Permaglas Industrial Fibreglass Sheeting has set the standard for Industrial skylights in Australia for many years. It provides cost effective high levels of light transmission, excellent spanning, and low thermal expansion. The highest quality materials available and the very latest resin technology are used in the manufacturing process making it a durable, cost effective alternative which filters out 99% of harmful UV rays, giving excellent protection from the elements while still letting the sunlight trough. More recently, Ampelite have developed Wonderglas GC, which provides all of the physical properties of standard Industrial Fibreglass, with ultimate durability through Ampelite’s unique Gel Coat Technology.
Profiles available in Polycarbonate sheeting are limited to Corrugated and Trapezoidal pan (5-Rib). There are no decking profiles.
| Profile | Available length |
|---|---|
| Corrugated | up to 8.1 meters |
| Trimdek (5-Rib) | 6 meters |
The 6 meter maximum length is well justified. Polycarbonate has a thermal co-efficient of 6.75 x 10-5 cm/cm °C, which equates to a linear expansion of up to 16.2mm over a 6 metre run
Maximum allowable spans, wind pressure up to 1kPa are as follows:
| Profile | Nominal thickness | Maximum Span |
|---|---|---|
| Corrugated | 0.8mm | 0.9 meter |
| Trimdek (5-Rib) | 0.8mm | 1.0 meter |
Polycarbonate is essentially a by-product of the petro-chemical industry. In turn, Polycarbonate is therefore susceptible to chemical reaction, especially to petro-chemical based products.
It is important to note, that even neutral cure silicone should not be applied to Polycarbonate, as it weakens the sheet causing it to rip or fracture, sometimes within weeks of application. If sealant is necessary, use only Seal-Once a special silicone containing polycarbonate. Using incorrect sealant voids the warranty.
While Polycarbonate has a very high impact strength when new, UV degradation substantially lowers this strength. Caution is always required to ensure that the UV protective coating is facing the sun in accordance with the product label or marking.
Safety mesh is always required with Polycarbonate roofing. Polycarbonate is non-trafficable and does not meet the requirements of AS/NZS 1562-3 1996: Resistance to impact (sandbag) for roofing sheet materials.
Alternative Ampelite Industrial sheeting
It is Ampelite’s experience that Polycarbonate has a number of limitations when used in Industrial/Commercial installations. The thermal co-efficient being a significant factor, also the relatively small spanning capacity, limited choice of profiles and general UV degradation. Clear Polycarbonate has unmatched light transmission properties, but this also means very high heat transmission which in many applications is unacceptable.
We have found that when Polycarbonate sheeting is specified, it is usually because the specifier is seeking to select a product, which hopefully, will outperform the industrial grades of fibreglass roofing generally available.
However, Ampelite have made a significant advance with the introduction of ‘Wonderglas GC’ gel coated premium grade industrial sheeting that has a 25 year warranty. The gel coating and base sheet are at the cutting edge of resin technology. UV resistance is so high, that loss of light transmission after 10 years is just 10%, with only minimal change in later years.
‘Wonderglas GC’ outperforms and outlasts other plastic roofing materials and is compatible in all respects to metal roofing.
Another option if you did require Polycarbonate would be to use Twinwall, which has many advantages over standard Polycarbonate.
It is important to note, that even neutral cure silicone should not be applied to Polycarbonate, as it weakens the sheet causing it to rip or fracture, sometimes within weeks of application. If sealant is necessary, use only Seal-Once a special silicone containing polycarbonate. Using incorrect sealant voids the warranty.
