Conservatory roof-glass or plastic

Basically glass is a lot heavier and all components including the walls may not be strong enough to support it. Glass is a lot quieter when it rains ! Simon,

Also anything falling on it - like bits of roof tile - are more likely to break glass than plastic. I suspect that triple layer plastic has much better insulating properties than glass too - or are they thinking of double-glazed glass (*frightfully* heavy!)?

They probably are too big then. I can't see them turning down business. I decided to have a plastic roof anyway as I don't want to be able to look up and see the stars, bird muck, etc. However it is a self supporting system that has panels about 70mm thick with self-contained metal strips to support the span. The span is limited to about 4m with the one I am using though.

Unless there is a good reason to take the plastic off why bother? Unless you tell us the reason it is shooting in the dark as different plastic systems have different benefits/problems. What is the roof ATM, plastic is so vague? How big?