Toughened Glass – Heat Soaking

Cordless Integral Blinds - Sunshade Blind SystemsSunshade blinds uses heat soaking  for the glass in its blinds inside double glazing – Sunshade Blind Systems.

Heat soaking involves heating Toughened Safety Glass to 2900 C for a given period of time. The Toughened Glass – Heat Soaking process accelerates the expansion of nickel sulphide stones, and at this temperature, glass panels with nickel sulphide stones are likely to shatter.

The purpose of heat soaking is to reduce the incidence of Toughened Safety Glass breaking spontaneously after installation. While the Heat Soak process does not guarantee there will be no spontaneous breakage after glazing, it is a safeguard for specifying glass in areas where safety from glass fallout is a concern and/or access for replacement is difficult.

Why Heat Soak?

In each case the specifier must assess the risk and consequences of failure before deciding whether to specify Heat Soaking Toughened Safety Glass.

Heat soaking will reduce the incidence of failure due to nickel sulphide inclusions, therefore reducing the associated replacement, maintenance and disruption costs and the risk of the building being classified as unsafe.

Heat Soaked Toughened Safety Glass is more expensive than ordinary Toughened Safety Glass, due to the additional processing. However, if a risk analysis indicates that the incidence of nickel sulphide induced or other inclusions failure should be minimised, Heat Soaked Toughened Safety Glass should then be specified unless a suitable alternative can be found.

When comparing alternatives or the actual costs of replacing broken Toughened Safety Glass in the field, there is substantial justification for the cost of the additional process.

The following applications should be considered for heat soaking:

  • Structural Balustrades
  • Infill Balustrades – if fall out is an issue
  • Sloped Overhead Glazing
  • Spandrels – if not Heat Strengthened
  • Structural Glazing with Spider or other fittings
  • Commercial Exterior Frameless Glass Doors

Download Briefing Document – Glass Breakage – Nickel Sulphide Inclusions