Why We Fitted 5 mm Instead of Waiting Five Days for 4 mm Toughened
On this page
The bottom panel of an aluminium window at a Torquay home unexpectedly shattered. The original glass was 4 mm toughened safety glass.
It was heading into a weekend, and that made the specification decision the whole job.
Toughened cannot be made on the spot
This is the constraint most people do not know about. Toughened glass has to be cut to final size and then heat-treated in a furnace, because it cannot be cut, drilled or trimmed afterwards.
That processing takes time. Matching the original 4 mm toughened panel would have meant roughly a five-day wait, with the window boarded across the weekend.
The alternative, and why it is still compliant
We fitted 5 mm glass the same day instead.
The point is that the replacement still fully meets AS1288 for that opening. This was not a downgrade to get it done quickly, it was a different compliant product that was available immediately. The homeowner got a safe, compliant, watertight window before the weekend rather than plywood and a five-day wait.
Where a matched toughened panel genuinely is required, the wait is unavoidable and we will say so. Here it was not, so the practical answer was the better one.
The job in short
- Site: Residential aluminium window, Torquay
- Original glass: 4 mm toughened safety glass, bottom panel
- Constraint: Matching toughened requires around five days of processing
- Solution: Compliant 5 mm glass fitted same day, before the weekend
- Standard: AS1288
