Trench Drain Grates

7 Considerations for Trench Drain Systems

by Kristie Pohlman on September 5, 2019 Comments Off on 7 Considerations for Trench Drain Systems

Trench drain systems come in all shapes, sizes and materials and it can be difficult to determine which system is best suited for your project. Here’s a breakdown on what you need to consider when planning a project that requires trench drain systems.

1. What are the load requirements for the drain?

Drainage in pedestrian areas

It’s particularly important to mitigate potential flooding situations in high pedestrian areas.

Knowing what kind of traffic that will cross over the drainage system is one of the most important factors for you to consider first. There’s a big difference between pedestrian traffic and a commercial airliner and, of course, not all channels are built to take on that kind of weight. You also have to consider that even though the channel may be able to take the weight, it needs to be topped off with grates that are able to mitigate rainwater (or other liquids) while being appropriate for the traffic.


2. What’s on top?

As with the drainage channels, grates play an important role. They vary in material from plastic and fiberglass to stainless steel and ductile iron. Even areas with pedestrian traffic force you to think about load ratings and material options. Plastic grates may be appropriate for a park landscape or pool side deck but gates at an airport require ductile iron grate patterns that are heelproof and ADA compliant. There are a wide variety of patterns that can control flow rates while providing the correct amount of support. If the area tends to stay water-logged such as in a water treatment plant or around a pool, you can find options that are non-slip and either grip boots tightly or are barefoot friendly. In many cases, you’ll also find options that will blend into the surroundings or designs that enhance the look of the project.


3.Going to extremes

Another important consideration is knowing what is going to flow through the trench drain system. Some systems are perfect for storm water but can’t take the extreme heat that it would see in a brewery situation or stand up to corrosive chemicals in a manufacturing facility. If the system is outdoors, it needs to withstand seasonal freeze-thaw or perhaps extreme heat seen in Texas and Arizona.


4. Keeping it legal

Trench Drain Systems at Airports

At smaller airports, trench drains can be found within the hangers as well as the entrances.

In some cases, projects have to adhere closely to local or federal laws such as MS4 programs or government builds. These can include courthouses, government buildings or flood control projects. A simple guideline to determine if it’s a state or federal project is knowing who controls the project. A state project can be funded federally but it is still a state-controlled project. However, a state land project may have the US Army Corps of Engineers working on it which then makes it a federally controlled project. It’s not a topic that can be covered easily since each state has a separate set of guidelines and laws to follow.


5. Surrounding landscapes

Trench drains to redirect stormwater

A well-placed drainage system can keep rain water separate from pool water.

Trees, mulch and stone are just a few of the possible types of debris that have the potential to obstruct the flow of a trench drain system. Make sure you know the plans for the landscape and surroundings. Any trees planted too closely have the potential for roots to interfere with the channels. Likewise, trees can create seasonal debris that can also clog up a system. Stones in some parking areas can get knocked into channels if the grate openings are large enough causing the storm water flow rate to drop.

Another landscape consideration is the land itself. Is there a natural slope to the area? How much solid surface area will there be versus the amount of green space for water to naturally absorb? You can take it a step further and look at what the soil is composed of. Why is it important? You won’t be able to rely on clay to help disperse storm water.


6. Long term maintenance

Trench drain systems maintenance

It’s important to have a maintenance plan in place to ensure that trench drains remain effective.

Is there a maintenance program planned for the drainage system? It may seem trivial now but we have just about seen it all: trenches completely filled with silt at the bottom of a ramp and sand-filled drains at the beach that are rendered ineffective. We frequently see warehouses with cracked and/or partial grates that hopped and broke over time from not having locking devices. It’s a potential hazard at airports where jets can easily lift grates and locking devices if they are not properly secured. Seasonal checks and cleanouts would be beneficial to the system for it to remain effective.


7. Expect the unexpected

We always say that it’s better to plan for a hundred-year flood than to explain why you didn’t plan for a hundred-year flood. The system you choose may not be able to keep a hurricane at bay, but if you plan well, you will help the waters to recede faster.


Putting it all together

Even when you take everything into consideration, you may still feel overwhelmed by all the possible configurations. Luckily, there are experts that can help you through the decision-making process.

Author Bio

Kristie Pohlman has been working in marketing for over 15 years. A great deal of her writing has been on topics related to construction, education and marketing. Her work has been featured in several industry specific trade magazines such as Modern Contractor Solutions, Utility Products and Crane Hotline to name a few.

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Kristie Pohlman7 Considerations for Trench Drain Systems

How to Replace 1″ Thick Grates

by Kristie Pohlman on March 26, 2018 Comments Off on How to Replace 1″ Thick Grates
By Hannah Schroer
Let’s just say it: 1” thick grates aren’t considered heavy duty anymore.
1in grates, 1in thick grating, trench drain grates 1in thick,

This 1 in. cast iron grate had seen better days before the owner called to replace them.

Standards change. Architects once specified one inch thick iron grates for loading docks, warehouses and industrial areas. Typically, contractors installed them in an angle iron frame using the old wooden box form method.

Why can’t I replace my 1” iron grates?

  • Increased traffic loads
  • Industry shift to modular systems
  • Market standardization

Expected loads increased, and the 1 in. thick grate became rare, a holdover from decades past. New construction projects specify newer, standard sizes such as the ¾” thick grate with a strengthening frame. Foundries offer 1-1/2” and thicker grates almost exclusively – no extra reinforcement needed.

How do I replace 1” thick grates?



Replace with FiberglassFiberglass Bar Grating

Already a popular replacement choice, fiberglass grates have several things going for them.

  • Chemical/rust resistant
  • Load bearing capability
  • Low scrap value

Fiberglass grates are durable, rust-proof and not stolen for the scrap value. They come in several patterns and load classes, so ask an expert before replacing anything. However, in the right circumstances a 1 inch fiberglass grate will make a suitable replacement for aged cast iron.


Replace with Foundry Grates

Most foundries moved to supplying 1-1/2” thick grates, but Trench Drain Systems knows a couple holdouts. The grates are no longer officially traffic rated, which means if they do break the foundry is not liable. The standard grate thickness changed for a reason, after all.

POLYCAST with SS GrateReplace with Steel Bar Grates

Steel bar grates might be the exception to the rule. You can find 1” thick bar grates pretty easily in custom widths, lengths and styles. Wider grates require more bearing bars to keep the same level of strength as narrower varieties, so be careful to account for the traffic crossing over your drain when deciding. If in doubt, ask an expert.


Install a Modern Drainage System

This is the least popular option, but it’s the one I recommend most. I don’t prefer it for any monetary benefit; sometimes this is the option that makes the most sense.

When to just reinstall the drain:

ZURN Trench Drain

  • Fiberglass or bar grating won’t be strong enough
  • Foundry grates don’t come in that width
  • The channel or surrounding concrete shows damage

If any or all of these criteria are met, you’re better off reinstalling the drain with a modern system that meets new construction expectations. When starting with a 12” wide (or larger) trench drain, you might not even have to cut out the old system!

Questions about replacing old, broken grates? Give the experts at Trench Drain Systems a call 610-638-1221 and find out your options! Shop online at

replacement grates, 1in grate new




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Kristie PohlmanHow to Replace 1″ Thick Grates