Most glass quotations in the UAE are written in a shorthand that hides the things that actually matter. "12mm toughened" and "12mm laminated" sound like specifications and are not. This guide sets out how glass is genuinely specified, so you can read a quotation, understand what you are being sold, and tell the difference between a cheaper price and a cheaper product.
The Five Glass Types, and Where Each Belongs
Everything installed in a UAE home or office is one of these, or a combination of two.
- Annealed float glass. Untreated base glass. Breaks into long, sharp shards, which is why it has almost no place in modern residential work.
- Heat strengthened. Roughly twice the strength of annealed. Breaks into large pieces that tend to stay in the frame.
- Toughened, also called tempered. Around four to five times stronger. Breaks into small blunt granules rather than shards, which is what makes it a safety glass.
- Laminated. Two or more panes bonded by a plastic interlayer. It still cracks, but the interlayer holds the fragments in place so the panel stays where it is.
- Toughened-laminated. Both processes. It dices like toughened glass and the pieces stay bonded like laminated glass. This is the specification for anything where a falling panel would be dangerous.
The practical rule: toughened alone is fine for shower screens, framed infill panels, and interior partitions. Toughened-laminated belongs on frameless balustrades, pool fencing, glass floors, and anything overhead. Roof and canopy glazing should effectively always be laminated, because if a panel fails you want it held in the frame rather than dropped on whoever is underneath.
The constraint nobody mentions until it is too late
Toughened glass cannot be cut, drilled, or edge-worked after toughening. The process puts the surface into compression, and cutting into it afterwards releases that stress and destroys the panel. Every hole, notch, and cut-out has to be on the drawing before the glass goes into the furnace.
This is why measuring properly is not a formality on glass work. A site error is not trimmed on the day. It is a new panel and a new lead time.
Clear Glass Is Not Actually Clear
Ordinary float glass contains trace iron oxide, which gives it a green cast. You will not see it looking through a thin pane face-on. You will see it in two situations, and both are common in the work we do.
At the edge. A polished exposed edge shows the green distinctly. On a frameless balustrade that edge sits at eye level along the whole run, which is precisely where people look.
As thickness increases. The tint compounds with the amount of glass light has to travel through. At 12mm and above, standard clear reads visibly green.
Low iron glass, sold as extra clear, ultra clear, or crystal, and under brand names including Guardian UltraClear, Pilkington Optiwhite, and Saint-Gobain Diamant, contains roughly a tenth of the iron oxide. Light transmission rises to around 91% against roughly 89 to 90% for standard clear at the same thickness, but the number understates the difference. What you actually notice is that the green is gone: the edge reads faintly blue rather than bottle green, and the glass stops tinting whatever is behind it.
Worth paying for on frameless balustrades, thick glass anywhere, shower screens against white or pale stone, and light interiors. Not worth paying for in framed systems where the edge is concealed, on thin glass, or in a dark room. Anyone recommending low iron for every application is selling rather than specifying.
Thickness, and What It Is For
Toughened glass is stocked in 4, 5, 6, 8, 10, 12, 15 and 19mm. Low iron is commonly held in 5, 6, 8, 10 and 12mm with a wider range available to order. Roughly where each lands:
- 4 to 5mm mirrors, cabinet glass, light framed infill
- 6mm framed shower screens, interior partitions, small framed panels
- 8mm frameless shower screens, lighter partitions
- 10mm frameless showers, partitions, framed balustrade infill
- 12mm the usual minimum for structural balustrade work
- 15 to 19mm long unsupported spans, tall frameless channel balustrades, glass floors and treads
How to read a laminated thickness
A figure like 11.52 is not a rounded number. It describes the sandwich:
- 6.38 is 3mm glass, 0.38mm interlayer, 3mm glass
- 11.52 is 5mm glass, 1.52mm interlayer, 5mm glass
- 13.52 is 6mm glass, 1.52mm interlayer, 6mm glass
- 21.52 is 10mm glass, 1.52mm interlayer, 10mm glass
If a quotation says "12mm laminated" with no build-up, it is not telling you what you are buying. Ask which build-up is meant. The answer distinguishes a contractor who specified the glass from one who repeated a number.
The Interlayer Decides What Laminated Glass Can Do
Two laminated panels of identical thickness can behave completely differently depending on what is between them. This is where cheap laminated quotations hide.
- PVB, the standard interlayer, supplied in 0.38, 0.76, 1.14 and 1.52mm. Cost effective and correct for most framed glazing.
- SGP or ionoplast, sold as SentryGlas, supplied in 0.89, 1.52 and 2.28mm. Published comparisons put it up to around a hundred times stiffer and roughly five times stronger than standard PVB.
- Acoustic PVB, a damping layer tuned to absorb sound. The right answer for a balcony over a busy road.
- EVA, better moisture resistance and able to carry decorative inserts such as fabric or mesh.
The one that matters commercially: on a frameless channel-fixed balustrade there are no posts, so the interlayer is doing structural work. SGP holds a broken panel far more rigidly than PVB does. A competitor quoting frameless balustrade in standard PVB is not offering you a better price on the same thing, they are offering a weaker product. Our guide to laminated balustrade build-ups goes into the thickness side of this in more detail.
Heat Soak Testing
Toughened glass carries a small but genuine risk of spontaneous breakage years after installation. The cause is microscopic nickel sulphide inclusions trapped during manufacture, which expand slowly over time until the panel fails without any impact.
Heat soak testing bakes finished panels in a controlled oven to force those rare failures to happen in the factory instead of on a client's balcony. It costs money and adds lead time, and it is not needed everywhere. It is worth specifying on overhead and roof glazing, large frameless facades, and anywhere a future replacement would mean cranes, scaffolding, or closing a business.
Comparing Two Quotations Properly
Ask both contractors to put five things in writing:
- The treatment: toughened, laminated, or toughened-laminated
- The full build-up in millimetres, interlayer included
- The interlayer type, PVB or SGP
- Standard clear or low iron
- For sealed units, whether there is a Low-E coating and whether the frame is thermally broken
Once those five lines match, the two numbers are finally describing the same product, and in our experience they move a lot closer together. Until then, a lower price usually means thinner glass, a weaker interlayer, standard clear where low iron was assumed, or a frame that will undo whatever the glass achieves.
