20 July 2015
People often call me saying that their double glazing has misted up and they need new windows. 9 times out of 10 this really isn’t the case. Glass can easily be replaced and it’s always much more cost effective.
I get asked why they fail a lot too. Mostly it’s just age; years of sunlight will make any seal fail eventually, but sometimes the packers which the glass sits on aren’t lined up correctly, leaving one sheet of glass unsupported. When they’re warm from the sun one slides, breaking the airtight seal and hey presto, misted unit.
Here’s a failed double glazed toughened unit in a door I swapped earlier today. Cost wise, it worked out about 7 times cheaper than a new door! When swapping, I always adjust to make sure they haven’t dropped and if so I’ll rectify the problem. Usually means using a glazing technique called ‘toe and heeling’ which supports the glass in such a way as to hold the door in the correct position.