Posted: 17/05/2013 at 00:33
Rather odd suggestion to drill holes in the sheets in the link. Why? Many years ago there was a diagram in a RHS manual of a former for making wire hoops to hold the sheets down. No drilling, no fixing long lengths of wood to the sheets.
I am using still using wire supports which came with plastic tunnels I obtained from Lakeland (then Lakeland Plastics) about 30 years ago.
I just use an old roofing slate on the ends.