If you’ve ever heard scuttling sounds coming from inside your walls or spotted droppings near your drains, you’re probably wondering how rats are even getting in. What might surprise you is how often the route they take is right under your nose – or rather, climbing up your drain pipes.

Yep, rats are excellent climbers. And when you’ve got a drainage system with a clear path into your home or loft, you’re pretty much handing them the keys. But you don’t have to put up with it. In this guide, you’ll learn exactly how to stop rats climbing drain pipes – step by step – without wasting time or money on things that don’t work.

Let’s start by getting clear on why they climb up there in the first place, and what you can do to block them out for good.

Why are rats climbing up your drain pipes?

It all comes down to shelter, warmth, and food.

Drain pipes – especially external soil pipes and rainwater pipes – give rats an easy vertical route towards your loft, kitchen vents, or even under floorboards. Once they’re in, they’ll nest wherever they find safety and access to food scraps or warmth.

If there’s even a tiny gap in your roofline, brickwork, or pipe junctions, a rat will find it. And once one gets in, more will follow – because they communicate and leave scent trails behind.

Your drainage system also stays relatively warm through the colder months, especially if it’s connected to internal heating vents or bathrooms. So they’ll use it to shelter and move between areas with little resistance.

That’s why the first sign of a rat problem might be scratching at night, strange smells, or droppings in places you didn’t expect.

Can rats really climb vertical pipes?

Yes, they absolutely can.

Rats have strong limbs and sharp claws. They can grip textured surfaces like rough brick or drain pipe joints without much effort. If the pipe is made of cast iron, older plastic, or has any kind of surface imperfections, they’ll get enough traction to scale it.

Even smooth PVC isn’t always safe if it’s positioned close to walls, ledges, or cables that give them a boost.

And they don’t give up easily. If they think there’s something worth getting to, they’ll try different angles – jumping, climbing, or squeezing through gaps you didn’t think possible.

So blocking them from below isn’t always enough. You’ve got to think about the whole route they might take – from ground level right up to the entry points near your roof.

How do you know if rats are using your drain pipes?

Before you start sealing things off, it’s worth checking for signs. Here’s what to look out for:

• Grease or dirt smears along the sides of the pipe – from their fur rubbing against it
• Scratch marks or gnawed sections near joints and pipe clips
• Droppings at the base or near pipe exits higher up
• Strange noises in the loft, cavity walls, or behind pipe boxing indoors
• A musky smell, especially around bathrooms or kitchens

If you’ve seen rats in your garden or near bins and compost, and you’ve noticed these signs near your pipes too, there’s a good chance they’re climbing up.

What stops rats climbing up drain pipes?

There are a few ways you can stop this from happening. The most effective approach depends on where the pipe is, how it’s fixed to the wall, and whether it’s a rainwater pipe or a soil pipe.

Let’s break it down into practical solutions.

1. Fit a drain pipe guard or rat barrier

The best starting point is to install a physical barrier that stops rats from climbing the pipe in the first place.

You can get stainless steel rat guards designed to fit around vertical pipes, especially cast iron and plastic downpipes. These guards usually clamp around the pipe and flare outwards, making it impossible for a rat to continue upwards past the barrier.

Make sure to:

• Choose the right diameter for your pipe
• Fit the guard around 30–40cm off the ground so rats can’t jump past it
• Use stainless steel or galvanised options – rats will chew through plastic

You can find these online or at most pest control suppliers. Some are adjustable, and others are purpose-built for common pipe sizes.

2. Use anti-climb paint on the pipe surface

Another option is to apply anti-climb paint. This is a thick, non-drying coating that makes surfaces slippery and difficult to grip.

It’s especially effective on smooth plastic pipes, but you’ll need to apply it in a band – not the whole length – around the middle of the pipe, or just below roof access points. That way, rats lose their grip before they reach anywhere important.

Make sure you:

• Use paint specifically labelled as anti-climb
• Apply warning signs – it’s a legal requirement in the UK
• Keep it away from areas where people might brush against it

This won’t stop all rats, but it’ll seriously slow them down and make climbing harder.

