Woke up this morning to find the none opening bottom part of the downstairs toilet window has gone bang. It's only the inside obscure glass, the outer pane is still intact. It's got a lot of cracks in it and a few small pieces had been thrown across the room.
The only thing I can think off is pressure from above but the opening part of the window above has been opening with no problems. The only reason I mention the pressure is that we've had new lintels added above a couple of windows as the outer skin only had a soldier course of bricks above the windows. This was fine when the windows were wooden but a few years before we bought the house the wooden windows were replaced with pvc which doesn't appear to be reinforced. We have one large window at the back where you can clearly see the bend in the frame but that window has held up for over 10 years. It will be getting a lintel for the outer skin when we have the house repointed in a couple of months. There is no sign of any movement or cracks in the soldier course above the window that's broken so I doubt it is pressure.
Is obscure glass weaker than plain glass and prone to sudden self destruction?
All theories no matter how barking mad would be welcome.
