- Fast Turnaround
- Strong and durable
- Custom cut up to 6.1m lengths
Place Your Order
GRP Rooflight Panels| Daylight Solutions
Cardinal Steels helps bring natural light into your building with our high-quality glass reinforced rooflight panels (GRP). Manufactured from glass reinforced polyester, these durable rooflight panels integrate seamlessly into a wide range of roofing systems, helping to reduce reliance on artificial lighting and improve internal working environments.
GRP can be moulded into a variety of profiles and is available to match both box profile roofing sheets and corrugated roofing sheets, ensuring a consistent and weather-tight finish across your roof system. We also have roof lights in other shapes, such as Big 6 (Big Six), which was generally the profile used for roofing made from asbestos.
GRP Roofing That Allows The Natural Light In
GRP rooflight panels provide a practical way to introduce natural daylight into industrial, commercial and agricultural buildings while maintaing a durable roofing system. By increasing natural light, GRP roofing lights help reduce reliance on artifical lighting, lowering energy use and running costs.
- Improved Working Environments – Natural daylight improves visibility and working conditions in warehouses, factories and agricultural buildings.
- Energy Efficiency – Reduced reliance on artifical lighting helps lower energy consumption and operating costs.
- System Compatibility – GRP roof lights are designed to integrate with a range of box profile and corrugated roofing sheets for both new and refurbishment projects.
Stock lengths are available up to 6.1m. Please contact us with your requirements.
Custom Made GRP Roof Lights
Our custom-made glass-reinforced plastic roof lights are made to the highest standards and are available in lengths up to 6.1m long. They can be produced to precisely match the size of our insulated and steel roofing sheets.
Cardinal’s roof lights are weatherproof, have high impact resistance, and have a film layer applied to them to enhance UV protection. The protective film helps stop UV damage such as discolouring or yellowing and helps extend the product’s life expectancy to its max.
Roof Light Specifications
CS32/1000 Box Profile Roof Light – Specs
CS34/1000 Box Profile Roof Light – Specs
13.5 / 3 Corrugated Roof Light – Specs
Big 6 Corrugated Roof Light – Specs
Double 6M Corrugated Roof Light – Specs
-
What are GRP roof sheets?
GRP roof sheets (Glass Reinforced Plastic) are lightweight, translucent roofing panels made from plastic reinforced with fine glass fibres. They’re strong, durable, and ideal for letting natural light into industrial, agricultural, or domestic buildings.
-
What are the benefits of GRP roof sheets?
GRP sheets combine strength, weather resistance, and light transmission. They don’t corrode, are easy to handle and install, and are suitable for both new builds and refurbishment projects. They’re especially popular for agricultural buildings and factory skylights.
-
Are GRP roof sheets the same as fibreglass roofing?
Yes – GRP and fibreglass refer to the same material. Both terms describe a composite of plastic and glass fibres, known for being strong, lightweight, and translucent.
-
Can GRP roof sheets be used with steel roof sheets?
Absolutely. GRP roof sheets are often used alongside steel box profile or corrugated sheets to provide natural daylighting within a roof system. They’re typically manufactured to match the same profile and pitch for seamless integration.
-
How long do GRP roof sheets last?
With correct installation and maintenance, GRP roof sheets typically last 20 to 25 years. They are UV-resistant and maintain their strength and light transmission over time, even in harsh weather conditions.
-
Do GRP roof sheets yellow or discolour over time?
High-quality GRP sheets are manufactured with UV-stabilised resin to prevent yellowing or loss of clarity. Cheaper, lower-grade sheets may discolour faster, so choosing a quality product is important for long-term performance.
-
Can GRP roof sheets be cut to size?
Yes. GRP sheets can be supplied in custom lengths and easily trimmed on site with a fine-toothed saw or cutting disc. Always wear protective gear when cutting, as fibreglass dust can irritate the skin and eyes.
-
Are GRP roof sheets suitable for residential use?
Yes – while GRP sheets are common in industrial and agricultural settings, they’re also ideal for carports, sheds, lean-tos, greenhouses, and patios where natural light is beneficial.
-
How are GRP roof sheets fixed to the roof?
They’re typically fixed using roofing screws with sealing washers through the crown of the sheet. It’s important to allow for thermal expansion by not overtightening fixings and using the correct pre-drilled holes.
-
Do GRP sheets provide insulation?
Standard GRP sheets are not insulated, but they help regulate indoor temperatures by allowing natural light in. For thermal performance, GRP can be combined with insulated systems such as twin skin roofing
or over-cladding.











