How do I join pvc glazing strip together for DIY greenhouse?

I am building my own greenhouse on the end of the house which now looks more like a conservatory. I've framed it out using 47x47mm treated timber and intend to glaze it using 10mm twinwall polycarbonate sheets and glazing strip screwed into the frame. The sheets go the full height of the greenhouse, but it will take 3 separate sheets to fill it widthways. So there will be some vertical glazing strips which have to join on to others at the top and bottom. Can I just cut the glazing strips to length and then seal them later with silicon, or do I have to cut mitres for the corners and v shapes for the other joins? This is my first attempt at anything like this so any advice would be appreciated.

Thanks

Phil

Why not construct your GH like you have out of wood and just buy some snap-fix timber supported glaxing bars for your poly? Would look nice and neat and a tight fit without any silicone etc...