Mysterious broken window?

Question

My window is broken and for no apparent reason. Earlier i put up some padding i got out of a box in my window to help block sunlight then i noticed that about 2weeks later right behind the padding my window is broken and only behind the padding. Is it possible that extra heat generated because of the padding caused my window to break or is it something else?

Answer 1

I've heard that some glues can crack glass - so if you glued the padding with superglue or similar that may be the reason.  I guess the glue contracts and expands at different rates to the glass.

Answer 2

Yes this could be possible, especially it it was clear and acted as a magnifying glass and caused extra heat.

If not clear it could have expanded from sunlight and caused undue pressure on the glass.