Frequently Asked Question
Got any question?
Welcome to our GFRC FAQ page – your go‐to resource for everything you need to know about Glass Fibre Reinforced Concrete. Whether you’re planning a sophisticated commercial installation or designing unique architectural features, our team of industry experts is here to help you navigate the world of GFRC with confidence.
Drawing on years of experience and a passion for quality, we’ve seen it all – from complex installations to those unexpected challenges that arise on the job. Our commitment is to provide you with trusted advice, top-notch products, and the insights you need to make your project a success.
Browse through our frequently asked questions to find answers on everything from mould preparation and casting techniques to finishing and long-term maintenance. And if you don’t find exactly what you’re looking for, please feel free to get in touch. We’re always happy to help and love talking about all things GFRC.
Thank you for considering our GFRC products – we look forward to supporting your next project and ensuring a smooth, successful experience.
Climatic and environmental conditions influence GFRC manufacturing processes and curing times?
Australia’s warm and, in many regions, coastal climate necessitates adjustments during manufacturing. High temperatures can accelerate hydration, so controlled curing environments—such as covering pieces with plastic to retain moisture—are essential. Additionally, lower water-to-cement ratios and carefully selected admixtures help mitigate rapid evaporation and ensure that GFRC develops its designed strength and durability.
How do manufacturers address the challenges of mixing and spraying GFRC to minimise defects?
Manufacturers address these challenges by:
- Using precision mixing equipment to achieve a uniform blend and ensure proper fibre distribution.
- Fine-tuning spray parameters (such as pressure, nozzle design and technique) to avoid voids, pinholes and surface defects.
- Regular maintenance of equipment and continuous operator training.
- Adjusting admixture dosages as required to optimise workability and adhesion.
What future trends or technological advancements are shaping the evolution of GFRC?
Future trends include increased automation—such as robotic spraying and digital mould design—as well as a greater focus on sustainable practices (e.g. incorporating recycled materials and eco-friendly admixtures). Advances in fibre treatment technology and computer-aided manufacturing are enabling more complex, custom-designed panels. Ongoing research is continually refining mix designs and curing methods to better suit Australia’s diverse environmental conditions.
What exactly is GFRC and why is it a good choice for fabricating benches and tables?
GFRC is a composite product that combines high‐quality cement, fine aggregates, polymers and alkali‐resistant glass fibres – all premixed to the correct proportions. Its high strength‐to‐weight ratio, durability and capacity for being cast in thin, custom shapes make it ideal for creating stylish and long-lasting benches and tables for both indoor and outdoor use.
How do local building codes and regulatory requirements affect GFRC production?
GFRC manufacturers must comply with Australian building codes and standards relating to precast concrete, structural performance and safety. This means that production processes, material testing and installation methods are stringently monitored and documented. Close collaboration with local certifying bodies ensures that GFRC products meet all necessary performance and regulatory requirements.
What do I need to know about the premix product before starting my project?
With our premix product, all the ingredients are already proportioned for optimal strength and workability. This means you can focus on preparing your moulds and executing a neat cast rather than measuring raw materials.
How do I prepare and build moulds for casting GFRC furniture?
Moulds for benches and tables can be constructed from high-density foam, melamine, or even silicone for more intricate designs. It is essential that the mould is smooth, watertight and well supported. Pre-treat the interior with a quality release agent to ensure that the cured GFRC can be removed cleanly.
What Are The Typical Levels To Add The Different Admixtures Into MACt Mixes?
Typical additional admixtures levels for a 20kg:
- Water: 2.78L–3.0L
- Plasticiser: 10g – 50g
- Fibres HD: 50g-300g
- Fibres Bundled: 400g-700g
- Retarder: 5g-20g
- Accelerator: 5g–20g
- Defoamer: 1g-3g
- Colour: up to 800g
*NOTE: All admixes will alter the way the mix behaves.
Can We Use An Additive To Make The Gfrc Even Lighter?
What essential tools and equipment should I have before starting a GFRC project?
You will need:
- The GFRC premix (ready-made)
- A mixing container or bucket (if any additional water is required as per instructions)
- Trowels, brushes and rollers for spreading and finishing
- The moulds and supports
- Personal protective equipment (gloves, goggles, and a dust mask)
This list ensures you are well-equipped for a smooth fabrication proces
What is GFRC and why is it increasingly used in Australian construction?
GFRC (Glass Fibre Reinforced Concrete) is a composite material made by blending high‐quality cement, fine aggregates, polymers, water and alkali‐resistant glass fibres. Its high strength‐to‐weight ratio, versatility in form and capacity for intricate detailing make it popular in a range of Australian projects—from decorative facades and cladding to complex architectural elements. Its lightweight nature also reduces structural loads and foundation costs, a key advantage in coastal and high‐performance environments.
What are the primary methods (spray‐up, premix, hybrid) for manufacturing GFRC?
GFRC is typically produced using one of three methods:
- Spray‐up: A specialised spray gun (often with an integrated fibre chopper) sprays the fluid mix directly into a mould.
- Premix (Direct Cast): Fibres are thoroughly mixed into the concrete before it is poured or sprayed into moulds.
- Hybrid: A thin sprayed face coat is applied first, followed by a hand‐placed, fibrous backer layer.
In Australia, many manufacturers favour the spray‐up or hybrid methods as these yield a higher fibre content and a superior surface finish for both decorative and structural panels.
What safety protocols and workplace practices are critical in an Australian GFRC manufacturing facility?
Safety is paramount; protocols include:
- Ensuring all staff wear appropriate personal protective equipment (PPE) when handling cement, fibres and chemicals.
- Adhering strictly to Safe Work Australia guidelines on machinery operation and dust control.
