Thermal Stress

Any solid elements situated behind the glazing are considered as backups where thermal safety is a consideration, and can take the form of columns, dropped ceilings, dwarf walls or bulkheads.

Two of the key factors in assessing the levels of thermally induced stress generated are the intensity of incident solar radiation and the ambient temperature variations.

The temperatures of the edges of the glass are directly influenced by the thermal properties of the framing system into which they are glazed.

Temperature differences generated can be increased due to the presence of shading, which as well as blocking incident solar radiation from portions of the glass; can also block incident solar radia

Internal heating can create issue with the thermal safety of glass, either by adding more heat into the glass from convection from the localised heating of air, or by direct radiant heating.

The thermal safety of units that open, whether pivoting or sliding, must be considered separately to vertical units, and will typically be based on worst case conditions, depending on allowable mov

Whilst the behaviour of glass with conduction or convection is relatively consistent, the response of glass to radiant heating can be significantly influenced by glass colour, the presence of any c

It is becoming more commonplace to consider laminated glass types for the external leaf of spandrel units, predominantly to reduce the potential for falling glass in the event of fracture of the ou

Due to their opaque nature, and often the presence of insulation, glass panes within spandrels and shadow box assemblies will often reach relatively high temperatures, and so thermal stress and PVB

Blinds installed behind glazing will influence the temperature of glass exposed to incident sunlight, by reflection of incident solar energy back onto the glazing and by trapping heated air against

The resistance to glass to thermal stress is dependent upon its strength (determined by glass type), the quality of the edgework and the presence of any damage to the edges.

The thermal behaviour of materials is key to determined stress levels resulting from temperature differentials, as detailed within this document.

Thermally induced stresses, or thermal stresses, are generated when one region of a piece of glass expands more than another region, and detailed within this document.