Not all laminated glass for flat rooflights is the same.

Published: 8th October 2023

At Ofset, we offer the option of both Security and Acoustic glass on all our Blade rooflights. In most installations, these will not be required but we like to give our customers the opportunity to upgrade if necessary. Both these options are created by replacing the bottom pane of glass in the glazed unit with an extra-thick laminated pane.

We differ from many other manufacturers in that we only use the very best and safest laminated glass available. Our Ofset laminated glass is superior in two ways.

The first is that it is thicker. The thicker the laminated glass, the stronger it is. Most ‘laminated’ glass is made using two sheets of 3mm glass which sandwich a 0.8mm PVB (polyvinyl butyral) sheet in between the two panes to create a single laminated pane of 6.8mm. In contrast, the laminated glass in our Double-A units is 12.8mm thick. This is one of the thickest and strongest toughened laminated glass products in the industry. That’s two sheets of 6mm glass sandwiched together. Even our Triple-K units have a laminated pane of 8.8mm, still thicker than that used for most companies’ double glazed units.

The second and most important difference is that the laminated panes used for our Ofset Blades are made from ‘toughened’ glass as opposed to cheaper and weaker ‘annealed’ glass. Our toughened laminated glazing is 6 to 8 times stronger than other types of laminated glass.

Additionally, toughened laminated glass is far less prone to ‘heat stress fractures’, a recognised problem in the glazing industry. Due to the huge variance in temperatures a rooflight will experience, particularly in the spring and autumn when you can get frosty mornings building up to quite warm days, annealed laminated glass elements will often crack under the temperature variance, thus requiring the roof window to be replaced. NARM (National Association of Rooflight Manufacturers) highlights the problem in its Glass Rooflights Specification Guide

‘Where an annealed laminated pane is proposed, careful thought should be given to the risk of Thermal Heat Stress failure which could affect the durability of a laminated inner pane. To avoid this risk, and should additional strength be required to the inner pane, a toughened laminate can be specified’.

In order to be able to offer the Ofset Blade Lifetime Guarantee, we insist on using toughened laminated glass thus ensuring the long term reliability of our products.

You would hope that installing a skylight in your residential or commercial property or commercial  is a once in a lifetime experience so specifying your roof glazing to the highest standard possible is incredibly important. Toughened laminated glass may be more expensive than annealed laminated glass but at Ofset, we think it’s worth the peace of mind.

To check out our pricing and the Blade rooflight options available, please use our online  ‘Bladebuilder’ configuration tool

If you need any help in this procedure, please don’t hesitate to call or email us.