Hi All,
For Sky Light or Awning, use Lexan* Twin Wall, Grade Recommended is Lexan* 10mm Thickness Solar Control IR, Light Green in Color
In the 1960s, NASA used Lexan* Brand Polycarbonate for Astronaut helmet assemblies and visors which became known as "bubble helmets", including those used by the Apollo moon astronauts.

Advantages
1) 2 Wall , Better Heat Insulattion
2) Lower Cost
3) Reduce 30% Heat
4) 2 Side UV Resistant Coating ( Generally, Polycarbonate is NOT Chemical Resistant. Can be printed as label, example laptop Battery uses Polycarbonate FR Film as Label)
5) Impact Resistance. Virtually Un-Breakble Youtube has many Video on the Impact Test
6) 10 year Warranty - Against Yellowing ( yellow Index Not more than 2, which naked Eyes can see)
- Against Impact ( Drilled Holes Failure not Warrant)
- Against Lost of Light Transmission
7) Light Transmission - More than 65%,
More Details
http://en.wikipedia.org/wiki/Lexanhttp://www.sabic-ip.com/sfs/SFS/en/Product...ntrolsheet.htmlDust or Fungus will grow in the Slot but that can be eliminate if you get a Good Contractor.
Use Anti - Dust tape, which will allow the Water to Vaporize and 'Flow' out through the Special Membrane in the Anti-Dust Tape
It will prevent Water from Sipping in and Grow Fungus
Many Stadium are Built from Multi-Wall Sheet , which also uses the Anti-Dust Tape
Examples :


Material Cost for Lexan* 10mm Thickness Solar Control IR, Light Green in Color is approximately RM 6.80/square feet.
Note That The Structure is more Costlier that the Roofing Material
This post has been edited by jerryng75: Jan 15 2014, 04:38 PM