3. Seal up gaps near where pipes meet the building

It’s not just the pipe itself you’ve got to think about – it’s what the pipe connects to. Rats often climb up and then sneak in through:

• Gaps around where the pipe enters a wall or roof
• Openings behind pipe brackets
• Cracks in the render or brickwork nearby

Use steel mesh, expanding foam mixed with wire wool, or a proper sealant like cement or caulk. Avoid leaving even a 2cm gap – rats can squeeze through holes smaller than you’d think.

It’s a good idea to check in the loft too. Look for signs near the pipe boxing or where soil pipes run vertically through the house.

4. Keep the surrounding area clear and tidy

It’s easier for rats to get to your pipes if they’ve got help from nearby clutter. That includes:

• Overgrown plants or shrubs right next to the house
• Stacked items like bins, pallets, or firewood that give them a boost
• Ivy or climbing plants growing up the wall

Trim things back, remove anything they can jump from, and make the area around your walls harder to approach.

This also helps you spot activity more easily. If something is dragging leaves or debris near your wall regularly, you’ll be able to notice.

5. Fit rat flaps or valves in your drains

While this won’t stop them climbing external pipes, it’s vital for soil pipes and internal drainage. Rats often come up through the sewer and make their way into the house via toilets, u-bends, or pipe junctions.

Installing a one-way rat flap inside the drain chamber or soil pipe stops them entering that way. It’s a strong, stainless steel flap that lets waste flow out but blocks rats trying to swim or climb up.

This is especially important if you’ve had rats in the toilet bowl, or if your drainage connects to older combined sewer systems.

6. Replace or reinforce damaged drain covers

Sometimes, the problem starts lower down than you expect. A cracked or loose drain cover can give rats access to the vertical pipe system.

Check all drain lids around the garden. Make sure they’re made from solid metal or heavy-duty plastic. If anything feels loose or rocks when you press it, replace it or weigh it down until you can.

If you’ve got metal grates, make sure the gaps aren’t wide enough for rats to slip through.

Can you use repellents or traps on drain pipes?

Some people try using strong-smelling deterrents like peppermint oil or ultrasonic devices near their pipes. While these can work for mild problems, they don’t always go far enough.

Rats are persistent. Once they’ve found a good route or smell food, they’ll often ignore unpleasant scents. And things like sprays wear off quickly in rain or wind.

As for traps, you shouldn’t attach them to external drain pipes. It’s not safe, and you risk harming other wildlife or creating a mess.

Focus on physical barriers first. Once you’ve blocked their path, then you can deal with any rats already inside using humane traps or calling a pest control expert.

How do you stop rats coming back once they’re out?

Once you’ve stopped them climbing your drain pipes, you’ve got to make sure they don’t just find another way in.

Here’s what you can do:

• Check for any roof gaps or vents with missing covers
• Seal gaps around windows, doors, and pipe entries
• Fit mesh to air bricks – make sure it’s rodent-proof
• Don’t leave bin lids open or food waste accessible
• Avoid leaving pet food or bird seed out overnight

Rats only stay where they find shelter and a food source. If you take both away and keep them out physically, they’ll move on.

What’s the benefit of sorting it now rather than later?

Rats cause damage. They chew through wires, insulation, and even water pipes. They leave droppings and urine behind, which can cause health problems. And once they nest, they breed fast.

If you stop them early – especially by blocking climbing access like drain pipes – you avoid all of that.

You also avoid costly repairs, pest control bills, and sleepless nights. And you get peace of mind knowing your home’s protected.

Final thoughts – your action plan

To stop rats climbing your drain pipes, you don’t need to rip everything out or spend a fortune. Just be methodical.

Start by watching the pipes – are there any signs of climbing? Then fit a guard, apply anti-climb paint, and seal up gaps nearby. Check drains and roof access. Clear the ground. Fit a rat flap if needed.

It might take a couple of weekends, but once you’ve done it, you’ll stop rats in their tracks – literally.

If you’re dealing with a full-on infestation, or you’re unsure how they’re getting in, it’s worth speaking to a pest control specialist. But for most homes, these steps are enough to solve the problem for good.

You’ve got this. Seal it up now, and you won’t be hearing those night-time scratches ever again.