What is GRC?

Imagination is your only limitation.

GRC Environments brings projects, art installations and dream homes to life where others can’t. We do this by specialising in the design, supply and installation of Glass Reinforced Concrete (GRC) products.

Glass Reinforced Concrete (GRC) is a stone made from multiple elements, including fibreglass. That means it’s lighter than concrete, tougher than nails and more flexible than a lubed-up contortionist.

As one of Australia’s leading suppliers and manufactures of the stuff, GRC Environments is allowed to make big claims like that. In fact creating customised GRC products is our specialty. For more information on how we can help you create innovative structures, click here for products and services

The uses of GRC

It seems clichéd to say that GRC has endless applications, but a cliché is a cliché for a reason. GRC is so versatile that its specifications, shape and structure can be adapted to suit any project. No matter how bold or ambitious the task, how cutting-edge the design or how complicated the historic reproduction, Glass Reinforced Concrete will get it done. GRC’s diversity further extends to the finish, whether your preference is Stained, coloured, left for a natural look or flawlessly smoothed over.


GRC can be moulded into thin, lightweight panels with an extensive variety of different shapes, structures and surfaces, making it the ideal alternative for prefabricated cladding. GRC is also a practical and pliable alternative to precast concrete, as it’s a lighter material that offers greater creative control over shape and finish. GRC cladding is generally manufactured by the ‘spray’ production technique.

Kitchen Bench Tops

Glass Reinforced Concrete is becoming increasingly popular for kitchen bench tops as an alternative to heavy concrete and stone. It’s rare to source stone from the natural environment more than a few meters long, which results in clumsy joins that detract from the aesthetic. GRC bench tops can be designed to any length and specifications. They can also include integrated sinks.

Features & Moulds

GRC can be used to create stunning and innovative architectural moulds. It can be easily cast into fine details and artistic features, giving designers creative flexibility unrivalled by other materials. The moulds are easy to handle and corrosion-free. GRC features and moulds are typically manufactured by the premix production technique.


GRC is a tough material that can withstand extreme weather conditions, offering the same durability and finish quality as reconstructed stone. It’s also environmentally friendly and easy to manage, which is why it’s popping up more and more in leisure facilities, urban renewals and municipal projects. From outside seating to signs and statues, GRC’s flexibility has seen it applied in many of the world’s largest theme parks and zoos.

Photo Engraving

Photo engraving is just another innovative way in which GRC can be used.

The benefits of GRC

Call us biased, but we think Glass Reinforced Concrete is a truly unique material. An environmentally friendly product, it can be shaped into just about anything, offering endless versatility for customised projects. It is strong and lightweight, making it easier and  more affordable to manage and install, while still providing the durability of other precast materials.

Environmentally Friendly

GRC is constructed from naturally-occurring raw materials. The composite is based on natural earth oxides that are generally considered safe for the environment. The wash water used during manufacturing is also alkaline, and usually stored in settlement tanks and not released through drainage. Research is on it’s side, too showing that GRC has a lower environmental impact than other building materials due to its light weight, which also means that it consumes less energy during transport, reducing costs in the process.


The weathering characteristics of GRC are as good as any precast material and better than semi-dry materials. Unlike traditional reinforced cement, GRC is not at risk of corrosion and requires minimal maintenance. Its components can be specially formulated for greater protection and durability, with a wide range of products available that offer additional resistance to impact, weather, water, chemicals and fire. The resilience of GRC has been heavily tested and its robust nature is widely accepted as a result.

Strong and Lightweight

GRC’s combination of strength and flexibility means that designers can create lighter, thinner structures that are both tough and easy to handle. It’s a high-impact material with a strength-to-weight ratio above most alternatives. The glass fibre has a tensile strength three to four times greater than the equivalent steel fibre, while GRC’S compressive strength is better than regular cement. Typically manufactured to a thickness of 10mm, GRC panels are generally 80 per cent lighter than precast concrete, making them easier and cheaper to handle with reduced transport costs due to less reliance on scaffolding or heavy cranes.


Glass Reinforced Concrete offers unrivalled creative possibilities with the ability to accurately reproduce designs of any size, including intricate patterns, complex shapes and sweeping curves. The material can also be finished in a wide variety of textures and colours, giving designers greater control over the surface detail and quality of finish.

How is GRC made?

GRC is manufactured by spray or premix production techniques. The choice of technique is determined by the project requirements and depends on factors such as strength, size and specifications. Sprayed panels can be constructed with a larger glass fibre content (five to six per cent) than premixed structures (two to three per cent), creating a stronger material. Although premixed GRC is not as strong as sprayed GRC, the production technique of the former is a speedier way to create smaller structures.


The spray production technique involves spraying layers of mix into fibreglass or rubber moulds. The first layer is a cement aggregate mix that forms the surface, while subsequent layers contain chopped glass fibres. The spray gun contains both the grout nozzle and glass-chopping gun, which means grout and glass fibres are sprayed simultaneously. Each layer is compacted with rollers to create the required thickness, typically 10 to 15mm.

It takes two to four hours to produce the GRC unit, which is then left in the mould for an additional 18 hours. Polythene and a polymer-curing compound are used to prevent moisture loss before the unit is exposed to the elements. The unit can be fixed with stiffening ribs or support restraints.


The premix production technique involves pouring or pumping a cement fibre mix into a mould, similar to other precast production processes. The mix is compacted using vibration or by adding other components. The unit is then left in the mould to set and is de-moulded the following day. As with the spray method, polythene and a polymer-curing compound are used to maintain moisture before the unit is exposed to the elements.

Technical Information

GRC Specifications

Unlike traditional concrete, which is classified by its compressive strength, GRC is classified by flexural strength or Modulus of Rupture (MOR). GRC can be categorised into three grades: Grade 8, Grade 10 and Grade 18. Each is identified by its corresponding MOR value.

Over the last 50 years, GRC best practice standards have been developed and applied across Europe, America and Australasia. These standards set the benchmark for producing high quality Glass Reinforced Concrete. For more detailed information about the production standards for GRC products, refer to the GRC/GRFC Technical Information Document.