How do I protect my drains from rats?

Improperly installed or damaged drainage can easily be the precursor to a rat infestation of your home or business. The drains of your properties connect to sewers that are teeming with the vermin, so ensuring your drains are in good working order is crucial to protecting yourself from disease-carrying pests. It is also important, depending on the type of drain used by your property, to have additional, specialised measures in place to prevent rat entrance.

Rat in drain
Rat in drain found during CCTV Drainage Survey

In a perfect world, sewers would be doused in rodenticide to prevent the public from having to protect themselves from the sewers using these rodent control methods.

Unfortunately applying the chemicals would be highly labour intensive, which when combined with the costs of the chemicals themselves and the fact that regular applications would be required, makes this method too expensive for public authorities to utilise.

How do I protect my drains from rats?


Sealed Drainage

This essentially means no openings in the drainage pipework between the discharge stack of the home and the sewer. Although this does not protect the property from infiltration stemming from the sewer itself, as well as the protection it does offer to homes, it helps stop rats entering the sewer. This type of drainage will require regular access covers for inspection chambers and entry of rods to clear blockages. These should allow maintenance of the drainage pipes from the surface.

Rodent Barriers

This includes a variety of devices within the pipes such as:

  • Downward facing fins in the discharge stack
  • One way valves in the underground drainage
  • Enlarged sections of the discharge stack to prevent rat climbing

Intercepting traps

Also called the Buchan trap, the disconnecting trap or the Bristol interceptor, these devices are a U-bend section of a domestic sewer pipe made of fireclay. This U-bend is filled with water. Although this trap will prevent sewer smells from escaping the pipes, its worth in protecting against rodents is rather more dubious; they are often easily able to swim through an interceptor trap. Another downside of this type of protection is that it is easily blocked and will require frequent maintenance. Thus, it is crucial that the trap is installed such that a rod can be easily inserted to remove blockages.

Covers & Gratings

Placement of plastic covers or metal gratings that allow the passage of waste but block rats should be placed within the pipes.


Metal cages are often placed in the ventilation pipes that stem from over the discharge stack, blocking that route for rat escape & entry.

Our Rat Removal Service

We have years of experience and knowledge in rat removal. Using the latest drainage technology, such as CCTV surveys, we can identify the issue and resolve it. Give us a call to discuss your rat infestation problem with our drainage experts.


How useful was this post?

Click on a star to rate it!

Average rating 0 / 5. Vote count: 0

No votes so far! Be the first to rate this post.

Maintain Drains

Maintain Drains

Our frontline discount has now been extended until the end of June, please share amongst your friends & family if you think we might be able to help.