Haven't seen the program on BBC so don't know what type of glass it was they were smashing, could it be that it was toughened already and not float glass as assumed by God.....i don't know and im just asking?
I did 12 years working for the 2 biggest emergency glaziers in the UK, it was all insurance work and 90% of it was burglaries so i saw my fair share of broken glass (and have the scars to prove
), eventually the 24hr callout did me in and i had to get out of it.
Generally float glass is used in windows as its the cheapest form of glass available, this glass makes the horrible well glass breaking sound that we all cringe at when we hear it.
Toughened or safety glass which includes laminated has to be used in any frame that has glass lower than 800mm from the floor or any frame that is within 300mm of a door i.e. a door/flag combi or door/side panel, doors regardless have to have safety glass in them
UNLESS the area of the glass is below 0.4m2 of the door itself in which case you can use float glass but it needs to be 6mm and not 4mm
Toughened glass when it breaks just pops and is virtually silent, this glass although very strong if hit in the middle of the pane is very weak around the edge bordering on unstable due to the stress put in it due to the toughening process, i saw plenty of instances where the burglars didn't even bother jemmying a frame open - they just picked a planter up or a slab and threw it though a patio door or back door, the glass shatters and falls to the floor and you walk in.
I also saw instances where by they used screwdrivers forced down the edge of the rubber gaskets and wiggled so as to spelch the edge of the glass, toughened does not like this as its its weak point - again it just pops, do that for the inner pane and their in. You won't see them do this on float glass as it mainly stays together, ok some falls out but is makes a hell of a noise, they also don't like climbing through it or even putting an arm through, any cuts mean blood and blood means DNA, if ever i'd cut myself sweeping glass up at 2am i would get it up by any means possible, SOCO are usually 48hrs behind me and no way was i letting them find my blood and implicate me in any burglaries.
Laminated glass is ideal as it has a PVB layer sandwiched between 2 sheets of glass, usually 3mm with a 0.4mm pvb giving a total of 6.4mm - about the same as a windscreen, this just cracks and stays in one piece, burglars hate this glass with a passion, i saw times where they'd used the screwdriver trick only to see the glass just crack and not fall away, in an ideal world we would fit this everywhere but the downside is it is heavy due to its thickness hence doors generally have toughened glass which can start at 4mm.
What a lot of people do now though is to specify laminated for the outer pane of a DGU for security, even windows that are ok with float glass get a laminated outer pane especially the downstairs windows, upstairs are unlikely to smashed and gotten through. You could do the same with doors and patios too, to save weight just specify the outer as laminated and 4mm toughened inside
Hope this all made sense?