Complete mystery ..............

[Ann]

I have just gone into our lounge and had a fright as one side of our patio door is completely shattered, just like a windscreen goes, there isn't a single inch of glass which isn't "mosiac" and it looks just like frosted glass. The other side which slides, is completely normal. OH immediately thought a bird had hit it but there is nothing dead outside on the patio and it would take some force to break the double glazed glass, in the past we even had an owl hit the other side of the patio door and left its imprint but didn't break it, so what could be heavier than an owl. There is no actual hole but you can just about make out the point of "impact" as lines radiate out from it but its very low down 18" from the ground. It can't be a stone (none on the ground anyway) or an airgun pellet as our garden is very private with high fences and conifers at the bottom. What on earth do I tell the insurance company? Could it have been a hailstone do you think? We didn't hear any noise and although we had a few heavy showers, we didn't hear hail this morning.
O-er how weird! Any ideas?

[Eve]

How strange! Could there have been a tiny chip or crack you hadn't noticed and something like a lorry going past could have just shattered it?

I work near a main road and some of the lorries going past shake the whole building. Similarly when I worked near a large demolition site. Even maybe a tremor or something?

[Ann]

No Jenna - good idea but its the patio door which overlooks the back garden and nowhere near a road.

[Ann]

Do you think the glass will fall out, I daren't touch it! Of course being double glazed its only the outer glass.

[Eve]

How weird! Militant moles tunnelling underneath? ;)

I'm not sure where you live but is there anything underneath, underground?

No chance of any kind of explosion anywhere? I'm sure you would have heard it though! I remember a big gas explosion near me a couple of years ago (took out a row of houses) but it was really loud even miles away and you could almost feel it.

Anywhere near an airbase or somewhere military aircraft could be flying? Again though you'd be likely to hear something like a boom - there was an article about a typhoon (the aeroplane, not the weather :)) causing one recently. Not sure if it could cause anything like that though - I'm not very scientific!

[tonyav]

Something similar happened to us once Ann, one of the double glazed windows in the conservatory, but just the inside pain of glass was broken and the outside pain was still OK, strange !!!!

[Ann]

I can't even ring the insurance broker (shop) as they are closed on Sundays!

[Jemisa]

Were you singing at the top of your voice Ann? That could do it...
We've all heard of wine glasses shattering :o))

jem.

[tonyav]

Ann, check your Yellow pages for emergency glazing repairs, maybe they would send the bill directly to your insurers.

[Ann]

HaHa Jem - thats a good one! No I usually sing in the shower! :)

[marden40]

An outer pane that just breaks like this can happen when a cold outer pane is warmed quickly by the Sunlight bearing on it. The pane of glass subjected to the thermal stress cannot cope beyond a certain amount of deflection, and it will suddenly crack along the whole length of the unit, always along the long length, or it can suddenly shatter altogether.

[Eve]

Some more ideas here re house movement and improperly fitted glass and such.

http://www.physicsfor...ndex.php/t-69198.html

Maybe take photos now for the insurers in case it all goes?

[naomi24]

We had something similar when a stone was thrown up by the lawn mower. We left the shattered glass where it was until the repairers came, making sure we opened and closed the door very carefully!

As for the reason, perhaps the glass has been inadvertently knocked recently, and took its time to shatter. It happens.

[cupid04]

Do you live any where near a military firing range. That can affect your glass even if your miles away!

[Prudie]

Exactly same thing happened to inlaws and they never knew the reason so not uncommon - at least Insurers will be aware it can happen.

[tonyav]

Did the earth move for you Ann lol.

[weecalf]

is it in the direct sunlight .over a period the build up heat can maybe weaken it then, when weakened over a time it may just shatter

[sunny-dave]

Thermal stress - builds up over time & then one of the two sheets of the double glazed just shatters.

[Hopkirk]

Did you have a frost last night, then bright sunshine this morning?

[Ann]

Thanks for all your good ideas. We do get the early morning sun directly on the doors for a couple of hours. We haven't mown the lawn for the past week and the lawn is a good 10 feet away across the patio and under a rose arch. We have looked at the date we had them fitted and was amazed to see it was 17 years ago, (where do the years go?) so I am wondering if they do a different type of glass these days. I do hope they replace the whole patio door, but I expect, knowing our luck it will be just bodged up with new glass which is different to the other pane :(

[Maydup]

I can't think what it could be but I would suggest your ring the insurance company today and log your claim. They will send someone out to make it safe. In the meantime take plenty of photos.

(No need to wait for the broker's office to open, you have a claims number on your policy documents)