This page is for property owners planning a new installation and for plumbers evaluating the best way to integrate rat protection into a compatible drainage system.
If there is no existing compatible non-return valve in place, the correct approach is not flap replacement — it is installation planning. In that situation, the first step is to have a plumber assess the drainage system, determine the most appropriate location, and confirm what is permitted under applicable codes and local requirements.
This is important because effective protection depends not only on the component itself, but also on where and how it is installed within the system.
Rat-Proof Flap OUT is designed to work inside a compatible non-return valve by replacing the internal flap component. When no compatible valve is already present, installation begins with selecting the right valve, identifying the right location, and ensuring that the planned setup fits the drainage system and intended use.
In other words, this is not simply a matter of adding a part wherever convenient. Proper installation requires evaluation of the system, access, serviceability, and compliance.
The best installation point depends on the layout of the drainage system and the conditions of the property. A plumber must determine whether the location is suitable, whether the installation remains serviceable, and whether the system continues to comply with all applicable requirements.
For the property owner, that means the correct path is to contact a plumber rather than guess where the system should be installed.
This installation approach does not replace a backwater valve and must not be treated as a substitute for any code-required backflow protection device. It is intended to function within a compatible system as part of a targeted anti-rat protection approach.
Any new installation must comply with all applicable requirements, including:
The exact requirements may vary depending on the building, the drain line, the valve type, and the authority having jurisdiction.
If you do not already have a compatible valve, the next step is to speak with your plumber. They can determine:
If a customer is looking for a stronger anti-rat approach through drains, installation of a compatible valve with Rat-Proof Flap OUT may provide a practical solution where conditions allow. The concept is straightforward: integrate targeted rat protection into a compatible valve assembly while preserving proper system planning, serviceability, and code compliance.
This makes the system relevant not only for replacement situations, but also for new installations where the customer wants a more durable anti-rat solution built into the planned drainage protection strategy.
Correct installation is what turns a good component into a reliable system. When the valve type, location, access, and compliance requirements are all properly considered, the result is a cleaner and more professional anti-rat installation approach.
That is why installation planning should always come first when there is no existing compatible valve already in place.
Whether you are replacing a damaged flap or planning a new installation, the goal remains the same:
improve protection at the point where rats can enter.
Rat-Proof Flap OUT is designed to work within compatible systems,
providing a targeted and practical solution where it matters most.
For full details, see our
Terms & Conditions and
Disclaimer.