Constructing an outdoor covered plunge bed

[meanie]

Thanks for the answers . I was going to be a cheapskate, but I'll buy the proper stuff now.

[Maggi Young]

As a rough guide, I think 45mm tape is  the size for 25mm  sheeting.
Plenty available at good prices via Amazon or Ebay ( edit to add- of the solid and perforated types) so your  bargain sheeting is still going to be a "steal of a deal"    
I'm a great believer in recycling!

[meanie]

I'm a great believer in recycling!

Me too! The local freegle group is very active around here. 90% of my plastic pots come from there, and here is my potting bench which I "won" on there.......................