Polycarbonate panel thickness for secure windows? Answered
I need to glaze 16 small panes (430 x 275 mm) in very strong, cast aluminium window frames (8 per frame, either side of the door). Is 3 mm frosted polycarbonate going to be impact resistant enough to keep people out? The building these windows are part of is in a fairly remote place, so security is a concern but for cost and aesthetic reasons we don't want to glaze with glass and install a metal security screen. The current ugly solution is boarding them up and securing with screws but this doesn't allow us light inside.
Cost is a consideration since I've been given permission by the company that owns the land to reglaze them and if I provide the labour they will supply the materials.
16 off 3 mm sheets, £3.85 each = £61.60
16 off 4 mm sheets, £5.14 each = £82.24
16 off 6 mm sheets, £7.70 each = £123.20
I've found lots of sites shouting "yeah polycarb is badass! It's unbreakable!" but not one that gives an idea for thinner sheets. Am I wasting money by going for thicker sheets? Or if someone's trying to get in might a 3 mm sheet be breakable?