I am looking to buy my first greenhouse. Can anybody give me advice on the differences between tradtional glass and polycarbonate?
The main differences are in lifetime and safety. If there are children or anyone who is a bit frail or clumsy about, polycarbonate or safety glass is recommended. Polycarbonate will eventually become less clear or crazed after over the years, with useful life depending on the quality of the UV stabilization used. Expect 10 to 20 years. Standard greenhouse (annealed) glass will stay clear effectively forever, but produces dangerously sharp shards when broken and does become more brittle over time. Hail can be a problem. Safety (tempered) glass is much safer, but also more expensive. If you will be heating the greenhouse, look at multi-wall polycarbonate panels, as they have greatly increased insulation properties over glass (although extremely expensive double-glazed glass panels are available, too.)
We have a polycarbonate greenhouse and are very happy with it. We replaced the glass with it. We are in a real wind tunnel so glass kept breaking. The polycarbonate is safer, with being opaque you have no worries of scorching. The temp in the greenhouse feels different, with glass its very hot with polycarbonate it feels like a general heat if that makes sense, Id say its better for overwintering too.
Thankyou for your answers. We will go ahead with the polycarbonate one, let you know how we got on. Thanks again.