Well it's just chucked it down & I debated leaving the washing out!!
The roof panels on that side are elderly, non horticultural, single thickness polycarbonate. We fitted them some yrs ago after on-going vandalism from the adjacent alleyway, which has ceased, thank goodness. Last incident was early 08 & a panel got pushed in by a thrown brick !! At least no smashed glass over everything.
Now the leylands I planted to the alleyway side, north luckily, are kept above the greenhouse height & there is a generation of kids that dont know it's there. The panels never fitted brilliantly & last yr daughter had the bright idea of using masking tape as well as the wire fittings, to secure the panels to the frame. So far so good. They can slip & sometimes flip out, but, whilst no plants in there, not a problem.
Typical sun now!!! J.