Does glass rot

Well, it really depends on several factors:

- Type and quality of the glass.

- Exposure to elements

- Heating up and cooling down over long periods of time.

So to answer it as best as I can, I would say Yes. Glass can become weaker the older it is, but not indefinitely. Something has to cause it to weaken, over time. It typically isn't something that happens in a few months or years. Take good care of the glass, and it should last quite well.