Glass flooring is very expensive to replace once installed, and so the added strength benefit from using fully toughened glass is counterbalanced by its increased vulnerability.
In general, heat-strengthened and ordinary float glass is preferred in the laminate make up of glass flooring. The use of heat-strengthened rather than float glass is particularly appropriate for installations involving large panes of glass. In these cases reducing the thickness of the laminate by using heat- strengthened glass, whilst not necessarily reducing overall glass cost, reduces the weight of the glass, and this can reduce the installation and transport costs.
For a given loading and laminate type, the most critical factor in the determination of glass floor thickness is the maximum widths that the glass has to span.
For example, given four-sided support, a 1.0M2 triple laminated glass flooring panel of dimensions 1000mm x 1000mm would need to be over 50% thicker than a similar panel of dimensions 2000mm x 500mm.
Tables 2 and 3 show the relationship between spans and laminate thickness required for an imposed loading of 5.0KN/M2 for panes supported on two-sides (Table 2) and four sides (Table3) for a system comprising a heats strengthened 6mm Top-sheet and two lower layers of float glass.