Advice fitting polycarbonate sheet to greenhouse

[reubin78]

Hi,

Looking to upcycle the greenhouse which we inherited with our house. There are various panes of glass missing and I have been pondering over replacing these with polycarbonate sheets (in part as we have an almost 2-year old son running around the garden). Is this the best option? We would very much like to keep the greenhouse.

I can find lots of people selling the polycarbonate sheets - mostly 4mm thick (is this rigid enough?) but mostly at 1220mm (4 ft) long. I require 1350mm for the sides and 1500mm for the roof - how do I join? Do I over lap the pieces (like glass) or do I need to purchase a "H" shaped connector strip?

Do I need to seal the top to prevent rain/dirt ingress?

Is there a good way of firming up the edges (at the points where the clips hold the sheets in place)?

Thanks from this Greenhouse Novice!

 

[Burnerman]

There's no problem with using the polycarbonate sheets, but if your existing glass is 3mm then you could have a job using thicker stuff with the W clips if that is what you have. No matter, use silicone to seal where necessary and create an overlap as if it was glass anyway. It's easy enough to fabricate overlap clips with some copper strips or similar.
John