- Conducting regular safety training, equipment maintenance and air quality monitoring in mixing and spraying areas to prevent accidents.
What are the environmental benefits and potential impacts of GFRC manufacturing?
GFRC panels are thinner and lighter than traditional concrete panels, which reduces overall material use and transport emissions. Their durability and low maintenance requirements further contribute to sustainability. However, as cement manufacturing is energy-intensive, many facilities adopt practices such as using recycled materials and optimising water use to minimise their carbon footprint.
How do I prepare the mould surface before pouring the GFRC premix?
Ensure that the mould is clean, free of debris and properly sealed. Then, apply a uniform coat of your chosen release agent. This preparation helps to achieve a smooth surface finish on your bench or table and makes demoulding easier.
What safety precautions should I take when handling the GFRC premix?
Always wear personal protective equipment such as gloves, eye protection and a dust mask when handling cement-based products. Work in a well-ventilated area and follow all safety instructions provided on the product packaging. Familiarise yourself with local safe work practices for handling cement and polymers.
How long should I allow my GFRC bench or table to cure before demoulding it?
Generally, allow the cast piece to cure for approximately 16 to 24 hours before carefully removing the mould. Although initial strength is achieved in this time frame, full strength may take several days, so handle the item gently during early curing.
Are there any common mistakes or pitfalls I should avoid when fabricating GFRC?
Common pitfalls include:
- Demoulding too early before the piece has adequately cured
- Inadequate mould preparation, which can lead to surface imperfections
- Neglecting safety protocols
Taking your time with mould setup and following product guidelines closely can help avoid these errors.
How do I ensure that my GFRC piece is strong enough for everyday use?
The premix is formulated to deliver excellent strength without the need for additional raw material adjustments. For larger or load-bearing pieces, you might consider incorporating embedded supports (such as AR Glass Scrim) into your mould to further enhance structural integrity.
What if I notice minor defects such as pinholes or surface blemishes in my GFRC piece?
Small imperfections can typically be repaired by applying a thin layer of fresh GFRC Grout Premix over the affected area. Once cured, sand lightly to blend the repair with the surrounding surface, and reseal as needed.
What are the main differences between GFRC and traditional precast concrete panels ?
Traditional precast panels are generally thicker and heavier, requiring more robust structural support. By contrast, GFRC panels are lighter, can be cast in thinner sections (often 20mm to 40mm) and offer greater design customisation. This means reduced transport and installation costs, along with more creative freedom—qualities that are highly valued in the Australian construction market.
What essential raw materials are required for a quality GFRC mix in Australia?
A quality GFRC mix requires:
- Portland Cement: A high‐grade cement that meets local specifications.
- Fine Aggregates: Typically, well-graded sand that ensures a smooth finish.
- Polymers: Often acrylic-based, to enhance bonding and durability.
- Water and Superplasticisers: To maintain a low water-to-cement ratio while ensuring proper flow.
- Alkali‐Resistant Glass Fibres: The key reinforcing element, which must comply with Australian standards for durability under local environmental conditions.
What specialised equipment and machinery are needed for GFRC production?
The production process typically requires:
- High‐Pressure Spray Guns: Equipped with integrated fibre choppers for the spray‐up method.
- Mixing Equipment: Either continuous or batch mixers to achieve a homogenous blend of all ingredients.
- Vibration Tables or Mould Vibrators: Used to consolidate the mix in the mould for premix or hybrid processes.
- Quality Control Devices: To monitor mix consistency, fibre dispersion and mechanical properties.
Many Australian facilities also employ CAD/CAM systems to design custom moulds for intricate panel details.
What quality control measures are recommended for ensuring the consistency and durability of GFRC produced in Australia?
Recommended measures include:
- Rigorous testing of mix proportions (such as slump tests and checks for even fibre dispersion).
- Mechanical testing including compressive, flexural and tensile strength assessments.
- In-process inspections to monitor mould filling and curing conditions.
- Strict adherence to both Australian and international standards to ensure every batch meets design specifications.
How is colour and texture integrated into GFRC panels during production?
Colour can be added directly into the face coat via integral pigments or applied post-production through painting. Texture is achieved using specialised moulds, surface treatments (such as sandblasting or acid etching) and controlled finishing techniques. Australian manufacturers offer extensive customisation options—from natural stone finishes to bold, engineered textures—to meet both aesthetic and functional requirements.
What are common troubleshooting tips for issues such as poor adhesion, pinholes or voids in GFRC?
Troubleshooting steps include:
- Reviewing and adjusting the mix proportions and water content.
- Ensuring proper compaction and consolidation during casting, using tools such as rollers or brushes.
- Verifying that moulds are thoroughly cleaned, correctly sealed and pre-treated with suitable release agents.
- Fine-tuning spray equipment settings and maintaining a consistent spraying technique to reduce surface imperfections.
How do Australian manufacturers test the mechanical properties of GFRC?
Testing is carried out using standard laboratory procedures such as:
- Compressive strength tests with hydraulic presses.
- Flexural (bending) tests using three- or four-point loading setups.
- Direct tensile tests and impact resistance evaluations.
These tests typically adhere to international methods (ASTM, EN) that are adapted for local Australian conditions.
How do GFRC manufacturers in Australia innovate to reduce production costs while maintaining high quality?
Innovations include:
- Optimising mix designs to use locally sourced, cost-effective materials.
- Automating mixing and spraying processes to improve consistency and reduce labour costs.
- Researching and incorporating new admixtures that enhance performance while reducing energy consumption.
- Collaborating with research institutions and industry bodies to refine production techniques and ensure compliance with stringent quality standards.
