In article , says...


"Charlie Pridham" wrote...
Bob Hobden wrote
"Charlie Pridham" wrote in message
Anyone know the best way of cutting the large triple walled
Polycarbonate
sheets? I am thinking of making a lean too shade greenhouse using this
to
help with heat loss in winter. Roof is easy as I have made the base so
its
whole sheets in each direction but sides will obviously have some funny
shapes and I need to check how easy it is to work with.

When I made the roof of our little greenhouse out of twin wall I used a
jigsaw with the correct blade for such stuff, quite easy actually. Just
make
sure you mark the plastic and keep a firm hand of the saw making sure
it's
flat against the sheet at all times.
You will need to tidy up (carefully) with a file or sandpaper afterwards.
The thought was much worse than the deed.


Thanks to all posters for the encouraging words, I will keep you all
posted when I start (next year now, but I am building the base so wanted
some idea what I was doing!)

I might add that from the same place you get the sheet you will find various
plastic strips of different profile to stick on with silicon sealer to cover
up any imperfections that only you will then know about. The open end of the
sheet needs to be sealed anyway to stop water ingress and there are special
breathable membranes for this which then get covered with a plastic strip
which will hide small errors.
You have to watch condensation inside though, a sloping roof means the water
will run down onto any supporting beam unless you stick on something to
guide it away.


The roof system I have seen is self supporting ie not on a wooden rafter,
its a lot more expensive but avoids any roof maintainance and as I intend
grow Lapageria under it on wires thats important, but it was the vertical
parts I was pondering as they will be all sorts of funny shapes, hence
the ease of cutting question, same firm does all the trims tapes and
fixings. I may yet change my mind as it only has one wall and when I
build the other next year the problem may look very different!
--
Charlie Pridham, Gardening in Cornwall
www.roselandhouse.co.uk
Holders of national collections of Clematis viticella cultivars and
Lapageria rosea