GRP vs. Polycarbonate: Selecting the Best Material for Telecom Shrouds 

When it comes to protecting telecom equipment outdoors, the material you choose matters more than most people realise. Telecom shrouds and radomes sit exposed to sun, wind, rain, and temperature swings — sometimes for decades — while housing antennas and network equipment that cannot afford to fail. 

Two materials come up most often in these applications: GRP (glass reinforced plastic, also called fibreglass) and polycarbonate. Both have their strengths, but they perform very differently in real-world conditions. Choosing the wrong one can mean degraded signal performance, expensive repairs, or premature replacement. 

This article breaks down the differences between GRP and polycarbonate for telecom shrouds and radomes, so you can make an informed decision for your next project. 

What Are Telecom Shrouds and Radomes? 

Telecom shrouds are protective enclosures fitted around antennas, base station equipment, and other network infrastructure. They shield equipment from the elements while maintaining signal performance. In some cases, they also serve an aesthetic purpose — concealing equipment in urban or heritage-sensitive environments. 

Radomes are a specific type of shroud designed to be radio-transparent, meaning they allow signal to pass through without interference. These are used where the shroud itself sits directly over the antenna and any signal loss through the material would affect network performance. 

Both shrouds and radomes need to be: 

• Weatherproof and UV-stable 
• Structurally rigid enough to handle wind loading and vibration 
• Compatible with the RF performance requirements of the antenna 
• Low maintenance over a long service life 
• Able to be manufactured in custom sizes and shapes 

The question is which material — GRP or polycarbonate — does a better job of meeting all these requirements. 

Understanding the Two Materials 

GRP (Glass Reinforced Plastic) 

GRP is a composite material made from glass fibres embedded in a resin matrix. It has been used in demanding industrial and infrastructure applications for more than 50 years. In telecom applications, GRP is valued for its combination of strength, weather resistance, and RF transparency when correctly specified. 

GRP can be moulded into virtually any shape, making it well-suited for large, complex shroud designs. It can also be manufactured with fire-retardant resins and UV-stable pigments, which are important for outdoor installations that need to look good and perform well for 20 or more years. 

Polycarbonate 

Polycarbonate is a tough thermoplastic that is widely used in applications requiring optical clarity or impact resistance — think safety glasses, skylights, and riot shields. It is lighter than GRP and can be formed into sheets or moulded components relatively quickly. 

In telecom applications, polycarbonate has traditionally been used for smaller enclosures and components where its clarity or impact strength is a key requirement. However, its long-term outdoor performance is a known limitation. 

GRP vs. Polycarbonate: Head-to-Head Comparison 

Here is how the two materials compare across the factors that matter most for telecom shroud applications. 

The comparison makes clear that GRP holds the advantage across most of the factors that matter most for long-term outdoor telecom installations. Let us look at the most important areas in more detail. 

Key Differences That Matter for Telecom Applications 

1. Long-Term UV and Weather Resistance

Australia’s climate is harsh. High UV intensity, coastal salt air, humidity in tropical regions, and extreme temperature swings all take a toll on materials used outdoors. 

GRP manufactured with UV-stable resins and gel coats holds its colour, structure, and performance for decades in these conditions. Polycarbonate, on the other hand, is well known for yellowing and hazing when exposed to prolonged UV — even when UV-coated. Over time, this yellowing can affect the cosmetic appearance of the shroud and may also impact signal performance in radome applications if the material’s optical and RF properties change. 

For telecom infrastructure that is expected to remain in service for 15 to 25 years, GRP’s UV stability is a significant practical advantage. 

2. Structural Rigidity and Wind Loading

Telecom shrouds — particularly those on rooftops, towers, and masts — are exposed to significant wind loading. A shroud that flexes, warps, or deforms under load can move antennas out of alignment, which directly affects network performance. 

GRP is a stiffer material than polycarbonate and can be engineered to meet specific structural requirements, including the wind load standards applicable in Australian conditions. Polycarbonate, particularly in sheet form, is more prone to flexing under load and can permanently deform over time, especially in warmer climates where it softens slightly. 

