🛡️ Thicker Sandwich
In dedicated Anti-Burglary Glass, the "sandwich" gets thicker. Thicker panes are used and, crucially, multiple layers of extremely tough PVB membrane (e.g. 1.52mm or more).
Anti-Burglary Glass (P4A, P5A etc.): How Easy Is It to Break Your Window?
You've invested in an expensive armoured front door. You've installed an alarm and cameras. You upgraded your windows and ordered multi-point locking mechanisms. You feel safe. But let's be honest and look at the "elephant in the room": 80% of your window's surface area is glass.
How easy is it, really, for a determined burglar to ignore the lock and simply smash the balcony door glass to get inside?
The harsh reality is that, if you have conventional double glazing (e.g. 4mm – gap – 4mm), the answer is: Frighteningly easy. With a simple car spark plug or a small hammer, plain glass shatters instantly, often making very little noise. If, however, you have chosen Anti-Burglary Glass, the scenario changes dramatically. Let's see how glass resistance is categorised and what the cryptic "P4A" and "P5A" actually mean.
1. The PVB "Shield": How Does Anti-Burglary Glass Work?
As we saw in the previous article, Triplex (Laminated) glass consists of glass sheets bonded with elastic membranes. In basic Triplex, this membrane is thin (e.g. 0.38mm) - just enough to hold the fragments together if someone stumbles into the pane.
🔨 Energy Trampoline
When the burglar strikes the glass with a sledgehammer, the glass will crack, but the membrane behaves like an elastic trampoline. It absorbs the impact energy and refuses to tear.
2. The EN 356 Standard: A Survival Guide
To know what you're buying, the European Union has established the strict EN 356 standard, which classifies glass panes by their resistance to violent attacks.
🏀 P1A – P5A: Drop-Weight Resistance
In the laboratory, a steel ball weighing 4.11 kg is dropped freely onto the glass from various heights (up to 9 metres), again and again. P1A – P3A: Basic protection against stones and vandalism. P4A: The gold standard for residences. Withstands multiple drops. The burglar must strike with immense fury for several minutes, creating deafening noise. P5A: Even higher protection, ideal for isolated houses or holiday homes.
🪓 P6B – P8B: Axe Resistance
Here things get serious. The test uses not a ball but a mechanical axe that strikes the glass with absolute violence. To pass, the glass must withstand 30 to over 70 axe blows before an opening large enough for a person is created! P6B – P8B: Intended for jewellery shops, banks, museums and panic rooms.
3. The Golden Rule: The Weakest Link
Don't make the mistake of ordering an impenetrable P5A pane and fitting it into a cheap frame with a simple lock.
🔗 The Chain
Security is a chain. If the glass won't break, the burglar will lever the aluminium frame and "pop" the door open.
✅ The Right Combination
An anti-burglary pane (at least P4A) only makes sense when combined with a certified anti-burglary frame (category RC2 or RC3), which features security mushroom pins, steel strike plates and a lockable handle.
4. Summary
No glass (except ballistic) is completely unbreakable. The purpose of anti-burglary glass is not to remain intact, but to buy time.
⏱️ Time Is the Enemy
To make the break-in so time-consuming, exhausting and noisy that the intruder gives up and looks for an easier target.
Related Articles
Triplex (Laminated) vs Securit (Tempered) Glass: What Are the Differences Safety Regulations: Where Is Safety Glass Mandatory? Ballistic & Blast-Resistant Glass: Categories, Weight and Applications Fire-Rated Glass (E, EW, EI): How It Withstands Fire
Glass Panes & Glazing Units: 80% of the Window
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