The different types of Polycarbonate Sheet
Where polycarbonate is used as a roof sheet it is nearly always “multiwall” (the only major exception to this is where solid polycarbonate sheets are used for Overdoor canopies). Multiwall sheets are extruded to produce a number of internal walls which create chambers within the sheet. The number of chambers differs depending upon which sheet thickness you are using.
4mm, 6mm and 10mm thick polycarbonate sheets normally have just two walls and are refered to as twinwall
16mm polycarbonate sheets have three walls, creating two chambers and are known as triple wall
25mm Polycarbonate comes in a variety of designs but the most popular has an “X” type structure with 7 internal walls