Why have my double glazing seals become damaged?
The most common cause is the age of the unit, with the continuous changes in temperature throughout the year, the air/gas inside the sealed unit causes fluctuations in the size of the unit. Since they expand in warmth and contract in the cold, and over time this can loosen and damage the seals. Other reasons for your unit failing includes faulty installations or faulty production methods. The side effect of a seal going is that the window will fog up, as water vapour condenses on the inside surface of the window. There is no cure for the units except replacement as they will not get better with time.
Why has my double glazed unit shattered?
The most common cause for a unit shattering is impact, this could be whilst cutting the grass, using a strimmer or thermal shock. The first two causes are self-explanatory with stones flying at great speed, thermal shock is a lesser known cause that can happen without impact and just suddenly break.
Thermal shock is a variation in temperature which causes tension in a material. It frequently causes breakage in the material, and is most common in molecular material such as toughened glass. In the example of the hot glass, this means that the rapid temperature change causes some parts of the glass to quickly become much hotter than other parts. This, in turn, causes uneven expansion, which puts stress on the molecular structure. If the stress becomes great enough, the strength of the material is overcome and the glass breaks.
Toughened glass has a different molecular structure to annealed glass. The glass is cut to size then placed onto a roller table, taking it through a furnace that heats it well above its transition temperature of 564 °C (1,047 °F) to around 620 °C (1,148 °F). The glass is then rapidly cooled with forced air drafts while the inner portion remains free to flow for a short time, changing the structure of the glass into a molecular structure giving it more strength.
Why has my double glazed unit cracked?
The most common cause for an annealed unit to crack is impact, This could be whilst cutting the grass, using a strimmer or even a bird strike.