BS EN 14449BS EN 12600 (Class 1B1 / 2B2)BS EN 356 (P1A to P5A security)Reviewed Technical Specification
Laminated Safety & Security Glass
High-integrity polymer interlayers providing mandatory post-breakage retention and anti-drop protection.
Engineering Definition: An assembly of two or more panes of glass permanently bonded under heat and pressure using one or more polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), or structural ionoplast interlayers (BS EN 14449).
Material Construction Matrix
21.52mm Structural Toughened Laminated Glass
Thermal Transmittance:5.2 W/m²K
Acoustic Reduction:Rw 41 dB
Explode Layers
1
Front Structural Glass Ply(10mm Heat-Soaked Toughened)
10.0mm
2
Structural Ionoplast Interlayer(SentryGlas Polymer Sheet)
1.52mm
3
Rear Structural Glass Ply(10mm Heat-Soaked Toughened)
10.0mm
Physical & Mechanical Performance Characteristics
Safety Class:Class 1B1 or 2B2 (BS EN 12600)
Bending Strength:Equivalent to constituent panes; structural ionoplast interlayers achieve post-yield load capacity
Thermal Shock Resistance:Dependent on base glass (annealed laminate ~40°C, toughened laminate up to 200°C)
Fracture Behaviour:Glass panes crack upon high impact but fragments adhere tenaciously to interlayer; aperture remains sealed
Typical U-Value (Ug):5.4 W/m²K to 5.7 W/m²K monolithic; 1.0 to 1.4 W/m²K in sealed units
Acoustic Reduction (Rw):Rw 33 dB to Rw 42 dB (acoustic PVB achieves +3 to +5 dB reduction over monolithic)
Max Sheet Dimension:Up to 3210mm × 6000mm depending on autoclave autoclave dimensions
Density & Mass:2.50 kg/m² per 1mm glass + ~0.8 kg/m² per 0.76mm PVB interlayer
Key Architectural Advantages
- •Post-breakage retention: remains in frame after breakage, preventing fall from height or weather ingress
- •Superior acoustic damping: polymer viscoelastic core interrupts sound wave resonance coincidence dip
- •Blocks >99% of UV radiation (280–380nm), protecting commercial merchandise and furnishings from photodegradation
Critical Engineering Constraints
- •Annealed laminated glass (e.g. 6.4mm) can be cut cold, but toughened laminated glass MUST be cut and processed before tempering
- •Open edge exposure in damp or marine environments requires edge seal compatibility checks to prevent delamination or moisture clouding
- •Heavier assemblies demand structural verification of framing, hinges, and handling equipment
Fabrication & Edge Processing Tolerances
Cut After Toughening:PROHIBITED (Catastrophic Fracture)
Heat Soak Testing (HST):Recommended to BS EN 14179
Toughened laminate must have individual plies fully processed and heat-treated prior to autoclave lamination.
Architectural Specifier Checklist
Verify these technical criteria prior to contract documentation:
1State interlayer type explicitly (standard PVB vs Acoustic PVB vs Structural Ionoplast).
2For wet-glazed or exterior exposed edges, specify compatible silicone neutral-cure sealants (acidic silicones degrade PVB).
3Ensure balustrade calculations account for cantilever deflection under design point loads to BS 6180.
Frequent Commercial Applications
Network Procurement Routing
GlassSuppliers.co.uk
Intended public marketplace destination for discovering regional glass processors, independent glaziers, and commercial installation contractors across the UK.
Recommended Action: Specify interlayer performance requirements and reach qualified regional architectural laminators.
Proceed to GlassSuppliers.co.ukReviewed by: Senior Glass Materials Technologist, BuyGlass Technical Panel
Last Standard Verification: 2026-10-30