21.5mm Toughened Laminated Glass Panels - Heavy-Duty Safety Glazing

21.5mm toughened laminated glass panels - the heavier-duty laminated build for high-load balcony fall-protection, structural glass walls, larger overhead glazing and tall balustrades. Two 10mm toughened sheets bonded with a PVB interlayer (10.10.4 build) for combined strength, stiffness and post-breakage integrity. All panels are 1087mm high in standard stocked widths from 500mm to 1200mm. From £140 inc VAT with 3-5 working day UK delivery.

Technical Specification

21.5mm vs 17.5mm Laminated - Which Do I Need?

The 17.5mm laminated build (8.8.4) is the standard specification for general balcony and balustrade fall-protection - the most common choice for domestic juliet balconies and standard balustrade infill. The 21.5mm (10.10.4) is the heavier-duty upgrade: the thicker 10mm toughened sheets make it noticeably stronger and stiffer, suited to higher fall heights, longer unsupported spans, larger panels, structural glass walls, and any application under heavier loading. Pick 21.5mm when the structural engineer or installer specifies it, or when you need that extra margin of strength.

Toughened Laminated Construction

Laminated glass is two or more sheets of glass permanently bonded together with a polymer interlayer (PVB) using heat and pressure. When both sheets are also toughened (as here), you get the impact strength of toughened glass combined with the post-breakage integrity of lamination. Under sufficient force the glass will still break, but the fragments stay bonded to the PVB interlayer rather than falling free - the panel stays largely in place and the risk of injury from falling glass is sharply reduced. This is what makes laminated glass the standard choice for overhead and high-fall applications.

Common Uses

High-load balcony fall-protection (upper-floor balconies, taller balustrades), juliet balconies on higher floors, larger overhead glazing spans (canopies, skylights, roof glass), structural glass walls and partitions, frameless or minimally-supported balustrade systems, stairwell and atrium balustrades, and security or acoustic glazing where the extra mass helps.

Available Sizes

Need a Different Size?

The sizes listed here are the standard stocked panels. For bespoke sizes, cut-outs or shaped panels, please contact us for a quote. All shaping must be done before the toughening and lamination process - it cannot be cut or drilled on site.

Frequently Asked Questions

What is 21.5mm toughened laminated glass?
Two panes of 10mm toughened glass bonded with a 1.52mm structural interlayer to form a 21.5mm laminated unit. The heaviest-duty glass in the range, designed for high-load sole-barrier balustrade and structural glazing.

When is 21.5mm needed instead of 17.5mm?
For higher line loads (commercial, public and assembly areas), taller barrier panels, and applications where the structural engineer specifies a heavier glass makeup to meet the loading under BS 6180.

What is the weight of 21.5mm laminated glass?
Approximately 52 kg per square metre. A 1087mm x 900mm panel weighs approximately 51 kg. Mechanical handling or two-person lifting is needed on site.

What interlayer is used?
PVB (polyvinyl butyral) or ionoplast interlayer bonding the two toughened panes. The interlayer holds the broken glass in place if either pane fails, maintaining the barrier function.

Is 21.5mm laminated glass suitable for Juliet balconies?
Yes. 21.5mm toughened laminated is commonly specified for Juliet balconies, which are sole-barrier applications by definition (no handrail, glass is the only thing preventing a fall).