ABSTRACT
Float glass is highly durable in most environments encountered in construction applications, and it does not degrade or change over time, other than the accumulation of microscopic surface damage, which reduces the strength of new glass but tends to stabilise after several years. Therefore, monolithic single glazing can usually be regarded as maintenance free for the lifetime of a glazing system, aside from routine cleaning and replacement in the event of breakage. Stacked glass also has to be kept dry because it can be permanently marked if wetted when in contact with other glass or packing materials, especially in the presence of cement dust. Laminated glass is generally resistant to occasional wetting of its edges, if allowed to dry out but, like insulating units, can be rapidly damaged by standing in water. Whenever glass is tested to destruction or glass breaks in service, there are lessons to be learnt by the designer from a study of the fracture markings.
