Determining the thickness of glass

Determining the thickness of glass





Despite its brittle nature, glass is an enormously strong material. Under compression loads, a 1 cm cube of glass can withstand up to 10 tonnes before breaking.



When loads are applied to glass, it causes both compression and tensile stresses as illustrated in the diagram. The face of the glass that has the load imposed on it is subject to compressive stresses for which glass has a high resistance. The opposite face has tensile stresses applied to it for which glass has a lower resistance.



The majority of loads which glass has to withstand are caused by bending and probably the most important external factor in specifying a suitable glass thickness is the design wind load. DUAL SEAL GLASS can give general guidance on short duration wind load pressures.

The actual working wind load pressure for each individual application should be determined according to EN 1991-1-4.



For this reason stress analysis calculations performed by DUAL SEAL GLASS take into account both the stress and sensible deflection limits of glass specifications. Another factor to consider is the duration of the imposed loads.



For example in addition to wind loads, inclined glazing has to be able to support its own weight and consideration also has to be given to loads that could be caused by snow, the appropriate loads are determined with EB 1991-1-3.

Where glass acts as guarding differences in finished floor level, the glass thickness is determined from the loads in EN 1991-1-1, the National Annex and PD 6688.

In the case of insulating glass units the environmental loads need to be considered, particularly barometric pressure and unit cavity temperatures, as these may limit the maximum glass dimensions and minimum cavity width, see 'Glass Thickness in Insulating Glass' in the download section.


Please contact DUAL SEAL GLASS for more information.