Last year I bought ten 10mm thick glass panes to build a ‘glass box’ porch to fit into an ‘L’ shaped corner of my house. The seller (an experienced glass merchant about to retire) told me the 1.98 x 1.015m 'roof' panes would self support on the long dimension – that is with a shallow pitch and the top edge fixed using car windscreen bonding adhesive or suitable silicone … spanning 1.9m sloping down to the glass wall frame.
The glass 'wall' will sit on low block walls about one metre high with a top frame (acting as a wall plate) and door frame providing support for four 1.219 x 0.710m panes – one used for a sliding door.
Having checked an online Dow Corning structural glass guide for vertical silicone butt joint info, it seems normal practice to use laminated glass for an application like this. The panes are not marked to say they are safety glass. Alarm bells are ringing about breakage of such heavy glass then falling on someone below.
The aim is for minimal framing but I wonder if safety dictates using two strong, inverted ‘T’ metal section for butt joining/supporting the three glass ‘roof’ panes – with a wall support at one side and a strong frame on the other. That would still leave an unsupported span width of almost one metre.
I would rather not have to chicken out and use a light multi-wall polycarbonate sheet roof system. Any thoughts will be appreciated.
