17.5mm toughened and laminated glass, cut to your sizes. Two pieces of 8mm toughened glass bonded with a 1.5mm interlayer, 17.5mm overall.

Some of our suppliers use a thinner interlayer, so the overall thickness may reduce nominally. If that dimension is critical to your job, get in touch before ordering and we will confirm exactly what you will receive.

What 17.5mm is for

External frameless balustrades with no handrail. This is the combination that asks the most of a domestic balustrade panel: nothing at the sides, nothing along the top, and outdoors with wind loading to take. The glass is doing all of it.

Typically a balcony, terrace or garden run where the whole point is an uninterrupted view — no posts, no top rail, just glass set into a base channel or spigots.

Why laminated, and why this thick

With no handrail there is nothing spanning the top of the run, so if a panel broke there would be nothing left in the opening. The interlayer holds a broken panel together and keeps it in place, which is why frameless-without-handrail is laminated rather than simply thicker single glass.

The thickness above that is about exposure and load. Bring the same frameless run inside, or put the external run in posts, and 13.5mm is usually enough. Take it into a commercial setting and it goes up to 21.5mm.

Which laminate thickness?

Once you are into laminated glass the thickness is decided by three things: whether the run is inside or outside, how much frame is holding the panel, and whether it is domestic or commercial.

• 13.5mm — external balustrade with no handrail in a posted system, or an internal frameless balustrade with no handrail.
• 17.5mm — external frameless balustrade with no handrail.
• 21.5mm — external frameless balustrade, commercial.

If your balustrade does have a handrail, you may not need laminated at all — a framed run is usually 10mm toughened and frameless with a handrail is usually 15mm toughened. Our glass balustrade regulations guide explains why the handrail changes the answer.

Ordering and delivery

Every panel is made to your own dimensions, to the millimetre. We hold no standard sizes — put the length and height you need into the calculator and the price shown is for that exact panel.

It can also be supplied drilled, shaped, notched, frosted or painted, all specified up front and done as part of manufacture. Toughened glass cannot be cut or drilled once it has been through the furnace, so nothing can be altered on site. For anything unusual use our bespoke toughened glass service.

This listing is for glass only. Complete systems with the glass sized to suit are in our balustrade category, and we supply glass clamps and balustrade components separately.

Edges and standards

All edges polished, corners with a proper 5mm radius as standard unless otherwise specified — not the dubbed corner, knocked off by hand, that a lot of suppliers will quote you. Details on our material and finish standards page. All glass toughened in accordance with BS EN 12150 and BS EN 12600.

More information

• Buying toughened glass online
• Types of glass
• Glass toughening
• All you need to know about toughened glass

Laminated glass is 4 weeks from order. Panels travel crated and must be signed for and checked on arrival. Made-to-size glass cannot be returned, as with any bespoke item. Call 0114 243 9009 or email sales@diometonline.co.uk.

A note on specification

The guidance on this page reflects what we typically supply for jobs of this kind, and is offered in good faith to help you order the right thing. It is not a structural specification and it is not a substitute for project-specific design. Barrier heights, spans, loadings, fixings, substrates and exposure all vary from site to site, and the final specification for your project remains the responsibility of you, your designer, your structural engineer or your building control body. We manufacture and supply to the sizes and specification you give us. If you are unsure, send us the details before ordering and we will tell you what we would normally supply for a job like yours.