Double Glazing - Glass replacement/Sealed unit?

[johnnycab]

One of the double glazed windows in my flat, has 'popped'...I was away during summer for couple of weeks, when I returned one of the windows had a massive cracks from the inside; which really confused me as at first I thought someone had broken in!

However, having gathered my senses and trying to analyse - the only conclusion I could come to was; that due to combination of the build-up of heat inside the house and the sun beating down on the windows, the air inside the sealed unit might have expanded and the glass cracked under the pressure. There is a pebble sized stone mark right on the edge of the left hand side of the sealed unit, where the crack seems to have orginated.

I really don't know if this is a common occurrence, but I need to replace this unit which measures 38"x 37.5" approx. Please can someone advise on how much roughly it is going to cost and any reputable companies I can contact in the S. London area.

Your help and advice much appreciated as usual.

 

[Mw Roofline]

Is the glass put in from the inside or the outside? If its the outside and you live on the 127th floor of the Nelson mandela building i'd reckon about £12,500.

If its on the inside then about £150 once you've messed about getting the old unit out.

 

[Deluks]

the air inside the sealed unit might have expanded and the glass cracked under the pressure. There is a pebble sized stone mark right on the edge of the left hand side of the sealed unit, where the crack seems to have orginated. .

Are you in denial that someone might have thrown a stone at your window?

I've never heard of windows 'popping' in the heat?

 

[^woody^]

If the unit was not installed properly, it could get pressure from one of the packing pieces, or may be too big for the opening, so could crack with a bit of expansion

 

[johnnycab]

Thanks for your replies.

Is the glass put in from the inside or the outside? If its the outside and you live on the 127th floor of the Nelson mandela building i'd reckon about £12,500.

If its on the inside then about £150 once you've messed about getting the old unit out.

Thanks - that sounds reasonable enough. The crack is from the inside and the flat is on the 3rd floor - I would assume that the unit can be changed from the inside. I remember when the windows were installed 6yrs approx. ago they put the frame in by deploying a high-ladder and then put the sealed units from inside the flat. I have been quite happy with the windows and they cost £2,500 approx for 7 windows - all of them same size.

the air inside the sealed unit might have expanded and the glass cracked under the pressure. There is a pebble sized stone mark right on the edge of the left hand side of the sealed unit, where the crack seems to have orginated. .

Are you in denial that someone might have thrown a stone at your window?

I've never heard of windows 'popping' in the heat?

I am not a man who lives in denial ;--)) It would have been easier for me to come up with an explanation If the crack was from the outside, however - there are no marks on the outside part of the glass.

When I returned the flat itself felt like a sealed unit! Since, the flat was not broken into and the crack is from the inside and it is most definitely not shattered i.e. there is one big crack originating from slightly below the top left-hand corner and extending diagonally all the way across the glass panel to the bottom right-hand corner. In addition, there are a couple of small cracks extending to the top from the originating point. I really can't come up with any other explanation...

I cannot find the original installer, as they might have changed the name of their firm - apologies for sounding ignorant; but if I choose any other supplier, is there a chance that the glass or the unit might look a bit different from the rest? what I am trying to ask is that other than the size aspect of a window are all units pretty much standard? Also, any pointers on looking for approved installers/honest merchants etc.?

cheers

 

[johnnycab]

I took a punt on the local glazier, who came around measured the window and gave me a quote. He came back a day later and installed the new unit - took him less than 15 minutes - a real professional! I have to admit I was quite impressed at the service - no cock-ups and the price was £155.

I did ask him about sealed units cracking as mentioned earlier - he said that in his 12 yrs as a glazier he had seen a lot of units with exactly the same problems and they were largely due to manufacturing defects.

Thanks for all your help here, it has been much appreciated.