Breaking Glass

[MickCo]

Help
I had new windows fitted some10 years ago and all was fine until 3 years ago when various fanlight windows have shattered. It is always the outside glass.The units have a tulip design leaded pattern and I wondered could the lead be stopping natural expansion and contraction due to heat / cold. They were fine for 7 years and now we have replaced at least 8 units and a further 3 broke over Xmas. Is this common? There does not appear to be any movement in the house.

 

[masona]

Need more info,

Upvc, wood, double glazed etc

Was the opening made wider for a new window, is the lintel resting on top of the frame pushing onto it?

Has the unit been made the right size with equal gap all round?

Real lead or stick-on lead?

 

[Forest Grump]

Never heard of this before.
Are you sure you haven't upset anybody?..............about 3 years ago??

 

[MickCo]

Many thanks for your comments Masona

Upvc, Double glazed 25mm gap. The windows were fitted to existing openings. Steel catnic lintels fitted throughout (existing) no load bearing on the frame. The frame appears to be correct sized and equally spaced.
The lead is stick on. It is fitted to both sides of the external glass.

 

[masona]

Right, have a look at the clip-on beading, they have been known to expand and dig in to crack the glass, so give it a little trim back on the mitre edge. The other theory is you may have the wrong size rubber seal beading causing the glass to pressure to the outside. Is the cracks always in the same place, if so, where about is it?

 

[MickCo]

The windows have various types of breaks. Some have a single horizontal crack approx half way up the window and others that shatter as though they have been hit in the centre of the glass with a hammer. When the replacement unit is fitted the same style of break does not necessarily happen. The last window to break was a shatter type and it even stretched the lead inward with the break almost as if it were an implosion

Regards

Mick

PS Thanks for the interest

 

[salem2000]

Are the windows on the same side of the house?

You could look around the area in front of the windows for lead pellets or ball barings. It's not unheard of, for littles tykes (B******s) to use air guns on peoples windows when bored. Also have a word with Neighbours, ask if they know anyone else who's had problems.

Salem.

 

[MickCo]

Hi again
The windows are on 3 sides of the house and the rear is un overlooked with locked gate so I dont think the problem is with human aided breakages...But thanks

 

[masona]

I'm wondering also if the wrong size spacer bar between the glazed unit and the rubber seal expanded cracking the glass?

 

[AshfordSteve]

Hi, I was just browsing and saw your plight...

We went through a patch of replacing units such as yours.

The glass your describing is Deep Flemish. The pattern in the glass is so thin in places (apx 2mm ) that over time with movement it can crack.

As a company we have resorted to only supplying this pattern in toughened.

Your windows and house are fine. Just have a glazing company replace the units with a different pattern or toughened flemish.

Hope this helps