Choosing Replacement Trench Drain Grates

07/04/2025

Drainage grates play a crucial role in maintaining the proper functioning of a drainage system. They prevent debris, trash, and other materials from clogging the drain, allowing water to flow freely. However, over time, drainage grates can become damaged or broken due to wear and tear, weather conditions, or even vandalism. If left unrepaired, broken drainage grates can cause flooding, property damage, and even pose a safety hazard. To ensure that your drainage system remains efficient and effective, it’s important to promptly replace broken drainage grates. In this article, we’ll discuss the steps you can take to correctly identify and the process of replacing broken grates to ensure that your drainage system is operating at optimal levels.

Should I Replace My Trench Drain Grates?

If you are not proactive, and take steps to replace your trench drain grates as soon as damage is apparent, it can lead to larger, more costly issues. One of the most severe consequences of poor driveway drainage is damage to the foundation of your home. When water is not adequately diverted away from the driveway, it can seep into the ground around your house. Over time, this excess moisture can erode soil supporting the foundation, leading to cracks and potentially structural instability.

When to Replace Trench Drain Grates

Trench drain grates could fail for several reasons. They age with time, and the structure of the material breaks down.

Poor maintenance can also cause drain gates to fail sooner than normal. Drain grates wear out even faster if they don’t meet the specifications for your use.

A proper trench drain grate replacement can help you solve drainage issue

Replacing Broken Grates

Replacing broken drainage grates can be a challenging task, particularly when attempting to match the existing grate. Identifying the correct size and style of the broken grate can be difficult, as it may have been manufactured by a company that is no longer in business or no longer produces that specific model. Additionally, even if the manufacturer is still operational, it can be challenging to determine the original manufacturer of the grate. In many cases, the grate may have been customised or modified, making it even more difficult to locate a matching replacement. As a result, it’s important to have a thorough understanding of the grate’s specifications and design before attempting to replace it to ensure the correct replacement is installed.

Measuring

The first step you need to take when looking for replacement grates is to measure the existing channel & grate. There are many different sizes, shapes and profiles of grates & each measurement you take is important in determining whether your new grate will sit in the channel correctly.

Grate

Width at top of grate (take note of whether the grate has an edge that covers the side of the channel)
Height of grate
Width of underside of grate
Height of underside of grate
Grate length

note: not all grates will have the above characteristics to measure. See below image for examples of types of grate profiles

Channel

Internal Width
Internal Height
External Width
External Height (if accessible)
Edge of channel

Identifying what type of channel is used with the grate will also be helpful. Polymer & polypropylene/plastic are common. Check the channel for damage as well.

Identifying The Grate Material

Identifying the material of a drainage grate is an important step when replacing or repairing it. One way to identify the material is through a visual inspection. Common materials for drainage grates include cast iron, steel, aluminium, and plastic. Cast iron is the most common material used for drainage grates due to its durability and resistance to corrosion. Steel is also a popular material and is often used for its strength and ability to handle heavy loads. Aluminium is lightweight and resistant to corrosion, making it an excellent choice for outdoor environments. Plastic grates are also available, and while they are less durable than metal grates, they are lightweight and easy to install. To determine the material of a drainage grate, you can also consult the manufacturer’s specifications or use a magnet to test for ferrous materials such as iron or steel.

Manufacturers Mark

Most grates will have a manufacturers mark on it that will help you determine the grates origins.

Replacing Broken Grates : Your Options

If you have identified the original manufacturer of the drainage grates, the next step is to contact them to purchase the replacement grates. The manufacturer can provide information on the specifications and requirements of the grates, ensuring that you get the exact match for your drainage system. However, if the original manufacturer is no longer in business or does not produce that specific model, it can be challenging to find a matching replacement. In this case, you may be able to find a similar grate using the measurements taken or consult with a plumber. They can recommend suitable alternatives or suggest custom solutions to ensure proper functioning of the drainage system. It is important to avoid using mismatched or poorly fitting grates, as they can cause uneven water flow, blockages, and potential damage to the system.