Panel reinforcement and tying back to the perimeter opening
Stainless steel ribbed reinforcement bars are used to tie to the opening. The rods penetrate the expansion material and anchor the panel in place by connecting to the perimeter frame. This can be located by drilling an over-sized hole a minimum depth of 25–35mm and should be filled with silicone to cushion any movement of the re-bar.
Rods are 1200mm long and when the panel is longer than the reinforcement bar, rods are overlapped by a minimum of 150mm and are loosely joined using tie wire/cable tie.
One reinforcement bar should be used in each horizontal and vertical joint – regardless of the panel size – to ensure standard calculations are met for wind loadings and integral strength. When working with perimeter borders or U-channel, two ø6-8mm bars should be used as strengtheners to stop the mortar cracking (similar to mesh in concrete).
The rods should be at least ø5.5-6mm and ribbed to create a better key in the mortar. Only stainless steel re-bars should be used in vertical glass block walling.
In some instances two stainless steel reinforcement bars are required per course, for example if a glass block wall is exposed on one edge, like a showewall using end glass blocks or – if a panel is being used in a sensitive location – as an anti-vandal partition.
TF30 fire-rated glass blocks require two stainless steel reinforcement rods – vertically and horizontally each course – and TF60 blocks require three.
In the joints during construction spacer pegs have a cross section perpendicular to the rods. In a row the rod rests on the spacer whilst ensuring the bars are separated from touching the glass collar (as metal and glass should never be in direct contact with each other).
For situations where connecting the rods to the opening may prove difficult by drilling an over-sized hole, panel anchors can be used (similar to the brick-tie principle). An isolation pad is required to separate the stainless steel panel anchor from the surround to avoid a bi-metallic reaction. These are secured by either screw or bolt-fixing or can mechanically shot fired.
Ensure steel gauge is thick enough to avoid the panel anchor fixing from piercing and protruding.