3. RF Signal Performance

For radome applications — where the shroud sits directly over the antenna — the material’s RF transparency is critical. A material that absorbs or reflects RF energy will reduce signal strength and degrade network performance. 

GRP, when correctly specified for radome use, offers excellent RF transparency across a wide range of frequencies. Polycarbonate also has reasonable RF performance, but the consistency of that performance can vary depending on the specific grade of material, additives, and whether the surface has been treated or coated. Yellowing over time may also affect RF consistency. 

4. Fire Performance

Telecom equipment is often housed in or near buildings where fire performance requirements apply. GRP manufactured with fire-retardant resins can meet stringent fire, smoke, and toxicity standards. Standard polycarbonate, while offering some fire resistance, can melt and drip when exposed to flame, which is a risk in enclosed or built-up environments. 

For installations on buildings or in areas where fire compliance is required, GRP with fire-retardant properties is the safer and more certifiable choice. 

5. Custom Design and Manufacturing

Telecom shrouds are rarely standard off-the-shelf items. Network equipment comes in a wide variety of sizes and configurations, and shrouds often need to be tailored to fit specific antenna models, mounting arrangements, or site aesthetics — particularly in urban environments where councils and building owners may impose appearance requirements. 

GRP excels in custom manufacturing. A mould can be produced from a 3D CAD file, technical drawing, or physical sample, and from that mould, components can be reproduced consistently at whatever volume is required. The surface finish, colour, and texture can all be controlled during manufacture, reducing the need for post-production painting or treatment. 

Polycarbonate is easier to work with for simple flat or curved sheet forms but becomes less practical when complex three-dimensional shapes are required. 

When Does Polycarbonate Make Sense? 

It is worth being clear: polycarbonate is not a bad material. It has genuine advantages in the right context. For telecom applications, polycarbonate may be a reasonable choice when: 

• The installation is in a sheltered location with limited UV exposure 
• The component is small and simple in shape 
• The expected service life is short — less than five to ten years 
• Optical clarity is a specific requirement of the application 
• Budget constraints make a lower upfront cost a priority 

However, for outdoor telecom shrouds and radomes that need to perform reliably for 15 or more years in Australian conditions, polycarbonate’s degradation characteristics make it a higher-risk choice in the long run. 

Why Australian Telecom Projects Choose GRP 

Craft Fibreglass Composites has been designing and manufacturing GRP telecom shrouds, radomes, and FRP structures for Australian telecom providers for many years. Their work covers a wide range of applications, from antenna shrouds on urban rooftops to radomes on communication towers in regional and remote areas. 

Working from customer specifications — whether that is a 3D CAD model, a technical drawing, or a sample part — Craft Fibreglass produces custom GRP shrouds that meet the structural, RF, fire, and aesthetic requirements of each specific project. Their manufacturing processes, including pattern and mould making through to finished component supply, are covered by ISO 9001 certification, which provides assurance of consistent quality across every production run. 

For telecom operators and contractors who need a reliable supply of custom GRP shrouds with short lead times and local technical support, this kind of specialist capability makes a practical difference. 

The Verdict: GRP Wins for Outdoor Telecom Shrouds 

When you stack up the performance of GRP and polycarbonate across the factors that matter most for outdoor telecom shrouds and radomes — UV resistance, structural rigidity, RF transparency, fire performance, and long-term durability — GRP is the stronger choice for most applications. 

Polycarbonate has its place, particularly for short-term or indoor applications. But for infrastructure that needs to perform reliably in Australia’s tough outdoor conditions for 15 to 25 years, GRP delivers better value and lower risk over the life of the asset. 

If you are planning a telecom shroud or radome project and want to discuss the right material specification for your application, the team at Craft Fibreglass Composites is happy to help. With over 40 years of experience in custom composite manufacturing, we can guide you from initial design through to finished product supply.