unwanted Guests Out
Did you know that the most common way rats enter a property is through the drainage system? Rats are excellent swimmers and can navigate U-bends, swim up pipes, and even surface in toilets.
If you are hearing scratching in the walls or finding evidence of rodents but can’t find a hole in your brickwork, the drains are the likely culprit.
In simple terms: A Rat Blocker is a one-way steel gate that fits inside your pipe. It lets wastewater flow out, but stops rats from coming in.

Why Do I Need a Rat Blocker?
Pest control can put down bait, but that only deals with the rats that are already there. It doesn’t stop new ones arriving. Rats view your drainage pipes as a superhighway into your home.
You should consider a rat blocker if:
- You have had a recent infestation: And you want to make sure it never happens again.
- You hear scratching: Noises coming from behind walls or under floors are often caused by rats in the pipes.
- You are a landlord: You have a duty to keep your property pest-free for tenants.
- You run a food business: Restaurants and cafes need to protect their hygiene rating.
How It Works
It is a simple but brilliant device. We install a stainless steel unit inside your drain pipe.
- Water flows out: When you flush a toilet or run a tap, the force of the water opens the flap, letting waste pass through easily.
- Rats stay out: If a rat tries to push up from the sewer, the flap locks shut. They cannot push through it and are forced to turn back.
The best part? It is non-toxic, humane, and requires no electricity or maintenance.
How We Install It
We don’t need to dig up your garden to fit one. We usually do it through a manhole.
1. The Camera Check (CCTV) – Before we fit anything, we send a camera down the drain. We need to check that the pipe is in good condition. If the pipe is collapsed or full of roots, a blocker won’t fit, and we will advise you on the necessary repair instead.
2. Selecting the Size – Most homes use 100mm (4 inch) or 150mm (6 inch) pipes. We select the correct size blocker for your system to ensure a snug, rat-proof fit.
3. Installation & Testing – We lower the device into the pipe from the manhole and lock it in place. We then test it to make sure the flap opens freely for water but stays firm against pressure from the other side.
Is It Suitable for Every Home?
Almost, but not all. To install a rat blocker, we need:
- Access: We need a manhole or inspection chamber to reach the pipe.
- Good Condition: The pipe needs to be round and unbroken.
If your system has no access points, is “blind” or the pipes are damaged, we will be honest with you and suggest alternative solutions.

The Benefits to You
- Immediate Protection: As soon as it is fitted, the entry route is closed.
- No Poison: Safe for pets and the environment as it doesn’t use chemicals.
- Cost-Effective: A one-off installation is cheaper than repeated visits from pest control.
- Peace of Mind: You can sleep soundly knowing your home is sealed against intruders.
Stop rats at the source. Ask ASL about installing a Rat Blocker today.
When installed correctly, rat blockers stop rodent access at the point where most infestations begin — the drainage system.
Testimonials
What Our Clients Say
“I called at 08:10 hours to report a blocked drain. A little while later, Darren rang to tell me he’d arrive in half an hour. He arrived on time and resolved the problem quickly and without fuss. He was polite and friendly throughout. Within two hours of reporting the blockage, all was well. Thank you.” Customer, Surrey
“I unreservedly recommend ASL. All the glowing reviews of ASL are true. They had to lift paving slabs to fix my drains, and I was concerned there might be unavoidable damage. I should not have worried. Liam and Richard did a superb job. Thanks, ASL” Customer, Surrey
“Darren arrived very promptly and got to work quickly. He did an excellent job and explained what he was doing. We would have no hesitation in recommending ASL Services.” Customer, Surrey
“Very efficient to book them to sort out a sewer drain blockage, and the cost was exactly what they quoted. Called before they arrived with a clear ETA. Got on with the job and sorted it out within the hour. Darren was excellent – very courteous and helpful, did more than we expected to help sort the problem out and was a font of knowledge on all things sewer-related. Given the subject matter (eeew) the whole experience with ASL was an absolute pleasure.” Customer, Surrey
“ASL recently carried out a drain repair at our house. They responded quickly to the call for help, came out and soon diagnosed the problem – tree roots blocking the drain. The remedial work on site was carried out by Lester and George – they worked hard and were very thorough. This is a long-established company that seems to know what they are doing.” Customer, Surrey
Areas we cover
Surrey, Hampshire, Berkshire, West Sussex and South West London
The ASL Limited HQ is in Guildford, but our operating area is the whole of Surrey and parts of Berkshire, Hampshire, West Sussex and South West London.

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Contact Us
Get in touch today
You can call us on 0800 181 684, email info@asllimited.co.uk or use the form below:
