Choosing the right sump grate.

With such a large variety of sump grates available, we understand that it can be difficult choosing the most appropriate one. Below is a summary of the key criteria on which our range of sump grates has been designed.

If you're unsure about some of the terminology used when describing grates, browse our "Grate Terminology" section below.  In order to work out the most appropriate grate, look at the most important features (below) that apply to your application and select a sump grate range from the recommended range lists in each criteria.

If you're still unsure, feel free to ring us on (03) 9238 5888 or email us at so that we can assist you.

Understanding Grate Terminology

If you're unsure about terminology like "pit size", "frame size", "grate size", "junction or side entry" or "AS3996" click below for an explanation of the terminology.

More on some of our terminology

Understanding Pit Size

Confusion can arise about what size is actually being measured on a product.  Unless specified, all R&S Grating size measurements are the pit size (often referred to as clear opening size or internal size).  All measurements quoted by R&S Grating are in mm unless otherwise specified.

More on pit size.

The pit size is the internal measurement of the pit. The rebate measurement is a measurement of the recess left when the formwork was completed, which houses the frame. The image below shows the distinction between the two.

Grate and Frame Sizes

Grate and frame sizes are not the pit size of a product. The grate and frame size should both exceed the pit size to ensure that the product fully covers the pit. The frame size generally exceeds the pit size by either 50mm (light duty), 90mm (medium/heavy duty) or 110mm (medium/heavy duty), however this can vary for individual products. The internal measurement of the frame, shown in the picture below, should closely match the pit size, ideally exceeding it a little (for example the internal measurements of a frame to suit a 900mm pit should be around 910mm or larger).

More on grate and frame sizes.

The overall frame size (cited on all product specifications as "frame size") is provided to give customers an indication of the necessary rebate that should be left to install the frame (see "Understanding Pit Size" above). Typically for grates we recommend a minimum rebate of 200mm around the clear opening of the frame to accommodate both the frame and the tags used to tie the frame into the concrete. Therefore, a 900mm x 900mm pit should have a minimum rebate of 1100mm x 1100mm.

The overall grate is always less than the overall frame size, as the frame houses the grate. Similarly, the grate size is always larger than the pit size, to ensure that the grate does not simply fall into the pit. Typically grate sizes exceed the pit size by 40mm (light duty), 80mm (medium/heavy duty) or 100mm (medium/heavy duty), however this can vary for individual products.

Understanding Australian Standard AS3996 – 2006: Access Covers & Grates

R&S Grating work to the Australian Standard for Access Covers and Grates, AS3996 – 2006. The standard sets a series of load classifications for products based on the anticipated load. These classes range from extra light duty (Class A) through to extra heavy duty – G (Class G). Below is a summary of the load classifications, including areas for their intended use.

More on AS3996 - 2006.

Class Logo Typical Use Nominal Wheel Loading (kg) Serviceability Design Load (kN) Ultimate Limit State Load (kN)
A Areas (including footways) accessible only to pedestrians and pedal cyclists and closed to other traffic (extra-light duty). 330 6.7 10
B Areas (including footways and light tractor paths) accessible to vehicles (excluding commercial vehicles) or livestock (light duty). 2, 670 53 80
C Malls and areas open to slow moving commercial vehicles (medium duty). 5, 000 100 150
D Carriageways of roads and areas open to commercial vehicles (heavy duty). 8, 000 140 210
E General docks and aircraft pavements (extra heavy duty – E). 13, 700 267 400
F Docks and aircraft pavements subject to high wheel loads (extra heavy duty – F). 20, 000 400 600
G Docks and aircraft pavements subject to very high wheel loads (extra heavy duty – G). 30, 000 600 900

What's the difference between junction and side entry?

In most cases involving residential and commercial properties, only junction pits will be installed. Side entry pits are usually only installed in roadways, allowing water that is being channeled in a gutter to enter a pit from the side. Junction pits catch water from the top (in the case of grates) or facilitate access to the pit from the top (in the case of access covers).

More on junction and side entry pits.

The picture below shows both a side entry and a junction pit.

Grate Features

Whether it's preventing children's fingers from penetrating a grate or concerns over flooding, we have a grate to suit your needs. Our grates are designed with three main concerns in mind: safety, strength and functionality. Below is a list of key features that are incorporated into our designs. Accompanying the description of the feature is a list of recommended grate ranges that address the relevant concern.

Use the jump menu below to jump to the relevant feature, or browse by scrolling down.

Maximum Water Intake
Bicycle & Wheel Chair Tyre Penetration Resistance
Heel Guard

Maximum Water Intake

Stormwater grating is designed to facilitate the intake of water into stormwater systems, while preventing danger to pedestrians and vehicles from an open pit and preventing large debris from entering the system. Some low-lying areas can be prone to flooding during heavy rain and so it is critical that any grate that is installed provides enough open area to facilitate the rapid intake of large volumes of water.

More on maximum water intake.

Several of our grate ranges have been developed with water flow capacity in mind. While allowing a significant intake area on these ranges, we have also sought to address safety and strength concerns. Below is a summary of the top performers in water intake capacity.

1. Weaved Grates

The integration of weaved bars in the weaved grate range allows for a significant increase in the open surface area of the grate, facilitating the intake of significant volumes of water. In addition to the higher intake capability, the weaved bars also strengthen the grate by distributing loads more uniformly. Finally the design also offers good bicycle and wheel chair tyre penetration resistance, improving safety.

2. EGAL Grates

The EGAL range has been largely developed with water flow capacity in mind, while maintaining strength and bicycle tyre penetration resistance. The EGAL range offers the largest water intake surface area in our grate range, while incorporating a twist bar to strengthen the grate and ensure safety for bicycles and wheel chairs. In addition to the high water intake capabilities and bike and wheel chair type resistance, the EGAL range also comes standard with an anti-slip serration, making them an ideal product for areas with frequent pedestrian traffic. The EGAL range is currently available in Class B of AS3996 – 2006, making them appropriate for residential properties and areas accessed by regular, light vehicular traffic (non commercial vehicles).

3. Straight Bar Grates

Straight bar grates represent the most traditional of grate designs. Their tried and tested design offers good water flow capacity, while utilising the strength of flat bar steel to ensure strength and longevity. The straight bar range is currently available in Class B of AS3996 – 2006, making them appropriate for residential properties and areas accessed by regular, light vehicular traffic (non commercial vehicles).

Bicycle & Wheel Chair Tyre Penetration Resistance

Whether it's children riding their bikes in the driveway or patients in wheelchairs at a hospital entrance, the bicycle tyre penetration resistance of grates has become a major concern. With this in mind, R&S Grating developed the weaved grate range of grates, however it is not the only range of grates that addresses tyre penetration concerns. The Australian Standard AS3996 – 2006 sets clear guidelines on the requirements of a product to meet bicycle tyre penetration resistance standards and R&S Grating has met these requirements with a variety of grate ranges.

More on bicycle and wheel chair tyre penetration resistance.

Below is a ranking of products from our products range for concerns about bikes and wheel chairs accessing the area of the installed grate.

1. Weaved Grates

The weaved grate range was initially developed to address concerns from local governments about bike tyres penetrating grates in public spaces. It has since become a signature product of R&S Grating due to its versatility, addressing not only issues of bike and wheel chair safety, but also providing a strong design that permits the passage of large volumes of water. As a result, weaved grates are now installed widely throughout Melbourne and rural Victoria. The strength of their design has even seen them utilised in trafficked lanes on major freeways around Melbourne.

Offering the best available bicycle tyre penetration resistance that maintains a high water flow capacity and provides unrivalled strength, the weaved grate is undoubtedly the first choice for use in areas accessible to the public and trafficked by vehicles, from light vehicular traffic through to extra heavy duty commercial traffic.

2. Small Gap (Heel Guard) Grates

Small gap (or heel guard) grates have been designed primarily to address concerns about high heel shoes penetrating or becoming lodged in the grate. Resistance against this is achieved by having a 5mm spacing between the mild steel bars. This gap resists even the narrowest of stilettos. This also results in the grate being fully bicycle and wheel chair tyre penetration resistant. In addition, the increased quantity of steel, accompanied by support bars underneath the grate results in a very strong design. Currently R&S Grating produce both Class B (light duty) and Class D (heavy duty) small gap grates. Small gap grates are ideal for areas frequented by people wearing high heel shoes, bicycles and wheel chairs. They also offer good resistance against children's fingers penetrating the grate, and the increased weight of the product (due to the increased use of steel) also reduces the likelihood of children removing the grate. Small gap grates are also appropriate for areas accessible by commercial vehicles and public spaces (for example, shopping centres).

3. EGAL Grates

The EGAL range offers twist bars spaced 95mm apart, making them compliant with AS3996 – 2006 bicycle tyre penetration resistant (BTPR) standards, which require a maximum slot width of 120mm for 5mm bars with 25mm spacing. The EGAL range is therefore ideal for residential properties and areas exposed to bikes and wheel chairs. Currently available in Class B (light duty), the EGAL range is appropriate for regular, light vehicle traffic (non commercial). In addition to their compliance with BTPR standards, the EGAL range also offers maximum water intake capability as well as a strong design. The EGAL range also comes standard with an anti-slip serration, making them ideal for areas regularly accessed by pedestrians. Their reduced weight also makes them a very economical alternative to heavier steel grates.


Strength is a primary concern for all grates, however the application and installation site significantly influences the required strength of a grate. All R&S Grating grates are manufactured in accordance with Australian Standard AS3996 – 2006, and it is recommended that you review the "Understanding AS3996" section at the top of this page if you're unsure about load classifications.

More on strength.

While strength is critical in ensuring the proper functioning of a grate, the required strength can vary significantly. For that reason, we have listed here the top performers in the heavy duty category (industrial and commercial applications). Each grate listed on our website cites its class rating of AS3996. Review "Understanding AS3996" to determine the most appropriate load rating for your application.

Below is a summary of the top grate ranges when it comes to design and application strength.

1. Weaved Grates

The use of alternating weaved and straight bars in the weaved grate design has resulted in the strongest possible design for a mild steel grate. As a result of the weld between the weaved and straight bars, the grate acts as if had a criss-cross pattern, distributing loads almost uniformly across the grate. Traditional straight bar grates carry the applied load along the length of the straight steel to the end supports, resulting in more stress in the straight steel. The distribution of the load on the weaved grate means that individual bars experience less stress and are less susceptible to non-elastic deformation. As a result, R&S Grating has never had a return of a weaved grate due to structural failure or permanent deformation. R&S Grating stock weaved grates in Class C (medium duty) and Class D (heavy duty), however we also regularly manufacture weaved grates to Class E (extra heavy duty).

2. Cast & Ductile Iron Grates

Due to nature of cast products, where the product forms as a single material, cast iron and ductile iron sump grates offer significant advantages in strength. Currently R&S Grating stock cast and ductile iron grates in Class B (light duty) through to Class G (extra heavy duty). Having been installed in wharfs, airports and other areas accessible by extra heavy duty vehicles, R&S Grating's ductile iron sump grates have stood the test of time and confirmed themselves as one of the strongest products available.

Heel Guard

Areas that are regularly accessed by pedestrians sometimes require grates that won't pose any risk to people wearing high heel shoes. High heel shoes can become lodged in grates that have spacing greater than 6mm, either damaging the shoe or possibly causing the individual to trip or twist their ankle. For this reason, R&S Grating has several ranges of grates that are heel guard, preventing high heel shoes from penetrating the grate.

More on heel guard.

Two types of grate are recommended for heel guard applications, both with their own advantages.

1. Small Gap (Heel Guard) Grates

Small gap (or heel guard) grates have been designed primarily to address concerns about high heel shoes penetrating or becoming lodged in the grate. Small gap grates are made with a maximum of 5mm spacing between parallel bars, successfully preventing the most stubborn of high heel shoes from penetrating the grate. Small gap grates are made from mild steel and are hot-dip galvanised to Australian Standards. The mild steel small grates are made to both Class B (light duty) and Class D (heavy duty) of AS3996, making them ideal for areas accessible to both pedestrians and vehicular traffic. Mild steel small gap grates are normally recommended to be installed in outdoor settings. If the grate is being installed internally or in an area accessible only by pedestrians, you may wish to consider a stainless steel heel guard grate.

2. Stainless Steel Heel Guard Grates

Stainless steel heel guard grates offer a sleek finish, while using a wedge-wire design that makes them fully heel guard. Stainless steel heel guard grates are appropriate for a variety of settings, but they are particularly beneficial for internal use, courtyards and areas around pools.  Stainless steel heel guard grates are typically used in areas accessible to pedestrians, bikes and wheel chairs, however if you would like a stainless steel heel guard grate in an area trafficked by vehicles, R&S Grating routinely manufacture stainless steel heel guard grates from stainless steel flat to Class B and Class C of AS3996.