What are the glazing risks when installing ultra-slim doors? Sunflex reveals the issues and how to avoid them

Over the past decade sliding doors have become the default option for homeowners wanting big glazed doors for their extension, renovation or self-build project. As demand has grown, so has the influx of different door systems, with manufacturers chasing slimmer frames to enable almost uninterrupted views out.

To achieve those thinner frames, the way the door systems have been constructed has changed significantly, but in doing so, it has introduced a significant risk that homeowners aren't always aware of.

The risks of using structurally bonded glass

"Windows and doors have traditionally been glazed using beads to hold the glass into the frame," says Will Mitchell, Sunflex UK's Technical Manager. "The bead clips into the frame, usually on the inside, and secures the double- or triple-glazed unit in place. The challenge with ultra-slim frames is that there is no space for a glazing bead, so manufacturers have had to opt for alternative methods of securing the glass in place. For most systems, that involves permanently glueing or bonding the glass directly to the frame, creating systems that are known as structurally bonded doors."

Structurally bonded sliding doors are easy to spot – they have narrow frames on all four sides of the panel and make up the vast majority of ultra-slim systems on the market. The issue is that by permanently bonding the glass to frame it is impossible to replace the glass without replacing the entire frame.

Financial implications

While standard home insurance policies will likely cover glass replacement, most won't cover the cost of the frame, leaving you significantly out of pocket. "Last year we completed a number of projects where the original supplier had ceased trading and the customer had enquired to us about a whole new door because they couldn't replace the glass," explains Will. "The risks involved with structurally bonded systems were never explained to them before they ordered the doors in the first place."

Luckily, there are alternative sliding door systems out there that allow for ultra-slim frames and aren't structurally bonded. The Sunflex UK SVG20 features 20mm sightlines, but due to its deeper outer frames, which can accommodate glazing beads, it is possible to remove the glass and replace it without damaging the frame.

For details, visit Sunflex UK or speak to one of the technical sales team on 01603 494424.